Should cardiovascular disease comorbidity scare you during the COVID-19 season?

by:
Dr. Jeemon Panniyammakal, PhD, MPH, FESC

The SARS-CoV-2 infection (corona virus infection) spread has reached pandemic proportions. Globally, as on 31 March, 2020 nearly 0.8 million corona virus disease (COVID-19) cases and 38,000 related deaths are reported. Countries around the world are particularly “shielding” or “protecting” individuals with cardiovascular disease (CVD) from external exposure (https://www.cdc.gov/coronavirus/2019-ncov/hcp/underlying-conditions.html) due to the observed spectrum of comorbidities in the initial and subsequent reports of deaths from COVID-19. 

In this context, the analyses by Zhou et al presented in the Lancet journal and published on 11^th March 2020, is thought provoking and interesting (https://doi.org/10.1016/S0140-6736(20)30566-3). In their laboratory confirmed cohort of 191 COVID-19 patients (62% males) from two major centres in China, 54 patients died in the hospital. The authors’ identified several factors associated with mortality by comparing the patient characteristics across survivors and non-survivors. Let us focus on the cardiovascular disease (CVD) related conditions. Hypertension was reported in 48% (26/54) and 23% of non-survivors and survivors, respectively. Diabetes was reported in 31% (17/54) of non-survivors, while it was 14% in survivors. Similarly, coronary heart disease was reported in 24% (13/54) and 1% (2/137) of non-survivors and survivors, respectively. During the hospitalisation period, acute cardiac injury was reported in 59% (32/54) of non-survivors, while it was just 1% in survivors. Similarly, 52% (28/54) and 12% of non-survivors and survivors reported heart failure during the hospitalisation period, respectively. The multi-variate model presented in the Zhou et al paper was however not robust enough to detect meaningful differences in cardiovascular conditions across the two groups due to inadequate sample size. 

The findings from Zhou et al paper suggest that co-morbid cardiovascular conditions probably increase the risk of mortality in COVID-19 patients. Consistent findings are also reported in other papers. For example, the case fatality was reported as 3-5 times higher in COVID-19 patients with hypertension, diabetes and cardiovascular diseases in an analyses of over 72,314 cases from China (https://doi:10.1001/jama.2020.2648). However, the relatively higher background mortality rate in patients with CVD in comparison to the general population should be accounted while comparing the case fatality rate. 

The findings from Zhou et al paper also suggest that in COVID-19 patients, the infection itself can probably increase CVD complications and death. However, it is not clear whether the CVD complications are more pronounced in individuals with background cardiovascular comorbid conditions. Acute myopericarditis (pericarditis is the inflammation of the thin tissue sac that surrounds the heart) in an apparently healthy male COVID-19 patient, several days after the symptom onset and even without the symptoms and signs of interstitial pneumonia, in a recent case report indicates a possible direct association with SARS-CoV-2 infection (https://doi:10.1001/jamacardio.2020.1096). Similarly, higher incidence of myocardial injury has been reported in patients with SARS-CoV-2 infection (doi:10.1001/jamacardio.2020.0950 and doi:10.1001/jamacardio.2020.1017).   Myocardial injury, cardiac arrhythmia, cardiac arrest, cardiomyopathy, heart failure, cardiogenic shock, venous thromboembolisms are some of the known cardiovascular sequel seen in patients with COVID-19. 

The higher incidence of cardiovascular outcomes in COVID-19  may be associated directly with the infection or the physiological response to the infection and the background comorbidity status. The mechanisms could be manifold, and multifactorial. However, the complex and often bi-directional relationship observed in a restricted number of high risk hospitalised patients may limit the causal interpretation of the observed association. We need to generate more data on cardiovascular comorbidities in COVID-19 patients and their likely impact on disease severity and survival for better management, future planning and resource allocation.