Impact of diabetes mellitus on percutaneous revascularization (CAVEAT-I). CAVEAT-I Investigators. Coronary Angioplasty Versus Excisional Atherectomy Trial

We examined the relation between diabetes mellitus and outcomes in patients undergoing percutaneous coronary revascularization in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT-I), a randomized trial comparing treatment with either percutaneous transluminal coronary angioplasty or directional atherectomy for de novo lesions in native coronary arteries. Acute success and complication rates, 6-month angiographic restenosis rates, and 1-year clinical outcomes were compared between diabetic and nondiabetic patients undergoing each procedure. Acute success rates between diabetic (n = 191) and nondiabetic (n = 821) patients were similar for both revascularization techniques. Except for the need for dialysis, complication rates were also similar. Six months after atherectomy, diabetic patients had significantly more angiographic restenosis than nondiabetics (59.7% vs 47.4%) and significantly smaller minimum luminal diameters (1.20 vs 1.40 mm). Diabetics undergoing atherectomy required more frequent bypass surgery (12.8% vs 8.5%) and more repeat percutaneous revascularizations (36.5% vs 28.1%) than nondiabetics undergoing atherectomy. Restenosis rates, minimum luminal diameters and repeat revascularizations between diabetics and nondiabetics undergoing angioplasty were similar. The higher restenosis and repeat revascularization rates and the smaller minimum luminal diameter at follow-up in diabetic patients suggest that atherectomy may provide only modest benefit for these patients. The increased restenosis rate in diabetics undergoing atherectomy (but not angioplasty) requires further evaluation.     

Percutaneous transluminal angioplasty in atherosclerosis

Percutaneous transluminal balloon angioplasty has achieved a dominant role in the interventional treatments of atherosclerotic peripheral, renal, and coronary artery disease. Improved operator's technique and equipment design have increased the primary success rate. Despite improved success rate and safety, acute closure, late restenosis and difficulty in treating chronic total occlusions or diffuse lesions remain as serious limitations of this procedure. To overcome these limitations of balloon angioplasty, new devices such as stenting, atherectomy or laser ablation have been developed. Although there are many problems for each device, these techniques appear to reduce the limitations in angioplasty.     

Predictors of angiographic findings when chest pain recurs after successful coronary angioplasty

The angiographic findings of 569 patients who underwent repeat coronary angiography for recurrence of chest pain after successful coronary angioplasty were evaluated. On the basis of angiographic findings, 250 patients (44%) were classified as having restenosis, 72 (13%) incomplete revascularization, 115 (20%) new significant coronary artery lesions, and 132 (23%) no significant disease. The number of diseased vessels at the time of coronary angioplasty (P < 0.001), number of vessels dilated (P < 0.001), and in particular, the time from angioplasty to recurrent chest pain (P < 0.001), were predictive of angiographic findings. When chest pain recurred within 4 weeks of angioplasty, 70% of patients had either incomplete revascularization or no significant coronary artery stenosis, when it recurred between 4 and 24 weeks of angioplasty, restenosis was the most common finding (71%), and when it recurred more than 24 weeks after angioplasty, new disease was the most common finding, occurring in 53% of patients. Of the 115 patients who developed new disease, angioplasty was initially performed on 133 vessels, and 222 vessels were not dilated. At repeat angiography, 81 of the 133 vessels (61%) that had had angioplasty and 109 of the 222 vessels (49%) that had not had angioplasty had new lesions; this difference was significant at P = 0.03. In conclusion, although the most common cause of recurrence of chest pain after initially successful coronary angioplasty was restenosis, other mechanisms may also be responsible. The time from coronary angioplasty to onset of recurrent chest pain was the most powerful predictor of angiographic outcome. The incidence of new lesion development was higher in the vessels that had instrumented angioplasty, possibly reflecting accelerated atherosclerosis or increased fibrocellular proliferation from intimal injury.     

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.     

