Early and late outcomes following aortic root enlargement: a multi-centred propensity matched cohort analysis

Abstract Objective The safety and efficacy of aortic root enlargement (ARE) at the time of aortic valve replacement (AVR) remains unknown. The objective of this multi-centre study was to compare AVR+ARE to AVR for early and late mortality and secondary safety outcomes. Methods Clinical and administrative databases in Ontario, Canada, were linked to obtain patients undergoing AVR±ARE from 2008-2017. Baseline characteristics were compared and 1:1 propensity score matching was performed to account for differences in baseline characteristics. Early outcomes were compared in the matched groups. Late mortality was compared using Kaplan-Meier survival curves and a Cox-proportional hazard model. Results 16,656 patients undergoing AVR in 11 Ontario institutions were reviewed. Patients who underwent ARE were younger, non-urgent, more likely male and had lower rates of hypertension, ischemic heart disease, and congestive heart failure. Propensity score matching yielded similar groups for comparison, with 809 pairs for AVR vs AVR+ARE. There was no difference in 30-day mortality between AVR+ARE vs AVR (2.0% vs 2.1%, p=1.00). Rates of chest reopening for bleeding, permanent pacemaker implantation, and blood transfusions were similar. Late mortality over 8 years was similar between AVR+ARE and AVR (p=0.45). In a sensitivity analysis, results were similar in 525 pairs comparing AVR+coronary artery bypass grafting (CABG)+ARE to AVR+CABG, except that chest reopening for bleeding was higher with AVR+CABG+ARE (7.2% vs 3.2%, p=0.006). Conclusions The addition of ARE to isolated AVR can be safely performed to increase implanted prosthesis size without compromising early mortality. Additional studies with longer follow-up are necessary.