Causes, Risk Factors, and Costs of 30-Day Readmissions After Mitral Valve Repair and Replacement

Postsurgical readmissions are an increasingly scrutinized marker of health care quality. We sought to estimate the risk factors and costs associated with readmissions after mitral valve (MV) surgery in a large, nationally representative cohort.

Adult patients undergoing MV repair or replacement were queried from the National Readmissions Database from 2010 to 2014. Data were collected on the prevalence and indications for readmission within 30 days as well as the hospital-, procedure, and patient-level risk factors as determined by multivariable logistic regression.

Among 76,342 patients undergoing MV surgery, the rate of 30-day readmission was 17.0%. Those undergoing replacement procedures had significantly higher readmission rates (20.7% vs 13.1%; P < .001) compared with repair. Significant independent predictors of readmission after both MV repair and replacement included length of stay ≥8 days, chronic lung disease, chronic renal disease, and low hospital procedural volume for MV surgery. Readmissions to nonindex hospitals accounted for 26.6% of all readmissions. The most common indications for readmission were heart failure (21.4%), arrhythmia (17.0%) and respiratory diagnoses (15.0%), and infections (10.2%). The mean cost per readmission was $15,397, and among readmitted patients, the cost of readmission accounted for 17.8% of the total cost of the episode of care.

Nearly 1 in 5 patients undergoing MV surgery are readmitted within 30 days. Treatment at a low-volume center was strongly associated with readmission, and much of the readmission burden falls on nonindex hospitals. Further characterization of readmissions may improve the quality of care associated with MV surgery.