Quantifying the incremental cost of complications associated with mitral valve surgery in the United States

Objective: The goal of this study was to quantify the net increase in resource use associated with complications after isolated mitral valve surgery. Methods: Deidentified patient-level claims data on a random sample of mitral valve operations performed in the United States from January 1, 2006, to December 31, 2007, were obtained from the National Inpatient Sample (n = 16,788). Patients with major concomitant cardiac procedures were excluded from the analysis for a net sample size of 6297 patients. Risk-adjusted median total hospital costs and length of stay were analyzed by major complications, including pneumonia, sepsis, stroke, renal failure requiring hemodialysis, cardiac tamponade, myocardial infarction, gastrointestinal bleed, and venous thromboembolism. Results: There were a total of 1323 complication events that occurred in 1089 patients. The most common complication was pneumonia (n = 346, 5.5%), which was associated with a $29,692 increase in hospital costs and a 10.2-day increase in median length of stay (P < .001). The most costly complication was cardiac tamponade, which resulted in an increase in hospital cost of $56,547 and an increase in length of stay of 19.3 days (P < .001). There was a stepwise association between the hospital costs and length of stay and the number of complications per patient (P < .001). There was also a significant association between the discharge location and the occurrence of a complication, with 25% more patients who underwent routine home discharge when there were no complications (P < .001). Conclusions: In patients undergoing isolated mitral valve surgery, postoperative complications were associated with significant increases in mortality, hospital costs, and length of stay, as well as with discharge location. With growing national attention to improving quality and containing costs, it is important to understand the nature and impact of complications on outcomes and costs. (J Thorac Cardiovasc Surg 2012;143:864-72)