Nonobstructive coronary disease leading to STEMI: assessment of residual stenosis after thrombus aspiration Pedro De Arau ´ jo Gonc ¸ alves a,b , Joa ˜o Brito a , Pedro Jeronimo Sousa a , Maria Salome ´ Carvalho a , Helder Dores a , Rui Campante Teles a , Luı ´s Raposo a , Henrique Mesquita Gabriel a , Jorge Ferreira a , Manuel Almeida a , Ana Aleixo b , Miguel Mota Carmo b and Miguel Mendes a Aims Nonobstructive coronary atherosclerotic lesions can lead to ST-elevation myocardial infarctions (STEMI). Thrombus aspiration during a primary percutaneous coronary intervention provides a setting to evaluate the degree of stenosis of culprit lesions leading to STEMI. The aim of this study was to assess the degree of culprit lesion residual stenosis after thrombus aspiration and to compare the demographic, clinical, and angiographic characteristics between patients with obstructive versus nonobstructive residual stenosis. Methods and results From a single-center registry of 483 consecutive patients with STEMI undergoing a primary percutaneous coronary intervention, 172 patients underwent thrombus aspiration and were eligible for our study. We defined two groups according to the residual stenosis after thrombus aspiration: group A (n = 119, 69%) with residual stenosis greater than or equal to 50%, and group B (n = 53, 31%) with residual stenosis less than 50%. In terms of the baseline angiographic characteristics, patients with residual stenosis less than 50% had significantly lower prevalence of multivessel disease (15.1 vs. 46.2%, P < 0.001). On multivariable analysis of the preprocedural variables, absence of vascular disease (odds ratio 4.99, 95% confidence interval 1.08–23.12, P =0.040) and age less than 59 years (odds ratio 2.67, 95% confidence interval 1.25–5.73, P = 0.011) were independent predictors of culprit residual stenosis less than 50%. Conclusion In this population, a significant proportion of patients with STEMI had nonobstructive residual stenosis after thrombus aspiration. These patients were younger, had a lower prevalence of vascular disease in other vascular territories, and less multivessel disease, suggesting an earlier stage of atherosclerosis. Coron Artery Dis 00:000–000  c 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins. Coronary Artery Disease 2012, 00:000–000 Keywords: acute coronary syndromes, atherosclerosis, coronary angiography, myocardial infarction, pathophysiology a Cardiology Department, Santa Cruz Hospital, West Lisbon Hospital Center and b CEDOC – Chronic Diseases Research Center – FCM-NOVA, Lisbon, Portugal Correspondence to Pedro De Arau ´ jo Gonc ¸alves, MD, Hospital de Santa Cruz, Centro Hospitalar de Lisboa Ocidental, Av. Prof. Reinaldo dos Santos, 2790-134, Carnaxide, Portugal Tel: + 351 966 866 455; fax: + 351 214 241 388; e-mail: paraujogoncalves@yahoo.co.uk Received 23 August 2012 Revised 12 October 2012 Accepted 25 October 2012 Introduction ST-elevation myocardial infarction (STEMI) because of acute coronary artery occlusion has two main compo- nents: underlying atherosclerotic plaque and thrombus. The relative contribution of each of these factors is variable as many clinical observations suggest that myocardial infarctions are not necessarily related to previous high-grade coronary stenosis [1–3]. More often, acute events are caused by the rupture of plaques that are not associated with severe luminal narrowing, and the total coronary occlusion occurs as a result of the super- imposed thrombus burden. Evidence supporting the concept that nonobstructive atherosclerotic lesions can lead to STEMI comes mainly from serial angiographic studies retrospectively evaluating the degree of stenosis in patients with a previous coronary angiography [4–7], and from studies of patients referred for angiography after thrombolytic therapy [8]. However, in more recent studies carried out in the setting of a primary percutaneous coronary intervention (PCI), it has been suggested that in most cases, STEMIs occurred at the site of severe obstructive stenosis [9,10]. In recent years, thrombus aspiration devices have gained an important role in primary PCI [11,12], and this provides a setting for the evaluation and better under- standing of the pathophysiology of coronary artery lesions leading to STEMI. The aim of this study was to assess the degree of residual stenosis in STEMI culprit lesions after thrombus aspiration and to compare the demographic, clinical, and angiographic characteristics between two groups of patients according to the degree of residual stenosis after thrombus aspiration. Therapy and prevention 1 0954-6928  c 2012 Wolters Kluwer Health | Lippincott Williams & Wilkins DOI: 10.1097/MCA.0b013e32835c46bd CE: Lasya ED: Jagadish Op: Sampath MCA 11495: LWW_MCA_11495