Impact of training on combined cardiopulmonary exercise test with stress echocardiography parameters in HFrEF patients

Background: Exercise-based cardiac rehabilitation is recognized to improve quality of life in heart failure patients. However, the effects on the cardiac function are understudied. The main objective was to assess the impact of a 4-week cardiac rehabilitation program on cardiopulmonary exercise testing (CPET) combined with simultaneous echocardiography parameters in chronic heart failure (CHF) patients. The secondary aim was to investigate patients' responses to training.

Methods: Forty-one CHF patients with reduced ejection fraction (29.3 ± 0.1%) underwent CPET and stress echocardiography before and after a 4-week of exercise-training program. Blood parameters, echocardiography and cardiopulmonary parameters were assessed before and after training. Potential echocardiography derived predictive parameters like left and right contractile reserves, left ventricle elastance, end systolic volume and right ventricle S wave response to exercise were also assessed.

Results: The training program increased the peak oxygen consumption (VO₂) (P < 0.001), the peak systolic blood pressure, the left ventricular outflow tract velocity time integral (P < 0.05) and the circulatory (P < 0.001) and ventilatory (P < 0.01) powers. It also decreased the VE/VCO₂ slope (P < 0.001). As the median value of peak VO₂ gain was 17%, patients above this value were considered as responders and patients below as non-responders to training. The responders presented a higher left ventricle contractile reserve compared to non-responder patients. The peak left ventricle elastance and peak right ventricle S wave response tended to be higher in responders.

Conclusion: Combination of CPET and stress echocardiography may contribute to establish the disease severity stratification and to predict response to training in CHF patients with reduced ejection fraction.