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Biomedical subjects

Martin B Leon

Publications and source records attributed to Martin B Leon.

At least 91 records · Page 5Linked to original sources
PubMed2004

Enoxaparin vs unfractionated heparin in high-risk patients with non-ST-segment elevation acute coronary syndromes managed with an intended early invasive strategy: primary results of the SYNERGY randomized trial.

CONTEXT: Enoxaparin has demonstrated advantages over unfractionated heparin in low- to moderate-risk patients with non-ST-segment elevation acute coronary syndromes (ACS) treated with a conservative strategy. OBJECTIVES: To compare the outcomes of patients treated with enoxaparin vs unfractionated heparin and to define the role of enoxaparin in patients with non-ST-segment elevation ACS at high risk for ischemic cardiac complications managed with an early invasive approach. DESIGN, SETTING, AND PARTICIPANTS: The Superior Yield of the New Strategy of Enoxaparin, Revascularization and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trial was a prospective, randomized, open-label, multicenter, international trial conducted between August 2001 and December 2003. A total of 10 027 high-risk patients with non-ST-segment elevation ACS to be treated with an intended early invasive strategy were recruited. INTERVENTIONS: Subcutaneous enoxaparin (n = 4993) or intravenous unfractionated heparin (n = 4985) was to be administered immediately after enrollment and continued until the patient required no further anticoagulation, as judged by the treating physician. MAIN OUTCOME MEASURES: The primary efficacy outcome was the composite clinical end point of all-cause death or nonfatal myocardial infarction during the first 30 days after randomization. The primary safety outcome was major bleeding or stroke. RESULTS: The primary end point occurred in 14.0% (696/4993) of patients assigned to enoxaparin and 14.5% (722/4985) of patients assigned to unfractionated heparin (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.86-1.06). No differences in ischemic events during percutaneous coronary intervention (PCI) were observed between enoxaparin and unfractionated heparin groups, respectively, including similar rates of abrupt closure (31/2321 [1.3%] vs 40/2364 [1.7%]), threatened abrupt closure (25/2321 [1.1%] vs 24/2363 [1.0%]), unsuccessful PCI (81/2281 [3.6%] vs 79/2328 [3.4%]), or emergency coronary artery bypass graft surgery (6/2323 [0.3%] vs 8/2363 [0.3%]). More bleeding was observed with enoxaparin, with a statistically significant increase in TIMI (Thrombolysis in Myocardial Infarction) major bleeding (9.1% vs 7.6%, P =.008) but nonsignificant excess in GUSTO (Global Utilization of Streptokinase and t-PA for Occluded Arteries) severe bleeding (2.7% vs 2.2%, P =.08) and transfusions (17.0% vs 16.0%, P =.16). CONCLUSIONS: Enoxaparin was not superior to unfractionated heparin but was noninferior for the treatment of high-risk patients with non-ST-segment elevation ACS. Enoxaparin is a safe and effective alternative to unfractionated heparin and the advantages of convenience should be balanced with the modest excess of major bleeding.

Aged↗
PubMed2004

Impact of final stent dimensions on long-term results following sirolimus-eluting stent implantation: serial intravascular ultrasound analysis from the sirius trial.

OBJECTIVES: We assessed the predictive value of minimum stent area (MSA) for long-term patency of sirolimus-eluting stents (SES) implantation compared to bare metal stents (BMS). BACKGROUND: Although MSA is a consistent predictor of in-stent restenosis, its predictive value in BMS is still limited because of biologic variability in the restenosis process. METHODS: From the SIRolImUS (SIRIUS) trial, 122 cases (SES: 72; BMS: 50) with complete serial intravascular ultrasound (IVUS) (baseline and 8-month follow-up) were analyzed. Postprocedure MSA and follow-up minimum lumen area (MLA) were obtained. Based on previous physiologic studies, adequate stent patency at follow-up was defined as MLA >4 mm(2). RESULTS: In both groups, a significant positive correlation was observed between baseline MSA and follow-up MLA (SES: p < 0.0001, BMS: p < 0.0001). However, SES showed higher correlation than BMS (0.8 vs. 0.65) with a higher regression coefficient (0.92 vs. 0.59). The sensitivity and specificity curves identified different optimal thresholds of MSA to predict adequate follow-up MLA: 5 mm(2) for SES and 6.5 mm(2) for BMS. The positive predictive values with these cutoff points were 90% and 56%, respectively. CONCLUSIONS: In this SIRIUS IVUS substudy, SES reduced both biologic variability and restenosis, resulting in increased predictability of long-term stent patency with postprocedure MSA. In addition, SES had a considerably lower optimal MSA threshold compared to BMS.

