Short- and long-term clinical and quantitative angiographic results with the new, less shortening Wallstent for vessel reconstruction in chronic total occlusion: a quantitative angiographic study

OBJECTIVES: This study was designed to examine whether oversized implantation of the new, less shortening Wallstent provides a more favorable long-term clinical and angiographic outcome in chronic total occlusions than does conventional coronary balloon angioplasty. BACKGROUND: Restenosis and reocclusion remain major limitations of balloon angioplasty for chronic total occlusions. Enforced mechanical remodeling by implantation of the oversized Wallstent may prevent elastic recoil and improve accommodation of intimal hyperplasia. METHODS: Lumen dimension was measured by a computer-based quantitative coronary angiography system (CAAS II). These measurements (before and after intervention and at 6-month follow-up) were compared between the groups with Wallstent implantation (20 lesions, 20 patients) and conventional balloon angioplasty (266 lesions, 249 patients) for treatment of chronic total occlusion. Acute gain (minimal lumen diameter after intervention minus that before intervention), late loss (minimal lumen diameter after intervention minus that at follow-up) and net gain (acute gain minus late loss) were examined. RESULTS: Wallstent deployment was successful in all patients. High pressure intra-Wallstent balloon inflation (mean +/- SD 14 +/- 3 atm) was performed in all lesions. Although vessel size did not differ between the Wallstent and balloon angioplasty groups, acute gain was significantly greater in the Wallstent group (2.96 +/- 0.55 vs. 1.61 +/- 0.34 mm, p < 0.0001). Although late loss was also significantly larger in the Wallstent group (0.81 +/- 0.95 vs. 0.43 +/- 0.68 mm, p < 0.05), net gain was still significantly greater in this group (2.27 +/- 1.00 vs. 1.18 +/- 0.69 mm, p < 0.0001). Angiographic restenosis (> or = 50% diameter stenosis) occurred at 6 months in 29% of lesions in the Wallstent group and in 45% of those in the balloon angioplasty group (p = 0.5150). CONCLUSIONS: Implantation of the oversized Wallstent, with full coverage of the lesion length, ensures resetting of the vessel size to its original caliber before disease and allows greater accommodation of intimal hyperplasia and chronic vessel recoil. Wallstent implantation provides a more favorable short- and long-term clinical and angiographic outcome than does conventional balloon angioplasty for chronic total occlusions.     

Are directional coronary atherectomy and Palmaz-Schatz stent more efficacious than conventional balloon angioplasty for treating de novo coronary artery lesions?

It is unclear whether new devices such as directional coronary atherectomy (DCA) or Palmaz-Schatz stent implantation improve long-term outcomes compared with conventional balloon angioplasty in patients with stable angina and de novo coronary artery lesions of type A or type B except for complete occlusive lesions investigated by the American College of Cardiology/American Heart Association task force on percutaneous transluminal coronary angioplasty. A total of 146 patients with stable angina and simple lesions were assigned to either conventional balloon angioplasty (62 patients), DCA (50 patients), or Palmaz-Schatz implantation (34 patients). The acute results and late outcomes were assessed by coronary angiography. The results of the three procedures were similar with respect to procedural success and complications. Patients who underwent stenting or DCA had a larger immediate increase in the diameter of the lumen and a larger luminal diameter immediately after the procedure than those who underwent balloon angioplasty. At six months follow-up, the patients treated by stenting continued to have a larger luminal diameter and a lower rate of restenosis than those treated with balloon angioplasty (2.30 +/- 0.66 vs 1.85 +/- 0.83 mm, p < 0.005; 5.9% vs 29%, p < 0.05) and DCA (2.30 +/- 0.66 vs 1.90 +/- 0.96 mm, p < 0.05; 5.9% vs 24%, NS). The patients treated with balloon angioplasty had a smaller late loss than those treated with DCA or Palmaz-Schatz stent. The patients treated with DCA had a larger loss index than those treated with balloon angioplasty or Palmaz-Schatz stent. Stenting was a significant factor in decreasing the rate of restenosis by logistic regression analysis, compared with balloon angioplasty. The angiographic outcomes were better in patients who received a stent than in those who received other treatments. This study suggests that even lesions stable for treatment by balloon angioplasty and DCA can also be treated with Palmaz-Schatz stents.     