Sulcus fixated posterior chamber lenses with and without suture in cases lacking capsular support

Although percutaneous transluminal coronary angioplasty (PTCA) has been an effective treatment for primary reperfusion in acute myocardial infarction, patients with thrombolytic ineligibility, thrombolytic failure, cardiogenic shock, and vein graft occlusion remain at high risk for complications with PTCA treatment. The transluminal extraction catheter may be useful for treatment for such patients owing to its ability to aspirate thrombus. At 2 clinical centers, extraction atherectomy was prospectively evaluated in 100 patients (age 62 +/- 10 years). High-risk features included thrombolytic failure in 40%, postinfarct angina in 28%, presence of angiographic thrombus in 66%, presence of cardiogenic shock in 11%, and a saphenous vein graft occlusion in 29%. Procedural success, defined as a final residual stenosis <50% and Thrombolysis in Myocardial Infarction 2 or 3 grade flow, was seen in 94%. Events during the hospitalization included death in 5%, bypass surgery in 4%, and blood transfusion in 18%. In a substudy, patients enrolled at William Beaumont Hospital (n = 65) underwent elective predischarge angiography, which revealed a patent infarct-related vessel in 95%. These patients were also followed for 6 months with angiographic follow-up in 60%. Target vessel revascularization was necessary in 38%, and 6-month mortality was 10%. Although long-term vessel patency was 90%, angiographic restenosis occurred in 68%. Acute myocardial infarction patients can be treated with extraction atherectomy with a high technical success rate and a low incidence of complication. Infarct artery patency at 1 week and 6 months was excellent; however, angiographic restenosis remains a problem. Extraction of thrombus in this high-risk group of patients is associated with low in-hospital mortality and a high rate of vessel patency at 6 months.     

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.     

Directional coronary atherectomy for the treatment of Palmaz-Schatz in-stent restenosis

Management of in-stent restenosis has become a significant challenge in interventional cardiology. The results of balloon angioplasty have been disappointing due to the high recurrence of restenosis at follow-up. Debulking of the restenotic tissue within the stents using directional coronary atherectomy (DCA) may offer a therapeutic advantage. We report the immediate clinical and angiographic outcomes and long-term clinical follow-up results of 45 patients (46 lesions), mean age 63+/-12 years, 73% men, with a mean reference diameter of 2.9+/-0.6 mm, treated with DCA for symptomatic Palmaz-Schatz in-stent restenosis. DCA was performed successfully in all 46 lesions and resulted in a postprocedural minimal luminal diameter of 2.7+/-0.7 mm and a residual diameter stenosis of 17+/-10%. There were no in-hospital deaths, Q-wave myocardial infarctions, or emergency coronary artery bypass surgeries. Four patients (9%) suffered a non-Q-wave myocardial infarction. Target lesion revascularization was 28.3% at a mean follow-up of 10+/-4.6 months. Kaplan-Meier event-free survival (freedom from death, myocardial infarction, and repeat target lesion revascularization) was 71.2% and 64.7% at 6 and 12 months after DCA, respectively. Thus, DCA is safe and efficacious for the treatment of Palmaz-Schatz in-stent restenosis. It results in a large postprocedural minimal luminal diameter and a low rate of both target lesion revascularization and combined major clinical events at follow-up.     

Long-term (4- to 6-year) outcome of Palmaz-Schatz stenting: paucity of late clinical stent-related problems

