Biomedical subjects

Ron Waksman

Publications and source records attributed to Ron Waksman.

At least 37 records · Page 2Linked to original sources

PubMed2006

Impact of chronic renal insufficiency on clinical outcomes in patients undergoing percutaneous coronary intervention with sirolimus-eluting stents versus bare metal stents.

Patients with chronic renal insufficiency (CRI) have higher rates of target vessel revascularization and mortality. The efficacy of sirolimus-eluting stents (SESs) to improve the clinical outcomes of these patients is unknown. We investigated the effect of SESs versus bare metal stents (BMSs) on outcomes of patients with CRI. Among the first 1,522 patients treated with SESs, 76 were identified with CRI and 1,446 without CRI. In-hospital and 1- and 6-month clinical outcomes were compared with 153 patients with CRI who were treated with BMSs. Patients with CRI were older, hypertensive, and diabetic and had more previous myocardial infarctions, revascularizations, and decreased left ventricular function (p <0.001). These patients had more saphenous vein graft lesions, were treated with more debulking devices (p <0.003), and had higher rates of in-hospital complications and mortality (p <0.001) compared with those without CRI. Among patients with CRI, treatment with SESs did not affect clinical outcomes at 1 month and was associated with lower incidences of target vessel revascularization (7.1% vs 22.1%, p = 0.02) at 6 months but did not affect other events, including mortality (16.7% vs 14.7% p = 0.89), compared with BMSs. However, treatment with SESs in patients without CRI was associated with significantly lower rates of major adverse cardiac events at 6 months (p <0.001). In conclusion, percutaneous coronary intervention with SESs in patients with CRI is associated with low rates of repeat revascularization compared with BMSs but has no effect on mortality at 6 months.

Aged↗

PubMed2006

Comparison of ruptured plaques in native coronary arteries and in saphenous vein grafts: an intravascular ultrasound study.

Intravascular ultrasound (IVUS) has been used to describe ruptured plaques in saphenous vein grafts (SVGs) and native coronary arteries. We compared clinical, angiographic, and IVUS features of ruptured atherosclerotic plaques in SVGs and native coronary arteries. We identified 95 plaque ruptures in 76 SVGs in 73 patients. These lesions and patients were matched with 95 lesions and patients from a database of 468 native artery ruptures. The matching criterion was IVUS mean reference lumen area. Patients with ruptured SVG plaques were older (68.4 +/- 10.1 vs 65.0 +/- 10.6 years, p = 0.021), more often had hypercholesterolemia (92% vs 74%, p = 0.015) and hypertension (78% vs 62%, p = 0.059), and more often had a history of a remote myocardial infarction (57% vs 32%, p = 0.002). In contrast, anginal symptoms were similar in the 2 groups (70% to 75% of each group had an acute coronary syndrome). Most (90% to 95%) ruptured plaques in each group were classified as angiographically complex. However, ruptured SVG lesions more often had an angiographically visible intimal flap (71% vs 38%, p <0.001). More than 70% of lesions in the 2 groups had positive arterial remodeling by IVUS, but there was a tendency for a higher remodeling index in ruptured plaque SVG lesions (1.18 +/- 0.30 vs 1.11 +/- 0.20, p = 0.085). The site of the initial tear occurred mainly (in approximately 70%) at the plaque shoulders in the 2 groups. In conclusion, although patients with SVG plaque ruptures are older and have more co-morbidities, the clinical presentation and angiographic and IVUS features are remarkably similar to those of native artery plaque ruptures.

Aged↗

PubMed2006

Impact of three or more versus a single sirolimus-eluting stent on outcomes in patients who undergo percutaneous coronary intervention.

