Muscle dysfunction and exercised-based rehabilitation in cardiac diseases: From muscular physiology in animals to prognosis impact on patients

Abstract

[eng] Cardiovascular diseases (CVD) such heart failure (HF) or acute coronary syndrome (ACS) impairs muscular dysfunction that affect cardiorespiratory fitness. Animals models realistically mimicking CVD, including the well-known diaphragm dysfunction observed in HF patients. The widely used isoproterenol-induced HF model has not been explored for new insights to improve muscular dysfunction. From a clinical perspective, the impact of muscular dysfunction is multiple but preventable and reversible. Exercise-based cardiac rehabilitation programs (EB-CRP) have a recommendation class 1A in clinical guidelines, but remains underused. Participant initially are evaluated and stratified with routine protocols to refer the best setting and conditions for exercise training (ET). Despite benefits of exercise training and prognosis studies, remains unknown the prognosis of these patients who accept all the others components of cardiac rehabilitation but not performing training. In the same way, it is unknown if these tools have a prognosis utility. The aim of this thesis was, by one hand, to describe diaphragmatic contractility of an animal model never described before. On the other hand, was to compare clinical outcomes and asses the predictive value of risk stratification (RS) between patients with different compliance and initial attitude for accept or reject exercise component of cardiac rehabilitation. Using ex-vivo and in-vivo measure of muscular function, conventional isoproterenol-induced HF model increases diaphragm contraction, a finding contrary to what is observed in patients with HF. In EB-CRP, completion of ET after ACS was associated with improved prognosis and with reclassification to low-risk. Only half of the patients completed the ET program and finally a Spanish easy-to-calculate risk score offers unreported robust prognostic information. No-exercise groups were independently associated with the worst outcomes. EB-CRP with participation in exercise component changed risk stratification, improving classification and prognosis.