Multi-Modality Imaging to Determine Underlying Causes of MINOCA in Women and Men

Exclusion criteria encompassed angiographic ≥50% diameter stenosis, coronary dissection, or alternative etiologies for the presentation.

Independent core laboratories performed blinded interpretations of the imaging data.

• This international, prospective diagnostic study enrolled patients with a clinical MI diagnosis across 28 sites in the United States, Canada, and the United Kingdom.
• After an initial women-only phase, enrollment included both sexes.
• All participants underwent multi-vessel coronary optical coherence tomography (OCT) during index coronary angiography and cardiac magnetic resonance imaging (CMR) within one week.

CMR was completed in 284 participants (85% of those enrolled for CMR).

The sex distribution did not reach statistical significance (p=0.18).

Non-ischemic patterns accounted for 23% of cases, with no sex difference reported (p=0.78).

• Of 754 enrolled, 389 had MINOCA, and 336 underwent OCT (270 women and 66 men).
• OCT identified a culprit lesion in 45% of the OCT cohort (116/270 women; 35/66 men).
• CMR revealed an ischemic pattern in 114 of 284 cases overall (40%), with no significant sex disparity (women: 96/225; men: 18/59; p=0.12).

• An etiologic cause for the clinical presentation was determined in 79% of patients who completed both imaging modalities: ischemic MINOCA accounted for 59%, while non-ischemic mimics comprised 20%.
• When evaluated independently, OCT alone identified a MINOCA etiology in 151/336 cases (45%), whereas CMR alone detected abnormalities in 180/284 cases (63%).
• The combined imaging approach clarified underlying mechanisms and yielded discordant findings in some instances, underscoring complementary value across modalities.

• OCT-detected culprit lesions were associated with older age, abnormal index angiography, and the breadth of vessels imaged; notably, 27% of angiographically normal cases still harbored a culprit lesion on OCT.
• Abnormal CMR correlated with higher peak troponin, shorter time to CMR, and non-Asian race; nonetheless, abnormal CMR occurred in 40% of cases even when troponin was less than fourfold above the upper limit of normal.
• The study found no significant sex differences in overall imaging results.

• Clinical factors alone showed limited utility in predicting imaging abnormalities, emphasizing the added value of multi-modality imaging for MINOCA workup.
• The study did not report post-imaging outcomes or long-term prognostic implications, focusing on diagnostic yield and modality-specific findings.
• It remains unspecified whether specific imaging findings translate into differential management or prognosis beyond the diagnostic categorization.