Functional Improvement After Outpatient Cardiac Rehabilitation in Acute Coronary Syndrome Patients is Not Related to Improvement in Left Ventricular Ejection Fraction.

Cardiac rehabilitation (CR) improves the functional capacity and the prognosis of patients with coronary artery disease. Our study was aimed at assessing the relationship between functional improvement (evaluated with 6-min Walk Test-6MWT) and the improvement in left ventricular ejection fraction (LVEF) after CR. We collected data from 249 patients (age 66.79 ± 11.06 years; males 81.52%) with a recent history of Acute Coronary Syndrome that performed CR. The functional improvement after CR was expressed as the Δ between distance covered at the final versus the initial 6-min Walking Test (6-MWT), while LVEF was calculated with transthoracic echocardiogram at the beginning and at the end of the CR. Patients were divided accordingly to their pre-rehab LVEF (≥ 55% vs < 55%). With superimposable age and baseline 6MWT distance covered (434.58 vs 405.12 m, p = 0.08), the latter group presented higher Δ meter values at 6MWT (167.93 vs 193.97 m, p = 0.018). However, no statistically significant positive correlation between Δ meters and Δ LVEF was found. Moreover, linear regression analyses found that nor baseline LVEF nor Δ LVEF were significant determinants of Δ meters when considering the whole group, with age, basal 6MWT and peak CK-MB as additional covariates in the model. Although it could be expected that an increase in LVEF is related to the functional improvement after CR, no significant correlation was found in our population.