Angioplasty, Balloon, Coronary↗
PubMed2004

Impact of sirolimus-eluting stents on outcome in diabetic patients: a SIRIUS (SIRolImUS-coated Bx Velocity balloon-expandable stent in the treatment of patients with de novo coronary artery lesions) substudy.

BACKGROUND: Randomized clinical trials have shown that a sirolimus-eluting stent significantly reduces restenosis after percutaneous coronary revascularization. Diabetic patients are known to have a higher risk of restenosis compared with nondiabetic patients. The purpose of this analysis was to determine the impact of sirolimus-eluting stents on outcomes of diabetic compared with nondiabetic patients. METHODS AND RESULTS: The SIRIUS (SIRolImUS-coated Bx Velocity balloon-expandable stent in the treatment of patients with de novo coronary artery lesions) trial is a randomized, double-blind study that compared sirolimus-eluting and bare metal stent implantation in 1058 patients with de novo native coronary artery lesions. Diabetes mellitus was present in 279 (26%) patients (diabetes mellitus group, 131 patients received sirolimus-eluting stents and 148 patients received bare metal stents) and was absent in 778 patients (no-diabetes mellitus group, 402 patients received sirolimus-eluting stents and 376 patients received bare metal stents). At 270 days, target lesion revascularization was reduced in diabetic patients from 22.3% with bare metal stents to 6.9% with sirolimus-eluting stents (P<0.001) and in nondiabetic patients from 14.1% to 2.99% (P<0.001), respectively. Major adverse cardiac events were reduced in diabetic patients from 25% with bare metal stents to 9.2% with sirolimus-eluting stents (P<0.001) and from 16.5% to 6.5% (P<0.001) in nondiabetic patients, respectively. CONCLUSIONS: Implantation of sirolimus-eluting stents compared with bare metal stents in de novo coronary lesions reduces major adverse cardiac events in patients with and without diabetes mellitus. However, among patients receiving sirolimus-eluting stents, there remains a trend toward a higher frequency of repeat intervention in diabetic patients compared with nondiabetic patients, particularly in the insulin-requiring patients.

Aged↗
PubMed2004

Short- and long-term results after multivessel stenting in diabetic patients.

OBJECTIVES: The present study evaluated clinical outcomes in diabetic patients after multivessel stenting. BACKGROUND: Multivessel angioplasty studies have reported decreased survival in diabetic patients undergoing conventional balloon angioplasty compared with coronary artery bypass graft surgery (CABG). However, several studies have demonstrated excellent procedural success and acceptable clinical outcomes after multivessel stenting. METHODS: Multivessel stenting was performed in 689 patients with 1,639 native coronary lesions. Patients were classified into three groups according to diabetes mellitus (DM) status: 1) no DM (501 patients/1,200 lesions); 2) DM treated with oral agents (102 patients/235 lesions); and 3) DM treated with insulin (86 patients/204 lesions). RESULTS: Procedural success was high overall. In-hospital CABG was higher in diabetics treated with insulin compared with the other two groups (3.5% vs. 0.4% vs. 1.0%, p = 0.02). There were no significant differences in the incidence of in-hospital cardiac death and myocardial infarction. Diabetic patients treated with oral agents or insulin had higher one-year target lesion revascularization rates than non-diabetic patients (25% vs. 35% vs. 16%, p < 0.001). Lower one-year survival was observed in diabetic patients treated with either oral agents or insulin, compared with non-diabetic patients (85% vs. 86% vs. 95%, p < 0.001). On multivariable analysis, DM was an independent predictor of one-year mortality, myocardial infarction, and target lesion revascularization after multivessel stenting. CONCLUSIONS: Despite a high technical success rate of multivessel stenting, diabetic patients, especially those treated with insulin, have higher in-hospital CABG, higher subsequent revascularization rates, and lower one-year survival than non-diabetic patients.

