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David J Cohen

Publications and source records attributed to David J Cohen.

At least 19 recordsLinked to original sources

Outcomes of optimal or "stent-like"balloon angioplasty in acutemyocardial infarction: the CADILLAC trial.

OBJECTIVES: We sought to compare outcomes between patients with acute myocardial infarction (AMI) undergoing percutaneous transluminal coronary angioplasty (PTCA) with an optimal or "stent-like" result versus patients who underwent routine stent placement. BACKGROUND: Recent studies in patients with AMI undergoing stent implantation have suggested that PTCA may no longer be a relevant treatment modality for stent eligible lesions. However, whether routine stent placement is superior or necessary when an optimal PTCA or "stent-like" result is achieved is unknown. METHODS: In the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial, 2,082 patients with AMI were randomly assigned to undergo PTCA alone, PTCA + abciximab, stenting alone, or stenting + abciximab. Outcomes were compared in patients achieving an optimal acute PTCA result (residual core laboratory diameter stenosis <30% without significant dissection) versus those assigned to routine stenting. RESULTS: Optimal PTCA was achieved in 40.7% of patients randomized to balloon angioplasty, including 38.5% and 42.7% assigned to PTCA alone and PTCA + abciximab, respectively. Ischemic target vessel revascularization (TVR) at 30 days occurred more frequently after optimal PTCA than routine stenting (5.1% vs. 2.3%, p = 0.007). The one-year composite adverse event rate (death, reinfarction, disabling stroke, or TVR) was greater after optimal PTCA than routine stenting (21.9% vs. 13.8%, p < 0.001), driven largely by increased rates of ischemic TVR (19.1% vs. 9.1%, p < 0.001); no significant differences were present in the rates of death, reinfarction, or disabling stroke between the two groups. Angiographic restenosis also was more common with optimal PTCA than routine stenting (36.2% vs. 22.2%, p = 0.003). Even a post-PTCA diameter stenosis of <20% (realized in 12% of patients) did not result in outcomes equivalent to stenting. CONCLUSIONS: Even if an optimal result is achieved after primary PTCA in AMI, early and late outcomes can be further improved with routine stent implantation.

Abciximab↗

Impact of a practice guideline for patients with atrial fibrillation on medical resource utilization and costs.

Health care resource utilization is high for patients presenting with acute atrial fibrillation (AF). The potential for treatment algorithms to safely reduce resource consumption in this setting has not been prospectively evaluated. We designed and implemented a practice guideline for the management of patients presenting to the emergency department (ED) with the primary diagnosis of AF, with emphasis on appropriate cardioversion, use of oral rate-controlling medications, and expedited referral to an outpatient AF clinic. We prospectively collected clinical and resource utilization data on all such patients for 14 months before and after institution of the guideline. Institution of the guideline was associated with a decreased rate of hospital admission (from 74% to 38%), with no differences in ED return visits or hospital readmission within 30 days. No strokes or deaths were observed. This large decrease in resource utilization during the intervention phase of the study translated to an average decrease in 30-day total direct health care costs of approximately $1,400 US dollars per patient. Our clinical and cost outcomes were minimally affected after statistical adjustment for baseline differences between study groups. We conclude that the implementation of our practice guideline was feasible, safe, and effective. Widespread adoption of such practices may have large financial implications for the health care system.

Aged↗

Effect of abciximab versus tirofiban on activated clotting time during percutaneous intervention and its relation to clinical outcomes--observations from the TARGET trial.

