RAAS blockers and region-specific variations in COVID-19 outcomes: findings from a systematic review and meta-analysis

ABSTRACT

BackgroundCoronavirus disease 2019 (COVID-19) has evolved as a global crisis with high mortality seen in elderly and people with cardiometabolic diseases. The use of renin angiotensin aldosterone system (RAAS) blockers in these patients is known to enhance the expression of ACE-2, the chief binding receptor of SARS-CoV-2 and may potentially enhance infectivity. ObjectiveTo provide a pooled estimate of the effect of RAAS blocker usage on COVID-19 outcomes. Data SourcesAn electronic literature search was performed for published (using MEDLINE/PubMed and Google Scholar) and preprint (using bioRxiv and medRxiv) studies of interest. The last search was conducted on 9th July 2020. Study SelectionStudies reporting data on RAAS blocker use and COVID-19 mortality and severity were included in the review. Data Extraction and SynthesisMortality data and severity data including hospitalization, intensive care unit (ICU) admission, invasive ventilation, steroid use and acute kidney injury (AKI) were recorded. Pooled Odds ratio (OR) estimates were reported with 95% CIs and level of heterogeneity (I2). Main Outcomes and MeasuresOdds of mortality in users of RAAS blockers with respect to non-users was the primary outcome. Odds of severity, hospitalization, ICU admission, mechanical ventilation, steroid use, and AKI in users with respect to non-users of RAAS blockers were the secondary outcomes. ResultsOf 1348 articles identified, 48 published studies were included in the final analysis, with a total of 26432 patients from 31 studies included in mortality analysis and 20127 patients from 23 studies included in severity analysis. Majority of the studies (41.6%) were from China. No increased risk of mortality (Pooled OR 0.91 (0.65-1.26), I2=89%) or severity (Pooled OR 1.08 (0.79-1.46), I2=88%) was seen with RAAS blockers. The drug class was protective in hypertension (pooled OR 0.63 (0.46-0.86), I2=58%). Severity of COVID-19 outcomes was found to be high for Europeans (Pooled OR 2.08 (1.52-2.85), I2=77%) and US patients (Pooled OR 1.87 (1.62-2.17) in users of RAAS-blockers. A nearly 4 times higher risk of hospitalization, two times higher risk of ICU admission and mechanical ventilation was observed in US patients on RAAS blockers. No net effect on mortality and severity outcomes was seen in Chinese patients. RAAS blocker usage did not have any effect on corticosteroid use and AKI in Chinese patients. Conclusions and RelevanceUse of RAAS blockers is not associated with increased risk of mortality in COVID-19 patients. Reduced mortality is seen in hypertensive patients with COVID-19 and therefore the drugs should be continued in this subset. US and European patients are at higher risk of severe outcomes. Pharmacogenomic differences may explain the ethnicity related variations.