Coronary Microvascular Dysfunction and Diastolic Load Correlate with Cardiac Troponin T Release Measured by a Highly Sensitive Assay in Patients with Nonischemic Heart Failure.
J Am Coll Cardiol. 2013 May 1;
Authors: Takashio S, Yamamuro M, Izumiya Y, Sugiyama S, Kojima S, Yamamoto E, Tsujita K, Tanaka T, Tayama S, Kaikita K, Hokimoto S, Ogawa H
OBJECTIVE: This study investigated factors associated with cardiac troponin T (cTnT) release from failing myocardium. BACKGROUND: Persistent and modest elevation of serum cTnT is frequently observed in heart failure (HF) patients free of coronary artery disease, although the mechanisms underlying this finding remain unclear. METHODS: We evaluated serum cTnT levels in aortic root (Ao) and coronary sinus (CS) using a highly sensitive assay in 90 nonischemic HF patients and 47 non-HF patients. Transcardiac cTnT and plasma B-type natriuretic peptide (BNP) release were described as the differences between CS and Ao cTnT levels [ΔcTnT (CS-Ao)] and BNP levels [ΔBNP (CS-Ao)], respectively. Coronary flow reserve (CFR) was measured in 68 HF patients using an intracoronary Doppler guidewire. RESULTS: ΔcTnT (CS-Ao) levels were available in 76 HF patients and 28 non-HF patients (84% vs. 60%; P=0.001), and higher in HF patients than non-HF patients (P<0.001). Among HF patients, log [ΔcTnT (CS-Ao)] correlated with log [ΔBNP (CS-Ao)] (r=0.368, P=0.001), pulmonary capillary wedge pressure (r=0.253, P=0.03) and left ventricular end-diastolic pressure (LVEDP) (r=0.321, P=0.005). Multivariate regression analysis identified LVEDP as an independent parameter that correlated with ΔcTnT (CS-Ao). ΔcTnT (CS-Ao) levels were available in 58 HF patients who were evaluated for CFR. Coronary microvascular dysfunction, diagnosed by CFR <2.0, was observed in 18 HF patients. ΔcTnT (CS-Ao) was higher in patients with coronary microvascular dysfunction [4.8 (2.0-8.1) ng/L] than those without [2.0 (1.2-4.6) ng/L; P=0.04]. CONCLUSIONS: cTnT release from failing myocardium correlated with diastolic load and coronary microvascular dysfunction in nonischemic HF patients.
PMID: 23644085 [PubMed - as supplied by publisher]