This retrospective analysis compared clinical outcomes of patients who underwent stenting with > or =3 sirolimus-eluting stents (SESs) with those who received a single SES. SES (Cypher) implantation for single vessels is proved to be effective and durable, but knowledge regarding the safety and effectiveness of multiple stenting with SESs is currently limited. In total, 929 consecutive patients who received SESs were identified; 63 received > or =3 SESs (multi group) and 866 received 1 SES (single group). The multi group had more non-Q-wave myocardial infarctions (MIs) during the index hospitalization (p = 0.02). At 30-day follow-up, death, Q-wave MI, subacute thrombosis, and major adverse cardiac events were higher in the multi group than in the single group. At 6 months, death, Q-wave MI, target lesion revascularization, and major adverse cardiac events continued to be higher in the multi group. Using multivariate analysis, > or =3 SES implantations, American College of Cardiology/American Heart Association type C lesions, and cardiogenic shock were identified as independent predictors for 6-month major adverse cardiac events. In addition, patients in the multi group had a significantly lower survival rate than patients in the single group (p <0.0001). Patients who required > or =3 SES implantations developed increased periprocedural non-Q-wave MI and worse adverse clinical outcomes at 30 days and 6 months compared with patients who required a single SES implantation. In conclusion, when patients present with multiple coronary lesions, percutaneous coronary intervention with multiple SESs should be undertaken with great caution.

Aged↗

PubMed2006

Sirolimus-eluting stents and calcified coronary lesions: clinical outcomes of patients treated with and without rotational atherectomy.

This study examined the outcomes of patients who underwent sirolimus-eluting stent (SES) implantation for the treatment of heavily calcified coronary lesions (HCCL) with and without the use of rotational atherectomy (rotablator). We investigated 150 consecutive patients with angiographic evidence of HCCL who underwent SES implantation. Sixty-nine patients underwent SES implantation without the need of rotablator (SES), and 81 patients required rotational atherectomy to modify the plaque and facilitate the delivery of the stent (SES + rotational atherectomy). Clinical success was equivalent in both groups (>98%) and there were no in-hospital outcome differences. At 6 months, the target lesion revascularization rate was 4.9% in SES vs. 4.2% in SES + rotational atherectomy groups, respectively (P = NS). Mortality at 6 months was 7.9% in the SES group vs. 6.8% in the SES + rotational atherectomy group (P = NS). SES performs well in patients with complex HCCL, with a relative low event rate. Lesions requiring rotational atherectomy to facilitate dilation and stenting had similar outcomes after SES implantation to those that could be stented without the need for rotablator.

Aged↗

PubMed2006

Impact of overlapping drug-eluting stents in patients undergoing percutaneous coronary intervention.

BACKGROUND: Sirolimus-eluting stent (SES) implantation for the treatment of single coronary lesions is proven to be effective and durable. However, the safety and efficacy of overlapping SES for the treatment of long lesions have not been well established. OBJECTIVES: We conducted a retrospective analysis to compare the clinical outcomes of overlapping versus nonoverlapping SES. METHODS: Fifty-five patients who received overlapping SES were compared with 39 patients who received nonoverlapping SES. RESULTS: The baseline clinical and angiographic characteristics were balanced between the two study groups. The in-hospital complications were similar between groups, except that non-Q-wave myocardial infarction was significantly higher in the Overlapping SES group when compared with the Nonoverlapping SES group (23.6% vs. 7.7%, P = 0.04). This higher rate of myonecrosis is due to periprocedural side branch compromises, including side branch narrowing, occlusion, and flow reduction. At 30 days and 6 months follow-up, all clinical outcomes were similar between the study groups. In addition, the event-free survival rate was similar between groups (P = 0.87). CONCLUSIONS: The implantation of overlapping SES for the treatment of long, native coronary lesions is feasible and effective but is associated with an increased rate of periprocedural myonecrosis. This phenomenon is caused primarily by side branch compromises, but does not have any adverse impact on late clinical events.

Aged↗

PubMed2006

A novel paclitaxel-eluting porous carbon-carbon nanoparticle coated, nonpolymeric cobalt-chromium stent: evaluation in a porcine model.

OBJECTIVES: We aimed to evaluate the response of porcine coronary arteries to a novel paclitaxel-eluting porous carbon-carbon nanoparticle coated, nonpolymeric cobalt chromium stent. BACKGROUND: Polymer based drug-eluting stents significantly reduce restenosis. However, the indefinite presence of polymer is thought to initiate and sustain inflammation and contribute to the occurrence of late complications. METHODS: Sixteen carbon-carbon coated, nonpolymeric cobalt chromium stents with two different doses of paclitaxel (eight of each) were implanted in porcine coronary arteries. In addition, eight cobalt chromium stents coated with a biodegradable polymer were also studied. Animals were sacrificed 6 weeks after stent implantation and histomorphometric analysis was performed. Results were compared among the three groups of stents. RESULTS: The cobalt chromium stents coated with carbon-carbon with low and medium doses of paclitaxel both showed acceptable performance characteristics, with respect to endothelialization, neointimal hyperplasia, percentage diameter stenosis, inflammatory response, and tendency to fibrin deposition, when compared to historical data with the Cypher stent. On the other hand, the stents coated with poly(lactide) and poly(lactide-co-glycolide) biodegradable polymers and 0.7 microg/mm2 paclitaxel showed poor performance. There was a significant tendency to poor endothelialization, greater neointimal hyperplasia, percentage diameter stenosis, greater inflammatory response, and tendency to fibrin deposition (P < 0.01 for all parameters). CONCLUSIONS: This preclinical evaluation demonstrates the safety and efficacy of a novel cobalt chromium stent with a carbon-carbon coating and low and medium doses of paclitaxel.

