Antithrombotic therapy after coronary stent placement

Subacute stent thrombosis and hemorrhagic complications due to intensive anticoagulant therapy limit the clinical benefit of coronary stenting. Antithrombotic therapy after coronary stent placement has not been standardized yet. From January 1994 to December 1995 a total of 338 Palmaz-Schatz stents were implanted in 285 patients. Procedural success rate was 98.8%. In the initial period, after stent placement, patients were treated with acetylsalicylic acid (ASA) and warfarin (135 patients, Group A), while subsequently, according to the results of other studies, patients were treated with ASA plus ticlopidine (146 patients, Group B). Two hours after sheath removal, Group A patients were treated with intravenous heparin until therapeutic INR (2.5-3.5) was reached; warfarin was stopped 3 months later. In Group B patients 2 hours after sheath removal a treatment with subcutaneous heparin 25,000 IU/die plus ticlopidine 500 mg/die was started. Subcutaneous heparin was maintained until hospital discharge, ticlopidine was stopped after 1 month and ASA was maintained indefinitely. There were no significant differences in baseline characteristics between the two groups. Most patients had unstable angina and in the majority of cases the stent was implanted due to intimal dissection after balloon dilation. Eleven patients had subacute thrombosis of the stent (3.9%): 9 patients were in Group A (6%) and 2 patients were in Group B (1.3%; p = 0.04). Seven patients (6 in Group A, 1 in Group B) were treated with emergency coronary angioplasty and 3 (2 in Group A, 1 in Group B) with coronary bypass; nevertheless 7 patients (6 in Group A, 1 in Group B) had an acute myocardial infarction. Eight patients (6 in Group A, 2 in Group B) had major bleeding due to a large groin hematoma requiring blood transfusion or vascular surgery. In conclusion, after coronary stenting antithrombotic therapy with ASA plus ticlopidine, as compared with anticoagulant therapy, reduces the incidence of both cardiac events and hemorrhagic complications.     

Intravascular ultrasound-guided optimized stent deployment. Immediate and 6 months clinical and angiographic results from the Multicenter Ultrasound Stenting in Coronaries Study (MUSIC Study)

OBJECTIVES: A study was set up to validate the safety and feasibility of intravascular ultrasound-guided stenting without subsequent anticoagulation, and its impact on the 6 months restenosis rate. METHODS: The study was designed to be multicentred, prospective, and observational. RESULTS: One hundred and sixty-one patients with stable angina and a de novo coronary artery lesion were enrolled. In four patients, the implantation of a Palmaz-Schatz (with spiral bridge) stent had failed. One of these four patients died 3 days following bypass surgery. In two other patients, intravascular ultrasound assessment was not performed. One hundred and twenty-five of the remaining 155 patients (81%) were treated with aspirin (100 mg x day(-1)), because all three criteria for optimized stent expansion were met. Twenty-two of the remaining 38 patients (25%), in whom at least one criterion was not met were treated with aspirin and acenocoumarol (3 months, INR 2.5-3.5), while 16 patients only received aspirin. Stent thrombosis was documented in two patients (1.3%) for which repeat angioplasty was performed. During the hospital stay, there were no deaths or Q-wave myocardial infarctions. Five patients (3.2%) sustained a non-Q-wave myocardial infarction. During the follow-up period (198+/-38 days, complete for all patients, except one), one patient (0.6%) sustained a Q-wave myocardial infarction, one (0.6%) underwent bypass surgery, and repeat angioplasty was performed in nine patients (5.7%). In two of the nine patients, repeat angioplasty involved another lesion. Therefore, the target lesion revascularization rate during follow-up was 4.5% (seven patients). At quantitative coronary angiography, the minimal lumen diameter (mean+/-SD) increased from 1.12+/-0.34 mm before to 2.89+/-0.35 mm after stenting. Repeat angiography at 6 months was performed in 144 patients (92%). The minimal lumen diameter at follow-up was 2.12+/-0.67 mm. Restenosis (diameter stenosis of 50% or more) was documented in 12 patients or 8.3%. When the two patients with documented stent thrombosis are included, the restenosis rate amounts to 97%. CONCLUSIONS: These data confirm that, in selected patients, stents can safely be implanted without the use of systemic anticoagulation, provided optimal stent expansion is achieved. The exact role of intravascular ultrasound in the achievement of these results needs to be established by appropriately designed studies. In the meantime, intravascular ultrasound coupled with the Palmaz-Schatz stent incorporating a spiral bridge, may have contributed considerably to the immediate angiographic outcome, which in turn may explain the favourable clinical and angiographic outcome at 6 months.     

