Right ventricular dysfunction and its improvement after GDMT in new-onset dilated cardiomyopathy

Background Right ventricular dysfunction (RVD) is frequently observed in dilated cardiomyopathy (DCM) patients, which is a well-established independent risk factor for adverse outcomes. However, data on the impact of guideline-directed medical therapy (GDMT) on RVD remain scarce. Purpose This study aimed to evaluate the effect of GDMT on right ventricular (RV) function and to explore the relationship between left ventricular (LV) and RV functional improvements in patients with new-onset DCM. Methods 185 patients (aged 49±14 years, 69.7% males) with new-onset DCM (defined as had symptoms or received GDMT <6 months) were prospectively enrolled who had completed 6-month follow up. RVD was defined as RV fractional area change (FAC) <35% or absolute RV free wall longitudinal strain (FWLS) <20%, while RV FAC ≥35% and RV FWLS ≥20%. Left ventricular (LV) recovery was defined 6-month follow-up LVEF ≥45%. Results RVD was observed in 104 (56.2%) patients at baseline including low FAC in 75 and low FWLS in 100. After 6 months of GDMT, RV function significantly improved in FAC (36.5±10.3 vs. 38.9±8.9% and FWLS (18.9±5.8 vs. 21.6±4.8%) (both P<0.001). RVD remained in 59 patients and newly developed in 19 at 6 months (42.2%). RVD recovery was observed in 45 (43.3%) patients. LV recovery was demonstrated in 78 (42.2%). Despite a baseline difference in the LVEDD (P=0.001) and the LVEF (P<0.001) between the baseline RVD (+) and RVD (-) groups, they both showed a significant LVEDD reduction (67±7 vs. 59±7mm; 64±6 vs. 58±8mm, both P<0.001) and LVEF increase (27±8% vs. 44±10%, 34±8 vs. 43±10%, both P<0.001) at 6 months, while the rate of LV recovery (53 vs. 54%, P=0.846). Between the 6-month RVD (+) and RVD (-) groups, although they were different in the baseline LVEF (28±9 vs. 31±9%, P=0.008), the rate of LV recovery was similar (50 vs. 56%, P=0.413). On the other hand, between the patient group of LV recovery (+) and LV recovery (-), the remaining RVD at 6 months was not different (46 vs. 41%, P=0.634). A significant but weak positive correlation was displayed between ΔLVEF and ΔFAC (r=0.199, P=0.007) or ΔFWLS (r=0.234, P=0.001) (Figure 1). Conclusion RVD was prevalent in patients with new-onset DCM that could be corrected by GDMT. Although baseline RVD was associated with more severe LV impairment, the RV function after GDMT improved with LVEF recovery.