Abstract 11004: Coronary Microvascular Dysfunction and Wall Stress Correlate with Cardiac Troponin T Release Measured by a Highly Sensitive Assay in Patients with Nonischemic Heart Failure
Background: Persistent and modest elevation of serum cardiac troponin T (cTnT) is frequently observed in heart failure (HF) patients without coronary artery disease, although the mechanisms underlying this finding remain unclear. This study investigated factors associated with cTnT release from failing myocardium.
Methods and Results: We evaluated serum cTnT levels in aortic root (Ao) and coronary sinus (CS) using a highly sensitive assay in 62 nonischemic HF patients and 19 non-HF patients. Transcardiac cTnT and plasma B-type natriuretic peptide (BNP) release were described as the differences between CS and Ao cTnT levels [Δ cTnT (CS-Ao)] and BNP levels [Δ BNP (CS-Ao)]. Coronary flow reserve (CFR) was measured in 45 HF patients using an intracoronary Doppler guidewire. The cTnT levels in Ao (Ao-cTnT) were detectable (cTnT >3 ng/L) in 55 HF patients and 11 non-HF patients (89% vs. 58%, P=0.003), and ΔcTnT (CS-Ao) was higher in HF patients (3.5±4.4 ng/L) than in non-HF patients (1.2±0.6 ng/L; P<0.001). Among HF patients, ΔcTnT (CS-Ao) correlated with ΔBNP (CS-Ao) (r=0.295, P=0.03), Ao-cTnT (r=0.440, P=0.001), and left ventricular end-diastolic pressure (LVEDP) (r=0.543, P<0.001). Multivariate regression analysis identified LVEDP and Ao-cTnT level as independent parameters that correlated with ΔcTnT (CS-Ao). Coronary microvascular dysfunction, diagnosed by CFR <2.0, was observed in 14 HF patients (31%). ΔcTnT (CS-Ao) was higher in patients with coronary microvascular dysfunction (6.7±7.5 ng/L) than in those without (2.2±1.8 ng/L; P=0.047).
Conclusions: The cTnT release from failing myocardium correlated with wall stress and coronary microvascular dysfunction in nonischemic HF patients.
- © 2012 by American Heart Association, Inc.