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Neil J Weissman

Publications and source records attributed to Neil J Weissman.

At least 73 records · Page 4Linked to original sources
PubMed2003

A paclitaxel-eluting stent for the prevention of coronary restenosis.

BACKGROUND: Intimal hyperplasia and resulting restenosis limit the efficacy of coronary stenting. We studied a coronary stent coated with the antiproliferative agent paclitaxel as a means of preventing restenosis. METHODS: We conducted a multicenter, randomized, controlled, triple-blind study to evaluate the ability of a paclitaxel-eluting stent to inhibit restenosis. At three centers, 177 patients with discrete coronary lesions (<15 mm in length, 2.25 to 3.5 mm in diameter) underwent implantation of paclitaxel-eluting stents (low dose, 1.3 microg per square millimeter, or high dose, 3.1 microg per square millimeter) or control stents. Antiplatelet therapies included aspirin with ticlopidine (120 patients), clopidogrel (18 patients), or cilostazol (37 patients). Clinical follow-up was performed at one month and four to six months, and angiographic follow-up at four to six months. RESULTS: Technical success was achieved in 99 percent of the patients (176 of 177). At follow-up, the high-dose group, as compared with the control group, had significantly better results for the degree of stenosis (mean [+/-SD], 14+/-21 percent vs. 39+/-27 percent; P<0.001), late loss of luminal diameter (0.29+/-0.72 mm vs. 1.04+/-0.83 mm, P<0.001), and restenosis of more than 50 percent (4 percent vs. 27 percent, P<0.001). Intravascular ultrasound analysis demonstrated a dose-dependent reduction in the volume of intimal hyperplasia (31, 18, and 13 mm3, in the high-dose, low-dose, and control groups, respectively). There was a higher rate of major cardiac events in patients receiving cilostazol than in those receiving ticlopidine or clopidogrel. Among patients receiving ticlopidine or clopidogrel, event-free survival was 98 percent and 100 percent in the high-dose and control groups, respectively, at one month, and 96 percent in both at four to six months. CONCLUSIONS: Paclitaxel-eluting stents used with conventional antiplatelet therapy effectively inhibit restenosis and neointimal hyperplasia, with a safety profile similar to that of standard stents.

Angiogenesis Inhibitors↗
PubMed2003

Paclitaxel coating reduces in-stent intimal hyperplasia in human coronary arteries: a serial volumetric intravascular ultrasound analysis from the Asian Paclitaxel-Eluting Stent Clinical Trial (ASPECT).

BACKGROUND: The aim of this study was to use serial volumetric intravascular ultrasound (IVUS) to evaluate the effect of a paclitaxel coating on in-stent intimal hyperplasia (IH). METHODS AND RESULTS: Patients were randomized to placebo (bare metal stents) or 1 of 2 doses of paclitaxel (low dose: 1.28 microg/mm2; high dose: 3.10 microg/mm2). Complete post-stent implantation and follow-up IVUS were available in 81 patients, including 25 control patients and in 28 receiving a low-dose and 28 receiving a high dose. Volumetric analysis of the stented segment and of both reference segments was performed. Baseline stent measurements and both reference measurements were similar among the groups. With increasing doses, there was a stepwise reduction in IH accumulation within the stented segment (31+/-22 mm3 in control, 18+/-15 mm3 in low dose, and 13+/-14 mm3 in high dose, P<0.001). Post hoc analysis showed less IH accumulation when low- and high-dose patients were compared with control (P=0.009 and P<0.001, respectively), but not when low-dose patients were compared with high-dose patients (P=0.2). Focal late malapposition was seen in 1 high-dose patient. With increasing doses, there was no significant change in the reference segments. CONCLUSIONS: Paclitaxel-coated stents are effective in reducing in-stent neointimal tissue proliferation in humans. They are not associated with edge restenosis or significant late malapposition.

Cell Division↗
PubMed2003

Late thrombosis after gamma-brachytherapy.

Late stent thrombosis (> 30 days after treatment) is a new phenomenon occurring after vascular brachytherapy. We report the analysis of 11 patients with late thrombosis after gamma-irradiation treatment of in-stent restenosis. All patients had in-stent restenosis and angina. Contributing factors to late thrombosis include long stents, small distal vessels, and complex lesion morphology.

Aged↗
PubMed2003

Impact of the acute results on the long-term outcome after the treatment of in-stent restenosis: a serial intravascular ultrasound study.

