Elevated High-Sensitivity Troponin T in Afib May Not Increase Coronary Event Risk
Although afib with dynamic hsTnT elevations but no known CAD does not present a higher risk for coronary events, patients do have a higher risk for all-cause mortality.
Elevated high-sensitivity troponin T (hsTnT) levels may not be associated with a major increased risk for coronary events in patients with atrial fibrillation (AF) but without coronary artery disease (CAD), according to study results published in BMC Cardiovascular Disorders.
Researchers from Lund University and Skåne University Hospital in Sweden analyzed patients who presented with AF but no known CAD to determine whether they were at an increased risk for cardiac events. The primary end point was acute coronary syndrome, revascularization, or death due to ischemic heart disease during follow-up.
A total of 522 patients were eligible for inclusion. At the beginning of the study, 300 patients (57%) had normal hsTnT and 49 (9.5%) had dynamic hsTnT elevations. During the course of a 12-month follow-up, 12 patients (4%) with normal hsTnT experienced the primary end point and 14 patients (4.7%) died. Of the patients with dynamic elevations, 4 (8.2%) experienced the primary end point and 12 (25%) died.
In addition, the age-adjusted hazard ratio (HR) for the primary end point in patients with dynamic hsTnT compared with patients with normal hsTnT was 1.9 (95% CI, 0.6-6.2; P =.28) and 3.8 for all-cause mortality (95% CI, 1.7-8.5; P =.001).
While patients with dynamic troponin elevations who have AF but not CAD do not have a significant increased risk for acute coronary syndrome, revascularization, or death due to ischemic heart disease, these patients do have an increased risk for all-cause mortality.
“Since the reason for dynamic troponin elevations in AF patients with [rapid ventricular response] still remains unknown it is hard to suggest a strategy [for] how to improve the prognosis for these patients,” the researchers wrote. “However, our results imply that it is unlikely that coronary events or death due to ischemic heart disease fully account for the observed adverse prognosis and that further evaluation regarding CAD may not be worthwhile in all these patients.”
The researchers noted several limitations to their study, including: nongeneralizable results because the study was conducted in only 2 Swedish university hospitals; the presence of CAD cannot be entirely excluded because not all patients were tested; calibration problems with the Elecsys Troponin T high sensitivity assay; and the inability to adjust for potential confounders because of the low number of primary end points.
Thelin J, Melander O. Dynamic high-sensitive troponin elevations in atrial fibrillation patients might not be associated with significant coronary artery disease [published online June 27, 2017]. BMC Cardiovasc Disord. doi:10.1186/s12872-017-0601-7