Relevance of subclinical right ventricular dysfunction measured by feature-tracking cardiac magnetic resonance in non-ischemic dilated cardiomyopathy.

Background: Right ventricular (RV) dysfunction in patients with non-ischemic dilated cardiomyopathy (NICM) is associated with cardiovascular events. To analyze the feasibility of assessing RV myocardial deformation by feature tracking (FT)-cardiac magnetic resonance (CMR), and its usefulness as a prognostic marker.

Methods: Retrospective study of NICM patients undergoing CMR. Longitudinal FT-RV free wall (LFT-RVFW) and fractional area change (FAC) were obtained. Correlation with standard RV parameters was studied. An association with combined event (heart failure (HF), ICD implantation or cardiovascular death) was assessed using a logistic regression model.

Results: 98 patients (64 ± 13 years) were included. Left ventricular (LV) systolic function (LVEF 29.5 ± 9.6%, 47% with LVEF ≥ 30%) and RV (RVEF 52.2 ± 14.6%, 72% with RVEF ≥ 45%). Follow-up of 38 ± 17 months, 26.5% presented at least one admission for HF. An excellent correlation of LFT-RVFW (r = 0.82) and FAC (r = 0.83) with RVEF was evident. No association of RV-FT parameters with prognosis entire study population was found. However, in patients with LVEF ≥ 30%, admissions for HF were associated with lower LFT-RVFW (-21.6 ± 6.6% vs -31.3 ± 10%; p = 0.006) and FAC (36.6 ± 9.6% vs 50.5 ± 13.4%; p < 0.001) values. Similar differences were observed when only patients with RVEF ≥ 45% were considered. An LFT-RVFW cut-off point of -19.5% and FAC of 36.5% showed good prognostic performance. Decreased LFT-RVFW or FAC represented an independent predictor of combined event in patients with LVEF ≥ 30%.

Conclusions: In NICM patients without severe LV dysfunction, decreased values of LFT-RVFW and/or FAC were associated with HF admissions, independently of RVEF.