Faculty Bibliography

BACKGROUND: The benefit of carotid endarterectomy (CEA) in female patients has been questioned by various randomized, prospective trials, particularly in asymptomatic cases; several have noted an increase in perioperative stroke among women after CEA. The outcome of carotid angioplasty and stenting (CAS) has not been extensively examined in women. This study examined the outcome of CEA and CAS in women vs men by using a national database. METHODS: Outcomes of CEA and CAS were stratified by sex using discharge data from the Nationwide Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality. The NIS was used to identify patient discharges that occurred during 2004 and 2005. Appropriate International Classification of Diseases, 9th Revision (ICD-9) procedure and diagnosis codes were used to identify CEA and CAS cases. Outcome measures included in-hospital perioperative stroke and death. Comparisons of demographics, procedures, and outcome were performed between men and women. Additional analysis was performed among women alone to attempt to identify whether improved outcome was noted with either procedure. RESULTS: Of 54,658 procedures, 94.2% were CEA and 5.8% were CAS. Women comprised 42.3% of the analyzed cases. Women and men were equally likely to be symptomatic (5.3% vs 5.3%, P = .8). Women were significantly less likely to undergo CAS than men (5.4% vs 6.1%, P < .001). Women and men had equivalent rates of perioperative stroke when undergoing CEA (1.0% vs 1.0%, P = .9) and CAS (2.7% vs 2.0%, P = .2). Symptomatic women had a significantly higher rate of perioperative stroke overall than did symptomatic men (3.8% vs 2.3%, P = .03). Asymptomatic women had a significantly lower perioperative stroke rate after CEA than after CAS (0.9% vs 2.1%, P < .001). Rates of perioperative showed a trend favoring CEA vs CAS among symptomatic women (3.4% vs 6.2%, P = .1). CONCLUSIONS: The concern regarding an increased perioperative stroke rate after CEA among asymptomatic women appears to be unfounded. The perioperative stroke rate among symptomatic women was higher than that of symptomatic men, but still well within the acceptable range for symptomatic patients undergoing a cerebrovascular intervention. Nationally, women underwent CAS significantly less frequently than did men. Outcome among women for perioperative stroke favored CEA over CAS, particularly in asymptomatic patients. CEA may be the preferred treatment in women seeking intervention for cerebrovascular disease, unless compelling reasons exist to perform CAS

OBJECTIVE: Subjects with peripheral artery disease (PAD) are at increased risk of cardiovascular morbidity and mortality, perhaps in part, related to increased levels of inflammation, platelet activity, and lipids. We therefore sought to investigate the relationship between PAD and levels of inflammatory, platelet, and lipid biomarkers and the treatment effect of darapladib, a novel lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) inhibitor. METHODS: This is a post hoc analysis of the 959 patients with coronary disease or their risk equivalent receiving atorvastatin who were randomized to receive darapladib or placebo to examine the effects of an Lp-PLA(2) inhibitor on the biomarkers of cardiovascular risk. We conducted an exploratory analysis evaluating the levels of biomarkers in subjects with PAD (n = 172) compared with those without PAD (n = 787). RESULTS: After adjustment for age, sex, smoking, body mass index, and diabetes, subjects with PAD had greater levels of matrix metalloproteinase-9 (between group comparisons 22%, 95% confidence interval [10-31], P < .01), myeloperoxidase (12% [2-20], P = .01), interleukin-6 (13% [4-21], P = .01), adiponectin (17% [7-26], P < .01), intercellular adhesion molecule-1 (7% [2-11], P < .01), osteoprotegrin (6% [1-10], P = .02), CD40 ligand (15% [1-28], P = .04), high-sensitivity C-reactive protein (17% [1-31], P = .04), and triglycerides (11% [0.2-21], P = .05). No significant difference was detected for Lp-PLA(2) activity, P-selectin, urinary 11-dehydrothroboxane B2, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol between subjects with and without PAD. Darapladib produced highly significant inhibition of Lp-PLA(2) activity when compared with placebo at weeks 4 and 12 (P < .01) in patients with and without PAD. CONCLUSIONS: Subjects with PAD had elevated levels of matrix metalloproteinase-9, myeloperoxidase, interleukin-6, adiponectin, intercellular adhesion molecule-1, osteoprotegrin, CD40 ligand, high-sensitivity C-reactive protein, and triglycerides compared with those without PAD. Darapladib, a novel Lp-PLA(2) inhibitor, was equally effective in reducing Lp-PLA(2) activity levels in subjects with and without PAD

