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Neil J Weissman

Publications and source records attributed to Neil J Weissman.

At least 37 records · Page 2Linked to original sources
PubMed2006

Clinical outcomes after percutaneous coronary intervention with drug-eluting stents in dialysis patients.

OBJECTIVES: We aimed to compare the clinical outcomes of dialysis versus nondialysis patients after coronary drug-eluting stent (DES) implantation. BACKGROUND: The revascularization of ischemic heart disease in dialysis patients has remained controversial due to consistent exclusion of this population from major trials, especially in the context of percutaneous coronary interventions (PCI) with DES. METHODS: We analyzed the data on 3,442 consecutive patients who underwent PCI and DES implantation since March 2003. Periprocedural events, 1- and 6-month clinical outcomes were then compared between dialysis (n = 72) and nondialysis patients (n = 3,370). RESULTS: Baseline characteristics revealed a higher prevalence of female gender (p = 0.03), African Americans (p < 0.001), hypertension (p < 0.001), diabetes mellitus (p < 0.001), number of diseased vessels (p = 0.04), lower ejection fraction (p < 0.001), and a higher prevalence of acute myocardial infarction (MI) (p = 0.04) in dialysis patients. Nondialysis patients showed more history of smoking (p < 0.001) and obesity (p = 0.02). Procedural success was higher (p = 0.05), while there was a trend toward a lower mortality rate, in the nondialysis group during hospitalization. At 6 months, the restenosis rate was low and comparable, but mortality occurred more often (16% vs. 3.8%; p < 0.001) in dialysis patients. Multivariate analysis revealed cardiogenic shock (p = 0.04) to be an independent predictor of mortality. CONCLUSIONS: PCI with DES in dialysis patients is safe and feasible, with a similar reduction of repeat revascularization when compared with nondialysis patients. There was, however, a higher incidence of mortality in dialysis patients at 6 months, mostly influenced by contributing comorbidities and more severe conditions at presentation.

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PubMed2005

Cardiovascular events in patients with coronary plaque rupture and nonsignificant stenosis.

The long-term outcome of patients who present with an identified plaque rupture in a nonflow-limiting lesion is not well known. We retrospectively studied 17 consecutive patients in whom intravascular ultrasound identified plaque rupture in nonflow-limiting lesions (minimum lumen area >4.0 mm2) that were not treated with coronary intervention. After a mean follow-up of 43 +/- 25 months, events related to those lesions were 1 death (6%) of undetermined cause (6%) that occurred after 69 months, no myocardial infarction, and 2 revascularizations (12%) that occurred at 3 and 67 months. Overall, the cumulative rate of cardiac events was 18%.

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PubMed2005

Impact of renal function on coronary plaque morphology and morphometry in patients with chronic renal insufficiency as determined by intravascular ultrasound volumetric analysis.

The aim of the present study was to use intravascular ultrasonography (IVUS) to assess plaque morphology and morphometry in patients with varying degrees of chronic renal insufficiency, including end-stage renal disease (ESRD) on dialysis replacement. Cardiovascular disease is the main cause of death for patients with chronic renal insufficiency, particularly in patients with ESRD. The impact of several degrees of renal insufficiency (including ESRD) on coronary plaque characteristics has not been determined. A total of 142 patients who underwent IVUS imaging of a de novo native coronary artery stenosis before percutaneous intervention were matched for age, gender, and diabetes and were grouped according to calculated creatinine clearance (CrCl): CrCl >70 ml/min (n = 39); CrCl 50 to 69 ml/min (n = 41); CrCl <50 ml/min, (n = 37), and ESRD (n = 25). Standard clinical, angiographic, and IVUS parameters were measured. The ESRD group had more African-American (p = 0.002) and hypertensive (p = 0.002) patients. No significant difference was found in any of the IVUS measurements among patients with CrCl >70, 50 to 69, and <50 ml/min: reference and lesion site arterial, lumen, and plaque areas and volumes, and arterial calcium (p = NS for all comparisons). Conversely, patients with ESRD had larger reference segment arterial and lumen areas and volumes; larger lesion site arterial, lumen, and plaque areas; and larger arcs of calcium (p <0.05 for all post hoc comparisons between patients with ESRD and patients with CrCl >70, 50 to 69, and <50 ml/min). Thus, chronic renal insufficiency in the absence of dialysis is not associated with increased reference segment or lesion site plaque burden and calcium. However, the transition to the need for dialysis is associated with progressive calcific atherosclerosis (larger lesion plaque area and calcium).