Aged↗
PubMed2004

Minimally invasive coronary artery bypass grafting versus stenting for patients with proximal left anterior descending coronary artery disease.

The purpose of this study was to compare the clinical outcomes of stenting and minimally invasive coronary artery bypass grafting (MIDCAB) in patients with proximal left anterior descending (LAD) coronary artery disease. The Patency, Outcome, Economics of Minimally invasive direct coronary bypass (POEM) study demonstrated that MIDCAB had similar safety and long-term efficacy for LAD revascularization compared with conventional coronary artery bypass grafting. Although LAD stenting is superior to conventional balloon angioplasty, whether it is comparable to MIDCAB is not known. We identified a matched population of 429 consecutive patients with 1-vessel disease who underwent elective proximal LAD stenting and compared their clinical outcomes with those of the 152 patients in the MIDCAB group of the POEM study. The in-hospital event rate was similar in both groups, except for a shorter length of hospital stay with LAD stenting compared with MIDCAB (2.68 vs 4.07 days, p <0.0001). At 6-month follow-up, the incidence of death and Q-wave myocardial infarction or that of cerebrovascular accident was not significantly different between these 2 groups. However, target vessel revascularization was significantly higher with LAD stenting than MIDCAB (13.3% vs 6.6%, p = 0.045). In the subgroup of patients without diabetes, all clinical events were similar in both groups, and the benefit of a shorter hospital stay associated with stenting was maintained. Compared with MIDCAB, LAD stenting is associated with higher repeat revascularization rates but offers the advantage of shorter hospitalization. For nondiabetics with proximal LAD disease, stenting may be the revascularization strategy of choice.

Coronary Artery Bypass↗
PubMed2004

Relation of final lumen dimensions in saphenous vein grafts after stent implantation to outcome.

Larger final lumen dimensions after percutaneous coronary interventions in native coronary arteries lead to lower restenosis rates. We sought to determine the impact of stent expansion, as assessed by intravascular ultrasound, on clinical results of stent implantation in saphenous vein grafts (SVGs). We identified 226 consecutive patients who underwent intravascular ultrasound-guided stenting of 234 de novo SVG lesions. Patients were divided into 2 groups based on the final stent cross-sectional area (CSA): group I (stent CSA <100% of the reference lumen CSA, n = 176 patients, 182 lesions) and group II (stent CSA >/=100% of the reference lumen CSA, n = 50 patients, 52 lesions). Baseline patient characteristics were similar between the 2 groups with the exception of smaller lesions in group II. More aggressive stent expansion (group II) was associated with (1) increased rates of in-hospital non-Q-wave myocardial infarction (29% vs 17%, p = 0.05), (2) any myocardial infarction (26% vs 8%, p = 0.003) at 1-year follow-up, and (3) no improvement in target vessel revascularization at 1 year (31% vs 26%, p = 0.3). Aggressive stent expansion in SVG lesions resulted in higher myocardial infarction rates and, unlike native arteries, no improvement in target vessel revascularization rate at 1 year. A less aggressive stent implantation strategy in SVGs than in native coronary lesions appears prudent.

Aged↗
PubMed2004

Non-polymer-based paclitaxel-coated coronary stents for the treatment of patients with de novo coronary lesions: angiographic follow-up of the DELIVER clinical trial.

