Long-term results of cardiac contractility modulation in patients with chronic heart failure

Abstract

Aim. Evaluate the overall effectiveness of cardiac contractility modulation (CCM) therapy in patients with chronic heart failure of various etiology.Methods. The study included 61 patients with chronic heart failure (NYHA class II-III), ejection fraction 20-40% and narrow QRS <130 ms, who were implanted the CCM devices. Depending on the etiology of heart failure, ischemic cardiomyopathy prevailed (41 patients). All patients were performed echocardiography, 6-min walk test and Minnesota Living with Heart Failure questionnaire (MHFLQ). Results. The observation period was 25 months. All 54 patients significantly improved left ventricular ejection fraction from 32.2% to 37.6% (р=0.026) and volume parameters (left ventricle end systolic volume from 150 to 137 ml (р=0.034), left ventricle end diastolic volume from 220 to 201 ml (р=0.044), reduced the heart failure NYHA class >1 in 29 (53.7%) patients (р=0.015), increased 6-min walk test from 265 to 343 m (р=0.029), and the MHFLQ improved from 46.1 to 35.8 (р=0.042). Non-ischemic cardiomyopathy was associated with significant improvement in MHFLQ (from 42.7 to 30.3, р=0.029) and lowering the heart failure NYHA class>1 (83.3%, vs 47.2%, p=0.012) compared to ischemic group. Conclusion. CCM is safe and effective in patients with chronic heart failure NYHA class II-III, ejection fraction 20- 40% and narrow QRS˂130 ms, who were implanted the CCM devices. Depending on the etiology of heart failure, ischemic cardiomyopathy prevailed (41 patients). All patients were performed echocardiography, 6-min walk test and Minnesota Living with Heart Failure questionnaire (MHFLQ).Results. The observation period was 25 months. All 54 patients significantly improved left ventricular ejection fraction from 32.2% to 37.6% (р=0.026) and volume parameters (left ventricle end systolic volume from 150 to 137 ml (р=0.034), left ventricle end diastolic volume from 220 to 201 ml (р=0.044), reduced the heart failure NYHA class >1 in 29 (53.7%) patients (р=0.015), increased 6-min walk test from 265 to 343 m (р=0.029), and the MHFLQ improved from 46.1 to 35.8 (р=0.042). Non-ischemic cardiomyopathy was associated with significant improvement in MHFLQ (from 42.7 to 30.3, р=0.029) and lowering the heart failure NYHA class>1 (83.3%, vs 47.2%, p=0.012) compared to ischemic group.Conclusion. CCM is safe and effective in patients with chronic heart failure NYHA class II-III, ejection fraction 20- 40% and narrow QRS˂130 ms. Non-ischemic etiology of cardiomyopathy was associated with significant improvement in MHFLQ and lowering the heart failure class.