99Non-ruptured plaque and platelet-rich thrombi in ST-segment elevation myocardial infarction: new insight into early spontaneous reperfusion

Abstract

Abstract Objectives To detect the potential mechanism of early spontaneous reperfusion (ESR) in STEMI. Background Early spontaneous reperfusion occurs in around 20% of STEMI and is associated with favorable outcomes. Optical coherence tomography (OCT) is more accurate in detecting subtle morphological details of the culprit lesion. Methods In this prospective study, a total of 107 consecutive patients with STEMI were enrolled from July 2016 to May 2017. Of that total, 21 (19.6%) met the criteria of angiographic ESR (TIMI-3 flow in the initial angiogram). Among those without ESR (TIMI-0 flow in the initial angiogram), 21 patients were assigned into the control group according to propensity score matching with the ESR group. The OCT findings and one-year clinical outcomes were compared between the two groups. Results Although baseline characteristics were comparable, plaque features significantly differed between the ESR and control group (P<0.001), including plaque rupture (23.8% vs. 66.7%), plaque erosion (47.6% vs. 33.3%), calcified nodule (9.5% vs. 0%) and vasospasm (19.1% vs. 0%). Red thrombus (19.1% vs. 85.7%) was far less found whereas white thrombus (61.9% vs. 14.3%) was more common in the ESR group. In addition, despite of less stent placement (0.6±0.5 vs. 1.3±0.9, P<0.001), patients in the ESR group had a non-statistically lower rate of cardiac adverse events (4.8% vs. 14.3%, P=0.269) during one-year follow up. The OCT finding Variables ESR group (n=21) Control group (n=21) P value The OCT imaging <0.001 Plaque erosion 10 (47.6) 7 (33.3) Plaque rupture 5 (23.8) 14 (66.7) Calcified nodule 2 (9.5) 0 (0) Vasospasm 4 (19.1) 0 (0) The Type of Thrombus <0.001 Red thrombus 4 (19.1) 18 (85.7) White thrombus 13 (61.9) 3 (14.3) No thrombus (vasospasm) 4 (19.1) 0 (0) MLA (mm2) 2.7±2.2 2.3±2.4 0.534 Values are n (%), mean ± SD. ESR = early spontaneous reperfusion; MLA = Minimum lumen area; OCT = optical coherence tomography. ESR and control group Conclusions Relief of coronary occlusion induced by non-ruptured plaque and platelet-rich thrombi may be one of the main mechanism underlying early spontaneous reperfusion in STEMI. Acknowledgement/Funding No.81470491 from the National Natural Science Foundation of China and No.7192078 from Beijing Municipal Natural Science Foundation to Dr. Li.