Faculty Bibliography

BACKGROUND: The Universal Definition of Myocardial Infarction recommends the 99th percentile concentration of cardiac troponin in a normal reference population as part of the decision threshold to diagnose type 1 spontaneous myocardial infarction. Adoption of this recommendation in contemporary worldwide practice is not well known. METHODS: We performed a cohort study of 276 hospital laboratories in 31 countries participating in the National Heart, Lung, and Blood Institute-sponsored International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial. Each hospital laboratory's troponin assay manufacturer and model, the recommended assay's 99th percentile upper reference limit (URL) from the manufacturer's package insert, and the troponin concentration used locally as the decision level to diagnose myocardial infarction were ascertained. RESULTS: Twenty-one unique troponin assays from 9 manufacturers were used by the surveyed hospital laboratories. The ratio of the troponin concentration used locally to diagnose myocardial infarction to the assay manufacturer-determined 99th percentile URL was <1 at 19 (6.6%) laboratories, equal to 1 at 91 (31.6%) laboratories, >1 to 5 to 10 at 43 (14.9%) laboratories. The variability in troponin decision level for myocardial infarction relative to the assay 99th percentile URL was present for laboratories in and outside of the United States, as well as for high- and standard-sensitivity assays. CONCLUSIONS: There is substantial hospital-level variation in the troponin threshold used to diagnose myocardial infarction; only one-third of hospital laboratories currently follow the Universal Definition of Myocardial Infarction consensus recommendation for use of troponin concentration at the 99th percentile of a normal reference population as the decision level to diagnose myocardial infarction. This variability across laboratories has important implications for both the diagnosis of myocardial infarction in clinical practice as well as adjudication of myocardial infarction in clinical trials.

Longstanding hypertension ultimately leads to heart failure (HF), and as a consequence most patients with HF have a history of hypertension. Conversely, absence of hypertension in middle age is associated with lower risks for incident HF across the remaining life course. Cardiac remodeling to a predominant pressure overload consists of diastolic dysfunction and concentric left ventricular (LV) hypertrophy. When pressure overload is sustained, diastolic dysfunction progresses, filling of the concentric remodeled LV decreases, and HF with preserved ejection fraction ensues. Diastolic dysfunction and HF with preserved ejection fraction are the most common cardiac complications of hypertension. The end stage of hypertensive heart disease results from pressure and volume overload and consists of dilated cardiomyopathy with both diastolic dysfunction and reduced ejection fraction. "Decapitated hypertension" is a term used to describe the decrease in blood pressure resulting from reduced pump function in HF. Progressive renal failure, another complication of longstanding hypertension, gives rise to the cardiorenal syndrome (HF and renal failure). The so-called Pickering syndrome, a clinical entity consisting of flash pulmonary edema and bilateral atheromatous renovascular disease, is a special form of the cardiorenal syndrome. Revascularization of renal arteries is the treatment of choice. Most antihypertensive drug classes when used as initial therapy decelerate the transition from hypertension to HF, although not all of them are equally efficacious. Low-dose, once daily hydrochlorothiazide should be avoided, but long-acting thiazide-like diuretics chlorthalidone and indapamide seem to have an edge over other antihypertensive drugs in preventing HF.

This retrospective cohort study compared blood pressure (BP) control (BP <140/90 mm Hg) and all-cause mortality between US- and foreign-born blacks. We used data from a clinical data warehouse of 41 868 patients with hypertension who received care in a New York City public healthcare system between 2004 and 2009, defining BP control as the last recorded BP measurement and mean BP control. Poisson regression demonstrated that Caribbean-born blacks had lower BP control for the last BP measurement compared with US- and West African-born blacks, respectively (49% vs 54% and 57%; P<.001). This pattern was similar for mean BP control. Caribbean- and West African-born blacks showed reduced hazard ratios of mortality (0.46 [95% CI, 0.42-0.50] and 0.28 [95% CI, 0.18-0.41], respectively) compared with US-born blacks, even after adjustment for BP. BP control rates and mortality were heterogeneous in this sample. Caribbean-born blacks showed worse control than US-born blacks. However, US-born blacks experienced increased hazard of mortality. This suggests the need to account for the variations within blacks in hypertension management.

