Hypertension and mortality in SARS-COV-2 infection: A meta-analysis of observational studies after 2 years of pandemic

Abstract

Background: The worldwide pandemic SARS-CoV-2 infection is associated with clinical course including a very broad spectrum of clinical manifestations, including death. Several studies and meta-analyses have evaluated the role of hypertension on prognosis, but with important limitations and conflicting results. Therefore, we decided to perform a new meta-analysis of the observational studies that explored the relationship between pre-existing hypertension and mortality risk in patients with SARS-CoV-2 infection, using more stringent inclusion criteria to overcome the limitations inherent previous meta-analyses.

Methods: A systematic search of the on-line databases available up to 31 March 2022 was conducted, including peer-reviewed original articles, involving the adult population, where the role of hypertension on mortality due to SARS-CoV-2 infection was determined by Cox-proportional hazard models. Pooled hazard ratio (HR) was calculated by a random effect model. Sensitivity, heterogeneity, publication bias, subgroup and meta-regression analyses were performed.

Results: Twenty-six studies (222,083 participants) met the pre-defined inclusion criteria. In the pooled analysis, pre-existing hypertension was significantly associated with mortality due to SARS-CoV-2 infection, both in unadjusted and adjusted models (HR: 1.55; 95% CI: 1.22 to 1.97). However, in separate analyses including results adjusted for crucial and strong predictors of mortality during SARS-CoV-2 infection (e.g. body weight), the association disappeared.

Conclusions: The results of this meta-analysis indicate that pre-existing hypertension is not an independent predictor of mortality during SARS-CoV-2 infection. Further studies should nevertheless be carried out worldwide to evaluate this role, independent of, or in interaction with, other confounders that may affect the mortality risk.

Keywords: COVID-19; Hypertension; Meta-analysis; Mortality; SARS-CoV-2.

Fig. 1

Forest plot of the predicting role of hypertension on the risk of mortality in SARS-CoV2 infection (results from adjusted data). Results are expressed as Hazard Ratio (HR) and 95% confidence intervals (95% CI). Squares indicate study-specific risk estimates (size of the square reflects the study-specific statistical weight); horizontal lines indicate 95% CI; diamond indicates the overall risk with its 95% CI.

Fig. 2

Sub-group analysis of the predicting role of hypertension on the risk of mortality in SARS-CoV2 infection (results from adjusted data). Results are expressed as Hazard Ratio (HR) and 95% confidence intervals (95% CI).