Effects of Cardiac Contractility Modulation Therapy on Right Ventricular Function: An Echocardiographic Study

Background. Cardiac contractility modulation (CCM) is a novel device-based therapy for patients with heart failure with reduced and mild reduced ejection fraction (HFrEF/HFmrEF). CCM increases cardiac performance and produces reverse left ventricular remodeling, with improved symptoms, functional capacity, quality of life, and reduced HF-related hospitalizations. However, to date, little evidence is available on the effects of CCM on right ventricle (RV) function. Therefore, we analyzed the effects of CCM on RV systolic function and RV-pulmonary artery (PA) coupling. Methods. Twenty-one (65 +/- 12.5 years) patients with NYHA class III, ejection fraction < 40% and QRS < 120 ms were assessed at baseline. During follow up, two patients had died, and so nineteen patients were evaluated six months after CCM therapy. Using echocardiography, tricuspid annular systolic excursion (TAPSE), myocardial systolic excursion velocity (RVs), and RV free-wall strain was measured. PA systolic pressure (PASP) was estimated from tricuspid regurgitation, adding the right atrial pressure estimation. The RV-PA coupling was calculated as TAPSE/PASP ratio. Results. After six months, patients who underwent CCM therapy showed a reduction in RV diameters and improved RV systolic function, as evidenced by the increase in both TAPSE (16.6 +/- 4.2 mm vs. 18.5 +/- 3.6 mm; p < 0.05), RVs (10.1 +/- 1.8 cm/s vs. 11.3 +/- 11.4 cm/s; p < 0.05), and RV strain (-13.7 +/- 1.8% vs. -15.6 +/- 2.3%; p < 0.05). CCM also determined a reduction in PASP (34.2 +/- 9.8 mmHg vs. 28 +/- 6.2 mmHg; p < 0.05) and an increase in the TAPSE/PASP ratio (0.52 +/- 0.14 mm/mmHg vs. 0.66 +/- 0.23 mm/mmHg; p < 0.05). Conclusions. At six months, CCM increases RV reverse remodeling and performance, reducing RV size and improving RV systolic function, PASP, and RV-PA coupling.