Use of the Medtronic Freestyle for aortic valve infection: A retrospective propensity score matched analysis

Abstract

Backgrounds: Aortic valve and prosthetic valve endocarditis present a challenging subgroup of patients at high risk. We analyzed our experience using the Medtronic Freestyle in full root technique for the treatment of these cases over 18-year time period.

Methods: We investigated the endocarditis subgroup from our cohort of 971 patients and compared results against other valve types with propensity score matching implementing nearest neighbor method. T-test, χ² test, logistic regression, and Cox regression were performed.

Results: Fifty-four patients from the Freestyle group (FS) were matched against 54 patients from a cohort of 376 aortic valve/root endocarditis patients treated by other valve types (non-FS). Hospital mortality was 9/54 (16.7%) in the FS vs 13/54 (24.1%) in the non-FS group (P = .33). Variables age (P = .003) and renal impairment (P = .026) had an impact on mortality according to Cox regression analysis for early results. Variables with significant risk for long-term mortality included postoperative renal impairment (P = .0001) and multiorgan failure (P = .0001). Recurrent infection was low (1.8% for FS and 3.7% for non-FS group), and freedom from reoperation was 97.2%. Use of the Medtronic Freestyle was no significant risk factor for long-term mortality.

Conclusion: The Freestyle stentless xenograft is a viable alternative for treatment of valve/root and prosthetic endocarditis. In our experience, it showed good postoperative performance with low rate of reinfection while having an acceptable operative risk-profile for this high-risk cohort.

Keywords: mortality and morbidity; root endocarditis; xenograft.