Overuse of Troponin? A Comprehensive Evaluation of Testing in a Large Hospital System.

Troponin assays are integral to the diagnosis of acute myocardial infarction (AMI), but there is concern that testing is over utilized and may not conform to published guidelines. We reviewed all testing performed at 14 hospitals over 12 months and associated troponin values with the primary and secondary diagnoses for each visit. Troponin was determined to be negative, indeterminate or elevated based on reference ranges. The majority of troponin measurements were single, not serial (64%). The rate of AMI was low, with only 3.5% of tested patients having a primary or secondary diagnosis of AMI. Sensitivity, specificity and negative predictive value were excellent, exceeding 90%. However, positive predictive value was low, suggesting testing of populations with diseases known to be associated with elevated troponin levels in the absence of AMI. The majority (79%) of elevated troponin values were associated with primary diagnoses other than AMI. Only 28% of elevated troponins were associated with a primary or secondary diagnosis of AMI. These data suggest possible overuse of troponin testing in our healthcare system. Journal of Hospital Medicine 2017;12:329-331.

Lifelong Physical Activity Regardless of Dose Is Not Associated With Myocardial Fibrosis.

BACKGROUND: Recent reports have suggested that long-term, intensive physical training may be associated with adverse cardiovascular effects, including the development of myocardial fibrosis. However, the dose-response association of different levels of lifelong physical activity on myocardial fibrosis has not been evaluated. METHODS AND RESULTS: Seniors free of major chronic illnesses were recruited from predefined populations based on the consistent documentation of stable physical activity over >25 years and were classified into 4 groups by the number of sessions/week of aerobic activities ≥30 minutes: sedentary (group 1), <2 sessions; casual (group 2), 2 to 3 sessions; committed (group 3), 4 to 5 sessions; and Masters athletes (group 4), 6 to 7 sessions plus regular competitions. All subjects underwent cardiopulmonary exercise testing and cardiac magnetic resonance imaging, including late gadolinium enhancement assessment of fibrosis. Ninety-two subjects (mean age 69 years, 27% women) were enrolled. No significant differences in age or sex were seen between groups. Median peak oxygen uptake was 25, 26, 32, and 40 mL/kg/min for groups 1, 2, 3, and 4, respectively. Cardiac magnetic resonance imaging demonstrated increasing left ventricular end-diastolic volumes, end-systolic volumes, stroke volumes, and masses with increasing doses of lifelong physical activity. One subject in group 2 had late gadolinium enhancement in a noncoronary distribution, and no subjects in groups 3 and 4 had evidence of late gadolinium enhancement. CONCLUSIONS: A lifelong history of consistent physical activity, regardless of dose ranging from sedentary to competitive marathon running, was not associated with the development of focal myocardial fibrosis.

Cardiovascular effects of 1 year of alagebrium and endurance exercise training in healthy older individuals.

BACKGROUND: Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. However, it is unclear whether a strategy of exercise combined with alagebrium would improve LV stiffness in sedentary older humans. METHODS AND RESULTS: Sixty-two healthy subjects were randomized into 4 groups: sedentary+placebo; sedentary+alagebrium (200 mg/d); exercise+placebo; and exercise+alagebrium. Subjects underwent right heart catheterization to define LV pressure-volume curves; secondary functional outcomes included cardiopulmonary exercise testing and arterial compliance. A total of 57 of 62 subjects (67 ± 6 years; 37 f/20 m) completed 1 year of intervention followed by repeat measurements. Pulmonary capillary wedge pressure and LV end-diastolic volume were measured at baseline, during decreased and increased cardiac filling. LV stiffness was assessed by the slope of LV pressure-volume curve. After intervention, LV mass and end-diastolic volume increased and exercise capacity improved (by ≈8%) only in the exercise groups. Neither LV mass nor exercise capacity was affected by alagebrium. Exercise training had little impact on LV stiffness (training × time effect, P=0.46), whereas alagebrium showed a modest improvement in LV stiffness compared with placebo (medication × time effect, P=0.04). CONCLUSIONS: Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening. CLINICAL TRIAL REGISTRATION- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01014572.