Subacute stent thrombosis: evolving issues and current concepts

During percutaneous coronary revascularization, intracoronary stents are effective in the treatment of abrupt vessel closure and improvement of suboptimal angioplasty results, and compared to balloon angioplasty, they reduce stenosis recurrence. Opposing these benefits, subacute thrombosis of stents is associated with a substantial increase in periprocedural morbidity and mortality. To review factors associated with stent thrombosis and to study the impact of evolving procedural techniques on the incidence of stent thrombosis, we reviewed all English articles from MEDLINE (1988 to 1995) with key words "stent" and "thrombosis." Stent registry data and recent abstracts from scientific meetings were also reviewed. Factors related to the clinical setting, the lesion, the stent and the procedural technique that affect the risk of stent thrombosis were identified. Sixty clinical studies were reviewed and include 7,914 patients receiving intracoronary stents. Studies were separated into those reporting stents placed emergently or electively without adjunct high-pressure balloon inflations, stents placed in saphenous vein graft conduits, and stents placed with high-pressure balloon inflations but without subsequent oral anticoagulants. Overall, subacute thrombosis was substantially higher in stents placed emergently (10.1%) compared to those placed electively (4.3%). Among contemporary trials employing high-pressure balloon inflations, the rate of stent thrombosis appears markedly lower (1.3%) despite reduced postprocedural anticoagulation. Taken together, these studies suggest factors associated with a heightened risk of stent thrombosis, many of which can be avoided with proper case selection and contemporary techniques.     

The oxidative metabolism of catecholamines in the brain: a review

The EBI (BARD-XT, C.R. Bard, Murray Hill, NJ) stent is a new radiopaque balloon expandable coronary stent with high resistance to external radial forces. It does not shorten significantly with expansion and allows stent implantation in bifurcation lesions. A total of 28 EBI stents were implanted in 23 lesions in 21 patients. Indications for stent implantation were acute closure in 1, threatened closure in 15, and electively in 7 lesions. In 2 cases, the lesion involved a bifurcation where a stent was implanted in both vessels. All patients received aspirin and ticlopidine. No anticoagulant therapy was given. The stenting procedure was successful in 22 of 23 lesions. No complications occurred with the exception of 1 patient with a thrombotic reocclusion within 1 hr after stent implantation and 1 patient with a temporary occlusion of a side branch. The mean minimal luminal diameter (MLD) increased from 0.74+/-0.46 mm before balloon dilatation to 1.27+/-0.62 mm before stent implantation and 2.32+/-0.57 mm after stent implantation. Percent stenosis decreased from 71+/-19% before angioplasty to 46+/-25% after angioplasty to 5+/-8% after stent implantation. MLD at the time of follow-up angiography after 4 months was 1.98+/-0.77 mm and percent stenosis was 26+/-21%. Restenosis of more than 50% occurred in 2 lesions. In these lesions, a second percutaneous transluminal coronary angioplasty was performed. Advantages of this stent are its flexibility together with an acceptable radial strength as well as enabling radiopacity without obscuring the arterial lumen. Stenting of bifurcation lesions is possible.     