The current study used serial (postintervention and follow-up) intravascular ultrasound (IVUS) to assess the impact of acute results on long-term follow-up of patients with in-stent restenosis (ISR). All patients (n = 180) with serial IVUS studies of ISR lesions from the following gamma-irradiation brachytherapy trials were included: Washington Radiation for In-Stent Restenosis Trial (WRIST), Gamma-1, and Angiorad Radiation Technology for In-Stent Restenosis Trial in Native Coronaries (ARTISTIC). There were 106 irradiated and 74 placebo patients. Quantitative analysis was performed according to the American College of Cardiology Clinical Expert Consensus Document on Standards for Acquisition, Measurement and Reporting of IVUS. Images were acquired using motorized transducer pullback, cross-sectional analysis was performed every 1 mm, and volumetric and mean planar dimensions were calculated. The independent predictors for the absolute follow-up minimum lumen area (MLA) were the postintervention MLA, the postintervention minimum stent area, and the use of brachytherapy. Placebo patients lost 45% of the postintervention MLA while irradiated patients lost only 17% of the MLA. The independent predictors of the follow-up percent intimal hyperplasia (intimal hyperplasia volume divided by stent volume) and the independent predictors of the absolute increase in intimal hyperplasia were the postintervention percent intimal hyperplasia and the use of brachytherapy. Serial IVUS analysis shows that the follow-up MLA and percent intimal hyperplasia are dependent on the results obtained during the treatment of ISR lesions.

Brachytherapy↗
PubMed2003

Emboli capture using the Embol-X intraaortic filter in cardiac surgery: a multicentered randomized trial of 1,289 patients.

BACKGROUND: Particulate emboli are thought to play a significant role in the development of cardiac surgical complications. Intraaortic filtration of particulate emboli may reduce the burden of this morbidity in cardiac patients. METHODS: A multiinstitutional randomized trial was designed and enrolled 1,289 patients at 22 centers. Six hundred forty-five patients were assigned to the treatment arm and received the Embol-X intraaortic filter, whereas 644 patients were assigned to the control arm. The endpoints examined were mortality, stroke, transient ischemic attack, renal insufficiency/failure, myocardial infarction, gastrointestinal complications, and limb-threatening ischemia. All filters were examined for histologic evidence of particulate emboli. RESULTS: Particulate emboli were identified in 598 (96.8%) of 618 filters successfully deployed. Composite event rates for the clinical endpoints were similar in both the filtered and nonfiltered arm (110/645 = 17% vs 122/644 = 19%, respectively). Individual event rates were also similar in both arms. A post hoc comparison of patients with moderate or greater preoperative risk scores demonstrated event reduction favoring the filtered group for renal complications (17/124 = 14% vs 28/117 = 24%, p = 0.04) and for the composite endpoint (30/124 = 24% vs 42/117 = 36%, p = 0.047). No clinically evident complications attributed to the use of the filter were identified. CONCLUSIONS: The use of the Embol-X intraaortic filter is both safe and effective, as demonstrated by the emboli capture rate of 97%. In addition, post hoc analysis indicates a reduction in postoperative renal complications for patients with moderate or greater preoperative risk. Further study of high-risk patients is warranted.

Aged↗
PubMed2003

Impact of renal function on morbidity and mortality after percutaneous aortocoronary saphenous vein graft intervention.

BACKGROUND: Percutaneous coronary intervention in patients with chronic renal insufficiency (CRI) and native coronary artery disease is often problematic, marred by increased morbidity and mortality rates and a high incidence of restenosis and revascularization. However, little is known about the effect of CRI in patients who have undergone prior coronary artery bypass graft surgery and then undergo saphenous vein graft (SVG) intervention. METHODS: We analyzed the inhospital and 1-year outcomes of 1265 consecutive patients with normal renal function and varying degrees of renal insufficiency who underwent percutaneous SVG intervention and divided them into 4 groups on the basis of the calculated creatinine clearance (CrCl): group 1, CrCl > or =70 mL per minute (n = 626); group 2, CrCl 50 to 69 mL per minute (n = 357); group 3, CrCl 30 to 49 mL per minute (n = 228); and group 4, CrCl <30 mL per minute (n = 54). Patients undergoing dialysis replacement therapy were excluded from the study. RESULTS: Patients with lower CrCl more often were older, female, had diabetes mellitus, and had worse left ventricular function. Angiographic baseline characteristics were comparable among the 4 groups. Overall immediate procedural success was similar for all groups. Patients with a low CrCl had significantly higher inhospital overall and cardiac mortality rates (P <.001), including a significantly higher incidence of myocardial infarction, vascular complications, pulmonary edema, and renal function deterioration. At 1-year follow-up, the overall mortality rates remained significantly higher in patients with decreased CrCl, with an incremental rise in overall mortality rate associated with lower renal function (P <.001). CONCLUSIONS: This study suggests that renal function is a primary determinate of short- and long-term survival in patients undergoing percutaneous SVG intervention and that there is a clear relationship between CrCl and cardiovascular outcome.

