A Risk Prediction Model for Prolonged Length of Stay After Minimally Invasive Valve Surgery.

Objective: Minimally invasive surgery determines shorter postoperative hospital length of stay (LOS) even in cardiac surgery. Potential preoperative factors affecting LOS are still not known in minimally invasive heart valve surgery (MIVS). We aimed to identify preoperative variables influencing prolonged LOS in MIVS.

Methods: We reviewed 189 patients who underwent MIVS via minithoracotomy at our institution. Prolonged LOS was defined as more than 7 postoperative days. Poisson and logistic regression were used to screen the predictors.

Results: The mean postoperative LOS was 9.13 days, and 64 patients (33.9%) experienced a prolonged LOS. These patients were older, more frequently in New York Heart Association (NYHA) class III or IV, showed worse left ventricular ejection function (LVEF), and had a higher incidence of reoperation and chronic kidney disease (CKD). At univariate analysis, the most significant preoperative factors affecting prolonged LOS were age (odds ratio [OR] = 1.04), NYHA class III or IV (OR = 3.03), reduced LVEF (OR = 3.22), CKD (OR = 2.7), and redo surgery (OR = 3.6). After adjustment, the most significant preoperative factors predicting prolonged LOS were age (OR = 1.03, 95% CI: 1.01 to 1.06, P = 0.02) and redo surgery (OR = 3.33, 95% CI: 1.29 to 8.9, P = 0.01).

Conclusions: The most important factors affecting prolonged LOS after MIVS were represented by age and redo surgery, although other preoperative characteristics such as reduced LVEF, NYHA class III or IV, and CKD play a significant role in delaying recovery after MIVS. Further larger studies are needed to better identify potential preoperative predictors of prolonged LOS after MIVS.