Peak exercise myocardial deformation indices during cardiopulmonary exercise testing are associated with exercise capacity and ventilatory efficiency in patients with dilated cardiomyopathy

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 longi-tudinal 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 < 0.001). All MDI at rest and/or at peak exercise were related to several CPET-derived parameters, including peak VO2, load, O2 pulse, and VE/VCO2 slope. Peak exercise LSRS > -1.10 sec -1 (AUC = 0.80, p < 0.001) and GLS > -13% (AUC = 0.81, p = 0.002) predicted impaired exercise capacity (peak VO2 < 20 ml/min/kg) and ventilatory inefficiency (VE/VCO2 slope>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.(c) 2022 Hellenic Society of Cardiology. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

This study aimed to evaluate the myocardial deformation indices (MDI) at rest and their response at peak exercise during the same CPET session in DCM patients and investigate their relationship with exercise capacity and ventilatory sufficiency. The results showed that resting MDI were impaired but improved at peak exercise, and all MDI at rest and/or peak exercise were related to several CPET-derived parameters. Peak exercise MDI were independently related to exercise capacity and ventilatory efficiency, indicating their potential as predictors of future cardiovascular events in DCM patients.