Previous evidence suggests that the monoclonal antibody abciximab may have a more potent anticoagulant effect than small-molecule glycoprotein (GP) IIb/IIIa inhibitors. We prospectively reviewed collected heparin dose, activated clotting time (ACT), and corresponding clinical outcome data from The Do Tirofiban and ReoPro Give Similar Efficacy Outcome Trial (TARGET), a direct comparison of tirofiban versus abciximab in patients who underwent percutaneous intervention. Of the 4,809 patients enrolled in the trial, 3,739 patients (78%) had an ACT measured after the administration of GP IIb/IIIa and heparin (peak procedural ACT); this formed the population for the present study. Mean total heparin dose was 75 +/- 32 and 76 +/- 31 U/kg in the tirofiban and abciximab groups, respectively. The resultant mean peak ACTs were 296 +/- 91 and 299 +/- 89 seconds (p = 0.09). In a subset of patients with both baseline ACT (before any heparin or GP IIb/IIIa therapy) and peak procedural ACT measurements, the difference in ACT between these time points was 80 +/- 97 vs 82 +/- 101 seconds (p = 0.44) for the tirofiban and abciximab groups, respectively. After adjusting for patients' weight, weight-adjusted heparin dose, and method of ACT measurement in a multiple linear regression analysis, the type of GP IIb/IIIa inhibitor was not predictive of the peak ACT (p = 0.24). When stratified by ACT quartile, no statistically significant difference in bleeding or ischemic end points between the tirofiban and abciximab cohorts was observed. In this large contemporary percutaneous coronary intervention trial, there was no observed difference in the anticoagulant effect of tirofiban and abciximab, as measured by the ACT, or in the incidence of bleeding or ischemic complications in each ACT quartile.

Abciximab↗

Administration of rabbit antithymocyte globulin (thymoglobulin) in ambulatory renal-transplant patients.

BACKGROUND: Antilymphocyte globulins have been used for the treatment and prevention of acute rejection in renal-allograft recipients. Thymoglobulin, rabbit antithymocyte globulin (RATG), has been shown to be effective for these indications and has been used primarily on an inpatient basis because of the recommendation that it be administered through a central line. METHODS: We retrospectively reviewed the charts of all patients treated with RATG since its first use in 1999. After premedication, the dose of RATG was administered over 4 to 6 hours, with 1,000 units of heparin and 20 mg of hydrocortisone to reduce the incidence of thrombosis and local tissue reaction. All adverse reactions were recorded. RESULTS: Eighteen patients underwent a total of 57 outpatient infusions. Of the 57 infusions, 52 (91%) were without complication. Five infusions (9%) were complicated by infiltrates. No serious reactions were noted. CONCLUSIONS: These data confirm that peripheral, outpatient administration of RATG is safe.

Acute Disease↗

Bivalirudin and provisional glycoprotein IIb/IIIa blockade compared with heparin and planned glycoprotein IIb/IIIa blockade during percutaneous coronary intervention: REPLACE-2 randomized trial.

CONTEXT: The direct thrombin inhibitor bivalirudin has been associated with better efficacy and less bleeding than heparin during coronary balloon angioplasty but has not been widely tested during contemporary percutaneous coronary intervention (PCI). OBJECTIVE: To determine the efficacy of bivalirudin, with glycoprotein IIb/IIIa (Gp IIb/IIIa) inhibition on a provisional basis for complications during PCI, compared with heparin plus planned Gp IIb/IIIa blockade with regard to protection from periprocedural ischemic and hemorrhagic complications. DESIGN, SETTING, AND PARTICIPANTS: The Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 trial, a randomized, double-blind, active-controlled trial conducted among 6010 patients undergoing urgent or elective PCI at 233 community or referral hospitals in 9 countries from October 2001 through August 2002. INTERVENTIONS: Patients were randomly assigned to receive intravenous bivalirudin (0.75-mg/kg bolus plus 1.75 mg/kg per hour for the duration of PCI), with provisional Gp IIb/IIIa inhibition (n = 2999), or heparin (65-U/kg bolus) with planned Gp IIb/IIIa inhibition (abciximab or eptifibatide) (n = 3011). Both groups received daily aspirin and a thienopyridine for at least 30 days after PCI. MAIN OUTCOME MEASURES: The primary composite end point was 30-day incidence of death, myocardial infarction, urgent repeat revascularization, or in-hospital major bleeding; the secondary composite end point was 30-day incidence of death, myocardial infarction, or urgent repeat revascularization. RESULTS: Provisional Gp IIb/IIIa blockade was administered to 7.2% of patients in the bivalirudin group. By 30 days, the primary composite end point had occurred among 9.2% of patients in the bivalirudin group vs 10.0% of patients in the heparin-plus-Gp IIb/IIIa group (odds ratio, 0.92; 95% confidence interval, 0.77-1.09; P =.32). The secondary composite end point occurred in 7.6% of patients in the bivalirudin vs 7.1% of patients in the heparin-plus-Gp IIb/IIIa groups (odds ratio, 1.09; 95% confidence interval 0.90-1.32; P =.40). Prespecified statistical criteria for noninferiority to heparin plus Gp IIb/IIIa were satisfied for both end points. In-hospital major bleeding rates were significantly reduced by bivalirudin (2.4% vs 4.1%; P<.001). CONCLUSIONS: Bivalirudin with provisional Gp IIb/IIIa blockade is statistically not inferior to heparin plus planned Gp IIb/IIIa blockade during contemporary PCI with regard to suppression of acute ischemic end points and is associated with less bleeding.