Differences in restenosis propensity of devices for transluminal coronary intervention. A quantitative angiographic comparison of balloon angioplasty, directional atherectomy, stent implantation and excimer laser angioplasty. CARPORT, MERCATOR, MARCATOR, PARK, and BENESTENT Trial Groups

With the increasing clinical application of new devices for percutaneous coronary revascularization, maximization of the acute angiographic result has become widely recognized as a key factor in maintained clinical and angiographic success. What is unclear, however, is whether the specific mode of action of different devices might exert an additional independent effect on late luminal renarrowing. The purpose of this study was to investigate such a difference in the degree of provocation of luminal renarrowing (or 'restenosis propensity') by different devices, among 3660 patients, who had 4342 lesions successfully treated by balloon angioplasty (n = 3797), directional coronary atherectomy (n = 200), Palmaz-Schatz stent implantation (n = 229) or excimer laser coronary angioplasty (n = 116) and who also underwent quantitative angiographic analysis pre- and post-intervention and at 6-month follow-up. To allow valid comparisons between the groups, because of significant differences in coronary vessel size (balloon angioplasty = 2.62 +/- 0.55 mm, directional coronary atherectomy = 3.28 +/- 0.62 mm, excimer laser coronary angioplasty = 2.51 +/- 0.47 mm, Palmaz-Schatz = 3.01 +/- 0.44 mm; P < 0.0001), the comparative measurements of interest selected were the 'relative loss' in luminal diameter (RLoss = loss/vessel size) to denote the restenosis process, and the 'relative lumen at follow-up' (RLfup = minimal luminal diameter at follow up/vessel size) to represent the angiographic outcome. For consistency, lesion severity pre-intervention was represented by the 'relative lumen pre' (RLpre = minimal luminal diameter pre/vessel size) and the luminal increase at intervention was measured as 'relative gain' (relative gain = gain/ vessel size). Differences in restenosis propensity between devices was evaluated by univariate and multivariate analysis. Multivariate models were constructed to determine relative loss and relative lumen at follow-up, taking account of relative lumen pre-intervention, lesion location, relative gain, vessel size and the device used. In addition, model-estimated relative loss and relative lumen at follow-up at given relative lumen pre-intervention relative gain and vessel size, were compared among the four groups. Significant differences were detected among the groups both with respect to these estimates, as well as in the degree of influence of progressively increasing relative gain, on the extent of renarrowing (relative loss) and angiographic outcome (relative lumen at follow-up), particularly at higher levels of luminal increase (relative gain). Specifically, lesions treated by balloon angioplasty or Palmaz-Schatz stent implantation (the predominantly 'dilating' interventions) were associated with more favourable angiographic profiles than directional atherectomy or excimer laser (the mainly 'debulking' interventions). Significant effects of lesion severity and location, as well as the well known influence of luminal increase on both luminal renarrowing and late angiographic outcome were also noted. These findings indicate that propensity to restenosis after apparently successful intervention is influenced not only by the degree of luminal enlargement achieved at intervention, but by the device used to achieve it. In view of the clinical implications of such findings, further evaluation in larger randomized patient populations is warranted.     

Coronary-artery stenting compared with balloon angioplasty for restenosis after initial balloon angioplasty. Restenosis Stent Study Group

BACKGROUND: Intracoronary stenting reduces the rate of restenosis after angioplasty in patients with new coronary lesions. We conducted a prospective, randomized, multicenter study to determine whether intracoronary stenting, as compared with standard balloon angioplasty, reduces the recurrence of luminal narrowing in restenotic lesions. METHODS: A total of 383 patients who had undergone at least one balloon angioplasty and who had clinical and angiographic evidence of restenosis after the procedure were randomly assigned to undergo standard balloon angioplasty (192 patients) or intracoronary stenting with a Palmaz-Schatz stent (191 patients). The primary end point was angiographic evidence of restenosis (defined as stenosis of more than 50 percent of the luminal diameter) at six months. The secondary end points were death, Q-wave myocardial infarction, bypass surgery, and revascularization of the target vessel. RESULTS: The rate of restenosis was significantly higher in the angioplasty group than in the stent group (32 percent as compared with 18 percent, P= 0.03). Revascularization of the target vessel at six months was required in 27 percent of the angioplasty group but in only 10 percent of the stent group (P=0.001). This difference resulted from a smaller mean (+/-SD) minimal luminal diameter in the angioplasty group (1.85+/-0.56 mm) than in the stent group (2.04+/-0.66 mm), with a mean difference of 0.19 mm (P=0.01) at follow-up. Subacute thrombosis occurred in 0.6 percent of the angioplasty group and in 3.9 percent of the stent group. The rate of event-free survival at 250 days was 72 percent in the angioplasty group and 84 percent in the stent group (P=0.04). CONCLUSIONS: Elective coronary stenting was effective in the treatment of restenosis after balloon angioplasty. Stenting resulted in a lower rate of recurrent stenosis despite a higher incidence of subacute thrombosis.     

Comparison of balloon angioplasty versus debulking devices versus stenting in right coronary ostial lesions

Angioplasty of aorto-ostial stenosis is associated with lower procedural success and a higher complication rate. The aim of the present study was to compare the acute and long-term results of balloon and new device angioplasty in 110 consecutive patients with right coronary ostial lesions. Patients were divided into 3 groups according to the angioplasty device used: group I (balloon only, n = 26), group II (debulking devices including excimer laser, directional and rotational atherectomy, n = 26), group III (stent, n = 58). Procedural success was highest in group III (96%) followed by group I (88%), and group II (77%). In-hospital complications were similar among the groups (p = NS). Patients in group III achieved the highest acute gain (2.61 mm) followed by groups II (1.92 mm), and I (1.39 mm, p <0.05). During follow up, target lesion revascularization and/or bypass surgery was required in 24% of patients in group III compared with 47% and 40% in groups I and II, respectively (p <0.05). Cardiac-event free survival was highest in the stent group (74%, p <0.005) and was similar between the balloon (39%) and debulking device groups (45%). Thus, among the currently available technologies, stenting of right coronary ostial lesions appears to provide excellent angiographic and long-term results.     

