Renin–angiotensin system modulation and outcomes in patients hospitalized for interstitial SARS-CoV2 pneumonia: a cohort study

The role of cardiovascular (CV) pharmacotherapies in patients with severe COVID-19 pneumonia remains controversial. This study aims to assess the impact of renin–angiotensin system modulation (RASi) (either angiotensin-converting enzymes (ACEIs) or angiotensin-receptor blockers (ARBs)) on COVID-19 outcome.

We performed a cohort study on consecutive patients admitted for COVID-19 pneumonia at the Internal Medicine Unit of Sant'Orsola-Malpighi Hospital in Bologna, Italy. Patients with a possible alternative cause of respiratory failure other than COVID-19 were excluded. Clinical, pharmacological and laboratory data at admission and during the hospitalization were collected. Patients were treated with intravenous dexamethasone, low molecular weight heparin and nasal flow or Venturi mask oxygen. Subjects were followed until discharge, Intensive Care Unit (ICU) admission or death. Severe cases were defined by acute respiratory distress syndrome (arterial oxygen partial pressure and the fraction of inhaled oxygen ratio (P/F) ≤ 100 mmHg/%, or P/F ≤ 150 mmHg/% and respiratory rate ≥ 26/min). Patients with chronic use of RAS modulation were compared with those without for the composite outcome of in-hospital mortality or ICU admission. Hazard ratios (HR) were obtained by Cox regression, adjusted for several clinical factors.

Of the 268 patients enrolled in the study, 93 (35%, mean age 68 ± 13 years, 67% males) were treated with RASi (58% ACEIs and 42% ARBs). There were no meaningful differences between the RASI and no RASI group regarding clinical and laboratory parameters at admission. As expected, patients in the RASi group had a higher prevalence of hypertension, diabetes mellitus, atrial fibrillation, and ischemic heart disease. One hundred eight patients (40%) were admitted to ICU during hospitalization due to severe respiratory failure, and 24 (9%) died. The risk of in-hospital death or ICU admission was lower in the RASI group than in the non-RASI group (age and sex-adjusted HR 0.57, 95% CI 0.37–0.8), even after adjustment for several comorbidities (fully adjusted HR 0.44, 95% CI 0.26–0.74). Seven (7.5%) patients died in the RASi group vs 17 (9.7%) in the non-RASi group, leading to a non-statistically significant mortality risk reduction (fully adjusted HR 0.69, 95% CI 0.18–1.90). The lower risk in the RASi group was primarily related to ARBs use compared to ACEIs (HR 0.5, 95% CI 0.28–0.92 and HR 0.82, 95% CI 0.51–1.32, respectively).

Our study showed an inverse association between the chronic use of RASi and COVID-19 pneumonia severity (either ICU admissions or in-hospital death), even when significant comorbidities are considered.