Analysis of Variance↗

PubMed2006

Safety and efficacy of bioabsorbable magnesium alloy stents in porcine coronary arteries.

OBJECTIVE: We aimed to determine the safety and efficacy of biobasorbable magnesium alloy stents in porcine coronary arteries. Bioabsorbable magnesium stents carry the potential to overcome the limitations posed by permanent metallic stents such as chronic inflammation, late stent thrombosis, prolonged antiplatelet therapy, and artifacts when imaged by multislice-computed tomography or magnetic resonance imaging. METHODS: Magnesium alloy stents or stainless steel stents were randomly deployed in coronary arteries of domestic or minipigs. Domestic pigs were sacrificed at 3 days (n = 2) or 28 days, and minipigs at 3 months. RESULTS: At 3 days, magnesium alloy stents were intact, but started to show signs of degradation by 28 days. There was no evidence of stent particle embolization, thrombosis, excess inflammation, or fibrin deposition. At 28 days and 3 months, neointimal area was significantly less in magnesium alloy stent segments (2.44 +/- 0.88 mm(2) and 1.16 +/- 0.19 mm(2)) as compared with the stainless steel stent segments (5.03 +/- 1.5 mm(2) and 1.72 +/- 0.68 mm(2), P < 0.001 and 0.02). Quantitative coronary analysis indicates that percentage area stenosis and percentage diameter stenosis in magnesium alloy stent segments improved significantly at 3 months as compared to 28 days. Despite decreased neointimal hyperplasia, lumen area of the magnesium alloy stented vessels did not improve significantly. CONCLUSION: Magnesium alloy stents are safe and are associated with less neointima formation; however, reduced neointima did not result in larger lumen.

Absorbable Implants↗

PubMed2006

Impact of three or more sirolimus-eluting stents versus paclitaxel-eluting stents on clinical outcomes in patients undergoing percutaneous coronary intervention.

OBJECTIVES: The purpose of this study was to examine the clinical outcomes of patients who underwent stenting with > or =3 sirolimus-eluting stents (SES) when compared with those treated with > or =3 paclitaxel-eluting stents (PES). BACKGROUND: Drug-eluting stent (DES) implantation for single coronary lesions is proven to be effective and durable. METHODS: A total of 126 patients who received DES were identified, of which 66 patients received > or =3 SES (SES group) and 60 patients received > or =3 PES (PES group). RESULTS: The baseline clinical and angiographic characteristics were compatible between the two study groups. During the index hospitalization, all clinical outcomes were similar between the two groups. There were no deaths or Q-wave myocardial infarctions (MIs) in either group. At 30 days' and 6 months' follow-up, all clinical outcomes, including death, Q-wave MI, non-Q-wave MI, target lesion revascularization, target vascular revascularization, and major adverse cardiac events, were compatible between both groups. There were 2 patients (3.0%) with subacute thrombosis in the SES group and 1 patient (1.7%) in the PES group, but there was no statistical significance. There was no late thrombosis from either group. In addition, patients in the SES group had similar event-free survival rates as compared with those in the PES group (P = 0.56). CONCLUSIONS: Patients who require > or =3 DES implantations experienced increased adverse clinical events as compared with historical single stent implantation. However, there were no differences in safety and efficacy among the patients treated with SES as compared with those treated with PES.

Angioplasty, Balloon, Coronary↗

PubMed2006

Percutaneous coronary intervention with drug-eluting stents in octogenarians: characteristics, clinical presentation, and outcomes.