Randomised comparison of implantation of heparin-coated stents with balloon angioplasty in selected patients with coronary artery disease (Benestent II)

BACKGROUND: The multicentre, randomised Benestent-II study investigated a strategy of implantation of a heparin-coated Palmar-Schatz stent plus antiplatelet drugs compared with the use of balloon angioplasty in selected patients with stable or stabilised unstable angina, with one or more de-novo lesions, less than 18 mm long, in vessels of diameter 3 mm or more. METHODS: 827 patients were randomly assigned stent implantation (414 patients) or standard balloon angioplasty (413 patients). The primary clinical endpoint was event-free survival at 6 months, including death, myocardial infarction, and the need for revascularisation. The secondary endpoints were the restenosis rate at 6 months and the cost-effectiveness at 12 months. There was also one-to-one subrandomisation to either clinical and angiographic follow-up or clinical follow-up alone. Analyses were by intention to treat. FINDINGS: Four patients (one stent group, three angioplasty group) were excluded from analysis since no lesion was found. At 6 months, a primary clinical endpoint had occurred in 53 (12.8%) of 413 patients in the stent group and 79 (19.3%) of 410 in the angioplasty group (p=0.013). This significant difference in clinical outcome was maintained at 12 months. In the subgroup assigned angiographic follow-up, the mean minimum lumen diameter was greater in the stent group than in the balloon-angioplasty group, (1.89 [SD 0.65] vs 1.66 [0.57] mm, p=0.0002), which corresponds to restenosis rates (diameter stenosis > or =50%) of 16% and 31% (p=0.0008). In the group assigned clinical follow-up alone, event-free survival rate at 12 months was higher in the stent group than the balloon-angioplasty group (0.89 vs 0.79, p=0.004) at a cost of an additional 2085 Dutch guilders (US$1020) per patient. INTERPRETATION: Over 12-month follow-up, a strategy of elective stenting with heparin-coated stents is more effective but also more costly than balloon angioplasty.     

The relation between multiple sleep latency test findings and the frequency of apneic events in REM and non-REM sleep

OBJECTIVES: The purpose of this prospective study was to evaluate the immediate results and the 6-month angiographic recurrent restenosis rate after balloon angioplasty for in-stent restenosis. BACKGROUND: Despite excellent immediate and mid-term results, 20% to 30% of patients with coronary stent implantation will present an angiographic restenosis and may require additional treatment. The optimal treatment for in-stent restenosis is still unclear. METHODS: Quantitative coronary angiography (QCA) analyses were performed before and after stent implantation, before and after balloon angioplasty for in-stent restenosis and on a 6-month systematic coronary angiogram to assess the recurrent angiographic restenosis rate. RESULTS: Balloon angioplasty was performed in 52 patients presenting in-stent restenosis. In-stent restenosis was either diffuse (> or =10 mm) inside the stent (71%) or focal (29%). Mean stent length was 16+/-7 mm. Balloon diameter of 2.98+/-0.37 mm and maximal inflation pressure of 10+/-3 atm were used for balloon angioplasty. Angiographic success rate was 100% without any complication. Acute gain was lower after balloon angioplasty for in-stent restenosis than after stent implantation: 1.19+/-0.60 mm vs. 1.75+/-0.68 mm (p=0.0002). At 6-month follow-up, 60% of patients were asymptomatic and no patient died. Eighteen patients (35%) had repeat target vessel revascularization. Angiographic restenosis rate was 54%. Recurrent restenosis rate was higher when in-stent restenosis was diffuse: 63% vs. 31% when focal, p=0.046. CONCLUSIONS: Although balloon angioplasty for in-stent restenosis can be safely and successfully performed, it leads to less immediate stenosis improvement than at time of stent implantation and carries a high recurrent angiographic restenosis rate at 6 months, in particular in diffuse in-stent restenosis lesions.     

