Faculty Bibliography

BACKGROUND:Chronic kidney disease (CKD) is a risk factor for coronary heart disease and bleeding with antithrombotic therapy in patients with acute coronary syndromes (ACS). We evaluated the effect of renal function on efficacy and outcomes in high-risk patients with NSTE ACS in the SYNERGY trial. METHODS:Creatinine clearance (CrCl) at the time of randomization was analyzed as a continuous variable added to multivariable logistic regression models for 30-day death or MI, non-CABG-associated TIMI major bleeding, GUSTO severe bleeding, and transfusion in the overall study population, patients undergoing coronary angiography, and patients undergoing PCI. RESULTS:Of 9838 patients with a CrCl value, 70.6% (N=6950) had CrCl≥60 mL/min, 27.8% (N=2732) had CrCl 30-59 mL/min, and 1.6% (N=156) had CrCl<30 mL/min. No randomized treatment by CrCl interaction test was found to be statistically significant, suggesting renal insufficiency affected enoxaparin and unfractionated heparin outcomes similarly. After adjustment, CrCl was an independent predictor of 30-day death or MI (OR 1.06, 95% CI 1.03-1.09), TIMI major bleeding (OR 1.06, 95% CI 1.02-1.10), GUSTO severe bleeding (OR 1.10, 95% CI 1.03-1.17), and transfusion (OR 1.07, 95% CI 1.04-1.11). CONCLUSIONS:Patients with CKD had higher rates of 30-day death or MI and bleeding than those without CKD, regardless of randomized antithrombin therapy. While this analysis suggests that there is a rise in bleeding events as CrCl falls for patients in either treatment group, it is unknown whether a reduction in dose would decrease bleeding risk.

CONTEXT/BACKGROUND:The optimal unfractionated heparin regimen for percutaneous coronary intervention (PCI) in patients with non-ST-segment elevation acute coronary syndromes treated with fondaparinux is uncertain. OBJECTIVE:To compare the safety of 2 unfractionated heparin regimens during PCI in high-risk patients with non-ST-segment elevation acute coronary syndromes initially treated with fondaparinux. DESIGN, SETTING, AND PARTICIPANTS/METHODS:Double-blind randomized parallel-group trial in 179 hospitals in 18 countries involving 2026 patients undergoing PCI within 72 hours, nested within a cohort of 3235 high-risk patients with non-ST-segment elevation acute coronary syndromes initially treated with fondaparinux enrolled from February 2009 to March 2010. INTERVENTIONS/METHODS:Patients received intravenously either low-dose unfractionated heparin, 50 U/kg, regardless of use of glycoprotein IIb/IIIa (GpIIb-IIIa) inhibitors or standard-dose unfractionated heparin, 85 U/kg (60 U/kg with GpIIb-IIIa inhibitors), adjusted by blinded activated clotting time (ACT). MAIN OUTCOME MEASURES/METHODS:Composite of major bleeding, minor bleeding, or major vascular access-site complications up to 48 hours after PCI. Key secondary outcomes include composite of major bleeding at 48 hours with death, myocardial infarction, or target vessel revascularization within day 30. RESULTS:The primary outcome occurred in 4.7% of those in the low-dose group vs 5.8% in the standard-dose group (odds ratio [OR], 0.80; 95% confidence interval [CI], 0.54-1.19; P = .27). The rates of major bleeding were not different but the rates of minor bleeding were lower with 0.7% in the low-dose group vs 1.7% in the standard-dose group (OR, 0.40; 95% CI, 0.16-0.97; P = .04). For the key secondary outcome, the rates for low-dose group were 5.8% vs 3.9% in the standard-dose group (OR, 1.51; 95% CI, 1.00-2.28; P = .05) and for death, myocardial infarction, or target vessel revascularization it was 4.5% for the low-dose group vs 2.9% for the standard-dose group (OR, 1.58; 95% CI, 0.98-2.53; P = .06). Catheter thrombus rates were very low (0.5% in the low-dose group and 0.1% in the standard-dose group, P = .15). CONCLUSION/CONCLUSIONS:Low-dose compared with standard-dose unfractionated heparin did not reduce major peri-PCI bleeding and vascular access-site complications. TRIAL REGISTRATION/BACKGROUND:clinicaltrials.gov Identifier: NCT00790907.