Abciximab↗

Combination platelet glycoprotein IIb/IIIa receptor and lepirudin administration during percutaneous coronary intervention in patients with heparin-induced thrombocytopenia.

We evaluated a combination therapy using glycoprotein IIb/IIIa receptor antagonism and direct thrombin inhibition in nine patients with heparin-induced thrombocytopenia (HIT) undergoing 10 percutaneous coronary interventions (PCIs). In selected patients with HIT, the combination of a direct thrombin inhibitor, lepirudin, and abciximab, tirofiban, or eptifibatide appears to be a safe and effective anticoagulation strategy for PCI.

Abciximab↗

Comparison of analytic approaches for the economic evaluation of new technologies alongside multicenter clinical trials.

BACKGROUND: In reporting economic evaluations of clinical trials, results are often stated without a description of the methodology used to derive the cost estimates. We compared methods for measuring costs from multicenter clinical trials to determine the extent to which the methodology affects results. METHODS: Patient-level data (n = 1849) from 3 multicenter clinical trials of percutaneous coronary revascularization were used to compare 4 methods of estimating costs: 1) hospital charges; 2) hospital charges converted to costs by use of hospital-level cost-to-charge ratios; 3) hospital charges converted to costs by use of department-level cost-to-charge ratios; 4) itemized catheterization laboratory costs with nonprocedural hospital costs generated from department-level cost-to-charge ratios. RESULTS: The method used to approximate costs did not affect the main results of the economic comparisons for any of the trials. The magnitude of the cost estimates and the cost differences between treatment groups varied considerably by method, however. Charges were approximately twice as high as hospital cost estimates. At the patient level, costs generated by use of method 1 were within 10% of those generated by use of method 4 for only 5% of patients, compared with 34% and 22% of patients with methods 2 and 3, respectively. Only method 3 produced estimates of between-group cost differences that were consistently within $500 of the reference standard. CONCLUSION: Cost estimates derived from clinical trials in the cardiovascular arena vary substantially according to accounting methodology. Thus, in reporting the results of economic analyses, a detailed description of cost derivation is necessary, particularly when the absolute magnitude of the cost estimates is important to clinical decision-making or policy-level recommendations. For the purposes of group-level comparisons, conversion of hospital charges to costs on the basis of department-level cost-to-charge ratios appears to represent a reasonable compromise between accuracy and ease of implementation.

Angioplasty, Balloon, Coronary↗

Clinical and economic outcomes of multivessel coronary stenting compared with bypass surgery: a single-center US experience.

BACKGROUND: Randomized trials comparing multivessel stenting with coronary artery bypass surgery (CABG) have demonstrated similar rates of death and myocardial infarction but higher rates of repeat revascularization after stenting. The impact of these alternative strategies on overall medical care costs is uncertain, particularly within the US health care system. METHODS: We performed a retrospective, matched cohort study to compare the clinical and economic outcomes of multivessel stenting and bypass surgery. The stent group consisted of 100 consecutive patients who underwent stenting of >or=2 major native coronary arteries at our institution. The CABG group consisted of 200 patients who underwent nonemergent isolated bypass surgery during the same time frame, matched (2:1) for age, sex, ejection fraction, diabetes mellitus, and extent of coronary disease. Detailed clinical follow-up and resource utilization data were collected for a minimum of 2 years. Total costs were calculated by use of year 2000 unit prices. RESULTS: Over a median follow up period of 2.8 years, there were no significant differences in all-cause mortality rates (3.0% vs 3.0%), Q-wave myocardial infarction (5.1% vs 4.0%), or the composite of death or myocardial infarction (7.1% vs 7.0%) between the stent and CABG groups (P = not significant for all comparisons). However, at 2-year follow up, patients with stents were more likely to require >or=1 repeat revascularization procedure (32.0% vs 4.5%, P <.001). The initial cost of multivessel stenting was 43% less than the cost of CABG (11,810 dollars vs 20,574 dollars, P <.001) and remained 27% less (17,634 dollars vs 24,288 dollars, P =.005) at 2 years. CONCLUSIONS: Multivessel stenting and CABG result in comparable risks of death and myocardial infarction. Despite a higher rate of repeat revascularization, multivessel stenting was significantly less costly than CABG through the first 2 years of follow-up.