Restenosis rates in diabetic patients: a comparison of coronary stenting and balloon angioplasty in native coronary vessels

BACKGROUND: Diabetes is a major risk factor for restenosis after coronary balloon angioplasty. Recent studies have shown that coronary stenting significantly reduces restenosis compared with balloon angioplasty alone. However, limited information is available on the effect of coronary stenting in diabetic patients. METHODS AND RESULTS: We designed this study to analyze the effect of diabetes on restenosis in patients treated with either balloon angioplasty or coronary stenting who were enrolled in a 6-month angiographic follow-up program. Three hundred consecutive patients, 19% of whom were diabetics, who underwent coronary stent implantation during a single-vessel procedure on native coronary vessels and who had 6-month angiographic follow-up constituted the study group (stent group). Three hundred consecutive patients who underwent 6-month angiographic follow-up after single-vessel conventional balloon angioplasty served as control patients (balloon group). Preprocedural, postprocedural, and follow-up angiograms were analyzed with quantitative angiography. In the balloon group, the restenosis rate was almost twofold higher in diabetic than in nondiabetic patients (63% versus 36%; P=.0002) owing to both a greater late loss (0.79+/-0.70 versus 0.41+/-0.61 mm, respectively; P<.0001) and a higher rate of late vessel occlusion (14% versus 3%, respectively; P<.001). In the stent group, restenosis rates were similar in diabetics and nondiabetics (25% versus 27%, respectively). Furthermore, in the stent group, late loss (0.77+/-0.65 versus 0.79+/-0.57 mm, respectively) and the rate of late vessel occlusion (2% versus 1%, respectively) did not differ significantly between diabetic and nondiabetic patients. CONCLUSIONS: Although diabetics have increased rates of restenosis and late vessel occlusion after simple balloon angioplasty, they have the same improved outcome with coronary stenting that has been documented in nondiabetic patients.     

Short-term results and intermediate-term follow-up of laser wire recanalization of chronic coronary artery occlusions: a single-center experience

OBJECTIVES: This study sought to elucidate the short-term efficacy and intermediate-term outcome of excimer laser recanalization of chronic coronary artery occlusions in patients in whom attempts at mechanical revascularization had failed. BACKGROUND: Recanalization of chronic coronary occlusions with the use of a mechanical guide wire fails in 30% to 50% of cases, mostly because of inability to pass the wire through the lesion. The value of using excimer laser energy in this setting has not yet been determined. METHODS: The study group comprised 66 consecutive patients with 68 chronic coronary occlusions. Patients were eligible for inclusion in the study if a previous attempt at mechanical revascularization had failed and if their angiographic status was such that 1) the vessel segment distal to the occlusion could be visualized by way of collateral vessels, 2) the entry point of the occlusion was clearly outlined, and 3) not more than one anatomic bend was expected within the occlusion. Excimer laser energy was applied to the lesion through a 0.018-in. (0.046 cm) fiber-optic guide wire. Adjunctive balloon angioplasty and stenting were performed in all successfully treated patients but one. RESULTS: Thirty-four occlusions (50%) in 32 patients (48%) could be crossed with the laser wire. Location and age of the occlusion had no adverse influence on the outcome of laser wire recanalization, nor did the presence of bridging collateral vessels, a major side branch at the site of the lesion or a blunt stump of the occlusion. An inverse relation was found between the success rate and the length of the occlusion, such that a 19% reduction of the success rate accompanied each 10-mm increment of the mean occlusion length. Thus, the success rate was 68% for lesions < or = 10 mm but only 25% for lesions > 30 to < or = 40 mm. The presence of a bend in the lesion exceeding 60 degrees was strongly related to procedural failure. During a median angiographic follow-up period of 18 weeks, restenosis > 50% (n = 6) or reocclusion (n = 4) was found in 10 of the 32 successfully treated patients, for an intermediate-term success rate of 33% (22 of 66). Clinical follow-up revealed improved anginal status in 21 patients (66%) after a median of 24 weeks. Major complications (death, myocardial infarction, emergency operation) were not encountered. CONCLUSIONS: Successful recanalization of a chronic coronary occlusion by using currently available laser wires can be expected in 50% of selected patients in whom attempts at mechanical revascularization fail. Restenosis or reocclusion accounts for an overall 6-month success rate of 35%.     

Optimal coronary balloon angioplasty with provisional stenting versus primary stent (OCBAS): immediate and long-term follow-up results

OBJECTIVE: This study sought to compare two strategies of revascularization in patients obtaining a good immediate angiographic result after percutaneous transluminal coronary angioplasty (PTCA): elective stenting versus optimal PTCA. A good immediate angiographic result with provisional stenting was considered to occur only if early loss in minimal luminal diameter (MLD) was documented at 30 min post-PTCA angiography. BACKGROUND: Coronary stenting reduces restenosis in lesions exhibiting early deterioration (>0.3 mm) in MLD within the first 24 hours (early loss) after successful PTCA. Lesions with no early loss after PTCA have a low restenosis rate. METHODS: To compare angiographic restenosis and target vessel revascularization (TVR) of lesions treated with coronary stenting versus those treated with optimal PTCA, 116 patients were randomized to stent (n=57) or to optimal PTCA (n=59). After randomization in the PTCA group, 13.5% of the patients crossed over to stent due to early loss (provisional stenting). RESULTS: Baseline demographic and angiographic characteristics were similar in both groups of patients. At 7.6 months, 96.6% of the entire population had a follow-up angiographic study: 98.2% in the stent and 94.9% in the PTCA group. Immediate and follow-up angiographic data showed that acute gain was significantly higher in the stent than in the PTCA group (1.95 vs. 1.5 mm; p < 0.03). However, late loss was significantly higher in the stent than the PTCA group (0.63+/-0.59 vs. 0.26+/-0.44, respectively; p=0.01). Hence, net gain with both techniques was similar (1.32< or =0.3 vs. 1.24+/-0.29 mm for the stent and the PTCA groups, respectively; p=NS). Angiographic restenosis rate at follow-up (19.2% in stent vs. 16.4% in PTCA; p=NS) and TVR (17.5% in stent vs. 13.5% in PTCA; p=NS) were similar. Furthermore, event-free survival was 80.8% in the stent versus 83.1% in the PTCA group (p=NS). Overall costs (hospital and follow-up) were US $591,740 in the stent versus US $398,480 in the PTCA group (p < 0.02). CONCLUSIONS: The strategy of PTCA with delay angiogram and provisional stent if early loss occurs had similar restenosis rate and TVR, but lower cost than primary stenting after PTCA.     