BACKGROUND: The recent AHA/ACC guidelines on duration of dual anti-platelet therapy (DAPT) recommend DAPT for 1 year in patients presenting with an acute coronary syndrome, with a Class IIb recommendation for continuation. We aim to assess the evidence for these recommendations using a meta-analytic approach. METHODS: We searched electronic databases for randomized trials comparing short-term (12 months) DAPT in patients with an acute coronary syndrome undergoing percutaneous coronary intervention. We evaluated all-cause mortality, cardiovascular mortality, myocardial infarction, stent thrombosis and major bleeding. A random effects model was used to calculate pooled relative risk (RR) and 95% confidence intervals (CI). RESULTS: We included 8 trials comprising of 12,917 patients with an acute coronry syndrome; 5 trials compared short-term vs 12 months/extended DAPT, whereas 3 trials compared 12 months vs extended DAPT. There was no significant difference in cardiovascular mortality (RR: 1.04, 95% CI: 0.67-1.60), MI (RR: 1.08, 95% CI: 0.79-1.47) or major bleeding (RR: 0.91, 95% CI: 0.49-1.69) between short-term versus 12 months/extended DAPT. However, compared to extended DAPT, 12 months DAPT showed significantly higher risk of myocardial infarction (RR: 2.00, 95% CI: 1.47-2.73) but reduced risk of major bleeding (RR: 0.58, 95% CI: 0.34-0.98). All-cause mortality was found to be similar between 12 months vs extended DAPT. CONCLUSIONS: In acute coronary syndrome, short-term DAPT may be reasonable for some patients whereas extended DAPT may be appropriate in select others. An individualized approach is needed taking into account the competing risks of bleeding and ischemic events.

Background: The recent AHA/ACC guidelines on duration of dual anti-platelet therapy (DAPT) recommends DAPT for 1 year in patients presenting with acute coronary syndrome (ACS) and undergoing percutaneous coronary intervention (PCI), with a Class IIb recommendation for continuation. Methods: We searched electronic databases to identify randomized trials comparing short-term (<=6 months) vs 12 months vs extended (>12 months) DAPT in patients with ACS undergoing PCI. We evaluated allcause and cardiovascular mortality, myocardial infarction (MI), stent thrombosis and major bleeding. Random effects modeling was used to calculate pooled relative risk (RR) and 95% confidence intervals (CI). Results: We included 8 trials comprising of 12,917 ACS patients; 5 trials compared short-term vs 12 months or extended DAPT, whereas 3 trials compared 12 months vs extended DAPT. There were no significant differences in either ischemic or bleeding outcomes between short-term vs 12 months or extended DAPT. However compared to extended DAPT, 12 months DAPT showed significantly higher risk of MI (RR 2.00, 95% CI: 1.47 to 2.73, p<0.001) but reduced risk of major bleeding (RR 0.58, 95% CI: 0.34 to 0.98, p=0.04). All-cause mortality was similar between 12 months vs extended DAPT. The heterogeneity was low to moderate (I2 ranged from 17% to 39%). Conclusion: In ACS, DAPT beyond 1 year should be based on an individualized patient approach taking into account the competing risks of bleeding and ischemic complications. (Table Presented)

Background: Acute myocardial infarction (AMI) is a significant cardiovascular complication following non-cardiac surgery. We evaluated national trends in perioperative AMI, management, and outcomes using a large administrative database of United States hospital admissions. Methods: Patients who underwent non-cardiac surgery from 2005 to 2013 were identified using the National Inpatient Sample. Perioperative AMI was evaluated over time. Propensity score matching was used to compile cohorts of patients with perioperative AMI matched on their baseline characteristics who were managed invasively (defined as cardiac catheterization, percutaneous coronary intervention [PCI], or coronary artery bypass graft surgery [CABG]) versus conservatively. The primary outcome was in-hospital all-cause mortality. Results: Among 9,566,277 hospitalizations for major non-cardiac surgery, perioperative AMI occurred in 84,093 (0.88%). Over time, the rate of perioperative AMI per 100,000 surgeries declined by 170 (95% CI 158 - 181), from 898 in 2005 to 729 in 2013 (p for trend <0.0001). Perioperative AMI occurred most frequently in patients undergoing vascular (2.0%), transplant (1.6%), and thoracic (1.5%) surgery. In-hospital mortality was higher in patients with perioperative AMI than those without AMI (18.0% vs. 1.5%, p<0.0001; adjusted OR 5.76, 95% CI 5.65 - 5.88). Mortality associated with perioperative AMI declined over time (adjusted OR 0.86, 95% CI 0.84 - 0.88). In a propensity-matched cohort of 34,650 patients with perioperative AMI, invasive management was associated with lower mortality than conservative management (8.9% vs. 18.1%, p<0.001; OR 0.44, 95% CI 0.41-0.47). Conclusion: Perioperative AMI occurs in 0.9% of patients undergoing major non-cardiac surgery and is strongly associated with in-hospital mortality. Invasive management of such patients may mitigate some of this excess risk