New insights on the mechanisms of myocardial injury in hypertensive patients with COVID-19
Authors: Moll Bernardes R , Ferreira J R , Sousa A S , Schaustz E B , Tortelly M B , Pimentel A L , Figueiredo A C B S , Noya-Rabelo M M , Fortier S , Albuquerque D C , Rosado De-Castro P H , Camargo G C , Souza O F , Luiz R R , Medei E 
Published: November 2023

Abstract

Introduction
Cardiac comorbidities, particularly hypertension, are highly prevalent in patients hospitalized with COVID-19 and are related directly to the risk of clinical disease progression. Cardiac injury is the most frequently reported cardiac abnormality in these patients. Diverse forms and mechanisms of myocardial injury, including acute myocardial ischemia due to plaque rupture, oxygen supply/demand imbalance, non-ischemic injuries such as myocarditis, direct virus-mediated injury, and immune system dysregulation, have been described in patients with COVID-19.

Purpose
The mechanism of the association among hypertension, COVID-19 and cardiac injury and the reasons for worse clinical progression in these patients have not been elucidated clearly. Considering that myocardial injury due to direct SARS-CoV-2 infection is rare and that the immune system is often dysregulated in patients with COVID-19, and also that cytokine storm and lymphopenia are important immune markers of progression to severe disease, the present study aimed to investigate the immune profile of hypertensive patients with COVID-19 and myocardial injury to obtain a better understanding of the immune dysregulation and to provide new insights on the mechanism of myocardial injury in hypertensive patients with this disease.

Methods
All patients were selected prospectively from a multicenter registry of adults hospitalized with confirmed COVID-19. Cases had hypertension and myocardial injury, defined by troponin levels above the 99th percentile upper reference limit, and controls were hypertensive patients with no myocardial injury. Biomarkers and immune cell subsets were quantified and compared between the two groups. A multiple logistic regression model was used to analyze the associations of clinical and immune variables with myocardial injury.

Results
The sample comprised 193 patients divided into two groups: 47 cases and 146 controls. Relative to controls, cases had lower total lymphocyte count, percentage of T lymphocytes, CD8+CD38+ mean fluorescence intensity (MFI), and percentage of CD8+ human leukocyte antigen DR isotope (HLA-DR)+ CD38–cells and higher percentage of natural killer lymphocytes, natural killer group 2A (NKG2A)+ MFI, percentage of CD8+CD38+cells, CD8+HLA-DR+MFI, CD8+NKG2A+MFI, and percentage of CD8+HLA-DR–CD38+cells. On multivariate regression, the CD8+HLA-DR+MFI, CD8+CD38+MFI, and total lymphocyte count were associated significantly with myocardial injury.

Conclusion
Our findings suggest that lymphopenia, CD8+CD38+MFI, and CD8+HLA-DR+MFI are immune biomarkers of myocardial injury in hypertensive patients with COVID-19. The immune signature described here may aid in understanding the mechanisms underlying myocardial injury in these patients. The study data might open a new window for improvement in the treatment of hypertensive patients with COVID-19 and myocardial injury.