Detection of myocardial injury by CMR after transcatheter aortic valve replacement

Abstract

Background: Myocardial injury after transcatheter aortic valve replacement (TAVR) is common, but its cause and relationship to the extent of myocardial tissue loss remain unclear.

Objectives: This study sought to examine the incidence and degree of ischemic myocardial damage using cardiac magnetic resonance imaging and myocardial biomarkers in patients undergoing TAVR.

Methods: Patients with severe aortic stenosis (n = 61) underwent cardiac magnetic resonance imaging before and after TAVR for the assessment of new myocardial injury. High-sensitivity cardiac troponin T and creatine kinase-myocardial band were measured before and at 24, 48, and 72 h after TAVR.

Results: After TAVR, new myocardial late enhancement (LE) with an ischemic pattern occurred in 11 patients (18%), with a mean mass of 3.7 g (interquartile range: 1.2 to 6 g) or 1.8% (interquartile range: 1.3% to 4.1%) of the left ventricular mass. Patients with new LE had a decreased left ventricular function (ejection fraction: pre, 55.5 ± 14.1% vs. post, 45.3 ± 14.9%; p = 0.001). In patients without new LE, no differences were observed (ejection fraction: pre, 53.9 ± 17.3% vs. post, 54.6 ± 16.3%; p = NS) after TAVR.

Conclusions: New ischemic-type myocardial LE after TAVR can be observed in a notable proportion of patients and is assumed to be of embolic origin. Patients with new LE feature a significant decrease in left ventricular function at discharge.

Keywords: TAVR; embolism; magnetic resonance imaging; myocardial infarction.