Effect of Individualized Intradialytic Exercise on Left Ventricular Diastolic Function

Introduction Cardiovascular disease remains the leading cause of morbidity and mortality in patients undergoing hemodialysis, partly through structural changes leading to left ventricular (LV) diastolic dysfunction. Intradialytic exercise has emerged as a potential intervention, but its effect on diastolic function remains unclear. We evaluated the impact of a systematic intradialytic exercise program on LV diastolic function in hemodialysis patients. Methods We conducted a quasi-experimental, prospective pretest-posttest study in 21 patients undergoing thrice-weekly hemodialysis. The protocol consisted of a 16-week control period followed by a 16-week intervention. During the control period participants stopped unstructured intradialytic pedaling (standard of care) and received hemodialysis. The intervention involved intradialytic cycling (3 sessions/week) with intensity individualized by cardiopulmonary exercise testing (CPET). The primary outcome was LV diastolic function assessed by transthoracic echocardiogram, focusing on Left Atrial reservoir strain (LArs). Secondary outcomes included Global Longitudinal Strain (GLS) and functional capacity. Results Following the intervention, significant improvements were observed in diastolic mechanics, specifically LArs (26.2% vs. 30.4%, p=0.05). Regarding systolic mechanics, we observed a significant improvement in GLS (-15.5% vs. -17.4%, p=0.002). Functional capacity improved significantly (work rate at ventilatory threshold 1: 33.8 to 42.6 W, p=0.003), whereas VO 2 peak increased by 2.4 mL/kg/min without reaching statistical significance (p=0.24). No serious exercise-related adverse events occurred. Conclusion A systematic, individualized intradialytic exercise program significantly improved echocardiographic parameters of LV diastolic function (LArs) and subclinical systolic mechanics (GLS). These findings, alongside improved physical capacity, highlight the potential of personalized exercise prescription to mitigate cardiovascular risk in hemodialysis patients.