Acute Myocardial Infarction Due to Coronary Artery Dissection in the Postpartum Period

Abstract

Cardiac disease is the leading cause of mortality in pregnancy, and acute myocardial infarction (AMI) accounts for a large proportion (20%) of it. 1 It has a significant contribution not only to maternal mortality, but to maternal and fetal morbid-ity as well. 1–3 In a large population-based study in the United States, the estimated incidence of pregnancy-related AMI was 6.2 per 100,000 deliveries. In addition, the risk of AMI appears to be approximately three to fourfold higher in pregnant as compared with nonpregnant reproductive age women. 2 Moreover, 25% of the cases of AMI during pregnancy or the postpartum period are due to spontaneous coronary artery dissection. In contrast, in nonpregnant women it is only responsible for < 1%. 4 This risk varies according to age, race, ethnicity, and parity. 2,5 The highest risk of AMI is among black women older than 35 years. For white women aged 35 years and older, the odds of having an AMI is five times higher than for their younger counterpart. 2 Complications of pregnancy that are significantly associated with AMI are preeclampsia, postpartum hemorrhage, transfusion, postpar-tum infection as well as fluid and electrolyte imbalances. 2 AMI can occur at any stage in pregnancy and more common in multigravidas. The vast majority of MI involves the anterior wall (78%). 6 The most common coronary artery affected is the left anterior descending (LAD) branch. 7 Coronary dissection is the primary cause of infarction in the peripartum period and more commonly in the postpartum period. 6 As shown in the Keywords ► acute myocardial infarction ► coronary artery dissection ► reproductive age ► peripartum period Abstract Background Though rare, myocardial infarction secondary to coronary artery dissec-tion is a life-threatening event. In reproductive age women, it commonly occurs during pregnancy or the postpartum period. Case We present a case of pregnancy-related acute myocardial infarction due to spontaneous coronary artery dissection in a 37-year-old woman who presented to the emergency room with shortness of breath and sudden onset of retrosternal chest pain 8 days after delivery of premature twins. Coronary artery catheterization showed 75 to 90% stenosis in the left main coronary artery (LMCA), extending into the proximal and mid left anterior descending (LAD) branch. The LMCA appearance in the heart catheterization was consistent with vasospasm, but it was not responsive to medical management. Subsequently, she underwent a second coronary artery catheterization and was found to have dissection requiring emergent coronary artery bypass graft  3 in the LMCA, circumflex, and LAD that was followed by an uneventful recovery. Conclusion Early diagnosis and management of myocardial infarction due to coronary artery dissection in the peripartum period is crucial. This condition should be suspected in young reproductive age women, even in the setting of minimal risk factors. Angiography is required for diagnosis. Management should be individualized as it may include both invasive and noninvasive measures.