Cytochrome P450 2E1 mRNA in the rat prostate: detection and quantitation by competitive reverse transcription and polymerase chain reaction

Conventional balloon angioplasty treatment of aorto-ostial stenoses in native coronary arteries and saphenous vein grafts is associated with a low primary success rate, a high complication rate and a high incidence of restenosis. The short-term outcome of Palmaz-Schatz stent implantation in aorto-ostial lesions was compared with that of balloon angioplasty. Thirteen patients underwent stent implantation for 13 de novo lesions (four in the left main coronary trunk, two in the right coronary artery, seven in the vein graft) between January 1994 and December 1995. Fourteen patients underwent balloon angioplasty for 14 de novo lesions (five in the left main coronary trunk, four in the right coronary artery, five in the vein graft between January 1986 and April 1992. Both groups had similar clinical characteristics. Initial success was obtained in all patients in the stent group, compared with 71% of the balloon angioplasty group. Insufficient dilation was the main cause for such failure in the balloon angioplasty group. Baseline reference diameters were similar (3.40 +/- 0.65 mm in the stent group vs 3.36 +/- 0.42 mm in the balloon angioplasty group) and there was no difference in baseline minimal luminal diameter (1.41 +/- 0.74 vs 1.08 +/- 0.56 mm). Minimal luminal diameter was significantly greater in the stent group than in the balloon angioplasty group at both post-procedure and follow-up examinations (post: 3.36 +/- 0.58 vs 2.69 +/- 0.45 mm, p < 0.01; follow-up: 2.33 +/- 0.96 vs 1.52 +/- 0.68 mm, p < 0.05). There was no subacute occlusion in either group. The overall angiographic restenosis rate (> 50% stenosis) was lower in the stent group (17%) than in the balloon angioplasty group: the restenosis rates of native lesions were 0% in the stent group and 40% in the balloon angioplasty group; those of saphenous vein graft lesions were 33% in the stent group and 50% in the balloon angioplasty group. Although the number of patients was limited, these results suggest that Palmaz-Schatz stent implantation may be a safe and effective strategy for treating aorto-ostial lesions in both native coronary arteries and saphenous vein grafts.     

Effect of nadroparin, a low-molecular-weight heparin, on clinical and angiographic restenosis after coronary balloon angioplasty: the FACT study. Fraxiparine Angioplastie Coronaire Transluminale

BACKGROUND: Experimental studies suggest that the antiproliferative effect of heparin after arterial injury is maximized by pretreatment. No previous studies of restenosis have used a pretreatment strategy. We designed this study to determine whether treatment with nadroparin, a low-molecular-weight heparin, started 3 days before the procedure and continued for 3 months, affected angiographic restenosis or clinical outcome after coronary angioplasty. METHODS AND RESULTS: In a prospective multicenter, double-blind, randomized trial, elective coronary angioplasty was performed on 354 patients who were treated with daily subcutaneous nadroparin (0.6 mL of 10,250 anti-Xa IU/mL) or placebo injections started 3 days before angioplasty and continued for 3 months. Angiography was performed just before and immediately after angioplasty and at follow-up. The primary study end point was angiographic restenosis, assessed by quantitative coronary angiography 3 months after balloon angioplasty. Clinical follow-up was continued up to 6 months. Clinical and procedural variables and the occurrence of periprocedural complications did not differ between groups. At angiographic follow-up, the mean minimal lumen diameter and the mean residual stenosis in the nadroparin group (1.37+/-0.66 mm, 51.9+/-21.0%) did not differ from the corresponding values in the control group (1.48+/-0.59 mm, 48.8+/-18.9%). Combined major cardiac-related clinical events (death, myocardial infarction, target lesion revascularization) did not differ between groups (30.3% versus 29.6%). CONCLUSIONS: Pretreatment with the low-molecular-weight heparin nadroparin continued for 3 months after balloon angioplasty had no beneficial effect on angiographic restenosis or on adverse clinical outcomes.     