Age Factors↗
PubMed2003

Benefits of cutting balloon before stenting.

UNLABELLED: The objectives of this study were to prospectively evaluate the safety and feasibility of pretreating the culprit coronary artery lesion with cutting balloon (CB) angioplasty prior to coronary stent implantation. BACKGROUND: The CB has shown promise for the treatment of de novo coronary lesions and in-stent restenoses, but has not been prospectively evaluated for use prior to stent implantation. METHODS: Patients with significant coronary artery disease requiring stent placement had the culprit lesion pretreated with a CB. Stents were deployed to cover the entire segment pretreated with the CB. Intravascular ultrasound (IVUS) was used to interrogate acute luminal gain following stent implantation and after serial post-deployment inflation pressures ranging from 8 16 atmospheres (atm). Coronary angiograms were also obtained to determine luminal diameter. In-hospital complication rates were noted. RESULTS: Fifty-one patients were treated with the CB prior to stent implantation. Minimal stent cross-sectional area increased significantly with increasing inflation pressures between 8 and 10 atm (p < 0.0004) and between 10 and 12 atm (p = 0.0049). The minimal stent cross-sectional area achieved, as measured by IVUS, was 7.59 mm2 2.00 mm2 at 8 atm, 8.06 mm2 1.53 mm2 at 10 atm and 8.72 mm2 1.58 mm2 at 12 atm. The final in-stent percent diameter stenosis was lower compared to pre-procedure (5.4% 12.2% versus 64.1% 14.1%, respectively) by quantitative coronary angiography. CONCLUSION: The CB can be used prior to stent implantation to attain significant gains in minimal stent cross-sectional areas at relatively low pressures.

Aged↗
PubMed2002

Background incidence of late malapposition after bare-metal stent implantation.

BACKGROUND: Late stent malapposition has been reported to be an abnormal finding after vascular brachytherapy and, possibly, implantation of drug-eluting stents. It can only be detected if intravascular ultrasound (IVUS) is performed at follow-up. However, the "background" frequency of late stent malapposition after bare-metal stent implantation is not known. METHODS AND RESULTS: We studied 206 patients with native artery lesions who had tubular-slotted bare-metal stent implantation and who had IVUS performed at index and after 6+/-3 months of follow-up. There were 9 patients (4.4%) with late malapposition, which is separation of at least 1 stent strut from the arterial wall intima that does not overlap a side-branch, with evidence of blood flow (speckling) behind the strut, and where the immediate postimplantation IVUS revealed complete apposition of the stent to the vessel wall. The location of late malapposition was the stent edge in 8 of 9 patients. The maximum area, length, volume, and arc of late malapposition measured 3.1+/-2.4 mm(2), 3.3+/-2.2 mm, 21+/-27 mm(3), and 110+/-61 degrees, respectively. There was an increase in external elastic membrane (EEM) area (20.7+/-4.9 to 26.9+/-4.2 mm, P=0.0021) and plaque area (10.1+/-3.7 to 14.8+/-3.6 mm, P=0.0022); however, the increase in EEM was greater than the increase in plaque. The area of late malapposition correlated directly with the increase in EEM area (r=0.75, P=0.0205). CONCLUSION: Late malapposition occurs in 4% to 5% of slotted-tube bare-metal stents, usually at stent edges. The main cause is positive remodeling out of proportion to the increase in peri-stent intimal hyperplasia.

Blood Vessel Prosthesis Implantation↗
PubMed2002

Morphologic and angiographic features of coronary plaque rupture detected by intravascular ultrasound.

