Signal-morphology impedance cardiography is a non-invasive tool for predicting responses to exercise-based cardiac rehabilitation

Abstract Exercise Based Cardiac Rehabilitation (EBCR) is highly beneficial to improve the outcome and quality of life of patients suffering from cardiac diseases. Most of the time, it increases cardiorespiratory and muscle capacity. However, not all patients elicit these benefits because of the high variability in their response to EBCR. In this context, the present study aimed to determine the potential of a specific parameter, the Contractility index (CTi), to predict the response of cardiac patients to EBCR. This parameter is acquired during the baseline Cardiopulmonary Exercise Test (CPET), using Signal-Morphology based Impedance Cardiography (SM-ICGTM). Methods: 58 cardiac patients (59.7 ± 10.2 years old) were retrospectively enrolled in this study and admitted to EBCR, and 57 could be analyzed. Results: The patients were divided into 2 groups based on their CTi response during CPET (normal versus altered or compromised). After the EBCR program, there was an overall increase in peak oxygen uptake (VO₂peak) (+13.6 ± 22.9 %). EBCR induced a higher VO₂peak improvement in patients with normal CTi response compared to their counterparts with altered or compromised CTi profiles (+24.1 ± 21.4 % vs. + 3.36 ± 19.5 %, p < 0.01) Patients with a normal CTi response during the baseline CPET were more likely to have a greater than 5% improvement in VO₂peak (odds ratio 8.7, p = 0.012) and benefit from EBCR, as compared to the patients in the altered or compromised CTi group. Conclusion: This study demonstrated the predictive potential of the CTi profile observed during the baseline CPET to anticipate the response to EBCR in cardiac patients.