Aortic Valve Replacement in the Failing Left Ventricle: Worthwhile?

Abstract

Purpose: According to the 2020 American College of Cardiology/American Heart Association guidelines, the aortic valve should be replaced in the setting of severe aortic stenosis or regurgitation, independent of left ventricular function (even for EF <55%). However, in clinical practice, especially in a very low EF range, surgeons may avoid surgical aortic valve replacement (SAVR) because of concern over operative risk. This study examines outcomes of patients with EF ≤35% undergoing SAVR. Methods: From 2004 to 2019, 895 patients underwent SAVR for aortic stenosis (AS) and/or regurgitation (AR) by a single surgeon at our institution. From among these, 40 patients (4.47%) had an ejection fraction (EF) of 35% or less, forming the study group. Intra-aortic balloon pump was placed intraoperatively prophylactically pre-bypass in 18 out of the 40. Preoperative and post-operative echocardiograms were compared to determine changes in ejection fraction. Mid-term survival was assessed. Results: 16 patients presented with AS, 20 with AR, and 4 with a combination of AS and AR. Hospital survival was 97.5% (one patient death). The average ejection fraction progressively improved over time from 26% initially to 46% mid-term with mean follow-up of 43 months (0.1–140.7). Remarkably, five-year survival was comparable between the study group and an age- and gender-matched general population (p = 0.834). Downward trends in LV end-diastolic diameter and end-systolic diameter were seen. The former achieved statistical significance (6.0 cm to 5.3 cm; p = 0.0046), while the latter fell slightly short (4.8 cm to 4.1 cm; p = 0.056). Patients in whom an IABP was used had lower EFs than those without IABP (range 10–35, mean 23% vs. 15–35%, mean 27.6%). The EFs of the three subgroups improved significantly postoperatively (p < 0.001 for AS, p = 0.002 for AR, and p = 0.046 for AS and AR). Conclusions: Surgical AVR can be done safely in patients with a failing LV with EF ≤35%. Significant improvements in the ejection fraction are seen over time. We believe there is a role for prophylactic pre-bypass IABP. Five-year survival is normalized. Surgeons should not hesitate to perform AVR in these highly jeopardized patients.

Keywords

• aortic valve replacement
• ejection fraction
• heart failure
• intra-aortic balloon pump
• aortic stenosis
• aortic regurgitation