COVID-19 at Time of Heart Attack Linked to Higher Mortality Risk

Hospitalized patients who had both ST-elevation myocardial infarction (STEMI) and COVID-19 had an excess risk of mortality, even after discharge, according to long-term results from a registry analysis.

In a group of over 2,300 patients hospitalized with STEMI, the 1-year mortality rate was 45% in those who were also positive for COVID compared with 27% in those who tested negative and 11% of historical controls from 2018-2019, reported Payam Dehghani, MD, of Prairie Vascular Research in Regina, Saskatchewan, at the Society for Cardiovascular Angiography and Interventions (SCAI) annual meeting in Montreal.

The study was simultaneously published in JSCAI.

All-cause mortality was significantly higher in the COVID-positive group (HR 4.88, 95% CI 3.73-6.39, P<0.001) and the COVID-negative group (HR 3.93, 95% CI 2.92-5.29, P<0.001) compared with historical controls.

A majority of deaths (86%) occurred during the index hospitalization. Among survivors beyond hospitalization, the 1-year mortality rate was 12% in the COVID-positive group (HR 2.20, 95% CI 1.26-3.85, P=0.006), 9.6% in the COVID-negative group (HR 2.31, 95% CI 1.26-4.21, P=0.007), and 5.3% in historical controls (P<0.001).

“These findings suggest that the higher mortality observed in COVID-19-positive STEMI patients likely reflects both the system-level impact of the COVID-19 pandemic and a fundamentally different thrombo-inflammatory disease process,” Dehghani and colleagues wrote. “Post-discharge risk does not return to that of historical STEMI cohorts, supporting the need for closer follow-up and intensified secondary prevention in these higher-risk groups.”

The mortality differences between the pandemic-period patients and the prepandemic control group may have been driven by factors such as substantially longer door-to-balloon times, the researchers explained, which reflect the presentation and care delivery delays during the pandemic. “The intermediate outcomes observed in COVID-19-negative patients suggest that system-level disruptions during the pandemic, beyond confirmed infection alone, adversely affected STEMI prognosis,” they noted.

Patients with STEMI and COVID also likely face a “unique angiographic phenotype,” they cautioned, with a diffuse thrombotic burden and microvascular involvement. That can lead to more unsuccessful percutaneous coronary interventions, more thrombotic lesions, greater residual myocardial injury, and more microvascular dysfunction.

The researchers used data from the North American COVID-19 Myocardial Infarction (NACMI) registry, which tracks patients with suspected or confirmed COVID who present at a hospital with STEMI.

A previous analysis of NACMI data found that COVID-positive STEMI patients had a 36% risk of a composite outcome of in-hospital death, stroke, recurrent MI, or repeat unplanned revascularization. That was significantly higher than the 13% risk observed in patients suspected of infection without testing positive, and the 5% risk among matched controls (P<0.001 for both).

For the current analysis, Dehghani and colleagues included 2,358 patients hospitalized with STEMI (70% men, 79% white).

Patients with STEMI and COVID had a significantly longer median hospital length of stay compared with the historical controls (6 days vs 2 days) and a significantly lower prevalence of prior MI (15% vs 22%), and were significantly less likely to be white (55% vs 91%). They also were significantly more likely to have hypertension (69% vs 64%) and diabetes (43% vs 26%; P<0.001 for all comparisons).

Of the STEMI and COVID-positive patients, 59% underwent primary PCI compared with 77% of those in the COVID-negative and control groups (P<0.001). Positive patients were more likely than negative patients to receive only medical management (16% vs 9.1%).

Most of the deaths in the pandemic-period groups occurred during the index hospitalization — 84% in the STEMI and COVID-positive group and 71% in the COVID-negative group versus 44% in the control group. The median time to death was 27 days in the COVID-positive group versus 75 days in the COVID-negative group.

Study limitations included the potential for COVID infections to have caused some of the excess deaths, independent of STEMI. The historical control group may have experienced system-related differences that could confound comparisons.