One Health System Sees MI Hospitalizations Rebound

Heart attack hospitalizations fell during the early weeks of the COVID-19 pandemic but appeared to be rebounding by May in Texas and some Western states, a health system found.

Trends in weekly acute MI hospitalizations could be divided into three phases across 49 hospitals in the Providence St. Joseph Health system located in six states (Alaska, Washington, Montana, Oregon, California, and Texas):

• Before COVID (Dec. 30, 2018 to Feb. 22, 2020): average 222 cases per week
• Early COVID (Feb. 23, 2020 to March 28, 2020): –19.0 cases per week (95% CI –29.0 to –9.0) from pre-COVID
• Later COVID (March 29, 2020 to May 16, 2020): +10.5 cases per week (95% CI 4.6-16.5) from early COVID

The rebound in cases could be related to proactive “encouragement of patients with symptoms or signs of acute MI to seek immediate medical attention” during the pandemic, though weekly case rates still had not returned to baseline by the end of the observation period, according to Ty Gluckman, MD, of Providence St. Joseph Health in Portland, Oregon, and colleagues writing in JAMA Cardiology.

“Results of this cross-sectional study appear to validate previous concerns that large numbers of patients with acute MI initially avoided hospitalization during the COVID-19 pandemic, likely out of fear of contracting SARS-CoV-2.”

The study also found that patients who did come to the hospital for MI treatment during the pandemic had unexpectedly high mortality.

After adjusting for risk using an institutional model, Gluckman and colleagues calculated an observed-to-expected (O/E) in-hospital mortality ratio of 1.27 during the early COVID-19 period (95% CI 1.07-1.48). A similar trend was observed during the later COVID-19 period without quite reaching statistical significance (O/E mortality ratio 1.23, 95% CI 0.98-1.47).

There were no major differences in patient demographics, cardiovascular comorbidities, and treatment approaches across periods.

Patients with ST-segment elevation MI (STEMI) had particularly high O/E mortality ratios during both early COVID-19 (1.96, 95% CI 1.22-2.70) and later COVID-19 (2.40, 95% CI 1.65-3.16). Their risk of in-hospital mortality was markedly higher compared to similar STEMI cases before the pandemic (adjusted OR 1.52, 95% CI 1.02-2.26).

“Given the time-sensitive nature of STEMI, any delay by patients, emergency medical services, the emergency department, or cardiac catheterization laboratory may have played a role. Additional complications from delayed reperfusion (e.g., conduction disturbances, heart failure, cardiogenic shock, and mechanical complications) may have occurred in some patients,” Gluckman and colleagues said.

“Further research is needed to identify factors associated with the higher mortality rate in patients with STEMI,” they urged.

Their retrospective study included 14,724 adults (mean age 68 years, 66% men) who were hospitalized with acute MI during the study period.

Reliance on ICD codes to identify eligible patients meant the dataset was subject to miscoding, Gluckman’s team acknowledged. Their study also lacked information on the COVID-19 status of included patients, so it is unclear if the rise in acute MI mortality can be tied to concurrent SARS-CoV-2 infection.

“In the weeks and months to come, clinicians may see greater numbers of patients with more severe manifestations of acute MI. With the uncertainty on timing of a COVID-19 vaccine, this study reinforces the need to address important care processes for patients with acute MI to help mitigate further risk,” the investigators wrote.