Possibility of Cardio-renal Protection by Long-term Cardiac Rehabilitation in Elderly Patients with Cardiovascular Diseases

Objective Cardiac rehabilitation (CR) improves the mortality in patients with cardiovascular disease (CVD). Even in elderly patients with CVD, CR may improve the activities of daily living (ADL). Methods Eighty-eight outpatients over 65 years of age at the beginning of a CR program (baseline) at Fukuoka University Hospital who had CVD and could be followed-up for up to 5 years were enrolled. CVD included ischemic heart disease, postoperative valvular heart disease, dissecting aneurysm of the aorta and peripheral artery disease. The patients were divided into 2 groups according to the average estimated glomerular filtration rate (eGFR) at baseline (55.4±14.8 mL/min/1.73 m²): high (≥55.4, n=44) and low (<55.4, n=44)-eGFR groups. The anaerobic threshold (AT) during exercise and left ventricular ejection fraction (LVEF) were measured by cardiopulmonary exercise (CPX) and ultrasound cardiography, respectively. The serum brain natriuretic protein (BNP) was also measured every year. Results The average age at baseline in all patients was 73±6 years. In all patients, the level of eGFR did not significantly change for 5 years (55±15 mL/min/1.73 m² at baseline vs. 48±14 at the end of the study). The AT (3.7±1.0 METs at baseline vs. 3.3±0.5), LVEF (57±13% vs. 64±10%) and BNP (260±452 pg/mL vs. 308±345) were also maintained for 5 years. In both the low- and high-eGFR groups, the eGFR, AT during exercise, LVEF and BNP at the end of the study were not significantly changed compared to the baseline values, although some changes were observed during the follow-up period. Conclusion Long-term CR in CVD outpatients over 65 years of age helped maintain the AT, LVEF, BNP and eGFR for 5 years. CR afforded cardio-renal protection in elderly patients with CVD.