The objective was to assess in vivo culprit lesion morphologies that caused ST-segment elevation myocardial infarction (STEMI) using optical coherence tomography (OCT).Methods and results
Culprit lesions in 80 patients presenting within 6 h of STEMI onset from the CompariSon of Manual Aspiration with Rheolytic Thrombectomy in patients undergoing primary PCI (SMART) trial were evaluated. Underlying morphology of 64 culprit lesions was identifiable by OCT and included 37 lesions with plaque rupture, 25 lesions without plaque rupture, and 2 lesions with calcified nodules. Patients with plaque rupture tended to be younger (64 ± 12 versus 70 ± 10 years, P = 0.08) and less often female (11 versus 40%, P = 0.007) compared with patients without plaque rupture. More thin-cap fibroatheromas were identified (60 versus 20%, P = 0.002); and residual thrombus was greater in the rupture than in the non-rupture group. OCT at 6 months showed more stent malapposition (65 versus 33%, P = 0.04) in the rupture compared with the non-rupture group.Conclusion
OCT analysis showed two dominant culprit lesion morphologies in STEMI: (i) lesions with plaque rupture with a large amount of thrombus or (ii) lesions without plaque rupture and a lesser amount of thrombus.