Operator volume and outcome of patients undergoing coronary stent placement

OBJECTIVES: The aim of this study was to assess the relation between operator experience in coronary stent placement procedures and the clinical outcome of patients. BACKGROUND: The results of coronary balloon angioplasty are closely related to the experience of the operator performing the procedure. Data on the effect of operator experience on the results after coronary stent placement are missing. METHODS: The study included 3,409 consecutive patients undergoing coronary stent placement for the management of coronary artery disease. A composite end point of cardiac death, myocardial infarction and aortocoronary bypass surgery during the first 30 days after the intervention, was the primary end point and the procedural failure was the secondary end point of the study. RESULTS: Adverse clinical outcome occurred in 2.99% of the 3,409 patients undergoing coronary stent placement. Procedural failure was recorded in 2.08% of the patients. Operator volumes above 483 procedures were associated with a risk-adjusted adverse outcome rate of 1.70%+/-1.28%, which is significantly lower than the overall rate of 2.99%. Operator yearly volumes of under 90 procedures were associated with a risk-adjusted adverse outcome rate of 4.59%+/-1.17%, which is significantly higher than the overall rate of 2.99%. The operator experience was an independent predictor even after adjusting for the effect of other risk factors. The analysis demonstrated that an experience of at least 100 procedures is required to obtain better outcome even in patients with simple coronary lesions and that operators should perform at least 70 procedures annually to expect a better outcome in patients with both simple and complex coronary lesions. CONCLUSIONS: Operator experience is a significant and independent predictor of the outcome of patients undergoing coronary stent placement. An experience of at least 100 procedures and an annual volume of at least 70 procedures are required to ensure a significantly better outcome after coronary stent implantation.     

Bovine endometrial retinol-binding protein secretion, messenger ribonucleic acid expression, and cellular localization during the estrous cycle and early pregnancy

OBJECTIVES: We assessed the safety and efficacy of stent placement in patients with poorly controlled hypertension and renal artery stenoses, which are difficult to treat with balloon angioplasty alone. BACKGROUND: Preliminary experience with stent placement suggests improved results over balloon angioplasty alone in patients with atherosclerotic renal artery stenosis. METHODS: Balloon-expandable stents were placed in 100 consecutive patients (133 renal arteries) with hypertension and renal artery stenosis. Sixty-seven of the patients had unilateral renal artery stenosis treated and 33 had bilateral renal artery stenoses treated with stents placed in both renal arteries. RESULTS: Angiographic success, as determined by quantitative angiography, was obtained in 132 (99%) of 133 lesions. Early clinical success was achieved in 76% of the patients. Six months after stent placement, the systolic blood pressure was reduced from 173 +/- 25 to 147 +/- 23 mm Hg (p < 0.001); the diastolic pressure from 88 +/- 17 to 76 +/- 12 mm Hg (p < 0.001); and the mean number of antihypertensive medications per patient from 2.6 +/- 1 to 2.0 +/- 0.9 (p < 0.001). Angiographic follow-up at a mean of 8.7 +/- 5.0 months in 67 patients revealed restenosis (>50% diameter narrowing) in 15 (19%) of 80 stented vessels. CONCLUSIONS: Renal artery stenting is an effective treatment for renovascular hypertension, with a low angiographic restenosis rate. Stent placement appears to be a very attractive therapy in patients with lesions difficult to treat with balloon angioplasty such as renal aorto-ostial lesions and restenotic lesions, as well as after a suboptimal balloon angioplasty result.     

Long-term follow-up of a high risk cohort after stent implantation in saphenous vein grafts

OBJECTIVES: We sought to provide short- and long-term clinical outcomes of a high risk cohort treated with stents in saphenous vein grafts (SVGs). BACKGROUND: Data on the long-term outcome of SVG stenting in high risk patients are limited. METHODS: Johnson & Johnson stents were implanted in the SVGs of 186 patients (302 stents, 244 lesions). Ninety percent of patients presented with myocardial infarction (MI) or unstable angina (mean +/- SD ejection fraction [EF] 44 +/- 11%, patient age 71 +/- 9 years, graft age 9.4 +/- 5 years). Using a risk score classification, 155 patients (83%) were defined as high risk for repeat surgical repair or angioplasty. RESULTS: The procedural success rate was 97.3%, with 2.7% major complications (death, Q wave MI, coronary artery bypass graft surgery [CABG]). Clinical follow-up was obtained in 177 patients (mean 19.1 +/- 13.5 months, range 7 to 59). Event rates were 10% for death; 9% for MI; 11% for repeat CABG; and 15% for repeat angioplasty (total events 45%). Kaplan-Meier estimated survival and event-free survival at 4 years were 0.79 +/- 0.06 and 0.29 +/- 0.07, respectively. Predictors of death were congestive heart failure (p < 0.01) and EF <44% (p < 0.05). Predictors of combined events of death, MI and CABG were low EF (p < 0.01) and high SVG age (>10 years, p < 0.01). There were 66 revascularization procedures (35% of patients), 24% of which were in nontarget lesions. Fifty-three percent of the cardiac events occurred during the first year of follow-up. Of the 160 survivors, 36% were free of angina, 49% were in Canadian Cardiovascular Society functional class I or II, and 15% were in class III or IV. Sixty-nine percent of patients were in class I or II according to the Specific Activity Scale, and 31% of patients were in class III or IV. CONCLUSIONS: Balloon-expandable stent implantation in the SVGs of high risk patients is associated with a low early complication rate. Expected survival rates are good, as are the anginal and functional classifications, but there is a high rate of recurrent events and need for repeat revascularization. Vein graft stenting is an acceptable palliative option in many high risk patients.     

