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Biomedical subjects

Alexandra J Lansky

Publications and source records attributed to Alexandra J Lansky.

At least 109 records · Page 6Linked to original sources
PubMed2003

Intravascular brachytherapy for native coronary ostial in-stent restenotic lesions.

OBJECTIVES: We analyzed the effects of vascular brachytherapy (VBT) on ostial in-stent restenosis (ISR). BACKGROUND: In-stent restenosis has a high recurrence rate after percutaneous reintervention. The recurrence rate of ostial ISR lesions and the impact of VBT remain unknown. METHODS: We evaluated 133 patients with native coronary ostial ISR from a pooled database of 990 patients enrolled in randomized VBT trials. Independent quantitative angiography was performed at baseline and follow-up in 45 gamma, 27 beta, and 61 placebo patients. RESULTS: Binary restenosis was significantly higher in placebo than radiated patients (75.4% vs. 17.8% in gamma vs. 22.2% in beta, p < 0.0001). The treatment effect of both gamma (odds ratio [OR] 0.06; 95% confidence interval [CI] 0.02 to 0.17) and beta VBT (OR 0.10; 95% CI 0.03 to 0.31) was maintained after controlling for differences in baseline lesion length. Proximal and distal radiation edge restenosis rates were similar among the groups. Vascular brachytherapy of true aorto-ostial lesions (n = 34) was similarly beneficial: restenosis rates of placebo versus gamma or beta patients of 83.3% versus 6.7% versus 28.6%, p = 0.0002. CONCLUSIONS: Conventional treatment of ostial ISR is associated with a recurrence rate of over 75%. Vascular brachytherapy with either gamma or beta sources results in significant and similar reductions in restenosis compared with placebo. Similar benefits after VBT prevail in true aorto-ostial lesions.

Aorta↗
PubMed2003

Safety and efficacy of a novel device for treatment of thrombotic and atherosclerotic lesions in native coronary arteries and saphenous vein grafts: results from the multicenter X-Sizer for treatment of thrombus and atherosclerosis in coronary applications trial (X-TRACT) study.

Intervention in thrombotic lesions and diseased saphenous vein grafts frequently results in thromboembolic complications, including no-reflow, distal branch occlusion, periprocedural MI, and death. The utility of a novel thromboatherectomy device, the X-Sizer, was tested in 50 consecutive patients at nine U.S. centers. A total of 61 lesions were treated in 31 vein grafts and 19 native coronary arteries; thrombus was present in 78% of lesions, and TIMI 0-1 flow in 21%. TIMI 3 flow improved from 57% at baseline to 94% postprocedure. No patient developed visible distal thromboemboli, side-branch occlusion, or reduced antegrade flow. Thirty-day events included one death (2.0%), Q- or non-Q-wave MI in 4.0%, TVR in 6.0%, and any MACE in 6.0%. We conclude that the use of the X-Sizer prior to percutaneous intervention is safe in high-risk vein grafts and thrombotic lesions and results in a low rate of adverse events compared to historical controls.

Aged↗
PubMed2003

Impact of gender on the incidence and outcome of contrast-induced nephropathy after percutaneous coronary intervention.

BACKGROUND: Contrast-induced nephropathy (CIN) is a recognized complication after percutaneous interventions (PCI). We sought to determine the impact of gender on incidence and clinical outcome of CIN. METHODS AND RESULTS: Of a total 8,628 patients who underwent PCI, there were 1,431 (16.5%) who developed CIN (defined as > 25% rise in creatinine after PCI). Patients were followed clinically for one year. CIN was present in 23.6% of female versus 17.4% of male patients (p < 0.0001). Multivariate analysis showed that female gender (OR = 1.4, 95% CI = 1.25 1.60; p < 0.0001), pre-PCI chronic renal failure (CRF) (OR= 1.8, 95% CI = 1.53 2.10, p < 0.0001), diabetes mellitus (OR = 1.5, 95% CI = 1.34 1.70; p < 0.0001), age (OR = 1.01, 95% CI = 1.01 1.02, p < 0.0001), and hypertension (OR = 1.2, 95% CI = 1.06 1.36, p = 0.0035) were independent predictors of CIN. Clinical outcomes after CIN were examined in patients with or without CRF. Among patients without CRF who developed CIN, females (n = 465) had higher rates of one-year mortality, and MACE comparing to males (n = 710) without CRF (14% vs. 10% mortality, 36% vs. 30% MACE; p = 0.05 and 0.06, respectively). In patients with CRF who developed CIN, we found no significant gender differences in one-year clinical events (37% vs. 36% mortality, 42% vs. 45% MACE; p = 0.8 and 0.6, respectively). By multivariate analysis only baseline CRF, diabetes, age, functional NYHA IV class were identified as independent predictors of one-year mortality in patients with CIN after PCI. CONCLUSIONS: Female gender is an independent predictor of CIN development after PCI and a marker of worse 1-year mortality after CIN in patients without baseline CRF. After CIN is developed, pre-PCI CRF, diabetes mellitus, age, severe heart failure (not gender) are independent predictors of one-year mortality.

