Background: Although guidelines support aortic valve replacement (AVR) in patients with severe aortic regurgitation (AI) and left ventricular ejection fraction (LVEF) < 50%, severe left ventricular dysfunction (LVEF < 35%) is thought to confer very high surgical risk. The survival benefit associated with surgical intervention, however, is unknown. We evaluated long term outcomes of this patient population with and without surgical intervention.
Methods: To capture patients who did and did not undergo AVR, we queried a single institutions echocardiography database to identify all patients with severe AR and LVEF < 35%. Manual chart review was performed to identify key demographic, clinical, and operative details. This retrospective cohort was then merged with institutional patient data. Due to small sample size and population heterogeneity, corrected group prognosis method was applied, which calculates the adjusted survival curve for each individual using fitted Cox proportional hazard model. Average survival adjusted for co-morbidities and age was then calculated using the weighted average of the individual survival curves.
Results: Of 43 echocardiograms representing 41 unique patients, 40 patients met inclusion criteria. Of those, 18 (45.0%) underwent AVR and 22 (55.0%) were managed medically. After multivariate adjustment, end stage renal disease (HR = 17.633, p =0.0335) and peripheral arterial disease (HR = 6.050, p =0.0180) were associated with increased long term mortality. AVR was associated with decreased mortality (HR = 0.143, p =0.0490, see Figure 1). The mean survival for patients undergoing AVR was 6.3 years. The mean follow-up time was 6.58 years.
Conclusions: Even after adjustment for clinical characteristics and patient age, AVR is associated with increased survival for patients with severe systolic dysfunction and severe aortic insufficiency. Although treatment selection bias cannot be completely eliminated with this retrospective cohort design, these results support performing surgery on this high-risk patient group.