BACKGROUND: Paclitaxel, a microtubule-stabilizing compound with potent antitumor activity, has been shown to inhibit smooth muscle cell proliferation and migration. The DELIVER trial was a prospective, randomized, blinded, multicenter clinical evaluation of the non-polymer-based paclitaxel-coated ACHIEVE stent compared with the stainless steel Multi-Link (ML) PENTA stent. METHODS AND RESULTS: A total of 1043 patients with focal de novo coronary lesions, <25 mm in length, in 2.5- to 4.0-mm vessels were randomized (ACHIEVE n=524; ML PENTA n=519). Angiographic follow-up was performed in a subset of 442 patients (ACHIEVE n=228; ML PENTA n=214). Prespecified end points were a 40% reduction in target-vessel failure at 9 months (primary clinical end point) and a 50% reduction in binary restenosis at 8 months (major secondary end point). Baseline clinical characteristics were comparable between the groups. Patients in ACHIEVE had more type C lesions and a larger reference diameter. At follow-up, stent late loss was 0.81 versus 0.98 mm (P=0.003), stent binary restenosis was 14.9% versus 20.6% (P=0.076), and target-vessel failure was 11.9% versus 14.5% (P=0.12) for ACHIEVE and ML PENTA, respectively. CONCLUSIONS: The ACHIEVE paclitaxel-coated stent decreased neointimal proliferation compared with the bare-metal PENTA stent; however, this reduction was insufficient to meet the prespecified primary end point of target-vessel failure and the secondary end point of binary restenosis.

Combined Modality Therapy↗
PubMed2004

Comparison of differences in outcome after percutaneous coronary intervention in men versus women <40 years of age.

We evaluated the outcomes of 177 consecutive patients (43 women, 134 men) <40 years of age with premature atherosclerosis who underwent percutaneous coronary intervention. Women were younger, had more diabetes mellitus (37% vs 10%; p <0.001), but less hyperlipidemia (58% vs 75%; p <0.001) compared with men. In-hospital vascular complications and 1-year mortality rate or Q-wave myocardial infarction (7.9% vs 0.08%, p <0.01) were higher in women. By multivariable regression analysis, female gender was the only independent predictor of vascular complications (odds ratio, 14.1; 95% confidence intervals, 1.59 to 125, p = 0.01) and of 1-year mortality rate or nonfatal myocardial infarction (odds ratio, 12.5; 95% confidence interval, 1.14 to 111, p = 0.03). Women with premature coronary disease had a distinctive risk factor profile relative to men, with a predominance of diabetes and hypercholesterolemia, and were at higher risk of developing vascular and ischemic complications after percutaneous coronary intervention, warranting aggressive risk factor modification and vigilance in this population.

Adult↗
PubMed2004

First human experience with the 17-beta-estradiol-eluting stent: the Estrogen And Stents To Eliminate Restenosis (EASTER) trial.

OBJECTIVES: The purpose of the study was to examine the safety and efficacy of 17-beta-estradiol-eluting stent implantation on coronary de novo lesions. BACKGROUND: Recent animal data indicate that local delivery of 17-beta-estradiol promotes re-endothelialization, inhibits cell migration and proliferation, and prevents restenosis. METHODS: A total of 30 consecutive patients underwent 17-beta-estradiol-eluting BiodVysio (Biocompatibles Ltd., London, United Kingdom) stent implantation for the treatment of coronary de novo lesions. Clinical, angiographic, and intravascular ultrasound (IVUS) analysis was performed at six-month follow-up. RESULTS: All stents were successfully deployed and patients were discharged home without clinical events. A total of two patients exceeded 50% intra-stent narrowing by angiography, whereas no patients experienced edge restenosis. One patient had focal intra-stent restenosis (60% diameter stenosis) with no symptoms and negative stress test, whereas the other patient had diffuse restenosis, requiring target vessel revascularization. No other patient experienced any major adverse cardiac event. Follow-up IVUS revealed a neointimal hyperplasia volume of 32.3 +/- 16.4 mm(3), whereas the stent volume was 143.7 +/- 43.7 mm(3), resulting in a neointimal volume obstruction of 23.5 +/- 12.5%. None of the patients had > or =50% volume obstruction by IVUS. CONCLUSIONS: Implantation of 17-beta-estradiol-eluted BiodVysio stents appears feasible and safe, showing low rates of binary restenosis and revascularization. These results warrant further confirmation with a large, randomized multicenter trial.

