Trends in the incidence and in-patient outcomes of acute myocardial infarction in pregnancy: Insights from the national inpatient sample.

STUDY OBJECTIVE: Pregnancy-related morbidity and mortality rates in the United States are rising despite advances in knowledge, technology, and healthcare delivery. Cardiovascular disease is the leading cause of adverse pregnancy outcomes, with acute myocardial infarction (AMI) being a potential contributor to the worse outcomes in pregnancy.

DESIGN/SETTING: We analyzed data from the national inpatient sample database to examine trends in the incidence and in-hospital outcomes of myocardial infarction in pregnancy from 2016 to 2020.

PARTICIPANTS: Using ICD-10-CM codes, we identified all admissions from a pregnancy-related encounter with a diagnosis of type 1 AMI.

MAIN OUTCOME: Using the marginal effect of years, we assessed the trends in the incidence of AMI and utilized a multivariate logistic regression model to compare our secondary outcomes.

RESULTS: Of the 19,524,846 patients with an obstetric-related admission, 3605 (0.02 %) had a diagnosis of type 1 AMI. Overall, we observed an approximately 2-fold increase in the trend of AMI from 1.4 to 2.5 per 10,000 obstetric admissions, with the highest incidence trend of 2.5 to 5.2 per 10,000 obstetric admissions seen in Black patients. Among patients diagnosed with AMI, we found significantly higher rates of in-hospital mortality (Adjusted Odds Ratio (AOR): 22.9, 12.2-42.8), cardiogenic shock (AOR:54.3, 33.9-86.6), preeclampsia (AOR: 2.2, 1.65-2.94) and spontaneous abortion (AOR:6.3, 3.71-10.6).

CONCLUSION: Over the 5-year period, we found increasing trends in the incidence of AMI in pregnancy, especially among Black patients. Incident AMI was also associated with worse pregnancy outcomes.