STEMI Mortality at 1 Year Elevated in Setting of COVID-19: NACMI Registry

MONTREAL, Canada—The combination of COVID-19 and STEMI posed persistent risks during the pandemic that didn’t end when patients survived their hospitalization and went home, according to a long-term follow-up study from the North American COVID-19 Myocardial Infarction (NACMI) registry.

The uniquely high risk of patients with COVID-19 and STEMI was first documented by the registry in October 2020, showing in-hospital mortality rates of 33% versus 4% for historical STEMI patients prior to the pandemic. The new 1-year data show that the long-term outcomes continued to differ as well.

“This has never been done before because we sort of lost interest in this [COVID-19] population,” said Payam Dehghani, MD (Prairie Vascular Research, Regina, Canada), in a presentation at the Society for Cardiovascular Angiography and Interventions 2026 meeting. The findings were simultaneously published in JSCAI.

“The 1-year mortality of these patients looks different in a graded fashion,” Dehghani said.

In the full cohort, patients with COVID-19-positive status plus STEMI had the highest 1-year mortality (45%), followed by those with COVID-19-negative status plus STEMI (27%). The lowest rates were seen in a historical control cohort from the 2018-19 Midwest STEMI Consortium registry (11%).

 To TCTMD, Dehghani said he views the long-term analysis as a more informed look at the data than the original 2020 NACMI report. “We poked really hard at the data the second time along,” he said. “We went back to the statisticians. We really tried to look hard at exactly what happened.”

Some things from the registry do reflect pandemic-era conditions, however, such as longer door-to-balloon times in both the COVID-19-positive and COVID-19-negative patients compared with historical controls.

Still, Dehghani said the consistent excess risk of mortality is real and likely indicative of not just the system-level impacts of the pandemic, but also the distinct STEMI phenotype that occurs in the setting of COVID-19. Prior data have shown that this can involve greater thrombotic burden and microvascular dysfunction, often with atypical rates of nonculprit STEMI.

One drawback, however, is that by using all-cause mortality at 1 year as the primary endpoint, it’s impossible to know if some of the deaths in the COVID-19 group were related to things independent of infection and/or independent of STEMI.

According to Dehghani and colleagues, with COVID-19 still around, the data are a heads-up for physicians about the importance of close monitoring and follow-up in a patient who has a STEMI in the setting of an infection.

While this is likely one of the last reports to come out of NACMI, Dehghani said it served as “this amazing tool that really, under the microscope, blew up some of the differences in biology and in access to care.”

Six Years Later, Questions Remain

The substudy from the prospective, multicenter NACMI registry focused on 623 COVID-positive patients with STEMI, 694 COVID-negative patients with STEMI, and 1,041 STEMI control patients. COVID-negative patients were at one time referred to as persons under investigation (PUI) because they were suspected of having COVID at the time of their hospitalization but didn’t have a confirmed test.

Compared with the other two groups, patients with COVID and STEMI had longer lengths of stay, were less likely to be white, had a lower prevalence of prior MI, dyslipidemia, and smoking, and were less likely to undergo primary PCI. However, they had a higher prevalence of diabetes and hypertension. Additionally, more of the COVID-positive patients received medical therapy alone than did the COVID-negative patients (16% vs 9.1%).

The majority of deaths occurred during the hospital stay, with median time-to-death rates being shortest in the COVID-positive patients with STEMI.

Among those who survived the index hospitalization, 1-year mortality rates were 12% in the COVID-19-positive group, 9.6% in the COVID-19 negative group, and 5.3% in controls (P < 0.001).

“Six years after the height of the pandemic, we still have patients with long COVID, presumably immunologically mediated,” noted panelist Sandeep Nathan, MD (University of Chicago, IL). “Is it worth following these patients who have residual microvascular dysfunction long-term to see if there’s ever a point where it reverses?” He also wondered if there is evidence that patients remain hypercoagulable.

Timothy D. Henry, MD (The Christ Hospital, Cincinnati, OH), who presented the first NACMI report during TCT Connect 2020, and who was on the panel at the SCAI session, said there is no hard evidence to support a long-term hypercoagulable state in this patient population. He added that the availability of vaccinations and changing strains of COVID-19 appear to have improved the picture for today’s patients compared with those who had COVID-19 and STEMI during the pandemic.

“But the issue about microvascular dysfunction is a big one that we believe [improves] over time, but it’s been a little bit tough to get that data,” Henry added.