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PubMed2005

Serial intravascular ultrasound comparison of the extent and distribution of intimal hyperplasia six months after stent implantation for de novo versus in-stent restenosis lesions.

The aim of this study was to compare intimal hyperplasia (IH) growth at 6 months in patients with de novo lesions treated with stents versus IH regrowth in patients with treated in-stent restenosis. Intravascular ultrasound was performed after intervention and at the 6-month follow-up visit as part of a standardized protocol across several clinical trials. At 6 months, the lumen was larger in the de novo group (mean lumen cross-sectional area [CSA] 6.31 +/- 2.2 vs 4.48 +/- 1.9 mm(2), p = 0.0001; minimum lumen CSA 4.2 +/- 1.8 vs 2.59 +/- 1.5 mm(2), p = 0.0001). However, the total increase in the mean IH CSA volume was the similar in the de novo and ISR groups (2.89 +/- 1.6 vs 2.64 +/- 1.94 mm(2), respectively; p = 0.11). We found that IH regrowth in restented in-stent restenosis lesions was similar to that in de novo stent implantation and that the final lumen CSA was an important component of in-stent restenosis recurrence.

Coronary Restenosis↗
PubMed2005

Intravascular ultrasound assessment of ruptured atherosclerotic plaques in left main coronary arteries.

Atherosclerotic plaque rupture is the main cause of acute coronary syndromes. There is no systematic description of ruptured plaques located in the left main coronary artery (LMCA). The aim of our study was to describe ruptured plaques in the LMCA with intravascular ultrasound. We identified 17 LMCA plaque ruptures in 16 patients. Two patients had a recent myocardial infarction, 13 had unstable angina, and 1 had stable angina. Two left main ruptures were clinically considered to be incidental findings and were left untreated; the remaining 14 were culprit lesions that were treated with emergency coronary artery bypass grafting (n = 3) or LMCA stenting (n = 11). One patient died in the hospital after left main stenting for unstable angina; all other patients who underwent stenting or surgical bypass did well. Almost all ruptured plaques that were identified by intravascular ultrasound had an angiographic complex appearance that was defined by the presence of ulceration (81%), intimal flap (38%), aneurysm (12%), or thrombus (6%). All ruptures were located in the distal half of the LMCA; 6 ruptures involved bifurcation and 11 were confined to the LMCA proper. The angle between the maximum plaque cavity and the left anterior descending/left circumflex artery flow divider was 162.3 degrees +/- 15.6 degrees in bifurcation versus 71.3 degrees +/- 41.6 degrees in nonbifurcation lesions (p <0.0001). The LMCA minimum lumen area measured 6.0 +/- 3.3 mm2 in nonbifurcation lesions and 7.4 +/- 4.7 mm2 in bifurcation lesions (p = 0.5). LMCA plaque ruptures mostly present as unstable angina, are located in the distal portion and/or bifurcation of the LMCA, often do not compromise the lumen, and have an angiographic complex appearance. When ruptured plaques involve the bifurcation, they occur opposite the distal flow divider.

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PubMed2005

Incidence and clinical correlates of ruptured plaques in saphenous vein grafts: an intravascular ultrasound study.

OBJECTIVES: The goal of this study was to assess the incidence, clinical correlates, and angiographic appearance of ruptured atherosclerotic plaques detected in saphenous vein grafts (SVGs). BACKGROUND: Ruptured atherosclerotic plaques in native coronary arteries but not in SVGs have been well described with intravascular ultrasound (IVUS). METHODS: We reviewed 791 pre-intervention IVUS SVG studies and identified 95 ruptured plaques in 76 SVGs in 73 patients. Standard clinical, angiographic, and IVUS measurements were collected and/or measured. Ruptured plaques were compared with nonruptured plaques in 276 randomly selected patients. RESULTS: The IVUS-detected ruptured plaques had angiographically complex morphology (95%) with ulceration (79%), intimal flap (71%), and sometimes aneurysm formation (14%). Compared with control SVG lesions, ruptured plaques occurred more often in patients with acute coronary syndromes, in older SVGs (12.3 +/- 5.0 years vs. 8.6 +/- 5.2 years, p < 0.001), and in patients with hypercholesterolemia (92% vs. 81%, p = 0.021) and hypertension (78% vs. 63%, p = 0.015). Multiple ruptured plaques were identified in 22 patients in 19 grafts, more often in diabetic patients (55% vs. 29%, p = 0.054). A tear in the fibrous cap could be identified in 59% of plaques; in 70% it occurred at the shoulder of the plaque and in 30% at the center of the plaque. The IVUS features of ruptured plaques included positive remodeling in 71%, which was more common than in control plaques (40%, p < 0.001). CONCLUSIONS: Ruptured atherosclerotic plaques occur in old SVGs with an incidence of 9.7%. These lesions have a complex angiographic appearance and positive remodeling characteristics. This is similar to ruptured plaques in native arteries.