Comparison of primary coronary stenting to primary balloon angioplasty with stent bailout for the treatment of patients with acute myocardial infarction

This study compares the immediate and long-term outcomes of a primary coronary stenting strategy with primary balloon angioplasty with stent bailout in the treatment of patients with acute myocardial infarction (AMI). One hundred forty-seven consecutive patients who underwent primary balloon angioplasty with stent bailout (n = 94) or primary stenting (n = 53) for AMI were clinically followed for 8.1 +/- 5.7 and 8.5 +/- 4.5 months, respectively. Immediate results, as well as in-hospital and long-term ischemic events (death, reinfarction, and repeat revascularization) were compared between both groups. Angiographic success was 91.5% in the balloon angioplasty group and 94% in the stent group. In-hospital and late follow-up combined ischemic events were 22 of 94 (23%) versus 0 of 53 (0%); p < 0.001 and 33 of 78 (42%) versus 13 of 53 (25%), p = 0.04 for the balloon angioplasty and stent groups, respectively. At 6 months, the cumulative probability of repeat target lesion revascularization was higher in the balloon angioplasty group (47% vs 18%, p = 0.0006) as was the probability of late target revascularization (36% vs 18%, p = 0.046); the cumulative event-free survival after 6 months was significantly lower in the balloon angioplasty group (44% vs 80%, p = 0.0001). This study demonstrates that a primary stent placement strategy in patients with AMI is safe, feasible, and superior to primary balloon angioplasty with stent bailout. Primary stenting results in a larger postprocedural minimal luminal diameter, a lower early and late recurrent ischemic event rate, and a lower incidence of target lesion revascularization at follow-up.     

Laser angioplasty and recanalization

Percutaneous transluminal coronary balloon angioplasty (PTCA) still is the most frequently applied interventional technique for treatment of coronary artery disease. Plastic deformation of the obstructive plaque with creation of splits, intimal tears and dissections is the main mechanism of PTCA for lumen widening. As a result, acute complications due to flow limiting dissections and acute vessel closure can unpredictably occur resulting in myocardial infarction, urgent bypass surgery and death. Furthermore, long-term success of PTCA is limited by restenosis. In order to overcome these limitations of PTCA, alternative interventional techniques were developed, which instead of deforming the obstructive plaque ablate this tissue. These techniques include high and low speed rotational angioplasty, directional atherectomy, the transluminal extraction catheter, ultrasound angioplasty and laser (Light Amplification by Stimulated Emission of Radiation) angioplasty. 308 nm XeCl excimer laser angioplasty today is the laser technique of choice for clinical application. This pulsed laser requires direct contact to the obstructive plaque. It creates fast (< 200 microseconds) expanding gas bubbles which induce plaque ablation. Main indications for 308 nm XeCl excimer laser angioplasty are diffuse and long coronary lesions and total coronary occlusions. Despite promising initial results this technique showed no better acute and long-term results in comparison to PTCA for the treatment of these types of lesions ("Amsterdam-Rotterdam" Study, "Excimer Rotational Balloon Angioplasty Comparison" Study). As a result, this interventional technique was rarely applied for patient treatment. More recently, the concept of plaque ablation by 308 nm XeCl excimer laser angioplasty was renewed for the treatment of in-stent restenosis. This indication is being investigated in the "Laser Angioplasty of Restenosed Stents" trial. First results document the practicability and safety of this approach. Long-term results are awaited. With ongoing miniaturization, laser guidewires were developed for the recanalization of chronic total occlusions. The randomized multicenter "Total Occlusion Trial with Angioplasty assisted by Laser guidewire "Study documented a success rate of laser wire recanalization in up to 66% in contrast to 47.5% for mechanical wires only. Long-term results are still awaited. Technical and procedural progress including saline flush during laser application, homogeneous light distribution and the concept of smooth laser ablation is pushed foreward to make excimer laser angioplasty safer, more predictable and more effective.     

Mechanical debulking versus balloon angioplasty for the treatment of true bifurcation lesions

OBJECTIVES: The purpose of this study was to compare the immediate angiographic and long-term results of debulking versus balloon angioplasty for treatment of true bifurcation lesions. BACKGROUND: Previous studies have shown true bifurcation lesions to be a high risk morphological subset for percutaneous transluminal coronary angioplasty (PTCA). Although atherectomy devices have been used to treat bifurcation lesions, no studies have compared the outcomes of these alternative treatment modalities. METHODS: Between January 1992 and May 1997, we treated 70 consecutive patients with true bifurcation lesions (defined as a greater than 50% stenosis in both the parent vessel and contiguous side branch) with conventional PTCA (n = 30) or debulking (with rotational or directional atherectomy) plus adjunctive PTCA (n = 40). Paired angiograms were analyzed by quantitative angiography, and clinical follow-up was obtained in all patients. RESULTS: Acute procedural success was 73% in the PTCA group and 97% in the debulking group (p = 0.01). Major in-hospital complications occurred in two patients in the PTCA group and one in the debulking group. Treatment with atherectomy plus PTCA resulted in lower postprocedure residual stenoses than PTCA alone (16+/-15% vs. 33+/-17% in the parent vessel, and 6+/-15% vs. 39+/-22% in the side branch; p < 0.001 for both comparisons). At 1 year follow-up, the incidence of target vessel revascularization (TVR) was 53% in the PTCA group as compared with 28% in the debulking group (p = 0.05). Independent predictors of the need for repeat TVR were side branch diameter >2.3 mm, longer lesion lengths, and treatment with PTCA alone. CONCLUSIONS: For the treatment of true bifurcation lesions, atherectomy with adjunctive PTCA is safe, improves acute angiographic results, and decreases target vessel revascularization compared to PTCA alone. The benefits of debulking for bifurcation lesions were especially seen in lesions involving large side branches.     

