Faculty Bibliography

Cardiovascular disease is the number 1 cause of death in the western world and 1 of the leading causes of death worldwide. The lifetime risk of atherosclerotic cardiovascular disease (CVD) for persons at age 50 years, on average, is estimated to be 52% for men and 39% for women, with a wide variation depending on risk factor burden. Assessing patients' cardiovascular risk may be used for the targeting of preventive treatments of individual patients who are asymptomatic but at sufficiently high risk for the development of CVD. Risk stratifying patients for CVD remains challenging, particularly for those with low or intermediate short-term risk. Several algorithms have been described to facilitate the assessment of risk in individual patients. We describe 6 risk algorithms (Framingham Risk Score for coronary heart disease events and for cardiovascular events, Adult Treatment Panel III, SCORE [Systematic Coronary Risk Evaluation] project, Reynolds Risk Score, ASSIGN [Assessing Cardiovascular Risk to Scottish Intercollegiate Guidelines Network/SIGN to Assign Preventative Treatment], and QRISK [QRESEARCH Cardiovascular Risk Algorithm]) for outcomes, population derived/validated, receiver-operating characteristic, variables included, and limitations. Areas of uncertainty include 10-year versus lifetime risk, prediction of CVD or coronary heart disease end points, nonlaboratory-based risk scores, age at which to start, race and sex differences, and whether a risk score should guide therapy. We believe that the best high-risk approach to CVD evaluation and prevention lies in routine testing for cardiovascular risk factors and risk score assessment. We recommend that health care providers discuss the global cardiovascular risk and lifetime cardiovascular risk score assessment with each patient to better explain each patient's future risk. Appropriate intervention, guided by risk assessment, has the potential to bring about a significant reduction in population levels of risk

Background The 2007 American Heart Association guidelines for cardiovascular disease prevention in women drew heavily on results from randomized clinical trials; however, representation of women in trials of cardiovascular disease prevention has not been systematically assessed. Methods and Results We abstracted 156 randomized clinical trials cited by the 2007 women's prevention guidelines to determine female representation over time and by clinical indication, prevention type, location of trial conduct, and funding source. Both women and men were represented in 135 of 156 (86.5%) trials; 20 trials enrolled only men; 1 enrolled only women. Among all trials, the proportion of women increased significantly over time, from 9% in 1970 to 41% in 2006. Considering only trials that enrolled both women and men, female enrollment was 18% in 1970 and increased to 34% in 2006. Female representation was higher in international versus United States\Nonly trials (32.7% versus 26.7%) and primary versus secondary prevention trials (42.6% versus 26.6%). Female enrollment was comparable in government/foundation-funded versus industry-funded trials (31.9% versus 31.5%). Representation of women was highest among trials in hypertension (44%), diabetes (40%), and stroke (38%) and lowest for heart failure (29%), coronary artery disease (25%), and hyperlipidemia (28%). By contrast, women accounted for 53% of all individuals with hypertension, 50% with diabetes, 51% with heart failure, 49% with hyperlipidemia, and 46% with coronary artery disease. Sex-specific results were discussed in only 31% of primary trial publications. Conclusions Enrollment of women in randomized clinical trials has increased over time but remains low relative to their overall representation in disease populations. Efforts are needed to reach a level of representation that is adequate to ensure evidence-based sex-specific recommendations

Summary Aim: To determine if an association exists between mean platelet volume (MPV) and acute myocardial infarction (AMI) and other cardiovascular events. Platelet activity is a major culprit in atherothrombotic events. Mean platelet volume, widely available in clinical practice, is a potentially useful biomarker of platelet activity in the setting of cardiovascular disease. Methods and Results: We performed a systematic review and meta-analysis investigating the association between MPV and AMI, all-cause mortality following MI, and restenosis following coronary angioplasty. Results were pooled using random effects modeling. Pooled results from 16 cross-sectional studies involving 2,809 patients investigating the association of MPV and AMI indicated that MPV was significantly higher in those with AMI than those without AMI (mean difference 0.92 fl, 95% confidence interval [CI] 0.67 to 1.16, P < 0.001). In subgroup analyses, significant differences in MPV existed between subjects with AMI versus stable coronary disease (P < 0.001) and versus stable controls (P < 0.001), but not versus unstable angina (P = 0.24). Pooled results from three cohort studies involving 3,184 patients evaluating the risk of death following AMI, demonstrated that an elevated MPV increased the odds of death compared with a normal MPV (11.5% versus 7.1%, odds ratio 1.65, 95% CI 1.12 to 2.52, P = 0.012). Pooled results from five cohort studies involving 430 patients who underwent coronary angioplasty revealed that MPV was significantly higher in patients who developed restenosis compared with those who did not develop restenosis (mean difference 0.98 fl, 95% CI 0.74 to 1.21, P < 0.001). Conclusions: Elevated MPV is associated with AMI, mortality following MI, and restenosis following coronary angioplasty. These data suggest that MPV is a potentially useful prognostic biomarker in patients with cardiovascular disease. Whether the relationship is causal, and whether MPV should influence practice or guide therapy remains unknown