Predictors of major in-hospital ischemic complications and length of hospital stay after coronary stenting

Although recent data show that coronary stenting reduces procedural complications and late restenosis, major concern has been expressed about the greater hospital cost associated with the use of this device as compared to conventional coronary angioplasty. Since length of hospital stay after surgical procedures is a major determinant of resource use, the identification of variables associated with an excessively long hospital stay after intracoronary stent placement may have important practical consequences. The purpose of this study was to assess factors responsible for the occurrence of in-hospital complications and prolonged hospital stay after coronary stenting in 939 consecutive patients enrolled in the Registro Impianto Stent Endocoronarico (RISE Study Group). Consecutive patients undergoing coronary stent implantation at 16 medical centers in Italy were prospectively enrolled in the Registry. Clinical data, qualitative and quantitative angiographic findings were obtained from data collected in case report forms at each investigator site. Major ischemic complications were considered death, Q-wave myocardial infarction, emergency bypass surgery and emergency repeat angioplasty. The study group consisted of 939 patients (781 men, 158 women with a mean age of 59 years) in whom 1392 stents were implanted in 1006 lesions and expanded at a maximal inflation pressure of 14.7 +/- 3 atmospheres. The great majority of patients (92%) received only antiplatelet drugs after coronary stenting. During hospitalization, there were 45 major ischemic complications in 39 patients (4.2%): 13 events were related to acute or subacute thrombosis (1.4%). On multivariate logistic regression analysis, the following factors were predictive of in-hospital complications: increasing age (OR 2.19, 95% CI 1.18-4.07), unplanned stenting (OR 3.46, 95% CI 1.65-7.23) and maximal inflation pressure (OR 0.83, 95% CI 0.75-0.93). Mean hospital stay after stent implantation was 4.1 +/- 4.4 days and was related, by multivariate regression analysis, to female sex (p = 0.0001), prior bypass surgery (p = 0.03), non-elective stenting (p = 0.0001), use of anticoagulation (p = 0.0001) and development of major ischemic complications (p = 0.0001). This Registry shows that in an unselected population of patients undergoing coronary stenting, major ischemic complications occur at a relatively low rate (4.2%) and thrombotic events can be kept at 1.4%, despite the omission of anticoagulation in the great majority of patients. Length of hospital stay was affected by the occurrence of major ischemic complications, unplanned stenting, use of anticoagulation, female sex and prior bypass surgery. Accumulating experience, further reduction in complications and complete omission of anticoagulation may decrease length of hospital stay, thus reducing the use of resources after coronary stenting.     

Procedural results and late clinical outcomes following multivessel coronary stenting

OBJECTIVES: To evaluate in-hospital and long-term clinical outcomes in a large consecutive series of patients undergoing percutaneous multivessel stent intervention. BACKGROUND: High restenosis and recurrent angina rates have limited the clinical outcomes of multivessel coronary angioplasty before stents were available to improve angioplasty results. METHODS: We evaluated in-hospital and long-term clinical outcomes (death, Q-wave myocardial infarction [MI], and repeat revascularization rates at one year) in 398 consecutive patients treated with coronary stents in two (94% of patients) or three native arteries, compared to 1,941 patients undergoing stenting procedure in a single coronary artery between January 1, 1994 and August 29, 1997. RESULTS: Overall procedural success was obtained in 96% of patients with two- or three-vessel stenting and in 970% of patients with single-vessel stent intervention (p = 0.36). Procedural complications were also similar (3.8% for multivessel versus 2.9% for single vessel, p = 0.14). During follow up, target lesion revascularization was 15% in multivessel and 16% in single-vessel interventions (p = 0.38), and repeat revascularization (calculated per treated patient) was also similar for both groups (20% vs. 21%, p = 0.73). There was no difference in death (1.4% vs. 0.7%, p = 0.26), and Q-wave MI (1.2% vs. 0%, p = 0.02) was lower following multivessel interventions. Overall cardiac event-free survival was similar for both groups (p = 0.52). CONCLUSIONS: Unlike previous conventional angioplasty experiences, multivessel stenting has (1) similar in-hospital procedural success and major complication rates and (2) similar long-term (one year) clinical outcomes compared with single-vessel stenting. Thus, stents may be a viable therapeutic strategy in carefully selected patients with multivessel coronary disease.     