Angioplasty, Balloon, Coronary↗

Nephrogenic fibrosing dermopathy (scleromyxedema-like illness of renal disease).

Nephrogenic fibrosing dermopathy or scleromyxedema-like illness of renal disease is a recently reported disorder. It manifests as scleromyxedema-like skin lesions without associated paraproteinemia, occurring in the setting of renal disease. In the majority of cases skin lesions of nephrogenic fibrosing dermopathy develop after hemodialysis or renal transplantation; however, the origin is still unknown. We report 4 new cases of nephrogenic fibrosing dermopathy and review the literature. The clinical and histopathologic features, differential diagnosis, possible etiology, and treatment options are reviewed.

Adult↗

Upregulation of MHC class II, interferon-alpha and interferon-gamma receptor protein expression in HIV-associated nephropathy.

BACKGROUND: Renal cellular HIV infection has been linked to the pathogenesis of HIV-associated nephropathy (HIVAN), but mediators of its development are unknown. HIV infection is associated with disordered cytokine metabolism, and chemokine receptors are coreceptors for HIV immune cellular infection. Chemokines such as interleukin (IL)-8, monocyte chemoattractant protein-1 (MCP-1) and RANTES, and interferons (IFNs) have been implicated in the progression of nephropathy. Renal major histocompatibility complex (MHC) protein expression is involved in antigen presentation and modulating tissue cellular immune responses. Their relative importance in HIVAN pathogenesis is unknown. METHODS: We measured levels of chemokines, IFN-alpha, IFN-gamma receptor and non-polymorphic MHC Class II protein by high performance capillary electrophoresis, and incubation with antibodies for quantification by chemiluminesce in renal tissue of patients with HIVAN, compared with tissue without HIV infection, in the presence and absence of nephropathy. Renal biopsy tissue protein levels were correlated with the number and type of infiltrating tissue immune cells. RESULTS: Mean renal interstitial and glomerular MCP-1, RANTES and IL-8 tissue levels were higher in patients with HIV infection compared with tissue without HIV infection, regardless of the presence of renal disease. In contrast, mean renal interstitial and glomerular non-polymorphic MHC Class II, IFN-alpha and IFN-gamma receptor protein were higher in patients with HIVAN compared with all other groups. Tissue MHC Class II and IFN-gamma receptor protein levels did not correlate with immune cellular infiltration in patients with HIV infection and renal disease. CONCLUSIONS: The data suggest an upregulated renal immune microenvironment, capable of antigen presentation, exists in HIVAN. MHC Class II proteins and IFNs, and the capacity to present antigen may be crucial in HIVAN pathogenesis.

AIDS-Associated Nephropathy↗

Epidermodysplasia verruciformis.

Epidermodysplasia verruciformis is an uncommon cutaneous entity characterized by persistent human papillomavirus infection. A defect in cell-mediated immunity is the suggested causative factor. Numerous specific human papillomavirus types have been detected in this disease. Multiple nonmelanoma skin cancers are commonly seen in such patients; thus, early diagnosis is beneficial.

Epidermodysplasia Verruciformis↗

Practice and outcomes of percutaneous coronary intervention in the community before drug-eluting stents: a report from the HCA database.