Angioplasty, Balloon, Coronary↗
PubMed2004

Contribution of stent underexpansion to recurrence after sirolimus-eluting stent implantation for in-stent restenosis.

BACKGROUND: We used intravascular ultrasound (IVUS) to evaluate recurrence after sirolimus-eluting stent (SES) implantation treatment of in-stent restenosis (ISR). METHODS AND RESULTS: Forty-eight ISR lesions (41 patients with objective evidence of ischemia) were treated with SES. Recurrent ISR was identified in 11 lesions (all focal); repeat revascularization was performed in 10. These were compared with 16 patients (19 lesions) without recurrence as documented by angiography. Nine of 11 recurrent lesions had a minimum stent area (MSA) <5.0 mm2 versus 5 of 19 nonrecurrent lesions (P=0.003); 7 of 11 recurrent lesions had an MSA <4.0 mm2 versus 4 of 19 nonrecurrent lesions (P=0.02); and 4 of 11 recurrent lesions had an MSA <3.0 mm2 versus 1 of 19 nonrecurrent lesions (P=0.03). A gap between SESs was identified in 3 of 11 recurrences versus 1 of 19 nonrecurrent lesions. CONCLUSIONS: Stent underexpansion is a significant cause of failure after SES implantation treatment of ISR.

Combined Modality Therapy↗
PubMed2004

Randomized study to evaluate sirolimus-eluting stents implanted at coronary bifurcation lesions.

BACKGROUND: A sirolimus-eluting stent (Cypher, Cordis Corp) has been reported to markedly decrease restenosis in selected lesions; higher-risk lesions, including coronary bifurcations, have not been studied. METHODS AND RESULTS: This prospective study evaluated the safety and efficacy of sirolimus-eluting stents for treatment of coronary bifurcation lesions. Patients were randomly assigned to either stenting of both branches (group A) or stenting of the main branch with provisional stenting of the side branch (SB) (group B). Eighty-five patients (86 lesions) were enrolled. There was 1 case of unsuccessful delivery of any device at the bifurcation site. Given the high crossover, more lesions were treated with 2 stents (n=63) than with stent/balloon (n=22). Clinical follow-up at 6 months was completed in all patients and angiographic follow-up in 53 patients in group A (85.5%) and 21 in group B (95.4%). One patient died suddenly 4.5 months after the procedure. There were 3 cases of stent thrombosis (3.5%). The total restenosis rate at 6 months was 25.7%, and it was not significantly different between the double-stenting (28.0%) and the provisional SB-stenting (18.7%) groups. Fourteen of the restenosis cases occurred at the ostium of the SB and were focal. Target lesion revascularization was performed in 7 cases; target vessel failure occurred in 15 cases (17.6%). CONCLUSIONS: These results are an improvement compared with historical controls using bare metal stents. Restenosis at the SB remains a problem. At this time, no statement can be made regarding the most appropriate technique to use when treating bifurcations with the Cypher stent.

Aged↗
PubMed2004

Early experience with percutaneous transcatheter implantation of heart valve prosthesis for the treatment of end-stage inoperable patients with calcific aortic stenosis.

OBJECTIVES: This study was done to assess the results of percutaneous heart valve (PHV) implantation in non-surgical patients with end-stage calcific aortic stenosis. BACKGROUND: Replacement of PHV has been shown to be feasible in animals and humans. We developed a PHV composed of three pericardial leaflets inserted within a balloon-expandable stainless steel stent. We report the acute and early follow-up results of the initial six PHV implantations. METHODS: An anterograde approach was used in all cases. The PHV, crimped over a 22-mm diameter balloon, was advanced through a 24-F sheath from the femoral vein to the aortic valve and delivered by balloon inflation. Clinical, hemodynamic, and echocardiographic outcomes were assessed serially. RESULTS: All patients were in New York Heart Association functional class IV. The PHV was successfully delivered in five patients. Early migration with subsequent death occurred in one patient who presented with a torn native valve. Acute hemodynamic and angiographic results showed no residual gradient, mild (three patients) or severe (two patients) aortic regurgitation, and patent coronary arteries. On echocardiography, the aortic valve area was increased from 0.5 +/- 0.1 cm(2) to 1.70 +/- 0.03 cm(2) and the aortic regurgitation was paravalvular. Marked and sustained hemodynamic and clinical improvement was observed after successful PHV implants. The first three patients died of a non-cardiac cause at 18, 4, and 2 weeks, respectively, and the other patients are alive at 8 weeks with no signs of heart failure. CONCLUSIONS: Implantation of the PHV can be achieved in patients with end-stage calcific aortic stenosis and might become an important therapeutic option for patients not amenable to surgical valve replacement.