Introduction to coronary artery stents and their pharmacotherapeutic management

OBJECTIVE: To provide an introduction to coronary artery stents and their pharmacologic management, including anticoagulant therapy and newer antiplatelet regimens. DATA SOURCES: A MEDLINE and current journal search of relevant articles that evaluated coronary stent success rates and anticoagulation or antiplatelet regimens. STUDY SELECTION: Data from the use of primarily the Palmaz-Schatz stent were included. Studies using vitamin K antagonists that are not commercially available in the US were excluded unless they compared an antiplatelet regimen with anticoagulation using the international normalized ratio (INR). DATA SYNTHESIS: Limitations with percutaneous transluminal coronary angioplasty (PTCA), such as ischemic complications and restenosis, have led to the advent of intracoronary stenting. However, the placement of a stent within the coronary artery lumen is associated with a risk of thrombotic events. Despite current postprocedural anticoagulation and antiplatelet regimens, thrombosis occurs at rates ranging from 0.6% to 21%. When anticoagulation is deemed appropriate, it should be used for 1-2 months and the INR should be maintained between 2 and 3.5. Anticoagulation appears to have no effect on the development of restenosis, but has been shown to cause significant hemorrhagic events in 5-13.5% of patients. Newer data continue to define the subsets of patients who may be managed with antiplatelet agents alone. Combinations of aspirin and ticlopidine or aspirin alone may be used to manage patients who fulfill the following criteria: optimal stent placement, high-pressure inflation, and adequate coronary size. CONCLUSIONS: Coronary artery stenting is a novel approach for the management of coronary artery disease, but is associated with the complication of stent thrombosis. Anticoagulation reduces the risk of stent thrombosis, but is associated with bleeding risk. Selected patients may be successfully managed with antiplatelet agents only. More data are needed to better define the optimal antithrombotic regimen.     

Randomized multicenter comparison of conventional anticoagulation versus antiplatelet therapy in unplanned and elective coronary stenting. The full anticoagulation versus aspirin and ticlopidine (fantastic) study

BACKGROUND: Dual therapy with ticlopidine and aspirin has been shown to be as effective as or more effective than conventional anticoagulation in patients with an optimal result after implantation of intracoronary metallic stents. However, the safety and efficacy of antiplatelet therapy alone in an unselected population has not been evaluated. METHODS: Patients were randomized to conventional anticoagulation or to treatment with antiplatelet therapy alone. Indications for stenting were classified as elective (decided before the procedure) or unplanned (to salvage failed angioplasty or to optimize the results of balloon angioplasty). After stenting, patients received aspirin and either ticlopidine or conventional anticoagulation (heparin or oral anticoagulant). The primary end point was the occurrence of bleeding or peripheral vascular complications; secondary end points were cardiac events (death, infarction, or stent occlusion) and duration of hospitalization. RESULTS: In 13 centers, 236 patients were randomized to anticoagulation and 249 to antiplatelet therapy. Stenting was elective in 58% of patients and unplanned in 42%. Stent implantation was successfully achieved in 99% of patients. A primary end point occurred in 33 patients (13.5%) in the antiplatelet group and 48 patients (21%) in the anticoagulation group (odds ratio=0.6 [95% CI 0.36 to 0.98], P=0.03). Major cardiac-related events in electively stented patients were less common (odds ratio=0.23 [95% CI 0.05 to 0.91], P=0.01) in the antiplatelet group (3 of 123, 2.4%) than the anticoagulation group (11 of 111, 9.9%). Hospital stay was significantly shorter in the antiplatelet group (4.3+/-3.6 versus 6. 4+/-3.7 days, P=0.0001). CONCLUSIONS: Antiplatelet therapy after coronary stenting significantly reduced rates of bleeding and subacute stent occlusion compared with conventional anticoagulation.     