BACKGROUND: Percutaneous coronary intervention (PCI) using balloon angioplasty and/or intracoronary stents has increasingly become the treatment choice for myocardial revascularization. While acute clinical outcomes of the community-based PCI procedures have been examined, much less is known about long-term revascularization rates, disease progression and other adverse outcomes. METHODS AND RESULTS: Information on patient demographics, coronary risk factors, lesion characteristics, procedures and outcomes were derived from an HCA, Inc. database on all patients undergoing a PCI procedure in one of four community cardiac catheterization laboratories. A total of 3,192 consecutive patients were enrolled from July 1, 1999 through September 30, 2000. Analysis was limited to those patients undergoing PCI of native vessels with stents or conventional balloon angioplasty; target lesions in bypass grafts or those treated with atherectomy were excluded. Approximately one-third of enrolled patients were surveyed concerning their utilization of cardiovascular services 1 year following their initial procedure. The 1-year target lesion revascularization (TLR) was 9.9% while target vessel revascularization was 13.5%. Overall, 27.6% of patients underwent repeat revascularization within 1 year; 24.7% underwent at least 1 additional PCI and 5.6% underwent coronary artery bypass graft surgery. A total of 4.5% of patients reported an interval acute myocardial infarction with a major adverse cardiac event rate of 30.3% at 1 year. CONCLUSION: While clinically significant restenosis remains a problem for 10 15% of patients undergoing PCI, progression of coronary artery disease elsewhere appears to be an equally powerful driver in the need for recurrent revascularization. This analysis of contemporary PCI practice prior to drug-eluting stent utilization suggests that while these novel devices will likely reduce the incidence of TLR, many patients with coronary artery disease will still require additional revascularization for disease progression.

Aged↗

Clinical restenosis after coronary stenting: perspectives from multicenter clinical trials.

OBJECTIVES: We sought to evaluate clinical restenosis in a large population of patients who had undergone coronary stent placement. BACKGROUND: One-year success after coronary stenting is limited mainly by restenosis of and requirement for repeat revascularization of the treated lesion. We studied 6,186 patients (6,219 lesions) pooled from several recently completed coronary stent trials. Clinical restenosis was defined using three different definitions: target lesion revascularization (TLR) beyond 30 days, target vessel revascularization (TVR) beyond 30 days, and target vessel failure (TVF), defined as TVR, any death, or myocardial infarction (MI) of the target vessel territory after hospital discharge. RESULTS: By one year, 638 (12.2%) patients had TLR, 748 (14.3%) had TVR, and 848 (16.0%) had TVF, more than two-thirds higher than the rate of these end points at six months. The severity of angiographic restenosis (> or =50% follow-up diameter stenosis [DS]) in 419 of 1,437 (29%) patients undergoing routine angiographic follow-up correlated directly with the likelihood of TLR (73% vs. 26% for >70% DS compared with <60% DS). Smaller pretreatment minimum lumen diameter (MLD), smaller final MLD, longer stent length, diabetes mellitus, unstable angina, and hypertension were independent predictors of TLR. Prior MI and current smoking were negative predictors. CONCLUSIONS: At one year after stenting, most clinical restenosis reflected TLR, which was predicted by the same variables previously associated with an increased risk of angiographic restenosis. The lower absolute rate of clinical restenosis relative to angiographic restenosis was due to infrequent TLR in lesions with less severe (<60% DS) angiographic renarrowing.

Angioplasty, Balloon↗

Effectiveness of rheolytic coronary thrombectomy with the AngioJet catheter.

Thrombus-filled lesions are associated with a higher rate of acute complications and long-term restenosis following conventional coronary or saphenous vein graft (SVG) intervention. To evaluate the clinical effectiveness of rheolytic thrombectomy in a nonselected population in the glycoprotein IIb/IIIa blockade era, we reviewed clinical, angiographic, and procedural data on 119 patients who underwent 126 consecutive coronary AngioJet procedures (29% in SVGs, and 71% in native coronary arteries) from July 1998 to August 2000. Glycoprotein IIb/IIIa blockers were used in 88%. Most vessels (68% of SVGs, 74% of native coronary arteries) were occluded initially. Complete or substantial removal of filling defects was achieved in 76% of SVGs and 66% of native coronary cases. The AngioJet rheolytic thrombectomy device led to significant improvement in lumen diameter and Thrombolysis In Myocardial Infarction (TIMI) flow, with reduction in the thrombotic lesion length (p <0.05). Angiographic success (<30% residual stenosis, TIMI-3) was attained in 73% of SVGs and 87% of native coronary procedures. Distal embolization occurred in 13 cases, and was less likely to occur in patients treated with abciximab (0%) compared with patients treated with other glycoprotein IIb/IIIa blockers or heparin alone (17%, p = 0.02). A favorable response to the AngioJet (odds ratio 3.9) and freedom from embolization (odds ratio 14.6) were associated with a higher procedural success rate. In-hospital and long-term clinical outcomes were favorable. Thus, rheolytic thrombectomy resulted in significant reduction of the thrombus burden in most patients, restored TIMI-3 flow, and led to favorable short- and long-term outcomes.