Aged↗
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

Long-term outcome of patients treated with repeat percutaneous coronary intervention after failure of gamma-brachytherapy for the treatment of in-stent restenosis.

BACKGROUND: Although (192)Ir intracoronary brachytherapy has been demonstrated to dramatically reduce the recurrence of in-stent restenosis, up to 24% of these patients will still require repeat target-vessel revascularization. The short- and long-term outcomes of repeat percutaneous intervention in this population have not been characterized. METHODS AND RESULTS: Analysis was performed of all patients enrolled in the GAMMA-I and GAMMA-II brachytherapy trials who underwent repeat percutaneous target lesion revascularization (TLR) because of restenosis. Subjects were divided into 2 cohorts: those who had received (192)Ir brachytherapy and those randomized to placebo. Forty-five (17.6%) of a total of 256 patients whose index treatment was intracoronary radiation therapy and 36 (29.8%) of 121 patients whose index treatment was placebo required repeat percutaneous TLR. The mean time to this first TLR was 295+/-206 days in the irradiated group and 202+/-167 days in the placebo group (P=0.03). Acute procedural success occurred in 100% of irradiated patients and 94% of placebo controls (P=0.19). After the first TLR, a subsequent TLR was required in 15 (33.3%) of 45 brachytherapy patients versus 17 (47.2%) of 36 placebo failure patients (P=0.26). There was no significant difference in time to second TLR between the 2 groups. Other long-term major adverse event rates in both groups were comparable to those of other contemporary angioplasty/stenting series. CONCLUSIONS: In those patients who "fail" (192)Ir intracoronary brachytherapy for in-stent restenosis, treatment with (192)Ir delays the time to first TLR. Additionally, repeat percutaneous intervention in these patients is safe and efficacious in the short term, with acceptable long-term results.

Angioplasty, Balloon, Coronary↗
PubMed2002

Delivered dose and vascular response after beta-radiation for in-stent restenosis: retrospective dosimetry and volumetric intravascular ultrasound analysis.

BACKGROUND: Observations from previous intracoronary radiation therapy trials noted a considerable discrepancy between the prescribed radiation dose and the dose actually delivered. The aims of this study were to investigate the effect of actual delivered dose on vascular changes and to test the appropriateness of the current dose prescription. METHODS AND RESULTS: Serial volumetric intravascular ultrasound (IVUS) analysis was performed in 30 in-stent restenosis cases treated with a 40-mm (90)Sr/Y source train. The fixed dose was prescribed at 2 mm from the centerline of the source train (18.4 Gy at 2 mm for reference diameter < or =3.35 mm and 23 Gy for diameter > or =3.36 mm). Only stent segments with full radiation coverage and device injury were enrolled and divided into 2-mm-long subsegments (n=202). D(S90)EEM (the minimum dose absorbed by 90% of the external elastic membrane surface) was calculated as the delivered dose corresponding to each segment, assuming that the radiation catheter occupied the same position in the vessel as the IVUS catheter. Mean D(S90)EEM of 23.5+/-5.82 Gy (range 12.3 to 41.7 Gy) was delivered to these subsegments. Overall, intimal hyperplasia volume remained constant from postintervention to follow-up (2.23+/-1.10 to 2.32+/-1.09 mm3/m; P=NS). Regression analysis revealed there was no correlation between delivered dose intensity and changes in intimal hyperplasia volume. No particular dose-dependent complications were appreciated in this delivered dose range. CONCLUSIONS: The current dose-prescription protocol of (90)Sr/Y radiation to native in-stent restenosis lesions may provide substantial inhibition of neointimal reproliferation regardless of the actual delivered dose intensity.

Beta Particles↗
PubMed2002

7-hexanoyltaxol-eluting stent for prevention of neointimal growth: an intravascular ultrasound analysis from the Study to COmpare REstenosis rate between QueST and QuaDS-QP2 (SCORE).

