Outpatient Cardiac Rehabilitation Suppresses Deterioration of Renal Function in Patients ≥75 Years of Age With Heart Disease

Abstract

Background: This study investigated the effect of outpatient cardiac rehabilitation (OCR) and physical activity on the estimated glomerular filtration rate based on serum cystatin C (eGFRcys) in patients with heart disease (HD) aged ≥75 years. Methods and Results:This non-randomized prospective intervention study involved 136 patients (non-OCR group, n=66; OCR group, n=70), 55 of whom were aged ≥75 years (non-OCR group, n=29; OCR group, n=26). Renal function (eGFRcys) was evaluated at discharge and 3 months thereafter. A linear mixed model (LMM) was used to assess changes in renal function over time. The hospital readmission rate within 3 months after discharge was also evaluated. LMM analysis showed that the change in eGFRcys was −2.27 and +0.48 mL/min/1.73 m 2 in the non-OCR and OCR groups, respectively (F=2.960, P=0.022). Further, among patients aged ≥75 years in the non-OCR and OCR groups, the change in eGFRcys was −3.83 and −1.08 mL/min/1.73 m 2 , respectively (F=2.719, P=0.039). The proportion of patients aged ≥75 years who were rehospitalized due to exacerbation of HD was 16.9% (n=10) and 6.7% (n=2) in the non-OCR and OCR groups, respectively.Conclusions: Among patients with HD aged ≥75 years, participation in OCR reduces the decline in renal function and hospital readmission rates.

Effect of Cardiac Rehabilitation on Glomerular Filtration Rate Using Serum Cystatin C Concentration in Patients With Cardiovascular Disease and Renal Dysfunction

“…In addition, two earlier, prospective studies using eGFRcys showed that CR and high physical activity improved renal function. Because these studies have several potential limitations (one study had a small sample size of patients with severe renal function, 14 and the other study did not divide study patients into renal function severity 15 ), our findings should enhance the earlier knowledge.…”

“…Nevertheless, the observed findings should be an important basis for future investigations because limited evidence demonstrated the beneficial effects of CR on patients with severe CKD. 14 , 15 …”

“…Nevertheless, the observed findings should be an important basis for future investigations because limited evidence demonstrated the beneficial effects of CR on patients with severe CKD. 14,15 Although the mechanisms for the improvement of renal function have remained unclear, several potential mechanisms have been suggested. The decline of renal function is affected by coronary risk factors such as hypertension, hyperlipidemia, and diabetes mellitus.…”

“…[11][12][13] Recently, some studies using estimated glomerular filtration rate using the serum concentration of cystatin C (eGFRcys) evaluated the effect of CR on renal function of CVD patients, and they showed a favorable effect of CR on renal function. 14,15 However, for patients with CVD, little is known about whether CR improves renal function, as measured by Scys, particularly in patients with severe CKD. A previous small observational study using Scys (n = 41) demonstrated that high physical activity may suppress renal function decline in patients after acute myocardial infarction.…”

“…Since Scys is not affected by muscle mass, Scys can be an optimal marker of renal function in patients who undergo CR 11–13. Recently, some studies using estimated glomerular filtration rate using the serum concentration of cystatin C (eGFRcys) evaluated the effect of CR on renal function of CVD patients, and they showed a favorable effect of CR on renal function 14,15. However, for patients with CVD, little is known about whether CR improves renal function, as measured by Scys, particularly in patients with severe CKD.…”