Stent placement compared with balloon angioplasty for obstructed coronary bypass grafts. Saphenous Vein De Novo Trial Investigators

BACKGROUND: Treatment of stenosis in saphenous-vein grafts after coronary-artery bypass surgery is a difficult challenge. The purpose of this study was to compare the effects of stent placement with those of balloon angioplasty on clinical and angiographic outcomes in patients with obstructive disease of saphenous-vein grafts. METHODS: A total of 220 patients with new lesions in aortocoronary-venous bypass grafts were randomly assigned to placement of Palmaz-Schatz stents or standard balloon angioplasty. Coronary angiography was performed during the index procedure and six months later. RESULTS: As compared with the patients assigned to angioplasty, those assigned to stenting had a higher rate of procedural efficacy, defined as a reduction in stenosis to less than 50 percent of the vessel diameter without a major cardiac complication (92 percent vs. 69 percent, P<0.001), but they had more frequent hemorrhagic complications (17 percent vs. 5 percent, P<0.01). Patients in the stent group had a larger mean (+/-SD) increase in luminal diameter immediately after the procedure (1.92+/-0.30 mm, as compared with 1.21+/-0.37 mm in the angioplasty group; P<0.001) and a greater mean net gain in luminal diameter at six months (0.85+/-0.96 vs. 0.54+/-0.91 mm, P=0.002). Restenosis occurred in 37 percent of the patients in the stent group and in 46 percent of the patients in the angioplasty group (P=0.24). The outcome in terms of freedom from death, myocardial infarction, repeated bypass surgery, or revascularization of the target lesion was significantly better in the stent group (73 percent vs. 58 percent, P = 0.03). CONCLUSIONS: As compared with balloon angioplasty, stenting of selected venous bypass-graft lesions resulted in superior procedural outcomes, a larger gain in luminal diameter, and a reduction in major cardiac events. However, there was no significant benefit in the rate of angiographic restenosis, which was the primary end point of the study.     

Mechanisms of luminal enlargement and quantification of vessel wall trauma following balloon coronary angioplasty and directional atherectomy

OBJECTIVES: The purpose of this study was to assess the dual action of lumen enlargement and vessel wall damage following either balloon angioplasty or directional atherectomy, using intracoronary ultrasound, and angioscopy. BACKGROUND: Differences in the mechanisms of action of balloon angioplasty and directional atherectomy may have a significant bearing on the immediate outcome and the restenosis rate at 6 months. METHODS: A total of 36 patients were studied before and after either balloon angioplasty (n = 18) or directional atherectomy (n = 18). Ultrasound measurements included changes in lumen area, external elastic membrane area and plaque burden. In addition, the presence and extent of dissections were assessed to derive a damage score. Angioscopic assessment of the dilated or atherectomized stenotic lesions was translated into semi-quantitative dissection, thrombus and haemorrhage scores. RESULTS: Atherectomy patients had a larger angiographic vessel size compared with the angioplasty group (3.55 +/- 0.46 mm vs 3.00 +/- 0.64 mm, P < 0.05); however, minimal lumen diameter (1.18 +/- 0.96 mm vs 0.85 +/- 0.49 mm) and plaque burden (17.04 +/- 3.69 vs 15.23 +/- 4.92 mm2) measurements did not differ significantly. As a result of plaque reduction, atherectomy produced a larger increase in luminal area than the angioplasty group (5.80 +/- 1.78 mm2 vs 2.44 +/- 1.36 mm2, P < 0.0001). Lumen increase after angioplasty was the result of 'plaque compression' (50%) and wall stretching (50%). Additionally, in both groups there was indirect angioscopic evidence of thrombus 'microembolization' as an adjunctive mechanism of lumen enlargement. Angioscopy identified big flaps in six and small intimal flaps in 11 of the atherectomized patients as compared with five and 12 patients in the angioplasty group. Changes in thrombus score following both coronary interventions were identical (0.72 +/- 3.42 points atherectomy vs -0.38 +/- 3.27 points balloon angioplasty, ns). CONCLUSIONS: Lumen enlargement after directional atherectomy is mainly achieved by plaque removal (87%), whereas balloon dilation is the result of vessel wall stretching (50%) and plaque reduction (50%). Despite the fact that the luminal gain achieved by directional atherectomy is twice that achieved with balloon angioplasty, the extent of trauma induced by both techniques seems to be similar.     