OBJECTIVES: The purpose of this prospective single-center study was to evaluate the longer-term outcome of Palmaz-Schatz stenting in the treatment of native coronary and saphenous vein bypass graft disease. BACKGROUND: The STRESS (Stent Restenosis Study) and BENESTENT (Belgian Netherlands Stent) trials have demonstrated a decrease in both angiographic restenosis and the need for repeat revascularization in the 1st year for vessels treated by stenting rather than balloon angioplasty. Longer-term (1 to 5 years) clinical results of Palmaz-Schatz stenting are not yet well established. Late migration of the stent, metal fatigue, endarteritis and late restenosis have all been proposed as potential late clinical complications of coronary stent implantation. METHODS: The study cohort consisted of 175 consecutive patients who underwent elective placement of 194 Palmaz-Schatz stents in 185 vessels. Clinical events (death, myocardial infarction, recurrent angina or any revascularization) were assessed at 6 weeks, 2, 4 and 6 months, 1 year and yearly thereafter. Clinical follow-up was available on all patients at a mean +/- SD of 54 +/- 17 months. RESULTS: Angiographic success was achieved in 173 patients (98.9%); angiographic restenosis was observed at 6 months in 26.1% of target sites. The survival rate was 86.7% at 5 years, with a 5-year event-free survival rate decreasing progressively to 50.7%, reflecting primarily repeat revascularization procedures (41.2% at 5 years). However, the rate of repeat revascularization of the treatment site (target site revascularization [TSR]) was 14.4%, 17.7% and 19.8% at 1, 3 and 5 years, respectively, with late (> 1 year) TSR driven by in-stent restenosis in only 3 patients (1.7%). Rates of both 5-year survival (70.5% vs. 93.4%) and event-free survival (21.1% vs. 63.3%) were lower for patients who underwent saphenous vein graft (SVG) stenting than for those with native coronary artery stenting. However, 5-year TSR rates were similar for SVGs (21.9%) and native vessels (19.2%), indicating that the higher incidence of repeat revascularization for SVGs was due to an increase in non-TSR, driven by progressive disease at other sites. CONCLUSIONS: The long-term outcome of stenting shows stability of the treated lesion, with only a slight increase in TSR between 2 and 5 years (17.1% to 19.8%). The progressive increase in repeat revascularization over that period (24% to 41%) and most ongoing late events can be attributed to the progression of coronary disease at other sites, rather than to late deterioration of the stent result itself. Such non-TSR events account for the majority of clinical events in the patients who underwent SVG stenting.     

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.     

Gonadal hormones influence the immune response to PLP 139-151 and the clinical course of relapsing experimental autoimmune encephalomyelitis

Rotational atherectomy is effective acutely in treating complex coronary disease, but less is known about its long-term clinical outcome. We examined the acute results and late clinical outcome in 178 patients undergoing treatment with this device. Rotational atherectomy was used to treat 240 lesions in 178 individual patients. Nineteen percent had multilesion or staged multivessel procedures, and 71% had AHA-ACC Type B2/C lesions. The procedure was completed successfully in 94% of patients. Major complications occurred in 6% (death 1%, Q-MI 2.8%, and emergency bypass surgery 2.2%). Clinical follow-up was available for 167 (94%) patients at 13+/-6 months. Thirty-five percent required additional catheterization because of recurrent symptoms or an abnormal stress test. Clinical restenosis was confirmed in 18%, and an additional 2.2% of patients had progression of disease in previously untreated segments. At the end of 1 year, 14% had undergone repeat target vessel revascularization. Cumulatively at follow-up, approximately 80% had avoided an acute major complication and repeat revascularization for restenosis. Rotational atherectomy provides excellent acute and good late clinical results. At 1 year follow-up, the likelihood of developing clinical restenosis or significant progression of disease was 1 in 5, and patients had a 1 in 7 chance of requiring revascularization because of restenosis. These findings are encouraging and indicate that rotational atherectomy can be performed safely and with a high degree of acute and late clinical success in complex coronary disease characterized by multivessel or multilesion involvement and a predominance of B2 and C lesions.     

Improving the results of coronary angioplasty

Coronary angioplasty has changed dramatically in the past three years with major reductions in suboptimal results and restenosis rates, and improvements in safety, efficacy and cost-effectiveness. Intracoronary stent implantation with optimisation of strut expansion and the abandonment of anticoagulants after deployment, have led to less entry-site complications, facilitated early hospital discharge, virtually abolished subacute stent thrombosis and resulted in a 50% reduction in target vessel revascularisation. Adjuvant medical treatment with anti-platelet agents, including glycoprotein IIb/IIIa receptor inhibitors, improves the safety of angioplasty and may further reduce the restenosis rate. Selective use of debulking devices has extended the indications for angioplasty. High resolution fluoroscopy, quantitative coronary angiography and intracoronary ultrasound leading to improved diagnosis, equipment selection and treatment have contributed to better outcomes. Further clinical trials will compare angioplasty and stent implantation with coronary bypass surgery in patients with multivessel coronary disease, and may extend the indications for percutaneous transluminal coronary angioplasty (PTCA) to selected patients with three vessel disease.     