BACKGROUND: Smoking increases platelet aggregability and the degree of platelet inhibition by clopidogrel on ex vivo platelet function tests. Whether smoking status affects the relationship between clopidogrel and clinical outcomes is unknown. METHODS AND RESULTS: We evaluated the relationship between smoking status (current smoker, former smoker, or never-smoker) and treatment with clopidogrel on the risk of all-cause, cardiovascular, and cancer mortality among the 12 152 participants from the CHARISMA (Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance) trial who had established cardiovascular disease. Current smoking was associated with an increase in all-cause (adjusted hazard ratio [HR] 2.58, 95% confidence interval [CI] 1.85 to 3.60), cardiovascular (HR 2.26, 95% CI 1.48 to 3.45), and cancer (HR 3.56, 95% CI 1.96 to 6.46) mortality compared with never smoking. The impact of clopidogrel on mortality differed by smoking status (P for interaction=0.018 for current smokers). Among current smokers, clopidogrel was associated with a reduction in all-cause mortality (HR 0.68, 95% CI 0.49 to 0.94); clopidogrel did not reduce all-cause mortality among former smokers (HR 0.95, 95% CI 0.75 to 1.19) or never-smokers (HR 1.14, 95% CI 0.83 to 1.58). A similar pattern was noted for cardiovascular mortality. As expected, no relationship was observed between clopidogrel and cancer mortality by smoking status. The risk of bleeding appeared to differ according to smoking status; randomized clopidogrel was associated with a significantly increased risk of severe or moderate bleeding (HR 1.62, P=0.04) among current smokers but a smaller and nonsignificant increase among never-smokers (HR 1.31, P=0.15). CONCLUSIONS: Clopidogrel therapy may be more effective in current smokers, but it may also confer a greater bleeding risk than in nonsmokers. Further studies are needed to investigate this possibility

BACKGROUND: Inhibition of the P2Y12 ADP-receptor with oral antiplatelet agents given to patients undergoing primary percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) is associated with improved outcomes, but this strategy is limited by the time required for maximal antiplatelet effect after administration. We examined the safety and tolerability of a novel, direct-acting, reversible, intravenous P2Y12 ADP-receptor antagonist, elinogrel, versus placebo when administered to STEMI patients before primary PCI. METHODS: The ERASE MI trial was a pilot, phase IIA, randomized, double-blind, placebo-controlled, dose-escalation study designed to evaluate the safety and tolerability of escalating doses (10, 20, 40, and 60 mg) of elinogrel administered as a single intravenous bolus before the start of the diagnostic angiogram preceding primary PCI. Patients were randomly assigned in a 1:1 manner to either elinogrel or placebo within each dosing group; and all patients received a 600-mg clopidogrel loading dose, followed by a second 300-mg clopidogrel loading dose 4 hours after PCI. The major outcome, in-hospital bleeding, was assessed with the Thrombolysis in Myocardial Infarction and Global Strategies to Open Occluded Coronary Arteries bleeding scales. Pre-PCI corrected Thrombolysis in Myocardial Infarction frame count and ST-segment resolution were also evaluated. RESULTS: Seventy patients were randomized in the dose-escalation study, but the dose-confirmation phase was not started because the trial was prematurely terminated for administrative reasons. The incidence of bleeding events was infrequent and appeared to be similar in patients treated with all doses of elinogrel versus placebo. No differences in serious adverse events, laboratory values, corrected Thrombolysis in Myocardial Infarction frame count, or ST resolution were demonstrated between elinogrel and placebo. CONCLUSIONS: With the limitations of a small study sample size, this pilot study provided preliminary data on the feasibility and tolerability of escalating doses of a direct-acting, reversible, intravenous P2Y12 ADP-receptor antagonist, elinogrel, as an adjunctive therapy for primary PCI for STEMI