Coronary artery restenosis after balloon angioplasty in humans is associated with circumferential coronary constriction

Therapies that inhibit intimal hyperplasia do not prevent restenosis after coronary artery balloon angioplasty, suggesting that additional mechanisms may be responsible for restenosis in humans. Using an intravascular ultrasound (Hewlett-Packard Sonos Intravascular Imaging System). 3.5F, 30-MHz (Boston Scientific) monorail imaging catheter, we studied 17 patients with clinical and angiographic restenosis at an average (mean +/- SD) of 7 +/- 6 months after balloon angioplasty (13 men age, 71 +/- 10 years; 12 left anterior descending coronary arteries, 4 right coronary arteries, and 1 left circumflex coronary artery) The lumen area (L.A), vessel wall area (VWA), and total cross-sectional area (CSA) within the external elastic lamina were measured at the restenosis site and at proximal and distal reference sites, which were defined as adjacent segments with the least amount of plaque. Consistent with coronary angiography findings, decreased LA at the restenotic site was detected in all 17 patients. The unique finding was that total CSA at the restenotic site was significantly decreased compared with both proximal and distal reference sites (10.1 +/- 2.4 versus 14.8 +/- 3.2 mm2 and 10.1 +/- 2.4 versus 13.8 +/- 3.1 mm2, respectively, P < .001), whereas VWA (intima plus media) was slightly increased at the angioplasty site compared with both proximal and distal reference sites (8.0 +/- 2.3 versus 7.6 +/- 2.3 mm2 and 8.0 +/- 2.3 versus 6.7 +/- 2.3 mm2, respectively, P = NS). Eighty-three percent of the loss in LA at the restenotic site was due to constriction of the total CSA, while the increase in VWA at the restenotic site accounted for only a 17% loss in LA. We then compared these results with the morphology of coronary artery segments in 14 patients without restenosis. These coronary artery segments had been previously treated with balloon angioplasty (7 +/- 5 months). Unlike that in restenotic lesions, the total CSA within the external elastic lamina at the sites of previous angioplasty was similar to that in distal and proximal reference sites (P = NS). Significant and consistent reduction in arterial CSA, with a minor increase in VWA, characterizes human coronary lesions that cause angiographic restenosis. These data suggest that in humans, "recoil" and/or vascular contraction with healing in response to balloon injury is a major contributor to restenosis after balloon angioplasty.     

Adult moyamoya disease progressing from unilateral to bilateral involvement

The effect of domestically-manufactured excimer laser with adjunctive balloon angioplasty in achieving revascularization and reduction of residual stenosis was assessed. 20 femoral arteries with thrombosis and occlusion from 12 dogs were subject to angiography. At first excimer laser angioplasty was done followed by balloon angioplasty. The diameter and residual stenosis of revascularized vessel were measured. The result showed that 17 out of 20 vessels (85%) were revascularized. The diameter of revascularized vessel by excimer laser were 1.22 +/- 0.14 mm, while residual stenoses were 54% +/- 5%. After adjunctive balloon angioplasty the diameter and residual stenoses were 2.04 +/- 0.16 mm and 20% +/- 7% respectively (P < 0.05 and P < 0.01). Complication in form of vasoperforation occurred in 3/20 vessels (15%). It is concluded that China- manufactured excimer laser angioplasty is effective when used for revascularization. While the reduction of narrowing and residual stenoses was enhanced after adjunction of balloon angioplasty. This method can be employed in treating peripheral occlusive disease effectively and safely.     

Prediction of incontinence following low anterior resection for rectal carcinoma

We evaluated the long-term angiographic outcome of balloon angioplasty by comparing original and follow-up target coronary narrowing. Rather than using restenosis to determine outcome, as in most angioplasty studies, we took an unusual approach and analyzed outcome in terms that are commonly used in progression and regression studies after medical interventions. Quantitative angiographic measurements were undertaken in 315 narrowings with an initial diameter stenosis <90% before and after angioplasty and at follow-up. Angiographic deterioration (>10% increase in follow-up diameter stenosis) was identified in 44 (14%) narrowings. Angiographic deterioration was not influenced by age, sex, risk factors, lipid profile, or the indication for angioplasty. Deterioration was also not predicted by the severity, length, or the location of the narrowing. The deteriorating narrowings had a higher recoil after dilatation compared with narrowings with angiographic improvement (21% +/- 31% vs 12% +/- 17%, p = 0.006); the residual stenosis after angioplasty was therefore higher. The late loss was also significantly increased compared with narrowings with angiographic improvement (65% +/- 26% vs 8% +/- 24%, p < 0.001). We conclude that the incidence of angiographic deterioration of coronary disease as a result of restenosis is uncommon but not negligible. Interventional cardiologists should resist the temptation to dilate mild, silent coronary narrowings because the procedure might have an unfavorable angiographic (and probably clinical) effect.