Magnetically labeled secretin retains receptor affinity to pancreas acinar cells

To clarify the mechanisms of restenosis, restenotic human tissue specimens obtained by directional coronary atherectomy (DCA) in 43 patients were immunohistochemically analysed for cell proliferation and deposition of PG-M/versican, an important extracellular matrix proteoglycan of the vessel wall. The patients were classified into five groups according to the period after percutaneous transluminal coronary angioplasty (PTCA): 0-1 month (N = 6), 1-3 months (N = 12), 3-6 months (N = 11), more than 6 months (N = 6) and de novo lesions (N = 8). The tissue specimens were of 35 restenotic lesions following PTCA and eight primary stenotic lesions with no prior PTCA. Total cell numbers in the atherectomy specimens increased significantly up to 3 months after PTCA. Most cells were alpha-smooth muscle actin (alpha-SMA)-positive. To evaluate cell proliferation, the specimens were immunostained for Ki-67 antigen (clone MIB-1). A significant increase in the positive ratio was observed up to 1 month after PTCA, although the labelling index was less than 1 per cent at every stage. The deposition of PG-M/versican, as analysed by immunohistochemistry, was greatest during the period 1-3 months after primary angioplasty, when restenosis detected by angiography progresses most actively. These results suggest that the peak of cell proliferation in the neointima occurs earlier than angiographic restenosis and that the deposition of PG-M/versican may be a major factor in restenosis following angioplasty.     

Isolation of human intestinal defensins from ileal neobladder urine

Restenosis is a major limitation of percutaneous transluminal coronary angioplasty (PTCA). In this study, we assessed the impact of restenosis on PTCA with reference to coronary angioplasty bypass grafting (CABG). In the Coronary Angioplasty versus Bypass Revascularisation Investigation (CABRI) PTCA population, those who had restenosis were defined as those needing a second revascularization at a site revascularized at the initial procedure. The 1-year clinical outcome of the nonrestenotic group (n=437) was compared with those who underwent CABG (n=453). There was no difference in deaths. In the nonrestenotic PTCA group, the incidence of more infarctions was insignificant (relative risk [RR] 1.9, 95% confidence intervals [CI] 0.96 to 3.75, p=0.064), there was a much greater need for repeat revascularization (RR 8.6, CI 5.14 to 14.41, p <0.0005), and patients had a poorer angina status (RR 1.46, CI 1.01 to 2.13, p=0.046). Using 2 measures of coronary disease, the degree of pre- and postrevascularization disease was compared between groups. There were no differences in prerevascularization disease. However, using either measure, residual postrevascularization disease was more frequent in the nonrestenotic PTCA group. Restenosis only partially accounts for the greater morbidity seen after PTCA, compared with CABG, in multivessel disease. The greater likelihood of residual disease post-PTCA may contribute to this greater morbidity.     

Proliferative activity in peripheral and coronary atherosclerotic plaque among patients undergoing percutaneous revascularization

We evaluated the proliferative activity of human atherosclerotic lesions associated with active symptoms of ischemia, by assessing the expression of the proliferating cell nuclear antigen (PCNA). We confirmed in vitro that PCNA, an essential component of the DNA synthesis machinery, is selectively expressed in proliferating human vascular smooth muscle cells. 37 atherosclerotic lesions (18 primary and 19 restenotic) retrieved by directional atherectomy from either coronary or peripheral arteries were then studied for the expression of PCNA, using in situ hybridization or immunohistochemistry. Among plaques studied by in situ hybridization, 7 out of 11 primary and 11 out of 11 restenotic lesions contained PCNA-positive cells. The mean rate of proliferation (percent of PCNA-positive cells) was 7.2 +/- 10.8% in primary lesions and 20.6 +/- 18.2% in restenotic lesions (P < 0.05). Among specimens studied by immunohistochemistry, five out of seven primary and eight out of eight restenotic lesions contained proliferating cells. The mean rate of proliferation was again higher in the restenotic (15.2 +/- 13.6%) than primary (3.6 +/- 3.5%) lesions (P < 0.05). Proliferating cells were detected as late as 1 yr after angioplasty. We conclude that cellular proliferation is a feature of atherosclerotic lesions which are associated with symptoms of ischemia, but that it is more prominent in restenosis compared to primary lesions. These findings have implications for therapies aimed at limiting lesion growth, particularly after percutaneous revascularization.     