OBJECTIVES: This study sought to investigate the efficacy and safety of clopidogrel in women and men. BACKGROUND: Previous analyses have shown sex-based differences in response to several antiplatelet medications. Little is known about the efficacy and safety of clopidogrel in women and men. METHODS: This study performed a meta-analysis of all blinded randomized clinical trials comparing clopidogrel and placebo (CURE [Clopidogrel in Unstable Angina to Prevent Recurrent Events], CREDO [Clopidogrel for the Reduction of Events During Observation], CLARITY-TIMI 28 [Clopidogrel as Adjunctive Reperfusion Therapy-Thrombolysis In Myocardial Infarction 28], COMMIT [Clopidogrel and Metoprolol in Myocardial Infarction Trial], and CHARISMA [Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance] trials), involving a total of 79,613 patients, of whom 30% were women. The relative efficacy and safety of clopidogrel at reducing cardiovascular events (cardiovascular death, myocardial infarction [MI], or stroke) in women and men was estimated using random-effects modeling. RESULTS: Overall, clopidogrel was associated with a highly significant 14% proportional reduction in the risk of cardiovascular events (odds ratio [OR]: 0.86; 95% confidence interval [CI]: 0.80 to 0.93), with no significant differences in treatment effect between women and men. Among the 23,533 women enrolled, there were fewer cardiovascular events in the clopidogrel group compared with the placebo group (11.0% vs. 11.8%; OR: 0.93; 95% CI: 0.86 to 1.01). In women the risk reduction with clopidogrel seemed to be greatest for MI (OR: 0.81; 95% CI: 0.70 to 0.93), with the effects on stroke (OR: 0.91; 95% CI: 0.69 to 1.21) or total death (OR: 0.99; 95% CI: 0.90 to 1.08) not statistically significant. Among the 56,091 men enrolled, there were fewer cardiovascular events in those receiving clopidogrel compared with placebo (7.8% vs. 9.0%; OR: 0.84; 95% CI: 0.78 to 0.91), and the risk reduction was significant for MI (OR: 0.83; 95% CI: 0.76 to 0.92), stroke (OR: 0.83; 95% CI: 0.71 to 0.96), and total death (OR: 0.91; 95% CI: 0.84 to 0.97). Clopidogrel increased the risk of major bleeding in both women (OR: 1.43; 95% CI: 1.15 to 1.79) and men (OR: 1.22; 95% CI: 1.05 to 1.42). CONCLUSIONS: Clopidogrel reduces the risk of cardiovascular events in both women and men

BACKGROUND: Although adequate representation of specific subgroups (eg, women and the elderly) in randomized controlled trials (RCTs) has been under intense scrutiny, there are few data on representation by race. METHODS: Using all RCTs cited by the 2007 American Heart Association guidelines for cardiovascular disease prevention in women (although trials were included whether or not there were female participants), we explored the extent to which information on race was reported in the baseline characteristics. Race/ethnicity categories were whites, blacks, Asians, Hispanics, and 'others.' RESULTS: Overall, 156 trials were analyzed. Demographic data on race/ethnicity were reported in 55 (35%) trials and increased significantly over time (1970s, 12.5%; 1980s, 25%; 1990s, 30.5%; 2000s, 46.2%; P for trend = .011). Among the 55 trials reporting any race/ethnicity information, trial inclusion of whites, blacks, Asians, Hispanics, and 'others' was reported in 27%, 13%, 14%, 5%, and 10% of trials, respectively, and increased over time (P for trend < .05 for all). Trials enrolling subjects only in the United States or globally, including the US, were more likely to report race composition than trials that included no US sites (US only 64% vs global 62% vs non-US 21%, P < .01). Industry- and federal/foundation-funded RCTs reported race with similar frequency (industry 36% vs federal 34% vs both 24%, P = .44). When we isolated our analyses to trials that were funded by the National Institutes of Health, 12 (67%) of 18 RCTs reported race/ethnicity as a baseline characteristic. CONCLUSION: Although reporting the race/ethnic composition of study populations is increasing over time, two thirds of all RCTs supporting a recent American Heart Association () guideline failed to publish any information on race. A necessary first requirement in translating RCT evidence to patients of all races is information regarding racial demographics. Such information should be strongly encouraged in future publications