Abstract 13879: Characterizing Post-Cardiac Surgery Infection Risk: A Statewide Experience

Introduction: Patients undergoing cardiac surgery are at risk for developing early (in-hospital or within 30-days) and late (up to 180 days after surgery) postoperative infections. Current national database infection metrics are limited in scope and duration of follow-up. Aim: Evaluate rates and types of early and late postoperative infections and mortality. Methods: Medicare claims from 8335 Michigan fee-for-service beneficiaries undergoing isolated coronary artery bypass grafting (CABG) (n=4162), isolated surgical aortic valve replacement (SAVR) (n=618), CABG + SAVR (n=627), or transcatheter aortic valve replacement (TAVR) (n= 2946) between 2017-2020 at 33 Michigan hospitals were linked to The Society of Thoracic Surgeons data. Nine infection types were tracked within 180 days following surgery. The relationship between infections and 180-day and 365-day mortality was evaluated. Results: The average age was 74.2 ± 9.1 years, 36.5% were female, 5.0% were Black and 1.4% were Hispanic. The in-hospital infection rate was 8.9%, while 17.8% within 180 days after surgery. Infection rates varied by hospital (9.1%-33.9%), year (2017 vs 2020: 20.1% vs 16.0%), and procedure type (CABG: 18.2%, SAVR: 14.9%, CABG+SAVR: 19.6%, TAVR: 17.4%). Most common infections were urinary tract infection (8.7%), pneumonia (7.0%) and sepsis (5.2%). The overall mortality rate was 5.9% at 180-days (and varied by infection type, Table ) and 9.0% at 365 days. Patients with an infection had higher associated 180-day mortality compared to those with no infection (17.7% vs 3.4%, p<0.001). Among infection types, sepsis was associated with the highest 180-day mortality rate. Conclusions: Nearly 20% of Medicare beneficiaries develop an infection within 180 days after cardiac surgery, with rates varying by 24% across hospitals and contributing to higher 180-day mortality. Future efforts should identify determinants of postoperative infections, especially given their impact on mortality.