Hellenic Journal of Cardiology (Mar 2023)
Peak exercise myocardial deformation indices during cardiopulmonary exercise testing are associated with exercise capacity and ventilatory efficiency in patients with dilated cardiomyopathy
Abstract
Objective: Little is known about the exercise-induced changes in the multidimensional mechanical properties of the heart. We aimed to evaluate the myocardial deformation indices (MDI) at rest and their response at peak exercise during the same cardiopulmonary exercise testing (CPET) session, investigating their relationship to exercise capacity and ventilatory sufficiency in dilated cardiomyopathy (DCM) patients. Methods: We evaluated left ventricular (LV) function using speckle tracking imaging (STI) at rest and peak exercise during the same CPET session in 57 idiopathic DCM patients in New York Heart Association (NYHA) I–II class [54 ± 12 years, 42 males, ejection fraction (EF) 33 ± 9%]. We measured global longitudinal strain (GLS), longitudinal strain rate at systole (LSRS) and diastole (LSRD), and circumferential strain rate (CircS). Results: Resting GLS, LSRS, and LSRD were impaired compared with the predicted values but were improved at peak exercise (p −1.10 sec−1 (AUC = 0.80, p −13% (AUC = 0.81, p = 0.002) predicted impaired exercise capacity (peak VO2 34). In multiple regression analysis, peak exercise LSRS and GLS were independently related to the peak VO2 (Beta = −0.39, p = 0.003) and VE/VCO2 slope (Beta = 0.35, p = 0.02), respectively. Conclusions: Peak exercise LSRS and GLS in NYHA I–II DCM patients subjected to CPET were associated with aerobic exercise capacity and ventilatory efficiency. Consequently, LSRS and GLS at peak exercise, through their association with CPET-derived CV risk indices, may underline the severity of heart failure and predict future CV events in this DCM population.