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PubMed2005

Intravascular ultrasound stent area of sirolimus-eluting stents and its impact on late outcome.

Stent area assessed by intravascular ultrasound is a strong predictor of late outcome after percutaneous coronary intervention. Because sirolimus-eluting stents (SESs) prevent intimal regrowth within the stent, achieving a larger final stent area might no longer be noteworthy; therefore, the investigators sought to determine the relevance and impact of the final stent area with SESs.

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PubMed2005

Polymer-based paclitaxel-eluting stents reduce in-stent neointimal tissue proliferation: a serial volumetric intravascular ultrasound analysis from the TAXUS-IV trial.

OBJECTIVES: The aim of this study was to use serial volumetric intravascular ultrasound (IVUS) to evaluate the effects of polymer-based, paclitaxel-eluting stents on in-stent neointima formation and late incomplete stent apposition. BACKGROUND: The TAXUS-IV trial demonstrated that the slow-release, polymer-based, paclitaxel-eluting stent reduces angiographic restenosis and the need for repeat revascularization procedures. Serial IVUS studies reveal details of the pattern of vascular responses provoked by stent implantation that provide insight into device safety and efficacy. METHODS: In the TAXUS-IV trial, patients were randomized to the slow-release, polymer-based, paclitaxel-eluting TAXUS stent or a bare-metal EXPRESS stent (Boston Scientific Corp., Natick, Massachusetts). As part of a formal substudy, complete volumetric IVUS data were available in 170 patients, including 88 TAXUS patients and 82 controls, at implantation and at nine-month follow-up. RESULTS: No baseline differences were present in the clinical characteristics or IVUS parameters between the control and TAXUS groups. At nine-month follow-up, IVUS lumen volumes were larger in the TAXUS group (123 +/- 43 mm(3) vs. 104 +/- 44 mm(3), p = 0.005), due to a reduction in neointimal volume (18 +/- 18 mm(3) vs. 41 +/- 23 mm(3), p < 0.001). Millimeter-by-millimeter analysis within the stent demonstrated uniform suppression of neointimal growth along the entire stent length. Late lumen loss was similar at the proximal edge of the stent between the two groups, and reduced with the TAXUS stent at the distal edge (p = 0.004). Incomplete stent apposition at nine months was observed in only 3.0% of control and 4.0% of TAXUS stents (p = 0.12). CONCLUSIONS: Polymer-based, paclitaxel-eluting TAXUS stents are effective in inhibiting neointimal tissue proliferation, and do not result in late incomplete stent apposition.

Antineoplastic Agents↗
PubMed2005

Incidence, location, magnitude, and clinical correlates of saphenous vein graft calcification: an intravascular ultrasound and angiographic study.

