Gadolinium cardiovascular magnetic resonance predicts reversible myocardial dysfunction and remodeling in patients with heart failure undergoing β-blocker therapy

Background - In some patients with heart failure, beta-blockers can improve left ventricular (LV) function and reduce morbidity and mortality. We hypothesized that gadolinium-enhanced cardiovascular magnetic resonance imaging (CMR) can predict reversible myocardial dysfunction and remodeling in heart failure patients treated with beta-blockers. Methods and Results - Forty-five patients with chronic heart failure underwent CMR. Contrast imaging using gadolinium was performed to obtain high-resolution spatial maps of myocardial scarring and viability. Cine imaging was performed to assess LV function and morphology and was repeated in 35 patients after 6 months of beta-blockade. Gadolinium CMR demonstrated scarring in 30 of 45 patients (67%). Scarring was found in 100% of patients with ischemic cardiomyopathy ( 28 of 28) but in only 12% with nonischemic cardiomyopathy ( 2 of 17). In the 35 patients who were maintained on beta-blockers and had a second study, there was an inverse relation between the extent of scarring at baseline and the likelihood of contractile improvement 6 months later ( P < 0.001). For instance, contractility improved in 56% ( 674 of 1207) of regions with no scarring but in only 3% with > 75% scarring ( 8 of 232). Multivariate analysis showed that the amount of dysfunctional but viable myocardium by CMR was an independent predictor of the change in ejection fraction ( P = 0.01), mean wall motion score ( P = 0.0007), LV end-diastolic volume index ( P = 0.007), and LV end-systolic volume index ( P less than or equal to 0.0001). Conclusions - For heart failure patients treated with beta-blockers, gadolinium-enhanced CMR predicts the response in LV function and remodeling.