OBJECTIVES: We aimed to compare clinical outcomes of octogenarians > or =80 years of age after coronary drug-eluting stent (DES) implantation. BACKGROUND: Although octogenarians constitute a fast-growing portion of cardiovascular patients, they are not adequately represented in current clinical revascularization trials. METHODS: We analyzed the data of 3,166 consecutive patients who underwent percutaneous coronary intervention (PCI) and DES implantation since March 2003. Periprocedural events, 1- and 6-month clinical outcomes were compared between octogenarians (n = 339) and patients <80 years of age (n = 2,827). RESULTS: Baseline characteristics revealed a higher prevalence of females (P < 0.001), Caucasians (P = 0.004), chronic renal failure (P < 0.001), heart failure (P < 0.001), number of diseased vessels (P = 0.009), and lower ejection fraction (P = 0.03) in octogenarians. Patients <80 years showed more positive family history (P < 0.001), hyperlipidemia (P = 0.006), smoking (P < 0.001), and obesity (P < 0.001). Clinical presentation and procedural success were similar in both groups as were death, myocardial infarction (MI), and repeat revascularization in-hospital. At 6 months, restenosis rates were low and comparable. In the subgroup of octogenarians who presented with acute coronary syndrome, mortality (15% vs. 3%, P < 0.001) and Q-wave MI occurred more often. Multivariate analysis revealed age >80 (P = 0.008), cardiogenic shock (P < 0.001), Q-wave MI at presentation (P = 0.003), and length of hospital stay (P = 0.003) to be independent predictors of mortality. CONCLUSIONS: PCI with DES in octogenarians results in a similar reduction of restenosis rates when compared to patients <80 years. Yet in octogenarians who presented with acute coronary syndrome, incidence of mortality and Q-wave MI at 6 months was higher as compared to younger patients.

Aged↗

PubMed2006

Intravascular ultrasound assessment of the spatial distribution of ruptured coronary plaques in the left anterior descending coronary artery.

BACKGROUND: Plaque rupture is a substrate for thrombosis, occlusion, and myocardial infarction. The left anterior descending coronary artery (LAD) subtends the largest amount of myocardium; therefore, the location of LAD plaque rupture is of particular importance in detecting vulnerable plaques. The aim of our study was to assess the location of ruptured atherosclerotic plaques in the LAD. METHODS: Using intravascular ultrasound, we detected 160 ruptured LAD plaques. Of these, accurate intravascular ultrasound distance measurements (with consistent automatic transducer pullback [0.5 mm/s] to the LAD ostium) could be determined in 112 ruptured plaques. RESULTS: There were 104 patients (91 men, age 63.8 +/- 11.7 years). The total length of the LAD that was imaged measured 48.8 +/- 24.8 mm. The distance from the LAD origin to the maximal plaque cavity was 16.2 +/- 10.3 mm; the maximal plaque cavity was localized to the first 20 mm of the LAD in 71% and the first 30 mm in 88%. Only 2 ruptured plaques were found beyond 40 mm from the LAD ostium. CONCLUSIONS: The majority of LAD ruptured plaques are located within the proximal 30 mm of the artery. This area of the LAD should be targeted for vulnerable (rupture-prone) plaque detection and prevention.

Aged↗

PubMed2006

The impact of cardiovascular risk factors on subclinical left main coronary artery disease: an intravascular ultrasound study.

BACKGROUND: The impact of cardiovascular risk factors on subclinical but measurable left main coronary artery (LMCA) atherosclerosis is not well known. METHODS: We analyzed 150 consecutive patients with first-time coronary artery disease presentation undergoing intervention of a left anterior descending coronary artery or left circumflex lesion with motorized intravascular ultrasound transducer pullback that included a nonstenotic LMCA. Framingham, PROCAM, and European SCORE risk assessments were determined in 107 patients <65 years of age (because the Framingham, PROCAM, and European SCORE studies excluded patients >65 years old). Intravascular ultrasound measurements were compared in patients with <10% vs 10% to 20% risk of events. RESULTS: Plaque volumes were greater in patients with higher risk scores: P = .007 in patients with 10% to 20% PROCAM risk, P = .063 in patients with 10% to 20% Framingham risk, and P = .059 in patients with 10% to 20% SCORE risk (P = .059). The mean arc of LMCA calcium (12 degrees +/- 25 degrees overall) correlated with plaque volume (51 +/- 28 mm3, r = 0.30, P = .0001) and with the number of coronary risk factors (P = .048) and ranged from 0.28 degrees +/- 0.74 degrees in patients with 0 to 1 risk factors to 9.95 degrees +/- 21.55 degrees in patients with 2 to 4 risk factors to 19.38 degrees +/- 32.51 degrees in patients with 5 to 7 risk factors. Regression analysis showed obesity and age were the most important factors contributing to LMCA calcium. CONCLUSION: Intravascular ultrasound measurable atherosclerosis in nonstenotic LMCA correlates with conventional primary coronary risk scores. Left main coronary artery calcium correlates both with LMCA plaque volume and risk factors. Thus, subclinical LMCA atherosclerosis may be a marker for events that are predicted by commonly used primary risk-assessment algorithms.