Age Factors↗

The nondirected live-kidney donor: ethical considerations and practice guidelines: A National Conference Report.

BACKGROUND: The success of kidney transplantation from a genetically unrelated living spouse or friend has influenced transplant physicians to consider the requests of individuals wishing to volunteer to be a kidney donor who have no intended recipient specified. Representatives of the transplant community gathered in Boston, MA, on May 31, 2001, to deliberate on the experience of live kidney donation from such volunteers, currently termed nondirected donors (NDD). OBJECTIVE OF CONFERENCE PARTICIPANTS: The objective of the conference was to recommend ethical and practice guidelines for health care professionals considering the transplantation of a kidney from a live NDD. CONFERENCE PARTICIPANTS: This conference was convened under the sponsorship of The National Kidney Foundation, with representation from The American Society of Transplantation and The American Society of Transplant Surgeons, The American Society of Nephrology, The United Resource Networks, The United Network for Organ Sharing, The Association of Organ Procurement Organizations, The National Institutes of Health, and The Division of Transplantation of the Health Resources and Services Administration (see Appendix). CONFERENCE REPORT: The suggested content of screening interviews, which provide information regarding the donation process, elicits pertinent medical and psychosocial history, and assesses NDD motivation are presented in this report. Approaches to identifying the center that would evaluate the suitability of the NDD, to performing the kidney recovery, and to selecting the NDD recipient are also proposed. Other ethical issues such as the use of prisoners as an NDD, compensation for the NDD, media involvement, and communication between the NDD and recipient are discussed. CONCLUSION: The willingness of health care professionals to consider NDD volunteers is driven by the compelling need to provide organs for an ever-expanding list of patients awaiting a kidney transplant. However, the psychological impact and emotional reward of donation has yet to be determined for NDD who may not have any relationship to the recipient or knowledge of the recipient's outcome. Transplant centers that accept NDD should document an informed consent process that details donor risks, assures donor safety, and determines that the goals and expectations of the NDD and the recipient can be realized.

Communication↗

Cost-effectiveness of gamma radiation for treatment of in-stent restenosis: results from the Gamma-1 trial.

BACKGROUND: Recently, several randomized trials have demonstrated that intracoronary brachytherapy can reduce the rates of both angiographic and clinical restenosis in patients undergoing percutaneous coronary intervention (PCI) for in-stent restenosis. Whether this practice is cost-effective is unknown. METHODS AND RESULTS: Between December 1997 and July 1998, 252 patients with in-stent restenosis were randomized to receive brachytherapy or placebo after successful PCI as part of the Gamma-1 trial. We collected detailed resource utilization and cost data for each patient's initial hospitalization and for 1 year after randomization. Compared with conventional treatment, intracoronary brachytherapy increased procedure duration, physician services, and equipment costs. As a result, initial costs were increased by nearly $4100 per patient ($15 724 versus $11 675, P<0.001). Over the 1-year follow-up period, brachytherapy reduced the need for repeat revascularization by 21% and reduced the need for bypass surgery by 44%. Although follow-up medical care costs were $2200/patient lower with brachytherapy, total costs remained higher at 1 year ($28 543 versus $26 737, P=0.46). In a sensitivity analysis that incorporated recent technical modifications and the use of prolonged antiplatelet therapy to prevent late thrombotic occlusion, follow-up cost savings increased to $3600/patient, and 1-year costs were slightly lower with brachytherapy ($26 352 versus $26 729, P=0.87). Subgroup analysis demonstrated significant cost savings in patients with diabetes and patients who did not undergo repeat stenting. CONCLUSIONS: As performed in the Gamma-1 trial, coronary brachytherapy for in-stent restenosis improved clinical outcomes but increased 1-year costs compared with standard therapy. If late thrombosis can be eliminated, however, this technology has the potential to reduce overall medical care costs.

Angioplasty, Balloon, Coronary↗