OBJECTIVES: Long-term left ventricular assist device (LVAD) support can cause accelerated progression of aortic insufficiency (AI). The MOMENTUM trial has led to increased use of the HeartMate 3 (HM3) LVAD, due to greater hemocompatibility. However, the differential effect on the rate of progression of AI during HM3 support versus HeartMate 2 (HM2) has not been extensively studied. This analysis compares the rates of progression to moderate or severe AI (MSAI) comparing a cohort of patients supported with the HM2 versus HM3. METHODS: A retrospective review was performed on all consecutive patients implanted with HM2 or HM3 between May 2005 and June 2020. Follow-up time was limited to the first 6 years after LVAD implantation. Demographics and 4005 echocardiograms were assessed for 536 HM2 and 300 HM3 patients. The primary end point was progression to MSAI. Univariable and multivariable Cox proportional hazard regression and landmark analyses were performed. RESULTS: Progression to MSAI was greater in the HM2 (17%) versus HM3 (9.9%) cohort. On the univariable analysis, the hazard ratio for HM3 was 0.581 (95% confidence interval 0.370-0.909, P = 0.02) whereas on multivariable analysis hazard ratio was 0.624 (95% confidence interval 0.386-1.008, P = 0.0537). Preoperative AI, female sex and body surface area <2 were significantly associated with progression to MSAI. Landmark analysis suggests that LVAD type has the most significant effect on progression to MSAI between 1 and 2 years post-implantation. CONCLUSIONS: Current practice strategies achieved low rates of progression to MSAI. Preoperative AI, female sex and body surface area <2 were the most important predictors of progression to MSAI. Pump type appears to be of secondary importance.