Myocardial Infarction With Nonobstructive Coronary Arteries: A Significant Adverse Effect of Dihydroergotamine

Dihydroergotamine (DHE), a semi-synthetic ergot alkaloid, has been widely used for decades as an effective treatment for refractory migraines due to its potent vasoconstrictive properties and favorable tolerability profile. Acting primarily through serotonin 5HT1B and 5HT1D receptors, DHE reduces neurogenic inflammation and trigeminal nerve-mediated nociception. However, its broad receptor activity, including alpha-adrenergic, dopaminergic, and serotonergic receptors, also underlies significant cardiovascular risks. In particular, DHE-induced vasoconstriction extends beyond cranial vessels to coronary arteries, potentially leading to serious adverse outcomes such as coronary vasospasm and myocardial infarction. This case report presents a rare instance of DHE-induced myocardial infarction with nonobstructive coronary arteries (MINOCA), emphasizing the importance of recognizing this potentially life-threatening complication. Despite long-term use without prior adverse effects, our patient developed MINOCA after receiving DHE to treat migraine attacks, highlighting the unpredictable nature of DHE's vasoconstrictive effects and underscoring the need for heightened clinical vigilance, especially in patients with underlying cardiovascular risk factors. Given the diagnostic and prognostic ambiguity surrounding MINOCA, this case contributes to the growing body of literature advocating for individualized risk assessment and cautious DHE administration.