Cardiopulmonary exercise testing combined with echocardiography and response after a cardiac rehabilitation program in chronic heart failure patients

Abstract

Exercise training is strongly recommended to improve quality of life in chronic heart failure (CHF) patients. The magnitude of improvement of peak oxygen consumption (VO 2 ) is highly variable between patients and a lack of response to training has been described as a predictor of poor prognosis. We aimed at evaluating the efficiency of an experimental approach combining cardiopulmonary exercise testing (CPET) and echocardiography to detect non-responder patients. Forty-one CHF patients (88% male, 57 ± 12 yrs) referred to cardiac rehabilitation were recruited to perform CPET-echocardiography before and after 20 exercise training sessions. Patients underwent 2 CPET-echocardiography using a ramp protocol on a semi-supine bicycle. Measures were performed at rest, at the ventilator threshold 1 (VT1) and at peak exercise for VO 2 , CO 2 output, ventilation, heart rate, blood pressures, cardiac output, left ventricular (LV) filling pressure (E/A, E/e’), LV global strain, LV ejection fraction and pulmonary pressure ( Table 1 ). Cardiac rehabilitation program included exercise training (ET), patients’ education, diet and psychosocial counselling. The ET combined endurance (continuous form, 2 sessions/week and interval form, 3 sessions/week) and resistance sessions. After the ET, VO 2 peak increased from 16 ± 5 to 20 ± 6 ml/kg/min ( P < 0.05) and the median value of the VO 2 peak gain was 17%. The peak of cardiac output increased from 6.5 ± 2.8 to 7.4 ± 3.0 L/min ( P < 0.05) without significant increase in LV end-diastolic volume, LV filling and pulmonary pressures. Non-responder’ patients (VO 2 peak gain < 17%) had a lower weight, suffered more frequently from ischemic cardiomyopathy, had beta blockers therapy and a higher increase of pulmonary pressure at baseline. CPET baseline measures were non-discriminant. Our results suggest that the CPET-echocardiography may be used to define different response to ET phenotypes. Further studies are needed to determine the most appropriate ET for non-responder patients.