Evaluation of myocardial work during exercise echocardiography in a healthy population

Abstract Background Exercise echocardiography (ExE) is an essential diagnostic tool for evaluating ischemia, heart failure with preserved ejection fraction (HFpEF), and the underlying causes of symptoms like dyspnea. Recently, the myocardial work index (MWI), derived from speckle-tracking echocardiography, has emerged as a promising marker of cardiac performance. This study aims to assess the impact of exercise on myocardial work parameters in a healthy population. Methods We conducted a single-center retrospective analysis of 845 patients referred for ExE between January 2022 and November 2024. Of these, 280 individuals (aged 30–65 years) without known coronary artery disease and with normal ExE results (no wall motion abnormalities, good functional capacity 80% predicted work, and ≥6 minutes of exercise) were included. Myocardial work (MW) parameters—global longitudinal strain (GLS), global work efficiency (GWE), global work index (GWI), global constructive work (GCW), and global wasted work (GWW)—were evaluated at rest and at a heart rate of 100 bpm. Results The cohort consisted of 59% male, mean age 59 ± 4.5 years, BMI 27.5 ± 3.8 kg/m², 21% obese, 14% with diabetes, 65% with hypercholesterolemia, and 39% current or former smokers. Baseline MW parameters were within normal ranges (NORRE study): GLS = -16.4% ± 2.5%, GWE = 92% (IQR 5%), GWI = 1501 (IQR 389 mmHg%), GCW = 1856 (IQR 444 mmHg%), GWW = 134 (IQR 118 mmHg%). Multivariable analysis identified age as the only independent factor influencing MW parameters, with a modest effect onGWE (p = 0.038, partial eta squared = 0.085). During exercise, all MW parameters significantly increased compared to baseline (p 0.001). No demographic or clinical factors were associated with exercise-induced changes in MW parameters. Conclusion In individuals without known coronary artery disease and with normal ExE results, myocardial work parameters significantly increase during exercise, reflecting the heart's adaptive response to physiological stress. Baseline age was the only demographic factor affecting myocardial work efficiency, suggesting a potential impact of aging on cardiac performance. These findings provide reference values for myocardial work during exercise and establish a foundation for future studies examining myocardial work in pathological conditions.