Determinants of mortality in hypertensive patients admitted with COVID-19: a single-centre retrospective study at a tertiary hospital in South Africa

Abstract

Background

The Coronavirus Disease 2019 (COVID-19) pandemic has significantly impacted global health, with successive outbreaks leading to substantial morbidity and mortality. Hypertension, a leading cause of cardiovascular disease globally, has been identified as a critical comorbidity in patients with severe COVID-19, exacerbating the risk of adverse outcomes. This study aimed to elucidate the impact of hypertension on COVID-19 outcomes within the South African context.

Methods

A retrospective analysis was conducted at King Edward VIII Hospital, KwaZulu-Natal, South Africa, encompassing patients aged 13 years and above admitted with laboratory-confirmed SARS-CoV-2 infection between June 2020 and December 2021. The study investigated the association between hypertension and COVID-19 outcomes, analysing demographic, clinical, and laboratory data. Statistical analysis involved univariate and multivariate logistic regression to identify predictors of mortality among the hypertensive cohort.

Results

The study included 420 participants—encompassing 205 with hypertension. Hypertensive patients demonstrated significantly greater requirements for oxygen and steroid therapy (p < 0.001), as well as higher mortality rates (44.88%, p < 0.001)) compared to their non-hypertensive counterparts. Key findings demonstrated that a lower oxygen saturation (adjusted odds ratio (aOR) 0.934, p = 0.006), higher pulse pressure (aOR 1.046, p = 0.021), elevated CRP (aOR 1.007, p = 0.004) and the necessity for mechanical ventilation (aOR 5.165, p = 0.004) were independent risk factors for mortality in hypertensive COVID-19 patients. Notably, the study highlighted the pronounced impact of hypertension-mediated organ damage (HMOD) on patient outcomes, with ischemic heart disease being significantly associated with increased mortality (aOR 8.712, p = 0.033).

Conclusion

Hypertension significantly exacerbates the severity and mortality risk of COVID-19 in the South African setting, underscoring the need for early identification and targeted management of hypertensive patients. This study contributes to the understanding of the interplay between hypertension and COVID-19 outcomes, emphasising the importance of considering comorbidities in the management and treatment strategies for COVID-19. Enhanced pandemic preparedness and healthcare resource allocation are crucial to mitigate the compounded risk presented by these concurrent health crises.