Coronary stenting in cardiac allograft vasculopathy

OBJECTIVE: The purpose of this study was to evaluate acute angiographic success, in-hospital complications and long-term outcome after intracoronary stenting in patients with cardiac allograft vasculopathy. BACKGROUND: The application of conventional interventional modalities to treat discrete lesions in patients with cardiac allograft vasculopathy is associated with higher procedural morbidity, mortality and higher restenosis compared to atherosclerotic coronary artery disease. Elective coronary stenting has been shown to lower restenosis rates and improve long-term outcome in selected patients with native coronary artery disease; however, its safety and efficacy in reducing restenosis in patients with cardiac allograft vasculopathy is unknown. METHODS: Ten patients with 19 discrete lesions in a major coronary artery without diffuse distal disease underwent intracoronary stenting using Palmaz-Schatz stents. The average stent size was 3.4 mm, and the stent/artery ratio was 0.99+/-0.07. Eight of ten (80%) patients received antiplatelet therapy (aspirin plus ticlopidine) only. RESULTS: Procedural success was 100% with no in-hospital stent thrombosis, Q-wave myocardial infarction or death. Minimal luminal diameter increased from 0.83+/-0.38 mm to 3.23+/-0.49 mm after stenting. Diameter stenosis decreased from 74.91+/-11.52% to 5.90+/-4.09% after stenting. Follow-up angiography was performed in 8 of 10 (80%) patients and 16 of 19 (84%) lesions. Target lesion revascularization was required in 2 of 10 (20%) patients and 3 of 16 (19%) lesions. Allograft survival was 7 of 10 (70%) at the end of 22+/-11 months follow-up. CONCLUSIONS: Intracoronary stenting can be performed safely with excellent angiographic success in selected patients with cardiac allograft vasculopathy. The restenosis rate appears to be low despite the aggressive nature of the disease. A multicenter study with a larger number of patients is required to assess its efficacy in reducing restenosis and improving allograft survival.     

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.     

Dietary and non-dietary factors associated with iron status in a cohort of Danish adults followed for six years

PURPOSE: Suboptimal distal coronary flow reserve after successful balloon angioplasty has been attributed to angiographically unrecognized inadequate lumen expansion, and adjunct coronary stenting has been shown to improve coronary flow reserve. The aim of this study was to investigate whether myocardial fractional flow reserve (FFRmyo) would increase further after coronary stenting compared with balloon angioplasty alone in the same patient group. METHODS: FFRmyo and quantitative coronary angiography were obtained before and after pre-stent balloon dilation, and again after stent placement in 11 patients (7 left anterior descending artery, 3 right coronary artery and 1 left circumflex artery). FFRmyo was calculated as the ratio of Pd/Pa during intracoronary adenosine 5'-triphosphate (50 micrograms and 20 micrograms in the left and right coronary arteries, respectively)-induced maximum hyperemia, where Pd represents mean distal coronary pressure measured by a 2.1 Fr infusion catheter and Pa represents mean aortic pressure measured by the guiding catheter. RESULTS: Percent diameter stenosis significantly decreased after balloon angioplasty (74% +/- 15% vs 37% +/- 17%, p < 0.001), and decreased further after stent placement (18% +/- 10%, p < 0.001 vs baseline and balloon angioplasty). FFRmyo after coronary stenting (0.85 +/- 0.09) was significantly higher than that at baseline (0.51 +/- 0.16, p < 0.001) and after balloon angioplasty (0.77 +/- 0.11, p < 0.05). There was a significant correlation between angiographic variables and FFRmyo. The increase in lumen dimensions after coronary stenting was followed by a further significant improvement of FFRmyo. CONCLUSION: These results suggest that coronary stenting may provide a more favorable functional status and lumen geometry of residual coronary stenosis compared with balloon angioplasty alone.     

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.     