BACKGROUND: Inhibition of neointimal tissue growth has been demonstrated in preliminary human feasibility studies with a stent-based polymer sleeve delivering 7-hexanoyltaxol. The Study to COmpare REstenosis rate between QueST and QuaDS-QP2 (SCORE) trial is a human, randomized, multicenter trial comparing 7-hexanoyltaxol (QP2)-eluting stents (qDES) with bare metal stents (BMS) in the treatment of de novo coronary lesions. The purpose of this substudy was to evaluate the acute expansion property and long-term neointimal responses of qDES compared with BMS as assessed by intravascular ultrasound (IVUS). METHODS AND RESULTS: A total of 122 (qDES 66, BMS 56) patients were enrolled into the IVUS substudy. All IVUS images (immediately after the procedure and at 6-month follow-up) were analyzed at an independent core laboratory in a blind manner. At baseline, qDES achieved stent expansion similar to BMS. At follow-up, qDES showed reduced neointimal growth by 70% at the tightest cross section and by 68% over the stented segment (P<0.0001 for both), resulting in a significantly larger lumen in qDES than in BMS. Unlike intracoronary brachytherapy, there was no evidence of negative edge effects, unhealed dissections, or late stent-vessel wall malapposition over the stented and adjacent references segments in either group. CONCLUSIONS: Detailed IVUS analysis revealed that qDES had comparable acute mechanical and superior long-term biological effects to BMS. Although the long-term benefits and limitations of this technology require further investigation, the reduction in neointimal thickenings demonstrated that local delivery of 7-hexanoyltaxol through polymer sleeves augments conventional mechanical treatment of atherosclerotic disease.

Blood Vessel Prosthesis Implantation↗
PubMed2002

Randomized trial of 90Sr/90Y beta-radiation versus placebo control for treatment of in-stent restenosis.

BACKGROUND: After conventional treatment of in-stent restenosis, the incidence of recurrent clinical restenosis may approach 40%. We report the first multicenter, blinded, and randomized trial of intracoronary radiation with the use of a 90Sr/90Y beta-source for the treatment of in-stent restenosis. METHODS AND RESULTS: After successful catheter-based treatment of in-stent restenosis, 476 patients were randomly assigned to receive an intracoronary catheter containing either 90Sr/90Y (n=244) or placebo (n=232) sources. The prescribed dose 2 mm from the center of the source was 18.4 Gy for vessels between 2.70 and 3.35 mm in diameter and 23.0 Gy for vessels between 3.36 and 4.0 mm. The primary end point, ie, clinically driven target-vessel revascularization by 8 months, was observed in 56 (26.8%) of the patients assigned to placebo and 39 (17.0%) of the patients assigned to radiation (P=0.015). The incidence of the composite including death, myocardial infarction, and target-vessel revascularization was observed in 60 (28.7%) of the patients assigned to placebo and 44 (19.1%) of the patients assigned to radiation (P=0.024). Binary 8-month angiographic restenosis (> or =50% diameter stenosis) within the entire segment treated with radiation was reduced from 45.2% in the placebo-treated patients to 28.8% in the 90Sr/90Y-treated patients (P=0.001). Stent thromboses occurred in 1 patient assigned to placebo <24 hours after the procedure and in 1 patient assigned to 90Sr/90Y at day 244. CONCLUSIONS: The results of this study demonstrated that beta-radiation using 90Sr/90Y is both safe and effective for preventing recurrence in patients with in-stent restenosis.

Beta Particles↗
PubMed2002

Late vascular response to repeat stenting for in-stent restenosis with and without radiation: an intravascular ultrasound volumetric analysis.

