Troponins May be Prognostic in Nonobstructive CAD Regardless
Get authentic, real-time news that helps you fight COVID-19 better.
Install PlexusMD App for doctors. It's free.
The retrospective study involved 474 patients with suspected CAD and no coronary stenosis of 50% or greater assessed at the First Affiliated Hospital of Harbin Medical University, China, from 2011 to 2017. The patients, with a median age of 57 years, 61% of whom were women, were followed for the composite of CV death or nonfatal MI. Patients with previous MI or coronary revascularization, any cardiomyopathy, obstructive coronary disease on imaging, or a left ventricular ejection fraction below 50% were excluded. The hs-cTnl assays had a 0.001 ng/mL lower limit of detection. Patients underwent pharmacologic stress MCE with adenosine triphosphate (ATP) disodium as the stressor; measurements included replenishment velocity and myocardial blood flow and myocardial blood-flow reserve (MBFR).

Of 474 patients, 214 (45.1%) had hs-cTnl concentrations greater than the assay's limit of detection. A total of 420 patients completed the follow-up, which lasted a median of 41 months, and 12 developed endpoint events (10 CV deaths and two nonfatal MIs). Patients with hs-cTnl levels of at least 0.007 ng/mL were significantly older (P < .05) and more likely to have atrial fibrillation (P < .001) and lower MBFR (P < .001) that those with undetectable levels. Detectable hs-cTnI levels were associated with reduced MBFR after covariate adjustment (odds ratio, 0.20; P = .039) and, independent of MBFR, with events in the composite endpoint (adjusted hazard ratio [HR], 8.93; P = .028). Higher hs-cTnl levels were associated with greater risk for new endpoint events (adjusted HR, 13.4; P < .001).