Causes and characteristics associated with early and late readmission after open-heart valve surgery

The objectives of the study were to describe the causes of readmission from discharge to 30 days and from day 31 to 180 after discharge and to investigate the characteristics associated with overall and cause-specific readmissions after open-heart valve surgery.

A single-center, retrospective cohort of 980 patients undergoing open-heart valve surgery from 2013 to 2016. Time to the first readmission was analyzed using univariable and multivariable Cox proportional hazard models. Results are reported as hazard ratios (HR) with 95% confidence intervals (CI).

In total, 366 patients (37%) experienced unplanned cardiac readmission within 180 days after discharge. Within 30 days after discharge, the most frequent causes of readmission were pericardial/pleural effusions (n = 87), infections (n = 50), and atrial fibrillation/flutter (n = 45). Accordingly, infections (n = 32) were the most common cause from day 31 to 180. No powerful predictors of overall cardiac readmission were identified, but several characteristics were associated with cause-specific readmissions: age ≤65 years (HR: 1.85; CI: 1.18-2.88), male gender (HR: 1.85; CI: 1.11-3.09), high alcohol intake (HR: 1.99; CI: 1.22-3.24) and mitral valve procedures (HR: 1.86; CI: 1.11-3.10) were associated with readmissions due to effusions. Ischemic heart disease with a prior percutaneous coronary intervention (HR: 2.94; CI: 1.53-5.63), mitral valve procedures (HR: 2.10; CI: 1.23-3.59), and postoperative atrial fibrillation/flutter (HR: 1.71; CI: 1.03-2.85) were associated with atrial fibrillation/flutter readmissions.

Predicting overall readmissions after open-heart valve surgery is difficult as causes of readmissions vary and different causes are associated with different characteristics. Future studies should target reducing cause-specific readmissions.