OBJECTIVES/OBJECTIVE:Review the use of drug-eluting stents (DES) to evaluate changes in use. BACKGROUND:The DES were approved after several small studies in carefully selected patients showed dramatic reduction in in-stent restenosis. The DES were then rapidly adopted into routine practice. In 2006, 3 years after introduction, serious concerns regarding long-term safety were raised. METHODS:We queried the American College of Cardiology/National Cardiovascular Data Registry (ACC/NCDR) CathPCI Registry. The percentage of DES used through mid-2009 was reviewed overall and in subgroups of patients categorized by lesion type, clinical factors, insurance, and hospital characteristics. Multivariable logistic models relating these covariates to DES usage were constructed for 3 relevant time intervals. RESULTS:A total of 2,247,647 coronary stent procedures were analyzed. By 2005 over 90% of first stents placed were DES. Safety concerns arising in 2006 reduced DES use to 64% of first stent placed. After publication of salutary outcomes data in 2008, usage increased to 76% by mid-2009. The logistic models demonstrated decreased likelihood of DES usage in patients with: 1) ST-segment elevation myocardial infarctions; and 2) no medical insurance. The DES usage increased for in-stent restenosis. Hospital characteristics were not associated with significant differences in DES usage. CONCLUSIONS:There was rapid adoption of DES into U.S. clinical practice. Concern for late stent thrombosis in 2006 significantly altered DES use with reductions seen in subgroups at risk for thrombosis and patients with no insurance. These rapid cyclic changes after DES introduction reinforce the need for continuous, timely reporting of outcomes data after the introduction of new technologies.

BACKGROUND:Measures for pay-for-performance and public reporting programs may be based on clinical practice guidelines. The impact of guideline changes over time-and whether evolving clinical evidence can render measures based on prior guidelines misleading-is not known. OBJECTIVE:To assess the impact of using different percutaneous coronary intervention (PCI) guidelines when evaluating whether PCI was indicated. RESEARCH DESIGN/METHODS:PCIs from the National Cardiovascular Data Registry's CathPCI registry performed in 2003-2004 were categorized into indication classes (Class I, IIa, IIb, III), using 2001 American College of Cardiology/American Heart Association guidelines for PCI, the guidelines available at the time of the procedures. The same procedures were recategorized using 2005 guidelines, which reflect the best evidence available to clinicians at the time of PCI. Procedures unable to be categorized were labeled as "Not Certain." SUBJECTS/METHODS:Patients undergoing PCI for stable or unstable angina in 394 hospitals. MEASURES/METHODS:Number of procedures changing classification categories using 2001 versus 2005 guidelines. RESULTS:A total of 345,779 PCIs were evaluated. Applying 2001 guidelines, 47.9% had Class I indications; 33.3% Class IIa; 5.9% Class IIb; 3.7% Class III; and 9.2% Not Certain. Applying 2005 guidelines to the same procedures, 25.1% had Class I indications; 57.5% Class IIa; 5.5% Class IIb; 3.7% Class III; and 8.3% Not Certain; 41.1% of procedures changed the classification overall. CONCLUSIONS:The changes in guidelines resulted in a marked shift in whether PCIs done in 2003-2004 were considered indicated. Guideline-based performance measures should be carefully evaluated before implementation to avoid incorrect assessments of quality of care.

BACKGROUND:Although bivalirudin compared with unfractionated heparin with glycoprotein IIb/IIIa inhibitors reduces bleeding and hospitalization costs in patients undergoing percutaneous coronary intervention (PCI), little is known about the economic impact of bivalirudin versus heparin alone and at what threshold of procedural bleeding risk bivalirudin would be considered cost-effective. METHODS AND RESULTS/RESULTS:A validated model was used to predict risk of major bleeding for 81,628 National Cardiovascular Data Registry (NCDR) CathPCI Registry patients from 2004 to 2006 who received unfractionated heparin only. Costs were derived from multiple sources including wholesale acquisition costs (for drugs) and single-center data (for PCI-related complications). Based on ISAR-REACT 3, we assumed that bivalirudin would reduce the risk of major bleeding by 33% compared with unfractionated heparin alone. A Markov model was used to estimate lost life expectancy associated with a major bleed. Major bleeding was predicted to occur in 2.2% of patients. Bivalirudin for all patients was estimated to increase costs by $571 per patient, yielding cost-effectiveness ratios of $287,473 per bleeding event averted and $1,173,360 per quality-adjusted life-year gained. Bivalirudin was cost saving for patients with a predicted bleeding risk >20% (0.16% of CathPCI population). At willingness-to-pay thresholds of $50K and $100K per quality-adjusted life-year gained, bivalirudin was cost-effective for patients with a bleeding risk > or = 8% (2.5% patients) and > or = 5% (7.9% patients), respectively. CONCLUSIONS:This decision-analytic modeling study demonstrates that for patients undergoing PCI, substitution of bivalirudin for unfractionated heparin monotherapy is projected to increase costs for virtually all patients and would be considered cost-effective for only a minority of patients with a high bleeding risk. From a policy standpoint, studies such as this, aimed at identifying the appropriate risk threshold for initiating treatment, may help in the development of informed guidelines for the use of expensive therapies.