Aged↗
PubMed2004

Analysis of 1-year clinical outcomes in the SIRIUS trial: a randomized trial of a sirolimus-eluting stent versus a standard stent in patients at high risk for coronary restenosis.

BACKGROUND: This study evaluated a large group of patients enrolled in a double-blind randomized trial of the sirolimus-eluting stent to document whether the initial clinical improvement seen in previous smaller series is maintained out to 12 months and to study the potential treatment effect in patient subsets known to be at increased risk of restenosis. METHODS AND RESULTS: A total of 1058 patients with de novo native coronary stenosis undergoing clinically indicated percutaneous coronary intervention were randomly assigned to sirolimus-eluting stent (533) or control bare stent (525). Procedural success and in-hospital outcomes were excellent and did not differ between the 2 groups. At 9 months, clinical restenosis, defined as target-lesion revascularization, was 4.1% in the sirolimus limb versus 16.6% in the control limb (P<0.001). At 12 months, the absolute difference in target-lesion revascularization continued to increase and was 4.9% versus 20% (P<0.001). There were no differences in death or myocardial infarction rates. In high-risk patient subsets, defined by vessel size, lesion length, and presence of diabetes mellitus, there was a 70% to 80% reduction in clinical restenosis at 1 year. CONCLUSIONS: Placement of the sirolimus-eluting stent results in continued clinical improvement at 1 year after initial implantation, with significant reduction in clinical restenosis as defined by target-lesion revascularization. Between 9 and 12 months, the absolute reduction of clinical restenosis continues to increase. Even in high-risk subsets of patients, there is a 70% to 80% relative reduction in clinical restenosis at 12 months with this drug-eluting stent.

Coronary Restenosis↗
PubMed2004

Comparison of frequency of hemorrhagic stroke in patients <75 years versus > or =75 years of age among patients receiving glycoprotein IIb/IIIa inhibitors during percutaneous coronary interventions.

We identified 1,369 consecutive patients who received glycoprotein IIb/IIIa inhibitors during 1,461 stenting procedures (2,382 lesions); of these, 240 (17.5%) were aged > or =75 years (253 procedures, 430 lesions). Very elderly patients (> or =75 years) had similar in-hospital outcomes but a higher hemorrhagic stroke rate than patients aged <75 years.

Age Factors↗
PubMed2004

Gamma radiation for in-stent restenosis: effect of lesion length on angiographic and clinical outcomes.

The relation between lesion length and effectiveness of gamma radiation treatment (gamma-RT) has not been well described. We evaluated the acute and long-term outcome according to baseline lesion length in 130 patients treated with (192)Ir in the Washington Radiation for In-Stent Restenosis Trial; 44 (35.5%) had baseline short in-stent restenosis (ISR) lesions (length < 15 mm) and 80 (64.5%) long ISR lesions (length > or = 15 mm). At 6-month follow-up after gamma-RT, the short ISR group had larger lumen dimensions and lower late loss than the long ISR group. Restenosis rate was significantly higher in patients with long ISR for both the placebo (74% vs. 39%; P = 0.01) and the gamma-RT arm (31% vs. 5.3%; P = 0.04). gamma-RT significantly improved the angiographic outcome in the short-lesion groups but had the more pronounced effect on the reduction of clinical events after treatment of long ISR group. Lesion length remains a powerful predictor of recurrent ISR and clinical events after treatment of ISR even with gamma-RT.

Brachytherapy↗