Complications prior to revascularization among patients waiting for coronary artery bypass grafting and percutaneous transluminal coronary angioplasty

AIM: To describe the occurrence of death, development of acute myocardial infarction and need for hospitalization among patients on the waiting list for coronary artery bypass grafting and percutaneous transluminal coronary angioplasty. PATIENTS AND METHODS: All the patients on the waiting list for possible coronary revascularization in September 1990 in western Sweden. RESULTS: Of 718 patients waiting for either coronary artery bypass grafting or percutaneous transluminal coronary angioplasty, 15 (2.1%) died between the actual week in September 1990 and prior to revascularization and 12 (1.7%) developed a non-fatal acute myocardial infarction during the same period. All 15 patients who died before undergoing revascularization died a cardiac death. Death and/or the development of an acute myocardial infarction was significantly more frequent among the elderly, among patients with a low ejection fraction and among patients with a history of diabetes mellitus. In all, 29% required hospitalization prior to the procedure. The most common reason was symptoms of angina pectoris requiring hospitalization in 23% of the patients. CONCLUSION: Among patients on the waiting list before either coronary artery bypass grafting or percutaneous transluminal coronary angioplasty, 15 (2.1%) died prior to the procedure and 1.7% developed a non-fatal acute myocardial infarction. The risk of either death or developing an acute myocardial infarction was highest among patients in the older age groups, among patients with a history of diabetes mellitus and among patients with a lower ejection fraction.     

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.     

Refractory angina pectoris in end-stage coronary artery disease: evolving therapeutic concepts

Refractory angina pectoris in coronary artery disease is defined as the persistence of severe anginal symptoms despite maximal conventional antianginal combination therapy. Further, the option to use an invasive revascularization procedure such as percutaneous coronary balloon angioplasty or aortocoronary bypass grafting must be excluded on the basis of a recent coronary angiogram. This coronary syndrome, which represents end-stage coronary artery disease, is characterized by severe coronary insufficiency but only moderately impaired left ventricular function. Almost all patients demonstrated severe coronary triple-vessel disease with diffuse coronary atherosclerosis, had had one or more myocardial infarctions, and had undergone aortocoronary bypass grafting (70% of cases). We present three new approaches with antiischemic properties: long-term intermittent urokinase therapy, transcutaneous and spinal cord electrical nerve stimulation, and transmyocardial laser revascularization.     

Bilateral reaching to asymmetrical targets: muscle and joint dynamic interlimb adaptations

Treatment of acute embolic and thrombotic occlusions of arteries has to be initiated immediately to save the limb at risk. Surgery has been the treatment of choice for the last decades. Percutaneous mechanical methods for thrombectomy and thrombolysis have evolved and offer alternative treatment options, reducing the peri-operative risk. Percutaneous aspiration thrombembolectomy (PAT), recirculation thrombectomy with the Amplatz device, and different systems for hydrodynamic thrombectomy and thrombolysis (Angiojet, Hydrolyer, S.E.T. catheter) are routinely used for percutaneous thrombectomy and mechanical thrombolysis. These 3.5-10 F systems allow for the rapid removal of a fresh clot from different vascular regions. Complete removal of the clot can be achieved in 19-49%; adjunctive use of other percutaneous methods (thrombolysis and thrombectomy: 60-80%; PTA and atherectomy: 81-100%) results in primary success rates of 67-100% for recanalization of acutely occluded vessels. Primary indications for percutaneous thrombectomy and mechanical thrombolysis are acute occlusions of peripheral arteries and dialysis fistulas; limited experience exists for the treatment of occlusions of the visceral and pelvic vessels. Percutaneous methods seem promising for treatment of acute pulmonary embolism.     