Despite current dual-antiplatelet therapy with aspirin and clopidogrel, adverse clinical events continue to occur during and after percutaneous coronary intervention (PCI). The failure of clopidogrel to provide optimal protection may be related to delayed onset of action, interpatient variability in its effect, and an insufficient level of platelet inhibition. Furthermore, the irreversible binding of clopidogrel to the P2Y(12) receptor for the life span of the platelet is associated with increased bleeding risk especially during urgent or emergency surgery. Novel antiplatelet agents are required to improve management of patients undergoing PCI. Elinogrel is a potent, direct-acting (ie, non-prodrug), selective, competitive, and reversible P2Y(12) inhibitor available in both intravenous and oral formulations. The INNOVATE-PCI study is a phase 2 randomized, double-blind, clopidogrel-controlled trial to evaluate the safety, tolerability, and preliminary efficacy of this novel antiplatelet agent in patients undergoing nonurgent PCI.

Antiplatelet drug therapy represents the cornerstone of treatment for cardiovascular atherothrombotic disease processes. Dual antiplatelet therapy with aspirin and oral ADP-receptor antagonists such as clopidogrel are currently the standard care for prevention of ischemic events in patients with acute coronary syndrome and who are undergoing percutaneous coronary intervention. However, despite the clinical benefit associated with clopidogrel therapy, this drug has several limitations, including a broad interindividual response variability, drug-drug interactions, slow onset of action and irreversible platelet inhibition, emphasizing the need for novel P2Y(12)-receptor antagonists. Elinogrel (PRT060128) is a reversible, potent and competitive inhibitor of the P2Y(12) receptor with a fast onset and offset of action that can be administered by both oral and intravenous routes and rapidly achieves near complete platelet inhibition. Preclinical and early-phase clinical testing have shown promising results with this novel compound, which awaits further testing in outcome-driven clinical trials. This article provides an overview of the current level of knowledge regarding elinogrel, focusing on its pharmacologic properties and preclinical and early-phase clinical development.

CONTEXT/BACKGROUND:Bleeding complications with percutaneous coronary intervention (PCI) are associated with adverse patient outcomes. The association between the use of bleeding avoidance strategies and post-PCI bleeding as a function of a patient's preprocedural risk of bleeding is unknown. OBJECTIVE:To describe the use of 2 bleeding avoidance strategies, vascular closure devices and bivalirudin, and associated post-PCI bleeding rates in a nationally representative PCI population. DESIGN, SETTING, AND PATIENTS/METHODS:Analysis of data from 1,522,935 patients undergoing PCI procedures performed at 955 US hospitals participating in the National Cardiovascular Data Registry (NCDR) CathPCI Registry from January 1, 2004, through September 30, 2008. MAIN OUTCOME MEASURE/METHODS:Periprocedural bleeding. RESULTS:Bleeding occurred in 30,654 patients (2%). Manual compression, vascular closure devices, bivalirudin, or vascular closure devices plus bivalirudin were used in 35%, 24%, 23%, and 18% of patients, respectively. Bleeding events were reported in 2.8% of patients who received manual compression, compared with 2.1%, 1.6%, and 0.9% of patients receiving vascular closure devices, bivalirudin, and both strategies, respectively (P < .001). Bleeding rates differed by preprocedural risk assessed with the NCDR bleeding risk model (low risk, 0.72%; intermediate risk, 1.73%; high risk, 4.69%). In high-risk patients, use of both strategies was associated with lower bleeding rates (manual compression, 6.1%; vascular closure devices, 4.6%; bivalirudin, 3.8%; vascular closure devices plus bivalirudin, 2.3%; P < .001). This association persisted following adjustment using a propensity-matched and site-controlled model. Use of both strategies was used least often in high-risk patients (14.4% vs 21.0% in low-risk patients, P < .001). CONCLUSIONS:In a large national PCI registry, vascular closure devices and bivalirudin were associated with significantly lower bleeding rates, particularly among patients at greatest risk for bleeding. However, these strategies were less often used among higher-risk patients.

Thrombocytopenia is associated with increased patient risk. However, the costs of this complication are not well defined. This study assessed the impact of thrombocytopenia on in-hospital costs using results from CATCH, an observational study that examined 1988 consecutive patients receiving prolonged heparin therapy (> or =96 h). Thrombocytopenia was defined as: (group 1) an absolute reduction in platelet count to <150 x 10(9)/L; (group 2) a relative reduction in platelet count of >50% from admission levels; or (group 3) both criteria. We found that the development of thrombocytopenia was associated with significantly higher total in-hospital costs for all groups: (group 1) (difference, $8,222; 95% CI, $5,020-$11,425; P<.001); (group 2) (difference, $15,429; 95% CI, $7,472-$23,385; P<.001); and (group 3) (difference, $27,077; 95% CI, $22,901-$31,252; P<.001). However, in our adjusted model, longer lengths-of-stay and greater use of blood transfusions accounted for most incremental in-hospital cost differences.