STEMI Outcomes, Mortality Improved Among COVID-19 Patients in 2021 Versus 2020

Santiago Garcia, MD

Patients with ST-elevation myocardial infarction (STEMI) faced significantly reduced risk of mortality while infected with COVID-19 over the course of the pandemic, according to new prospective registry data analysis.

In new findings presented in a late-breaking session at the American College of Cardiology (ACC) 2022 Scientific Sessions in Washington, DC, this weekend, a team of investigators reported a 10 percentage-point decrease in mortality rates among patients with an index severe myocardial infarction at the same time as a recent COVID-19 infection from the time prior to and after the regulation of mRNA COVID-19 vaccines in the US.

Presented by Santiago Garcia, MD, of the Christ Hospital and Minneapolis Heart Institute Foundation, the study derived data from the North American COVID-19 STEMI (NACMI) registry to define trends in clinical characteristics, management and outcomes of patients with STEMI treated for COVID-19 in 2020 versus those treated in 2021.

As Garcia and colleagues noted, COVID-19 infection has been associated with significantly increased risk of arterial and venous thromboembolic complications; MI risk has been observed to approximately double within a week of COVID-19 diagnosis, and is linked to increased mortality risk than the general population’s.

“Despite increased number of COVID-19 cases worldwide, significant progress has been made in both disease prevention and management during the course of the pandemic, which has contributed to a marked reduction in mortality in selected countries,” investigators wrote. “We previously reported very high (33%) in-hospital mortality for patients with STEMI and COVID-19 treated in North America during the early phase of the pandemic.”

The team conducted a multi-center observational analysis of the NACMI registry data, which includes non-exclusive, broad enrollment criteria from hospitalized COVID-19 cases among patients with STEMI.

Patients included in the trial wer adults ≥18 years old who tested postive for COVID-19 within 4 weeks prior to or during the index STEMI hospitalization. They also had ST-segment elevation in ≥2 contiguous leads, or a clinical correlate of myocardial ischemia.

Investigators sought a primary outcome of in-hospital mortality, and secondary outcomes of stroke and composite death, stroke or reinfarction.

The observed population was 586 COVID-19-positive patients with STEMI; 227 (38.7%) were treated in 2020 and 359 (61.3%) were treated in 2021. Though COVID-19 vaccines were not commercially available in 2020, and vaccine status was not routinely captured in NACMI’s 2021 data, investigators did observe that 171 of 193 (89%) patients with vaccine status data were reported as unvaccinated.

More than half of each arm was <66 years old (56%), and approximately three-fourths of all patients were male. Approximately one-fourth had a history of coronary artery disease; just 16% of patients in each arm had a history of heart failure.

Garcia and colleagues observed a 25% decrease in in-hospital mortality risk among patients with COVID-19 treated for STEMI in 2021 versus 2020 (95% CI, -47 to -5; P = .01). All hospitalized patients faced a 1.7-fold increased risk of mortality if infiltrates were observed on X-Ray examination (95% CI, 1.2 - 2.4; P = .002), and 2.9-fold greater if cariogenic shock was present (95% CI, 1.9 - 3.9; P <.001).

For composite in-hospital outcomes, 35% of patients in 2020 suffered all-cause mortality, stroke or reinfarction, versus 25% of patients in 2021 (P <.01). Patients in 2021 additionally reported 2 fewer mean days spent in the intensive care unit (2 vs 4; P = .01) as well as in the hospital overall (5 vs 7; P <.01).

Investigators observed no in-hospital mortality among the 22 patients vaccinated against COVID-19, versus 37 (22%) of unvaccinated patients.

When considering potential mediators in the improvement of STEMI mortality and outcomes among COVID-19 patients in 2021 versus 2020, Garcia and colleagues considered the lower risk profile of latter patients, as well as more typical ischemic symptoms, less cariogenic shock and pulmonary involvement.

They additionally noted the decreased likelihood of respiratory complications among patients to be vaccinated for COVID-19.

“In summary, the clinical profile, management and outcomes of STEMI patients with COVID-19 infection is evolving towards that of STEMI patients prior to the pandemic,” investigators concluded, “although mortality remains high for unvaccinated patients.”

The study, “Trends in Clinical Characteristics, Management Strategies and Outcomes of STEMI Patients with COVID-19,” was presented at ACC 2022.