BACKGROUND: The pattern of saphenous vein graft (SVG) calcification before percutaneous intervention has not been studied. METHODS AND RESULTS: We used diagnostic and preintervention intravascular ultrasound (IVUS) to determine the incidence and magnitude of SVG calcification in 334 SVG lesions in 274 consecutive patients. Calcium was found in 133 SVGs (40%). Calcium was uniformly distributed among 48 lesion sites (14%), 43 proximal references (13%), and 42 distal references (13%). Calcium was superficial in 20 (40%) and deep in 28 (60%). Over the entire length of the SVGs, the maximum arc and length of calcium (in calcium-containing SVGs) averaged 174+/-107 degrees and 6.8+/-4.8 mm, respectively. In calcium-containing SVGs, lesion site arc and length of calcium measured 151+/-107 degrees and 4.1+/-3.7 mm, similar to the proximal and distal references (175+/-121 degrees and 4.0+/-2.3 mm and 177+/-121 degrees and 4.1+/-2.5 mm, respectively). Graft age (7.5+/-4.7 versus 10.5+/-4.7 years, P<0.0001), insulin-treated diabetes mellitus (40% versus 60%, P=0.02), and tobacco use (44% versus 55%, P=0.06) were clinical independent predictors of SVG calcification. CONCLUSIONS: Sixty-five percent of calcium-containing SVGs had reference calcium in the absence of lesion calcium. Calcium was located primarily in SVG wall and not at the plaque. These data suggest that SVG calcium is not just part of lesion formation and maturation. SVG calcium occurred more commonly in older grafts, in insulin-treated diabetic patients, and in smokers.

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PubMed2005

Comparison of quantitative angiographic parameters with the magnitude of neointimal hyperplasia measured by volumetric intravascular ultrasound in patients treated with bare metal and nonpolymeric paclitaxel-coated stents.

We used data from the ASian Paclitaxel-Eluting Stent Clinical Trial (a 3-center, randomized, placebo-controlled trial of nonpolymeric paclitaxel-coated stents with a single-center intravascular ultrasound substudy) to compare angiographic indexes of drug-eluting stent efficacy with the magnitude of intimal hyperplasia (IH) assessed by intravascular ultrasound. Overall, percent IH (IH volume divided by stent volume) was larger in restenotic lesions than in nonrestenotic lesions (46 +/- 19% vs 15 +/- 13%, p <0.0001); angiographic late loss and follow-up diameter stenoses correlated strongly with percent IH.

Coronary Angiography↗
PubMed2005

Intravascular ultrasound assessment of neointima distribution and the length of stent that was free of intravascular ultrasound-detectable intimal hyperplasia in paclitaxel-eluting stents.

Using data from the ASian Paclitaxel-Eluting Stent Clinical Trial, a 3-center, randomized, placebo-controlled trial of nonpolymeric paclitaxel-coated stents with a single center, 81-patient intravascular ultrasound (IVUS) substudy, the length of a stent that was free of IVUS-detectable intimal hyperplasia measured 3.2 +/- 4.8 mm in placebo stents, 6.1 +/- 5.6 mm in low-dose stents, and 8.7 +/- 6.1 mm in high-dose stents (p = 0.0029). IVUS percent neointima volume obstruction correlated with the length of this IVUS neointima-free segment (r = 0.785, p <0.0001); angiographic late lumen loss and follow-up diameter stenosis also correlated with the IVUS neointima-free length of the stents (r = 0.670, p <0.0001 and r = 0.679, p <0.0001, respectively.

Coronary Restenosis↗
PubMed2005

Underexpansion of sirolimus-eluting stents: incidence and relationship to delivery pressure.

We aimed to assess the incidence of underexpansion and the relationship between delivery pressure and expansion with sirolimus-eluting stents. Adequate stent expansion contributes to early and late improved outcomes. In 51 patients (53 lesions) with native coronary artery narrowing, balloon-expandable sirolimus-eluting stents (Cypher) were serially expanded with gradual balloon inflations [14 atm, 20 atm, and in case of minimal stent cross-sectional area (CSA)/reference lumen CSA < 50% at 20 atm, postdilatation with 0.5 mm larger balloon]. Intravascular ultrasound (IVUS) imaging was performed before intervention and after each gradual balloon inflation. Stent expansion (minimal stent CSA/reference lumen CSA) was measured. Stent expansion was 72% +/- 16% after 14 atm balloon inflation, 90% +/- 18% after 20 atm balloon inflation (P < 0.001 vs. 14 atm), and 90% +/- 18% at the end of the procedure (including optional postdilatations with 0.5 mm larger balloon; P = NS vs. 20 atm). Stent expansion addressed by MUSIC criteria (all struts apposed, no tissue protrusion, and final lumen CSA > 80% of the reference or > 90% if minimal lumen CSA was < 9 mm2) was adequate in 15% of the cases after 14 atm balloon inflation, in 60% after 20 atm balloon inflation (P < 0.001 vs. 14 atm), and in 60% at the end of the procedure (P = NS vs. 20 atm). Sirolimus-eluting stent underexpansion is common when deployed at conventional pressures. Increasing balloon delivery pressure or assessing stent expansion with IVUS seems warranted in order to ensure adequate sirolimus-eluting stent deployment.

