Incidence of thrombosis in perioperative and non-operative myocardial infarction.

BACKGROUND: The contribution of thrombosis to the aetiology of perioperative myocardial infarction (MI) is uncertain. We used optical coherence tomography (OCT) to determine the presence of thrombus and plaque morphology in patients experiencing a perioperative MI and matched patients experiencing a non-operative MI using OCT. METHODS: We conducted a single-centre, prospective, cohort study. Thirty patients experiencing a perioperative MI and 30 matched patients experiencing a non-operative MI, without ST elevation, underwent OCT to determine the presence of thrombus and culprit lesion plaque morphology. Angiography and OCT were performed a mean of 1.93(1.09) days and 1.53(0.68) days after the onset of perioperative and non-operative MI, respectively. OCT images were evaluated by an independent core laboratory without knowledge of whether the patient had suffered a perioperative or non-operative MI. RESULTS: We identified thrombus at the culprit lesion in four of 30 patients (13.3%) who experienced a perioperative MI and in 20 of 30 patients (66.7%) who experienced a non-operative MI, P<0.01. The only non-culprit lesion with thrombus was in a perioperative MI patient who also had a culprit lesion thrombus. Perioperative and non-operative MI culprit lesions demonstrated fibroatheroma in 18 patients (60.0%) us 20 patients (66.7%), respectively (P=0.52) and thin cap fibroatheroma in one patient (3.3%) us five patients (16.7%), respectively (P=0.11). One perioperative MI patient (3.3%) suffered a cardiac death and no non-operative MI patient died during the 30-day follow-up. CONCLUSIONS: Thrombosis was less common in perioperative than non-operative MI, despite similar underlying plaque morphology.

Randomized Trial of Primary PCI with or without RoutineManual Thrombectomy

During primary percutaneous coronary intervention (PCI), manual thrombectomymay reduce distal embolization and thus improve microvascular perfusion. Smalltrials have suggested that thrombectomy improves surrogate and clinical outcomes,but a larger trial has reported conflicting results.MethodsWe randomly assigned 10,732 patients with ST-segment elevation myocardial infarction(STEMI) undergoing primary PCI to a strategy of routine upfront manualthrombectomy versus PCI alone. The primary outcome was a composite of deathfrom cardiovascular causes, recurrent myocardial infarction, cardiogenic shock, orNew York Heart Association (NYHA) class IV heart failure within 180 days. The keysafety outcome was stroke within 30 days.ResultsThe primary outcome occurred in 347 of 5033 patients (6.9%) in the thrombectomygroup versus 351 of 5030 patients (7.0%) in the PCI-alone group (hazard ratio in thethrombectomy group, 0.99; 95% confidence interval [CI], 0.85 to 1.15; P = 0.86). Therates of cardiovascular death (3.1% with thrombectomy vs. 3.5% with PCI alone;hazard ratio, 0.90; 95% CI, 0.73 to 1.12; P = 0.34) and the primary outcome plusstent thrombosis or target-vessel revascularization (9.9% vs. 9.8%; hazard ratio,1.00; 95% CI, 0.89 to 1.14; P = 0.95) were also similar. Stroke within 30 days occurredin 33 patients (0.7%) in the thrombectomy group versus 16 patients (0.3%)in the PCI-alone group (hazard ratio, 2.06; 95% CI, 1.13 to 3.75; P = 0.02).ConclusionsIn patients with STEMI who were undergoing primary PCI, routine manual thrombectomy,as compared with PCI alone, did not reduce the risk of cardiovasculardeath, recurrent myocardial infarction, cardiogenic shock, or NYHA class IV heartfailure within 180 days but was associated with an increased rate of stroke within30 days. (Funded by Medtronic and the Canadian Institutes of Health Research;TOTAL ClinicalTrials.gov number, NCT01149044.