Association of Cardiac Rehabilitation With Decreased Hospitalization and Mortality Risk After Cardiac Valve Surgery

Abstract

Importance: National guidelines recommend cardiac rehabilitation (CR) after cardiac valve surgery, and CR is covered by Medicare for this indication. However, few data exist regarding current CR enrollment after valve surgery.

Objective: To characterize CR enrollment after cardiac valve surgery and its association with outcomes, including hospitalizations and mortality.

Design, setting, and participants: This cohort study of patients undergoing valve surgery was conducted in calendar year 2014, with follow-up through 2015. The study included all fee-for-service Medicare beneficiaries undergoing open cardiac valve surgery in 2014. Patients identified by inpatient diagnosis codes for open aortic, mitral, tricuspid, and pulmonary valve surgery were included. Data analysis occurred from January 2018 to March 2019.

Exposures: Logistic regression was used to evaluate sociodemographic and clinical factors associated with CR enrollment.

Main outcomes and measures: We used Andersen-Gill models to evaluate the association of CR enrollment with 1-year hospitalization risk and Cox regression models to evaluate the association of CR enrollment with 1-year mortality risk.

Results: A total of 41 369 Medicare beneficiaries (median [interquartile range] age, 73 [68-79] years; 16 935 [40.9%] female) underwent open valve surgery in the United States in 2014. Fewer than half of patients (17 855 [43.2%]) who had valve surgery enrolled in CR programs. Several racial/ethnic groups had lower odds of enrolling in CR programs after valve surgery compared with white patients, including Asian patients (odds ratio [OR], 0.36 [95% CI, 0.28-0.47]), black patients (OR, 0.60 [95% CI, 0.54-0.67]), and Hispanic patients (OR, 0.36 [95% CI, 0.28-0.46]). Patients undergoing concomitant coronary artery bypass grafting had higher odds of CR enrollment (OR, 1.26 [95% CI, 1.20-1.31]) than those without the concomitant coronary artery bypass graft procedure, as did patients in the Midwest census region (OR, 2.40 [95% CI, 2.28-2.54]) compared with those in the South (reference). Cardiac rehabilitation enrollment was associated with fewer hospitalizations within 1 year of discharge (hazard ratio, 0.66 [95% CI, 0.63-0.69] after multivariable adjustment). Enrollment was also associated with a 4.2% absolute decrease in 1-year mortality risk (hazard ratio, 0.39 [95% CI, 0.35-0.44] after multivariable adjustment).

Conclusions and relevance: Fewer than half of Medicare beneficiaries undergoing cardiac valve surgery enroll in CR programs, and there are marked racial/ethnic disparities among those that do. Cardiac rehabilitation is associated with decreased 1-year cumulative hospitalization and mortality risk after valve surgery. These results invite further study on barriers to CR enrollment in this population.

Figure.. Hospitalization and Mortality Risk for Medicare Beneficiaries Undergoing Cardiac Valve Surgery, Stratified by Cardiac Rehabilitation Enrollment

A, Cumulative hospitalizations were calculated using an Andersen-Gill model. B, Mortality risk was calculated using a Cox regression model. Both models were adjusted for valve surgery type, age, sex, race, census region, median county income, comorbidities, discharge to an inpatient rehabilitation facility or skilled nursing facility, and length of stay during valve surgery. Shaded areas represent 95% CIs.