Aging↗

PubMed2006

Peroxisome proliferator-activated receptor gamma ligand pioglitazone alters neointimal composition in a balloon-denuded and radiated hypercholesterolemic rabbit.

Peroxisome proliferator-activated receptor (PPAR)-gamma activation suppresses inflammatory response, monocyte recruitment, and vascular cell proliferation. Because inflammation, deregulated growth, and migration of monocytes and vascular smooth muscle cells (VSMC) play important roles in the development of neointima, we tested the effect of pioglitazone, a high-affinity ligand, for PPAR-gamma on neointima formation in the iliac arteries of a balloon-denuded and radiated hypercholesterolemic rabbit. Rabbits were fed a 1.0% cholesterol diet for 7 days followed by denudation of endothelial layer and continued on a 0.15% cholesterol diet. On day 32, animals were divided into 2 groups. One group received a 0.15% cholesterol diet (n = 7) and the other group received a 0.15% cholesterol diet supplemented with 400 mg of pioglitazone per kilogram. On day 35, the balloon-denuded area was radiated. Four weeks after radiation, animals were sacrificed and arterial segments were processed for morphometry and immunohistochemistry. Data analysis showed that the pioglitazone group had smaller neointima (0.85 +/- 0.36 vs. 1.41 +/- 0.56, P < 0.05), with more cells positive for VSMC (23.07 +/- 6.16 vs. 18.33 +/- 5.19, P = 0.04), less for monocytes (16.01 +/- 5.33 vs. 21.29 +/- 4.33, P < 0.05), and fewer cells expressing metalloproteinase (MMP)-1 and MMP-9 (3.69 +/- 0.47 vs. 4.82 +/- 0.93, P < 0.05 and 3.24 +/- 0.71 vs. 4.29 +/- 0.74, P < 0.05, respectively). Pioglitazone reduced neointimal area and modified its composition in a balloon-denuded and radiated hypercholesterolemic rabbit model.

Actins↗

PubMed2006

Efficacy of sirolimus-eluting stents as compared to paclitaxel-eluting stents for saphenous vein graft intervention.

BACKGROUND: Saphenous vein graft (SVG) intervention is associated with a significantly increased rate of periprocedural complications and late clinical and angiographic restenosis. In the contemporary drug-eluting stent (DES) era, the comparison of the efficacy of sirolimus-eluting stents (SES) with paclitaxel-eluting stents (PES) in SVG interventions is currently unknown. We conducted this retrospective analysis to investigate this issue. METHODS AND RESULTS: Forty-seven patients with 50 SVG lesions who underwent standard percutaneous coronary intervention (PCI) with SES (SES group) were compared with 42 patients with 45 SVG lesions with PES (PES group). All patients received distal protection devices (DPDs) during the interventions. The in-hospital, 30-day, and 6-month clinical outcomes in both groups were compared. Baseline clinical and procedural characteristics were balanced between both groups except for the proximal and mid lesions. There were no deaths or Q-wave myocardial infarctions (MIs) during the index hospitalization. Non-Q-wave MI was similar between the two groups (SES vs PES, 4.3% vs 7.1%, P=0.55). At 30-day and 6-month follow-ups, all the clinical outcomes were similar between the two groups. There was no subacute thrombosis (SAT) or late thrombosis in either group. The event-free survival at 6 months was also similar between both groups (P=0.75). CONCLUSIONS: The use of DES in patients undergoing SVG intervention with a DPD is clinically safe and feasible. As compared to SES, PES have the same efficacy and clinical outcomes in SVG interventions up to 6 months.

