Abstract 20128: Effect of Renin-angiotensin Blockers on Left Ventricular Remodelling in Severe Aortic Stenosis

Abstract

Background: The use of renin-angiotensin blockers (RAB: angiotensin converting enzyme inhibitors, ACEI and angiotensin receptor blockers, ARB) in severe aortic valve stenosis (AS) remains controversial. We aim to explore the relation on their use with degree of left ventricular (LV) remodelling in patients with normal flow (NF) and low-flow (LF) severe AS despite preserved LV ejection fraction (LVEF). Methods: We studied 423 consecutive patients with aortic valve area (AVA) 50%. Subjects with concomitant valvular pathologies, congenital heart disease or prosthetic valves were excluded. NF was categorized as LV stroke volume index (SVi) > 35ml/m2. Increased left ventricular mass index (LVMI) was ≥96g/m2 and 116g/m2 in females and males respectively while abnormal relative wall thickness (RWT) was ≥0.45. Results: The median age was 74 yrs (IQR: 65-82). Prevalence of male subjects 52%, diabetes mellitus 61%, dyslipidemia 48% and hypertension 43%. A quarter of the patients were on RAB, with a mean duration of 6.7 months(IQR:1.0-72.3). Median LVMI for patients on RAB was 94.5 g/m2 (IQR: 87.3-144), whilst those without was 120.3 g/m2 (IQR: 102-159) (p=0.005). RAB use in patients with LF AS was significantly associated with normal LVMI, adjusted for hypertension (OR 2.00, p=0.002). The use of RAB had a duration dependent association with normal LVMI. Patients on RAB for a year were twice more likely to have normal LVMI (OR 2.24, p=0.048). This effect is greater in patients with 2 years of therapy (OR 3.417, p=0.002). In contrast, the use of RAB was not associated with normal LVMI in the NF group (p=0.428). There was no significant difference between use of either ACEI or ARB on LVMI (p=0.855). Patients on RAB had less risk of having concentric hypertrophy (OR= 0.373, p=0.009) and eccentric hypertrophy (0.392, p=0.025) as compared to those without. Conclusion: Use of RAB in LF severe AS may be associated with beneficial remodeling of the LV especially if prescribed for more than a year. Further studies are warranted to determine the deferential effects of RAB on clinical outcomes in LF versus NF AS.