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PubMed2005

Randomized comparison of carbon ion-implanted stent versus bare metal stent in coronary artery disease: the Asian Pacific Multicenter Arthos Stent Study (PASS) trial.

BACKGROUND: Heavy metal ions can cause allergic and inflammatory reactions that might be associated with in-stent restenosis. This randomized multicenter clinical study was designed to determine if carbon ion-implanted stents reduce luminal late loss by blocking heavy metal ion diffusion into the surrounding tissue. METHODS: A total of 225 patients with 230 native coronary lesions were randomly assigned to receive either a carbon ion-implanted Arthos Inert stent (group 1, n = 113) or a bare metal Arthos stent (group 2, n = 117). The primary endpoint was in-stent luminal late loss at 6-month angiographic follow-up, and the secondary endpoints were the 6-month angiographic restenosis rate and the occurrence of the major adverse cardiac events (MACE) including death, nonfatal myocardial infarction, and target lesion revascularization at 12 months. RESULTS: The baseline characteristics were similar in the 2 groups. In-hospital events did not occur in any patients. Angiographic follow-up at 6 months was obtained in 184 lesions (80%). At follow-up, the luminal late loss was similar in the 2 groups (0.91 +/- 0.77 mm in group 1 vs 0.88 +/- 0.80 mm in group 2, P = .79), and the angiographic restenosis rates were 11.0% in group 1 and 16.1% in group 2 (P = .31). The occurrence rates of MACE at 12 months were 9.1% in group 1 and 10.4% in group 2 (P = .73). CONCLUSIONS: The initial and long-term outcomes of the carbon ion-implanted stent were excellent. However, it did not improve long-term outcomes vs the bare metal stent.

Angioplasty, Balloon, Coronary↗
PubMed2004

Relation of intimal hyperplasia thickness to stent size in paclitaxel-coated stents.

To determine the relation of intimal hyperplasia thickness to stent size in nonpolymeric paclitaxel-coated stents, intravascular ultrasound was performed after stent implantation and at 6 months. Similar to bare metal stents, this study demonstrated that intimal hyperplasia thickness is independent of stent size. There was no deleterious effect of the increased concentration associated with using the same stent design in a smaller artery, and these results suggested that stent strut density may be a more important concept than drug concentration.

Antineoplastic Agents, Phytogenic↗
PubMed2004

Clinical, angiographic, and intravascular ultrasound characteristics of early saphenous vein graft failure.

OBJECTIVES: We sought to examine saphenous vein graft (SVG) lesions that fail within the first year after operation. BACKGROUND: Saphenous vein grafts remain patent for approximately 10 years; however, up to 15% to 20% of SVGs become occluded within the first year. METHODS: We studied 100 patients who underwent percutaneous coronary intervention (PCI) for early (<1 year post-implantation) SVG failure lesions and compared them with a diabetes- and hypercholesterolemia-matched cohort of late SVG failures (>1 year). Coronary angiography and intravascular ultrasound images were analyzed. RESULTS: The majority of patients in both groups were males who presented with unstable angina; 36% were diabetic. Graft ages were 6.0 +/- 2.9 months and 105.4 +/- 50.8 months, respectively. The early SVG failure lesion location was more often ostial or proximal (62% vs. 42%, respectively). Early SVG failures were angiographically smaller than late failures (reference: 2.47 +/- 0.86 mm vs. 3.26 +/- 0.83 mm, p < 0.001) but had similar lesion lengths. Intravascular ultrasound showed that early failure lesions had smaller proximal and distal reference lumen areas (7.3 +/- 6.8 mm2 vs. 10.6 +/- 3.8 mm2, p = 0.026) and greater reference plaque burden than late failures (52.3% vs. 36.1%, p < 0.001). After PCI, 20.6% of early and 30.6% of late failure lesions had creatine kinase-myocardial band (CK-MB) greater than twice normal. CONCLUSIONS: Early SVG failure is mostly proximal or ostial, lesions appear focal, and early SVGs appear smaller than late SVGs. Intravascular ultrasound shows significant reference segment plaque burden, suggesting more severe, diffuse SVG disease.

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