RAAS Inhibition & 1 Year Mortality Post LVAD Implantation: A Meta-Analysis

Abstract

<h3>Purpose</h3> Several single center retrospective studies have suggested a potential benefit with renin angiotensin aldosterone system inhibitors (RAASi) in patients with left ventricular assist devices (LVADs). Their effect on mortality in this population, however, has not been well described. <h3>Methods</h3> We previously reported a reduction in one-year mortality with RAASi at our center. To better define this potential relationship, we performed a meta-analysis of all studies evaluating the use of angiotensin-converting enzyme inhibitors (ACEI) and/or angiotensin receptor blockers (ARB) in LVAD patients and report their effect on mortality. We searched the PubMED database, for all relevant single and multi-center studies, regardless of publication year, using the key words LVAD, ACE and ARB. Publications utilizing registry data were excluded to avoid double counting patients. <h3>Results</h3> 4 studies met inclusion criteria with a total of 1,222 patients, of whom 36% were on RAASi (n=440). Adjusted effect measures were included in the analysis. The primary outcome was the overall mortality incidence using pooled HR to represent the overall effect size. Random-effects using DerSimonian and Laird model was used to calculate effect sizes due to anticipated high degree of heterogeneity (figure 1a). Sensitivity analysis was performed using the leave-one-out method with calculating the effect size after omitting each study at a time (figure 1b). Publication bias was deferred as less than 10 studies were included in the analysis. Our results showed borderline no mortality benefits for RAASi in LVAD patients with pooled HR of 0.41 (CI 0.17-1.02) albeit with a high degree of heterogeneity noted (I2 = 90.77%). <h3>Conclusion</h3> There is considerable heterogeneity in the literature examining outcomes of RAASi use in LVAD patients. Our meta-analysis suggests an unclear mortality benefit of RAASi use in LVAD patients at one year.