BACKGROUND: Re-stenting of in-stent restenosis (ISR) improves acute angiographic results. Methods and Results- Volumetric intravascular ultrasound analysis was performed in 70 ISR lesions that received either placebo (n=36) or (192)Ir radiation (n=34). ISR lesions treated by re-stenting were divided into 3 groups: old stent not re-stented (A), old/new stent overlap (B), and new stent only (C). ISR lesions treated without re-stenting were categorized as D. In placebo patients, postintervention lumen volume index (LVI) was significantly greater in re-stented segments B and C than in non-re-stented segment A (P<0.05).At follow-up, however, LVI was similar in all 4 segments secondary to the increased intimal hyperplasia (IH) reaccumulation within the re-stented segments. In patients treated with (192)Ir radiation, LVI was maintained from baseline to follow-up only in non-re-stented segments A and D. Conversely, there was a significant decrease in LVI in re-stented segments B and C (P<0.05). Qualitatively, 79% of patients in the irradiated group had stent struts with undetectable neointimal versus only 27% in the placebo group (P<0.001). Coefficient of variation of IH reaccumulation was greater in re-stented segments of (192)Ir patients (B=57.3% and C=58.9%) than in re-stented segments in placebo patients (B=27.3% and C 26.8%) and non-re-stented segments in irradiated patients. CONCLUSIONS: Additional lumen gain from re-stenting ISR lesions is counteracted by exaggerated neointimal proliferation in placebo patients. Maximum effectiveness and safety of radiation can be achieved for ISR lesions when treated without re-stenting. Thus, regardless of supplementary intravascular brachytherapy, repeat stenting strategies provided little long-term advantage.

Blood Vessel Prosthesis Implantation↗
PubMed2002

Comparison of clinical outcomes using stents versus no stents after percutaneous coronary intervention for proximal left anterior descending versus proximal right and left circumflex coronary arteries.

Previous studies have demonstrated that proximal left anterior descending (LAD) stenoses have higher rates of restenosis after angioplasty than stenoses in other coronary segments. Stenting strategies may reduce this high rate of LAD restenosis. The study population included 1,289 patients with proximal coronary artery stenoses treated with percutaneous coronary interventions (PCI) with or without stents for single-vessel coronary disease between 1994 and 1999. Patients were divided into 4 groups: non-stent PCI in the proximal LAD artery (n = 168), non-stent PCI in proximal right/circumflex artery (n = 217), stent in the proximal LAD artery (n = 364), and stent to proximal right/circumflex artery (n = 540). Procedural success was higher in the stenting groups, but there were no significant differences in the major in-hospital events between the different lesion locations among the groups. At 1-year follow-up, there was no difference in mortality or myocardial infarction between the groups. There was no significant difference in the rate of target lesion revascularization (TLR) in the patients with proximal LAD stents compared with the patients with proximal right/circumflex coronary artery stents (10.1% vs 13.8%, p = 0.11). In the patients who did not receive stents with proximal narrowings, there was a significant increase in TLR in the LAD group compared with the right/circumflex group (21.1% vs 12.5%, p = 0.04). Thus, patients with proximal stenoses treated with non-stenting strategies have lower procedural success than those treated with stenting strategies; the patients with proximal LAD non-stent PCI have significantly higher rates of clinical restenosis than patients with proximal right and circumflex stenoses. A stenting strategy for proximal LAD stenoses appears to attenuate the differences of clinical restenosis noted after non-stent PCI.

Aged↗
PubMed2002

Comparison of angioplasty with stenting, with or without abciximab, in acute myocardial infarction.

BACKGROUND: As compared with thrombolytic therapy, primary percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction reduces the rates of death, reinfarction, and stroke, but recurrent ischemia, restenosis, and reocclusion of the infarct-related artery remain problematic. When used in combination with PTCA, coronary stenting and platelet glycoprotein IIb/IIIa inhibitors may further improve outcomes. METHODS: Using a 2-by-2 factorial design, we randomly assigned 2082 patients with acute myocardial infarction to undergo PTCA alone (518 patients), PTCA plus abciximab therapy (528), stenting alone with the MultiLink stent (512), or stenting plus abciximab therapy (524). RESULTS: Normal flow was restored in the target vessel in 94.5 to 96.9 percent of patients and did not vary according to the reperfusion strategy. At six months, the primary end point - a composite of death, reinfarction, disabling stroke, and ischemia-driven revascularization of the target vessel - had occurred in 20.0 percent of patients after PTCA, 16.5 percent after PTCA plus abciximab, 11.5 percent after stenting, and 10.2 percent after stenting plus abciximab (P<0.001). There were no significant differences among the groups in the rates of death, stroke, or reinfarction; the difference in the incidence of the primary end point was due entirely to differences in the rates of target-vessel revascularization (ranging from 15.7 percent after PTCA to 5.2 percent after stenting plus abciximab, P<0.001). The rate of angiographically established restenosis was 40.8 percent after PTCA and 22.2 percent after stenting (P<0.001), and the respective rates of reocclusion of the infarcted-related artery were 11.3 percent and 5.7 percent (P=0.01), both independent of abciximab use. CONCLUSIONS: At experienced centers, stent implantation (with or without abciximab therapy) should be considered the routine reperfusion strategy.

Abciximab↗