OBJECTIVES: This study was designed to report the clinical and angiographic correlates of plaque rupture detected by intravascular ultrasound (IVUS). BACKGROUND: Acute coronary syndromes result from spontaneous plaque rupture and thrombosis. METHODS: We report 300 plaque ruptures in 257 arteries in 254 patients. Plaque ruptures were detected during pre-intervention IVUS. Standard clinical, angiographic, and IVUS parameters were collected and/or measured. One lesion per patient was analyzed. RESULTS: Multiple ruptures were observed in 39 of 254 patients (15%), 36 in the same artery. Plaque rupture occurred not only in patients with unstable angina (46%) or myocardial infarction (MI, 33%), but also stable angina (11%) or no symptoms (11%). The tear in the fibrous cap could be identified in 157 of 254 patients; 63% occurred at the shoulder of the plaque and 37% in the center of the plaque. Thrombi were more common in patients with unstable angina or MI (p = 0.02) and in multiple ruptures (p = 0.04). The plaque rupture site contained the minimum lumen area (MLA) site in only 28% of patients; rupture sites had larger arterial and lumen areas and more positive remodeling than MLA sites. Intravascular ultrasound plaque rupture strongly correlated with complex angiographic lesion morphology: ulceration in 81%, intimal flap in 40%, thrombus in 7%, and aneurysm in 7%. CONCLUSIONS: Plaque ruptures occur with varying clinical presentations, strongly correlate with angiographic complex lesion morphology, may be multiple, and usually do not cause lumen compromise.

Angina Pectoris↗
PubMed2002

Stroke complicating percutaneous coronary interventions: incidence, predictors, and prognostic implications.

BACKGROUND: Stroke associated with percutaneous coronary intervention (PCI) is an infrequent although devastating complication. We investigated the incidence, predictors, and prognostic impact of periprocedural stroke in unselected patients undergoing PCI. METHODS AND RESULTS: A total of 9662 patients who underwent 12 407 PCIs between January 1990 and July 1999 were retrospectively studied. Stroke was diagnosed in 43 patients (0.38% of procedures). Patients with stroke were older (72+/-11 versus 64+/-11 years, P<0.001), had lower left ventricular ejection fraction (42+/-12 versus 46+/-13%, P=0.04) and more diabetes (39.5% versus 27.2%, P=0.07), and experienced a higher rate of intraprocedural complications necessitating emergency use of intra-aortic balloon pump (IABP) (23.3% versus 3.3%, P<0.001). In-hospital mortality (37.2% versus 1.1%, P<0.001) and 1-year mortality (56.1% versus 6.5%, P<0.001) were higher in patients with stroke. Compared with hemorrhagic stroke, patients with ischemic stroke had higher rate of in-hospital major adverse cardiac events (57.1% versus 25%, P=0.037). Multivariate logistic regression analysis identified emergency use of IABP as the strongest predictors for stroke (OR=9.6, CI 3.9 to 23.9, P<0.001), followed by prophylactic use of IABP (OR=5.1), age >80 years (OR=3.2, compared with age <50 years), and vein graft intervention (OR=2.7). CONCLUSIONS: Stroke associated with contemporary PCI is associated with substantial increased mortality. Elderly patients who experience intraprocedural complications necessitating the use of IABP are at particularly high risk.

Aged↗
PubMed2002

Dose heterogeneity may not affect the neointimal proliferation after gamma radiation for in-stent restenosis: a volumetric intravascular ultrasound dosimetric study.

OBJECTIVES: The goal of this study was to use serial (postirradiation and follow-up) volumetric intravascular ultrasound (IVUS): 1) to evaluate the actual distribution of gamma radiation in human in-stent restenosis (ISR) lesions, and 2) to analyze the relationship between neointimal regrowth and the delivered radiation dose. BACKGROUND: The relationship between the neointimal regrowth and delivered dose during the treatment of ISR remains unknown. METHODS: We analyzed 20 actively (gamma emitter) treated, native artery ISR patients from the Washington Radiation for In-Stent restenosis Trial (WRIST) that met the following criteria: on both postirradiation and six-month follow-up IVUS imaging, > or =80% of the external elastic membrane circumference could be identified throughout the treated length including the lesion and proximal and distal reference segments. Intravascular ultrasound images were digitized every 1 mm. Proximal and distal reference and stented segment luminal and adventitial contours were imported and reconstructed. The source was placed circumferentially at the site of the IVUS catheter and longitudinally according to the relationship between the radioactive seeds and stent edges. Using Monte Carlo simulations, dose volume histograms for the adventitia and intima were calculated. The relationship between the neointimal regrowth and calculated doses were evaluated. RESULTS: There was large dose heterogeneity at both the intimal and adventitial levels. Most of the sites (93%) received >4 Gy at the adventitia, and all of the sites received >4 Gy at the intima. There was no relationship between neointimal regrowth and radiation dose. CONCLUSIONS: Although there may be large dose heterogeneity, gamma irradiation (using a fixed dose prescription) appears to deliver a sufficient dose to prevent neointimal regrowth.

Aged↗