Aims: Right ventricular (RV) dysfunction is a marker of poor prognosis in heart failure (HF) patients. It is still unclear whether RV function might influence response to cardiac resynchronization therapy (CRT).
Methods: Forty-four consecutive patients with HF, large QRS, and either intraventricular or interventricular dyssynchrony underwent echocardiographic evaluation before, 1 month after, and 6 months after CRT. Response to CRT was considered in case of significant LV reverse remodeling, defined as the occurrence of LV end-systolic volume (LVESV) reduction > or =15% at 6 months.
Results: All echocardiographic indexes of baseline RV function and dimensions were significantly more impaired in nonresponders versus responders to CRT: tricuspid annular plane systolic excursion (TAPSE 15 +/- 4 mm vs 20 +/- 5 mm, P = 0.001), RV systolic pulmonary artery pressure (RVSP 39 +/- 14 mmHg vs 27 +/- 8 mmHg, P = 0.02), RV end-diastolic area (RVEDA 23 +/- 6 cm(2) vs 16 +/- 3 cm(2) P < 0.001), RV end-systolic area (RVESA 16 +/- 6 cm(2) vs 8 +/- 2 cm(2), P = 0.001), and RV fractional area change (30 +/- 12% vs 48 +/- 8%, P < 0.001). All the indexes of RV function significantly correlated with the percentage of LVESV reduction after CRT. Severe RV dysfunction was defined as TAPSE < or =14 mm and the population was stratified into two groups based on baseline TAPSE < or = or > 14 mm. As compared to those with high TAPSE (n = 30), patients with low TAPSE (n = 14) were less likely to show LV reverse remodeling after CRT (76% vs 14%, P < 0.001).
Conclusions: Our study suggests that RV function significantly affects response to CRT. Poor LV reverse remodeling occurs after CRT in patients with HF having severe RV dysfunction at baseline.