In-hospital STEMI Mortality Higher With COVID-19

Batya Swift Yasgur, MA, LSW

November 03, 2021

Editor's note: Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

ST-segment elevation myocardial infarction (STEMI) with a concomitant diagnosis of COVID-19 is associated with higher rates of in-hospital mortality vs STEMI without COVID-19, new research suggests.

Investigators retrospectively analyzed data from more than 80,000 patients, using propensity score matching to compare those with COVID-19 and STEMI to two control groups: patients hospitalized with STEMI in 2019 and patients without COVID-19 who were hospitalized with STEMI in 2020.

After adjusting for patient and hospital factors, they found 15.2% of patients with COVID-19 and out-of-hospital STEMI died, compared with 11.2% of patients with STEMI but without COVID-19.

For those with in-hospital STEMI and COVID-19, in-hospital mortality was 78.5% vs 46.1% for those without COVID.

The researchers obtained similar findings when they compared patients with COVID-19 and STEMI to patients without COVID-19 and STEMI from 2020, or patients with STEMI from 2019, prior to the onset of COVID-19.

"With better understanding of the association between STEMI and COVID-19, we highly encourage practicing clinicians to educate their patients about the importance of mitigating the risk of contracting COVID-19 infection, both in those at risk for acute coronary syndromes and in those who are not, as they may still serve as carriers who may transmit infections to patients at risk," lead author Marwan Saad, MD, PhD, director of interventional structural heart research, Lifespan Cardiovascular Institute, Providence, Rhode Island, told | Medscape Cardiology.

The study was published online October 29 in the Journal of the American Medical Association.

Sparse Data

"Poorer STEMI-related outcomes have been reported throughout the pandemic, including higher rates of in-hospital mortality," but "whether these outcomes have been the result of pandemic-related factors or SARS-CoV-2 infection is unclear," the authors write.

Although data from small studies suggest poorer outcomes following out-of-hospital STEMI in those with COVID-19, "few broadly representative data exist" and there is little research that characterizes acute in-hospital STEMI in patients hospitalized with COVID-19, they state.

"While it is not unexpected that patients with any medical condition will fare worse if they have concomitant COVID-19, few published data were available characterizing the association between COVID-19 and outcome in patients with STEMI," said Saad, who is also an assistant professor of cardiovascular medicine at Warren Alpert Medical School of Brown University.

The researchers aimed to "better understand and quantify the risk of in-hospital mortality in patients with STEMI and COVID-19, including the less common situation where patients develop STEMI while hospitalized for another condition."

To investigate the question, they turned to the Vizient Clinical Database that includes information from patients hospitalized at 757 academic medical centers and affiliated hospitals in all 50 states. They included adult patients 18 and older hospitalized with STEMI at a percutaneous coronary intervention (PCI)-capable center between January 1, 2019, and December 31, 2020.

The analysis focused on patients from 509 centers who sustained out-of-hospital or in-hospital STEMI.

Of the out-of-hospital STEMI patients (n = 76,434), 64.1% fell between ages 51-74 years, and most (70.3%) were male; after propensity matching, 551 were found to have COVID-19, vs 2755 without COVID-19.

Of the in-hospital STEMI patients (n = 4015), 58.3% were between ages 51-72 years and 60.7% were male; after propensity matching, 252 were found to have COVID-19, while 756 did not.

Patients with COVID-19 were significantly more likely to receive self-standing fibrinolytics, compared with those without COVID-19 (8.1% vs 1% respectively). On the other hand, they were less likely to undergo coronary angiography (30.4% vs 50.8), any PCI (22.8% vs 36.5%), or coronary artery bypass grafting (0.3% vs 7.3% — all P values < .001). Moreover, mechanical circulatory support was used significantly less frequently in patients with COVID-19 (5% vs 12.1%).

Inflammatory Connection?

There were notably higher rates of in-hospital mortality in those with in-hospital STEMI and COVID-19, compared to those with in-hospital STEMI but no COVID-19. No similar difference was found among out-of-hospital STEMI patients.

Table. Mortality with out-of-hospital and in-hospital STEMI with and without COVID-19.

  In-hospital mortality with COVID-19  (%) In-hospital mortality without COVID-19  (%) Absolute difference
(95% CI)
P value
Out-of-Hospital STEMI 15.2 11.2 4.1
(1.1 - 7.0)
In-hospital STEMI 78.5 46.1 32.4
(29.0 - 35.9)
< .001

The researchers examined several secondary outcomes and found that patients with COVID-19 had significantly higher rates of a composite of death, stroke, or MI (80.9% vs 50.9%; absolute difference, 29.9% [95% CI, 26.7% - 33.2%]) and composite death or stroke (80.9% vs 50.4%; absolute difference, 30.5% [95% CI, 27.2% - 33.7%] both P s < .001).

In sensitivity analyses, rates of in-hospital mortality remained significantly higher in patients with COVID-19 compared with a control group from the same calendar year, a control group matched on center, and a control group excluding patients who were transferred, the authors report.

Multivariable regression analysis using propensity matching with a control group from 2019 showed COVID-19 was associated with significantly higher rates of in-hospital mortality (OR, 5.77; 95% CI, 3.93 - 8.46; P < .001).

"While our study did not elucidate the exact mechanism [or mechanisms] underlying the association between COVID-19 and STEMI outcomes, potential mechanisms include the inflammatory state present with respiratory viruses such as COVID-19," Saad commented. "It is well established that inflammation is associated with cardiovascular events, such as myocardial infarction and cardiovascular death."

In addition, COVID-19 is associated with an increased risk of thrombotic complications, including STEMI and stent thrombosis, he noted. "The high thrombotic burden in patients with STEMI has been linked to suboptimal results following primary PCI, including worse outcomes and larger infarctions."

Largest Study to Date

Commenting for | Medscape Cardiology, Alexander Fanaroff, MD, MHS, assistant professor of medicine at the University of Pennsylvania in Philadelphia, said, "The big picture here is that we've known for a while because of a number of large studies that outcomes are worse for patients that have concomitant MI and COVID-19," but one of the distinguishing factors of this study is that it is the "largest study, covering the entire year of 2020."

Moreover, the study included two control groups — one including patients who did not have COVID-19 and were hospitalized in 2020, which enabled the researchers to "isolate changes due to the pandemic" — and the other who were hospitalized in 2019 prior to the COVID era, which enabled them to "look at the holistic effect of changes in care delivery, as well as having COVID-19," added Fanaroff, who was not involved in the study.

One drawback is that the study used administrative rather than clinical data, so it is "important to be circumspect with conclusions," noted Fanaroff, who is the co-author of an accompanying editorial.

"What we can say with certainty is that it's better not to have COVID-19 than to have COVID-19, regardless of whether you have had an MI, and to the extent to which patients with cardiovascular disease can avoid being exposed to COVID-19 and get vaccinated is important — and this study reinforces the importance of that."

No source of funding was listed. Saad has disclosed no relevant financial relationships. The other authors' disclosures are listed on the original paper. Fanaroff reports receiving grants from the American Heart Association and the National Institutes of Health and personal fees from Intercept Pharmaceuticals outside the submitted work. His co-authors' disclosures are listed on the original editorial.

JAMA. Published online October 29, 2021. Full text, Editorial

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