Aged↗

PubMed2006

Update on bioabsorbable stents: from bench to clinical.

Permanent metallic stents are associated with limitations such as continued mechanical stress, transfer to the tissue, and continued biological interaction with the surrounding tissue. They are also associated with late stent thrombosis and artifacts when non-invasive technologies such as MRI and MSCT are used. The potential advantages of bioabsorbable polymeric or metallic stents are to leave no stent behind, they are fully compatible with MRI and MSCT imaging, and are not associated with late stent thrombosis. This review covers the different stent programs as they move from bench to bed and clinical trials. Bioabsorbable stents are considered the next frontier of stenting and we will discuss their potential to fulfill this promise in interventional cardiology.

Absorbable Implants↗

PubMed2006

Clinical applications of optical coherence tomography.

Rupture of vulnerable plaque (VP) is responsible for most coronary events. Optical coherence tomography (OCT) is a high-resolution imaging method that allows excellent characterization of atherosclerotic plaque. While this technique is limited by the need to interrupt blood flow and a shallow depth of penetration, its resolution is an order of magnitude greater than possible with intravascular ultrasound (IVUS), and it has demonstrated better sensitivity and specificity for accurately determining plaque composition. Early in vitro and in vivo experiences have affirmed the excellent quality of these images making it an attractive technology for the analysis of VP. Its high resolution likely renders it the best imaging modality currently available for the evaluation of proper stent deployment and of intracoronary pathology in the setting of percutaneous coronary interventions (PCI). Our institution is currently involved in a multicenter trial to evaluate the effectiveness of OCT when compared to IVUS in this setting. Ongoing technological improvements aim to permit rapid scanning which should alleviate its current major limitation of needing to scan in a blood-free space. OCT is a promising new technology in the evaluation of atherosclerotic plaque and coronary microstructure.

Coronary Artery Disease↗

PubMed2006

Biodegradable stents: they do their job and disappear.

Despite the development and progression of metallic stents, many concerns still remain because of their permanent nature. Although metallic stents are effective in preventing recoil and late restenosis after coronary angioplasty, they continue to have limitations such as stent thrombosis and mismatch of the stent to the vessel size. Thus, the concept of bioabsorbable stents has emerged as an alternative to permanent metal stents. This review will outline concepts, material designs, preclinical, and initial clinical experimental studies with bioabsorbable stents.

Absorbable Implants↗

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.

Aged↗

PubMed2006

Switching from Enoxaparin to Bivalirudin in Patients with Acute Coronary Syndromes without ST-segment Elevation who Undergo Percutaneous Coronary Intervention. Results from SWITCH--a multicenter clinical trial.

BACKGROUND: Enoxaparin is an established therapy for the treatment of patients with acute coronary syndrome (ACS), and bivalirudin is commonly used as the antithrombotic agent during percutaneous coronary intervention (PCI). This study was designed to examine the safety of switching from enoxaparin to bivalirudin in these patients. METHODS: The Switching from Enoxaparin to Bivalirudin in Patients with Acute Coronary Syndromes without ST-segment Elevation Undergoing Percutaneous Coronary Intervention (SWITCH) trial was a prospective, open-label, multicenter study including 91 patients who presented with an ACS without ST-segment elevation, and who had received greater than or equal to 1 dose of enoxaparin (1 mg/kg SC) within the 12 hours prior to PCI. Patients were enrolled into 3 time categories: Group 1: 0-4; Group 2: 4-8; and Group 3: 8-12 hours from last enoxaparin dose to PCI. The primary endpoint of the study was major bleeding complications. RESULTS: Baseline characteristics and average number of enoxaparin injections prior to PCI were similar in all 91 patients and among the groups. There was no occurrence of death, Q-wave myocardial infarction (MI), or acute revascularization in any group and no incidence of intracranial or retroperitoneal bleeding. The overall rate of major bleeding (7.7%) was comparable among groups (p = 0.39), as was the incidence of periprocedural non-Q-wave MI (overall 12%; p = 0.58), irrespective of the time interval between enoxaparin and bivalirudin administration. CONCLUSIONS: Switching from enoxaparin to bivalirudin for patients with ACS undergoing PCI appears to be clinically safe without increased risk of major bleeding complications, regardless of the time of enoxaparin administration, and is safe enough to warrant testing it in larger numbers.

Acute Disease↗