Multicenter investigation of coronary stenting to treat acute or threatened closure after percutaneous transluminal coronary angioplasty: clinical and angiographic outcomes

OBJECTIVES: This study reports on the initial experience with the Gianturco-Roubin flexible coronary stent. The immediate and 6-month efficacy of the device and the incidence of the complications of death, myocardial infarction, emergency coronary artery bypass surgery and recurrent ischemic events are presented. BACKGROUND: Abrupt or threatened vessel closure after coronary angioplasty is associated with increased risk of myocardial infarction, emergency coronary artery bypass graft surgery and in-hospital death. When dissection or prolapse of dilated plaque into the lumen is unresponsive to additional or prolonged balloon catheter inflation, coronary stenting offers a nonsurgical mechanical means to rapidly restore stable vessel geometry and adequate coronary blood flow. METHODS: From September 1988 through June 1991, 518 patients underwent attempted coronary stenting with the 20-mm long Gianturco-Roubin coronary stent for acute or threatened vessel closure after angioplasty. In 494 patients, one or more stents were deployed. Thirty-two percent of patients received stents for acute closure and 69% for threatened closure. RESULTS: Successful deployment was achieved in 95.4% of patients. Overall, stenting resulted in an immediate angiographic improvement in the diameter stenosis from 63 +/- 25% before stenting to 15 +/- 14% after stenting. Emergency coronary artery bypass graft surgery was required in 4.3% (21 of 493 patients). The incidence of in-hospital myocardial infarction (Q wave and non-Q wave) was 5.5% (27 of 493 patients). At 6 months, myocardial infarction was infrequent, occurring in 1.6% (8 of 493 patients). The incidence of in-hospital death was 2.2% (11 of 493 patients). Late death occurred in 7 patients (1.4%) and 34 patients (6.9%) required later bypass graft surgery. Complications included blood loss, primarily from the arterial access site, and subacute thrombosis of the stented vessel in 43 patients (8.7%). CONCLUSIONS: The early multicenter experience suggests that this stent is a useful adjunct to coronary angioplasty to prevent or minimize complications associated with flow-limiting coronary artery dissections previously correctable only by surgery. Although this study was not randomized, it demonstrated a high technical success rate and encouraging results with respect to the low incidence of emergency coronary artery bypass graft surgery and myocardial infarction.     

Intestinal epithelial cell regulation of macrophage and lymphocyte interleukin 10 expression

Patients with recurrent angina after coronary artery bypass graft surgery pose a problem. Stent implantation has been advocated in an effort to avoid repeat operation and to address the limitations of balloon angioplasty. Aim of the present study was to determine the in-hospital and long-term results of stent deployment in focal, de novo lesions of vein grafts. Thirty-five focal, de novo lesions of vein grafts in 31 patients were treated with stent deployment. Twenty-four patients (77%) had three vessels, 6 (20%) two vessels and 1 (3%) single vessel disease. Saphenous vein grafts aged 9.7 +/- 4.2 years (range 1-19 years). Twenty-two lesions (63%) were located within the body of the saphenous graft, 8 (23%) at the graft/coronary artery anastomosis and 5 (14%) at the aorta/graft anastomosis. The indications for stent deployment included: suboptimal result from balloon angioplasty (defined as > or = 50% post-angioplasty residual stenosis) in 29/35 lesions (83%); post-angioplasty coronary dissection with threatening occlusion in 4/35 (11%); abrupt closure in 2/35 (6%). Patients were screened for death, myocardial infarction, bypass surgery and repeat angioplasty during in-hospital stay and after a follow-up of 12 +/- 8 months. Even-free survival curve was constructed by the Kaplan-Meier method. Stent deployment was successful in all patients. One stent was deployed in 24/35 lesions (69%), half Palmaz-Schatz stent in 6/35 (17%) and 2 or more stents in 5/35 (14%). The balloon/vessel ratio resulted of 1.0 +/- 0.1 Minimal lumen diameter increased from 0.8 +/- 0.4 to 3.8 +/- 0.6 mm, with a mean gain of 1.8 +/- 0.6 mm (range 1.8-4.0 mm). During the in-hospital period 1 patient (3.2%) died and 1 (3.2%) had a non Q wave myocardial infarction. Therefore, the clinical success rate, was 94%. During the follow-up period, 2 patients died (6.9%), 2 (6.9%) developed a non Q wave myocardial infarction, 1 (3.4%) underwent bypass surgery and 3 (10.3%) underwent repeat angioplasty. The estimated 2-year event-free survival rate (free from myocardial infarction, repeat surgery and repeat angioplasty) was 62%. In conclusion, Palmaz-Schatz stent deployment in focal, de novo vein grafts presents a high rate of procedural success, a low rate of acute complications and good long-term results.     

