Factors associated with early readmission of cardiothoracic surgical patients

Objectives: An initial retrospective, matched case control study at our institution identified chronic lung disease and peripheral vascular disease (PVD) as risk factors for early readmission (ER) following cardiothoracic surgery.  This study’s purpose was to expand the analysis to include all of the patients in the database and utilize multivariate analysis to identify risk factors associated with ER.

Methods: A retrospective, case-control study was conducted on cardiothoracic patients from January 2009 to April 2010.  Demographic, surgical and readmission data was obtained from the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database.  Appropriate statistical analyses were completed.  

Results: Patients readmitted (Readmit, n=64) within 30 days after discharge following a cardiothoracic procedure were compared to patients who did not require readmission (No Readmit, n=293). The majority of patients were male (72%) and mean age was 65 +/- 11 years.  Coronary artery bypass graft (CABG) surgery was performed on 65% of patients and 71% of patients had an on-pump cardiac procedure.  Compared to No Readmit, Readmit patients had significantly more discharge medications (12.1 +/- 5.3 versus 10.6 +/- 4.9, p=0.021), higher STS risk score (0.045 +/- 0.056 versus 0.026 +/- 0.042, p=0.009), postoperative infection (5%  versus 1%, p=0.039), PVD (30% versus 14%, p=0.002), previous CABG (9% versus 3%, p=0.037), previous carotid surgery (11% versus 3%, p=0.010), and preoperative beta-blocker use (77% versus  72%, p=0.007).  More No Readmit patients had a concomitant atrial fibrillation correction surgery (9% versus 2%, p=0.052). The number of discharge medications, STS risk score, peripheral vascular disease, and prior CABG or carotid surgery were significantly (p < 0.04) correlated with Readmit patients. 

Conclusion: Numerous factors were correlated with ER. Based on these results, further research is necessary to understand if additional patient education targeting these populations may prevent ER after cardiothoracic surgery.