The Particulars: The Society of Thoracic Surgeons (STS) risk prediction score is currently only applicable for patients undergoing midline sternotomy. A simple risk score for predicting STS composite endpoints is not currently available for patients undergoing minimally invasive valve surgery (MIVS).

Data Breakdown: Patients who underwent MIVS in a study were randomized to a development and validation dataset. Based on odds ratios, five variables were assigned a weighted integer, the sum or which provided a total risk score. The variables included 1) age older than 55, 2) GFR less than 60 cc/min, 3) history of cerebrovascular accident, 4) heart failure in the preceding 2 weeks, and 5) left ventricular ejection fraction less than 55%. Patients with more of these variables had higher surgical risks than those with fewer variables. The model demonstrated good discriminatory power.

Take Home Pearl: For patients undergoing MIVS, the risk of STS composite endpoint appears to be easily assessed with readily available baseline clinical characteristics.