Relationship between glomerular epithelial cell injury and proteinuria in IgA nephropathy

The cost of in-hospital percutaneous transluminal coronary angioplasty (PTCA) has risen since the introduction of the coronary stent. Increased attention is now being given to the PTCA charges in Japan and a multicenter study is necessary with regard to in-hospital charges. To clarify the differences in in-hospital charges for PTCA with and without coronary stent [Stent Group and plain old balloon angioplasty (POBA) Group, respectively], we studied the PTCA charges of 352 patients in 6 hospitals. Age, male gender and extent of coronary artery disease were not different. The ratio of acute myocardial infarction ranged from 16% to 64% and that of coronary stenting ranged from 24% to 65% (p < 0.001). In-hospital charge ranged from 1.4 +/- 0.8 to 2.2 +/- 1.0 million yen (p < 0.0001). The procedural charge accounted for 53% to 75% of the in-hospital charge (p < 0.01). The in-hospital charge ranged from 1.6 +/- 0.7 to 3.3 +/- 1.6 million yen in the Stent Group, higher than the charge of 1.1 +/- 0.8 to 1.9 +/- 0.7 million yen in the POBA Group (p < 0.0001). There was a statistical difference in the number of balloon catheters used (1.1 +/- 0.4 to 2.1 +/- 0.9, p < 0.005) but not in the mean number of stents used (1.1 +/- 0.3 to 1.4 +/- 0.7). The procedural charge of the institutes with higher stenting rate (> 45%) seemed to be lower than that of the institutes with lower stenting rate (p < 0.02). In conclusion, there are large variation between institutions in PTCA charges, and in-hospital charges increased with the use of stents on introduction of the Diagnosis Related Group used in the United States. We should charge separately for coronary stenting and POBA. Despite any initial increase in the in-hospital charge for coronary stenting compared to POBA, successful stent implantation will result in a superior saving in procedural charges.     

Low-dose theophylline increases urine output in diuretic-dependent critically ill children

BACKGROUND: The pathogenesis of unstable angina involves the presence of intracoronary thrombus which may have potential bearing on the therapeutic efficacy of intracoronary stenting to reduce acute complications and restenosis rate. METHODS: In order to evaluate in-hospital and long-term outcome of coronary stenting in patients with unstable angina, we retrospectively examined our experience in 311 consecutive patients. Braunwald class III angina (B or C) was present in 35% of the cases. Three hundred seventy one stents were implanted in 315 lesions, most of them (62.4%) with complex morphology. Angiography identified an intraluminal thrombus in 22 target sites. Stent indication was elective in 146 cases (46.9%), for suboptimal results in 149 (47.9%) and for bail-out in 16 (5%). RESULTS: Procedural success was obtained in 96.3% of the study population. Major complications occurred in 12 (3.7%) patients: myocardial infarction in 6 (1.9%) cases, emergency bypass surgery in 3 (0.9%) and death in 3 (0.9%), none of them related to acute stent thrombosis. Vascular complications occurred in 5 patients (1.6%). The mean hospital stay after stenting was 2.8 +/- 1.6 days. Subacute stent thrombosis occurred in one patient and led to a Q-wave anterior myocardial infarction. Follow-up (9 +/- 5 months) status was ascertained in 216 patients and revealed an overall clinical success rate of 87.3%. Restenosis occurred in 23.5% of 157 patients who underwent angiographic follow-up. Late events included 3 non-fatal myocardial infarction, 6 new PTCA, 3 elective bypass surgery and 1 cardiac death. CONCLUSIONS: Intracoronary stenting appears safe and effective in patients with unstable angina, despite the presence of a thrombogenic milieu. Optimal immediate angiographic results, related to the mechanical properties of stents, together with a vigorous antithrombotic regimen, contributes to the favorable outcomes in this adverse setting.     

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.