MINOCA: The unexpected heart attack behind lower back pain and headache Myocardial infarction with non-obstructive coronary arteries (MINOCA)

Abstract

Introduction: Myocardial infarction with non-obstructive coronary arteries (MINOCA) is diagnosed when there is myocardial injury without significant obstructions in the coronary arteries. It accounts for 6% to 8% of all heart attacks and is more common in women. Diagnosis requires ruling out other causes of myocardial damage and identifying the underlying mechanism. Patients with MINOCA generally have a better prognosis than those with coronary artery disease myocardial infarction, although the prognosis varies depending on the underlying cause.

Clinical case: A 34-year-old woman with a history of renal lithiasis was admitted for severe low back pain, paresthesias in the right lower limb, and headache, with arterial hypertension (230/120 mmHg). Clinical outcomes with ECG-identified ischemia showed infranodal ST elevation in V2 to V6, DII, DIII, AVF. Troponins I and T were elevated, indicating myocardial injury. Echocardiogram revealed hypokinesia of the middle apical septum, anterior wall, lateral, and basal inferior segments. The reported ejection fraction (EF) was 46%. Coronary angiography showed no significant lesions, confirming the diagnosis of MINOCA. Magnetic resonance imaging of the spine detected a spinal tumor at T8 to T10.

Treatment and follow-up: After 2 weeks, follow-up showed a normal ECG. Troponins I and T were negative. Echocardiogram indicated no contractility disorders, with an improved ejection fraction of 63%. The patient underwent tumor removal, diagnosed as a grade I medullary astrocytoma.

Discussion: Female sex and physiological stress are factors that increase the risk of MINOCA. It is hypothesized that the severe pain caused by the spinal tumor may have triggered the release of catecholamines and cortisol, which could precipitate coronary spasm or arterial dissection. No cases of medullary astrocytoma have been reported in the literature as a cause of MINOCA.

Conclusion: This case suggests that the diagnostic algorithm for MINOCA should extend beyond the heart and consider spinal cord or brain pathology as potential causes of vasomotor instability.