Background: Prasugrel is effective at decreasing cardiovascular events compared to clopidogrel, but increases the risk of bleeding. In 2010, the FDA issued a black box warning to consider genetic testing in clopidogrel users. Our aims were to evaluate (1) the balance of potential benefits and harms and (2) the cost-effectiveness that would result from adopting a genotype-guided strategy of dual anti-platelet therapy following PCI for ACS vs. no testing strategies of prasugrel plus aspirin (prasugrel) or clopidogrel plus aspirin (clopidogrel). Methods: A Markov state transition model was used to conduct a decision analysis and compare strategies. Probabilities of adverse outcomes were derived from TRITON-TIMI 38 trial. Event rates on clopidogrel for carriers of CYP2C19*2 vs. wild-type were derived from the TRITON genetic substudy and a recent meta-analysis. Costs are expressed in January 2011 US dollars and estimated based on Medicare reimbursements for diagnosis-related group codes. Medication costs were used from the net wholesale price for prasugrel ($5.45/d) and a generic estimate for clopidogrel ($1/d). Results: In base case analyses, the genetic testing guided strategy yielded more benefits than harms, and was less costly compared to both 'no testing' strategies. Over 15 months, total costs were $83.8 ($1200.9 at 10 yrs) lower with a gain of 0.0007 QALY (0.0216 QALY at 10 yrs) in the genotype-guided strategy compared to prasugrel. Compared to clopidogrel, it was $0.38 ($2168.8 at 10 yrs) lower with a gain of 0.0036 QALY (0.112 QALY at 10 yrs). The strongest predictor of the preferred strategy was the relative risk (RR) of a thrombotic event occurring in CYP2C19*2 carriers versus wild-type. Below a RR of 1.5, a genotype-guided strategy is no longer more effective (but is less expensive) when compared to prasugrel. Compared to clopidogrel, below a RR of 1.3 a genotype-guided strategy is no longer cost effective (>$100,000/QALY). Clopidogrel costs ($1-$4/d) did not alter our results. Conclusions: Among ACS patients undergoing PCI, a genotype-guided strategy is economically favorable in determining which anti-platelet regimen is used, assuming that the risk of thrombotic events in CYP2C19*2 carriers is approximately 30-50% higher than wild type patients

PURPOSE: Acetylsalicylic acid (ASA) dosing guidelines for ACS treatment are inconsistent and lack supporting data. This analysis evaluated the relationship between ASA maintenance dosing and clinical outcomes in patients with ACS who did not undergo revascularization and are managed medically. METHODS: A meta-analysis was conducted with random-effects modeling to estimate the frequency of clinical outcomes for low (75-149 mg) and high (150-325 mg) doses of ASA, using data from worldwide clinical and observational trials published from Jan 1995 to Feb 2010, available from PubMed, EMBASE and Current Contents. Clinical outcomes measured were: revascularization rate (overall rate, percutaneous coronary intervention [PCI] or coronary artery bypass graft [CABG]), cardiovascular (CV) death, all-cause death, myocardial infarction (MI), stroke, and bleeding at 1, 3, 6 and 12 months. RESULTS: Sixty-eight studies including 207,523 patients were accepted and appraised for quality using Oxford Centre for Evidence- Based Medicine scoring. Significant heterogeneity was seen in the results (quantified using the Cochran's Q statistics and the I² measures), due to differences in enrolment procedures, medical management regimens and timing of administration, study designs and some inconsistencies in the definitions of bleeding and MACE. At one month, the incidence of clinical outcomes with high- and low-dose ASA groups were 4.9% and 5.0% for MI; 6.3% and 3.7% for revascularization; 1.4% and 1.3% for stroke; 5.5% and 3.4% for CV death; 5.7% and 4.3% for all cause death; and 4.0% and 1.7% for major bleeding, respectively. Meta regression demonstrated a significant association between aspirin dose and major bleeding (p=0.037). Further data will be presented at the meeting. CONCLUSIONS: This analysis suggests that in patients receiving medical management for ACS, major bleeding occurred more frequently in patients who received higher doses of ASA. ASA dose does not have a statistically significant impact on the other outcomes analyzed

OBJECTIVES: We sought to determine whether mean platelet volume (MPV) is associated with the prevalence of peripheral artery disease (PAD). BACKGROUND: Platelets play a pivotal role in the pathogenesis of atherosclerosis and PAD. MPV, a measure of platelet size available in every blood count, is increasingly recognized as an important marker of platelet activity. METHODS: We analyzed data from 6354 participants aged 40 years and older from the 1999 to 2004 National Health and Nutrition Examination Survey (NHANES), a nationally representative sample of the US population. PAD was defined as an ankle brachial index </=0.90 in either leg. Odds ratios and 95% confidence intervals were estimated by logistic regression. RESULTS: The prevalence of PAD in the cohort was 5.7%. MPV was significantly associated with PAD prevalence (tertile 1 - 4.4%, tertile 2 - 6.1%, tertile 3 - 7.0%, P for trend=0.003). After adjustment for age, sex, and race, the odds ratio of PAD comparing the highest tertile to the lowest tertile was 1.57 (95% confidence interval 1.15-2.13). After further adjustment for smoking status, hypertension, hypercholesterolemia, diabetes, glomerular filtration rate, body mass index, and platelet count the corresponding odds ratio was 1.58 (95% confidence interval 1.14-2.19). The addition of triglycerides, hemoglobin A1c, and C-reactive protein did not affect the results. The significant association between MPV and PAD was unchanged when MPV was used as a continuous variable. CONCLUSIONS: Mean platelet volume is independently associated with PAD. These findings support the hypothesis that platelet size is an independent predictor of increased risk for PAD