Faculty Bibliography

Antithrombotic and antiplatelet drugs and percutaneous interventions have decreased the ischemic outcomes of non-ST-elevation acute coronary syndromes, but they pose risks of bleeding. The authors review the scope of the problem and ways to prevent and manage bleeding in this situation.

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.

AIMS/OBJECTIVE:We studied the clinical and economic impact of bivalirudin in clinical practice. METHODS AND RESULTS/RESULTS:Consecutive patients undergoing PCI via the common femoral artery for stable, unstable, or atypical angina, silent ischaemia, or non-ST-elevation myocardial infarction indications during 2007-2008 were prospectively studied. In-hospital bleeding events were systematically assessed and classified as either major or minor. Use of bivalirudin, vascular closure devices, heparin and/or glycoprotein (GP) IIb/IIIa inhibitor was at the operator's discretion. Among 1,364 patients, 503 received bivalirudin and 861 received usual care consisting of either heparin monotherapy (n=687) or heparin+GP IIb/IIIa (n=174). Any post-PCI bleeding occurred in 356 (26.1%) patients, including 32 (2.3%) major and 324 (23.8%) minor events. Compared with usual care, bivalirudin was associated with reduced bleeding before adjustment (any: 17.3% vs. 31.2%, P<0.001; major: 1.2% vs. 3.0%, P=0.03; minor: 16.1% vs. 28.2%, P<0.01) and after propensity-matching (OR 0.46, 95% CI 0.34-0.63, P<0.001). Use of vascular closure devices was associated with an increase in any bleeding (32.2% vs. 17.7%, P<0.001), primarily due to an increase in minor bleeding (30.8% vs. 14.1%, P<0.001) while there was a significant decrease in major bleeding (1.4% vs. 3.7%, P=0.007). Bivalirudin was associated with total hospitalisation costs that were lower than usual care (mean cost savings, $463/patient; 95% CI 1,594 less to 621 more). CONCLUSIONS:In this prospective PCI cohort, bivalirudin was associated with reduced major and minor bleeding without a significant increase in hospital costs compared with other anticoagulation regimens. Closure device use was associated with decreased major but increased minor bleeding.

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.

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.

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.

OBJECTIVES/OBJECTIVE:The aim of this study was to evaluate practice of transradial approach (TRA). BACKGROUND:TRA has been adopted as an alternative access site for coronary procedures. METHODS:A questionnaire was distributed worldwide with Internet-based software. RESULTS:The survey was conducted from August 2009 to January 2010 among 1,107 interventional cardiologists in 75 countries. Although pre-TRA dual hand circulation testing is not uniform in the world, >85% in the U.S. perform Allen or oximetry testing. Right radial artery is used in almost 90%. Judkins catheters are the most popular for left coronary artery angiographies (66.5%) and right coronary artery angiographies (58.8%). For percutaneous coronary intervention (PCI), 6-F is now standard. For PCI of left coronary artery, operators use standard extra back-up guiding catheters in >65% and, for right coronary artery 70.4% use right Judkins catheters. Although heparin remains the routine antithrombotic agent in the world, bivalirudin is frequently used in the U.S. for PCI. The incidence of radial artery occlusion before hospital discharge is not assessed in >50%. Overall, approximately 50% responded that their TRA practice will increase in the future (68.4% in the U.S.). CONCLUSIONS:TRA is already widely used across the world. Diagnostic and guiding-catheters used for TRA remain similar to those used for traditional femoral approach, suggesting that specialized radial catheters are not frequently used. However, there is substantial variation in practice as it relates to specific aspects of TRA, suggesting that more data are needed to determine the optimal strategy to facilitate TRA and optimize radial artery patency after catheterization.