Optimal burr and adjunctive balloon sizing reduces the need for target artery revascularization after coronary mechanical rotational atherectomy

We analyzed the effect of differing burr and balloon sizes during mechanical rotational atherectomy on the need for target vessel revascularization at 6 months. The ideal burr/artery ratio and adjunctive balloon/artery ratio for optimizing acute luminal results and minimizing restenosis is unknown. Six-month clinical follow-up was obtained in 311 patients (339 lesions) treated with rotational atherectomy from August 1993 to September 1994, to determine whether procedural results or technique were related to the need for target vessel revascularization. Target vessel revascularization, defined as repeat percutaneous intervention or bypass surgery within 6 months after rotational atherectomy, occurred in 19% of patients. Larger burr/artery ratios, defined as the final burr size divided by the reference artery size, were correlated with decreased postatherectomy diameter stenosis (p <0.009) and decreased final diameter stenosis (p <0.03). However, there was no statistical association between postatherectomy or final diameter stenosis with need for revascularization (p = not significant [NS]). The need for revascularization was lowest for burr/artery ratio between 0.6 to 0.85 (15%) versus burr/artery <0.6 or >0.85 (25%) (p <0.04). Postatherectomy, smaller balloon/artery ratios, defined as the final balloon size divided by the reference artery size, were correlated with lower repeat revascularization rates. Balloon/artery ratios <0.95 (target vessel revascularization = 11% vs 25% in balloon/artery >0.95) were associated with the best luminal results and the least risk for clinical restenosis (p <0.006). For rotational atherectomy, despite improvement in acute luminal results with increased burr/artery ratio, the use of a moderate burr/artery ratio correlated with the lowest revascularization rates. There was no correlation between postatherectomy or final diameter stenosis and need for repeat interventions. However, the use of large balloon/artery ratios after rotablator was associated with higher target vessel revascularization rates.     

Characterisation of a pea hsp70 gene which is both developmentally and stress-regulated

OBJECTIVES: We sought to evaluate the immediate angiographic results and intermediate-term follow-up after percutaneous treatment of left main coronary stenoses in the new device era. BACKGROUND: Historically, balloon angioplasty of left main coronary stenoses has been associated with high procedural morbidity and poor long-term results. It is not clear whether new devices are more effective in this anatomic setting. METHODS: Between July 1993 and July 1995, we performed initial left main coronary interventions on 46 patients (mean age 67 +/- 12 years, 26% women). Quantitative angiography was available for 42 of 46 interventions, and clinical follow-up was obtained for all patients at 1 month, 6 months and 1 year after initial revascularization. RESULTS: Most interventions (42 of 46) were performed in patients with "protected" coronary stenoses to the left coronary system owing to the presence of one or more patent left main coronary grafts. Seventy-seven percent of screened patients were deemed unsuitable for repeat coronary artery bypass surgery. Procedures performed included stenting in 73% of patients (alone in 30% and after rotational atherectomy in 43%), rotational atherectomy in 58% (alone in 15% and before stenting in 43%), directional atherectomy in 4% and angioplasty alone in 7%. Initial procedural success was achieved in all interventions, with no deaths, myocardial infarctions (creatine kinase, MB fraction > 50 IU/liter) or emergent bypass surgery. Follow-up data to date (median duration 9 months, range 6 to 19) demonstrate a 98% overall survival rate and a 6-month event-free survival rate of 78% (six target vessel revascularizations [TVRs], four non-TVRs). CONCLUSIONS: Treatment of protected left main coronary artery stenoses can be accomplished safely and effectively with new device technology. Intermediate-term follow-up demonstrates an acceptably low rate of death, myocardial infarction or repeat revascularization at 6 months and 1 year.