CVD Risk Factors May Pose Greater Risk for COVID-19 Mortality than Preexisting Heart Disease

Risk factors for cardiovascular disease (CVD), including age, smoking, and type 2 diabetes, may put critically ill COVID-19 patients at greater risk of poor outcomes and death than preexisting heart disease itself, according to findings from a new study led by researchers from Michigan Medicine and published in Circulation: Cardiovascular Quality and Outcomes.

The study team analyzed hospital data from 5133 critically ill COVID-19 patients enrolled in the STOP COVID study. Records came from 68 US hospitals for patients admitted to intensive care units (ICU) between March 1 and July 1, 2020. Among those,1174 had preexisting coronary artery disease (CAD), congestive heart failure (CHF) or atrial fibrillation (AF).

When the investigators compared mortality for critically ill patients with preexisting CVD vs those without disease, mortality among the former was 30% higher than among the latter. However, after multivariable adjustment for risk factors including age, race, sex, body mass index, and smoking, the team found the relationship was no longer statistically significant.

“The fact that the association between cardiovascular disease and death was so heavily diminished when accounting for comorbidities suggests that cardiovascular risk factors rather than preexisting heart disease are the main contributors to in-hospital death in patients with severe COVID-19,” said senior author Salim Hayek, MD, assistant professor of internal medicine and medical director at the University of Michigan Health Frankel Cardiovascular Center Clinics.

“The fact that the association between cardiovascular disease and death was so heavily diminished when accounting for comorbidities suggests that cardiovascular risk factors rather than preexisting heart disease are the main contributors to in-hospital death in patients with severe COVID-19."

The STOP-COVID registry

To help learn more about the contribution of CVD, a common condition among patients with severe COVID-19, to mortality in these patients, the Michigan Medicine researchers took advantage of data collected for the multicenter observational/registry, the Study of the Treatment and Outcomes in Critically Ill Patients With COVID-19 or STOP-COVID. The project’s goal is to determine independent risk factors for hospital mortality and acute organ injury in patients critically ill with COVID-19 and to identify strategies that may improve survival.

Primary exposure was CVD (ie, CAD, CHF, AF/Fl). A secondary exposure was myocardial injury, measured on admission to the ICU and defined as a troponin I or T level >99th percentile upper reference limit of normal. The study’s primary outcome was 28-day in-hospital mortality and secondary outcomes included CV events within 14 days, including cardiac arrest, new-onset arrhythmias, new-onset heart failure, myocarditis, pericarditis, or stroke)

The original cohort of 5133 was 62.9% men and had an average age of 61 years. Among the 5133, preexisting CVD was identified in 1174 (22.9%). A total of 1178 (34.6%) patients died within 28 days of hospital admission and 90 (17.9%) had a CV event within 14 days.

After adjusting for age, sex, race, body mass index, history of smoking, and comorbidities, preexisting CVD was associated with a 1.15 (95% CI, 0.98–1.34) higher odds of death.

There was no independent association observed between preexisting CVD and CVD events, according to Hyek and colleagues.

Role of myocardial injury

The investigators found that whether or not a patient had preexsting CVD, those who were assessed with myocardial injury when admitted to the ICU had higher odds of death (adjusted odds ratio, 1.93 [95% CI, 1.61–2.31]) and CV events (aOR, 1.82 [95% CI, 1.47–2.24]).

Nearly half of ICU patients in the study presented to the ICU with myocardial injury, with higher troponin levels increasing the likelihood of death. In fact, mortality among patients with the highest troponin levels was nearly 3 times more likely than in those without evidence of the marker. Cardiac injury, the investigators suggest, may be a marker for severity of COVID-19 illness.

“While patients with severe COVID commonly had signs of cardiac injury, our findings reinforce COVID-19 as a pulmonary disease with multi-organ injury related to systemic inflammation,” Hayek said. “The evidence of heart damage that we frequently see in patients with severe COVID-19 is more likely a reflection of the severity of the illness and the stress it imparts on all organs rather than the development of new complications or the exacerbation of preexisting cardiovascular disease.”

Study authors caution that their findings should in no way minimize the current knowledge that CVD increases the risk of death due to COVID-19. Patients with CVD tend to have a high burden of risk factors for the disease, such as diabetes, hypertension, and smoking, adds co-first author Alexi Vasbinder, PhD, RN, a postdoctoral fellow in internal medicine at the University of Michigan.

“We are currently working on studies to further define groups of patients with COVID-19 at highest risk for severe outcomes, such as those with advanced heart failure or coronary artery disease,” Vasbinder said.

Reference: Vasbinder A, Meloche C, Azam TU, et al for the STOP-COVID investigators. Relationship between preexisting cardiovascular disease and death and cardiovascular outcomes in critically ill patients with COVID-19. Circ Cardiovasc Qual Outcomes. 2022;0:10.1161/CIRCOUTCOMES.122.008942. doi/10.1161/CIRCOUTCOMES.122.008942