Residual atherothrombotic material after stenting in acute myocardial infarction — An optical coherence tomographic evaluation Michael Magro, Evelyn Regar, Juan Luis Gutiérrez-Chico, Hector Garcia-Garcia, Cihan Simsek, Carl Schultz, Felix Zijlstra, Patrick W. Serruys, Robert Jan van Geuns ⁎ Thoraxcenter, Erasmus MC, Rotterdam, The Netherlands abstract article info Article history: Received 10 September 2011 Received in revised form 17 January 2012 Accepted 3 March 2012 Available online 28 March 2012 Keywords: ST-segment elevation myocardial infarction Primary percutaneous coronary intervention Thrombus aspiration Optical coherence tomography Myocardial perfusion Background: Thrombus aspiration (TA) in patients with ST segment elevation myocardial infarction (STEMI) results in a better myocardial perfusion. Optical coherence tomography (OCT) after stenting in STEMI, however, often reveals residual atherothrombotic material. We assessed the feasibility of quantification of residual ather- othrombotic burden and its relation to indices of myocardial perfusion. The effect of TA on residual in-stent atherothrombotic burden (ATB) is explored. Methods and results: Forty patients with STEMI within 12 h of symptom onset, underwent OCT after stent im- plantation. No complication related to the invasive imaging was detected and all cases had good image quality. All 40 cases revealed ATB (median, range; 2.85, 0.08–8.84) despite an optimal angiographic result. Patients were divided into two groups according to the ATB: ≥4=ATB high (n=15) and b 4=ATB low (n=25). Patients with ATB low more often obtained a myocardial blush grade (MBG) of 2/3: 24 (96%) vs. 11 (73%), p=0.04 and a ≥50% ST segment resolution 24 (96%) vs. 8 (53%) p=0.02. Incomplete stent apposition is more often detected with ATB low : 1.97 (0.62–4.73) vs. 0.33 (0.04–0.92), p=0.002. TA was performed in 20 (50%) patients. ATB was numerically lower in patients with TA: 2.37 (1.70–5.10) vs. 3.40 (1.45–4.96), p=0.67. Logistic regression iden- tified ATB as predictor of ST resolution failure (OR: 2.5 (95% confidence interval: 1.27–4.98), p value=0.008). Conclusions: OCT can be safely performed in patients presenting for primary PCI and allows quantification of re- sidual atherothrombotic material, the amount of which is associated with worse myocardial perfusion. © 2012 Elsevier Ireland Ltd. All rights reserved. 1. Introduction A high thrombus load as detected by coronary angiography during primary percutaneous coronary intervention is an important deter- minant of myocardial reperfusion and major adverse cardiac events [1,2]. Manual thrombus aspiration improves myocardial perfusion and may decrease cardiac death in STEMI patients [3,4]. This effect is at least in part driven by a reduction in thrombus burden which in turn improves distal blood flow, reduces distal embolisation and thereby improves microvascular perfusion [5]. The latter has a direct influence on the final infarct size and together have a significant impact on the short and long term clinical outcome [6]. Optical coherence tomography (OCT) can detect atherothrombotic material in the culprit lesion better than any other imaging modality [7]. Due to its high spatial resolution, OCT can also quantify very small intravascular structures especially those close to the surface of the endo- thelium. Residual intra-stent material representing atherothrombotic material has been observed with OCT particularly in the setting of acute coronary syndromes [8]. The significance of the amount of residual atherothrombotic material has not been established. Moreover whether primary percutaneous coronary intervention with manual thrombus as- piration effects the in-stent residual atherothrombotic burden is yet un- known. The aims of this prospective exploratory study were firstly to assess the feasibility and reproducibility of measurement of residual atherothrombotic burden after stenting. Secondly, the implications of a high versus a low residual atherothrombotic burden as measured by OCT on indices of microvascular perfusion were explored. Thirdly, we assessed if primary percutaneous coronary intervention (PPCI) with thrombus aspiration (TA) results in a lower atherothrombotic burden as compared to PPCI without TA. 2. Methods 2.1. Study population Patients referred to our hospital within 12 h of an episode of continuous chest pain lasting > 30 min and having a 12 lead electrocardiogram (ECG) with ST-segment eleva- tion ≥0.1 mV in 2 or more contiguous leads and an angiographically identifiable culprit lesion in a native coronary artery were eligible for enrolment in this study. Patients who were haemodynamically unstable even after corrective measures, as well as pa- tients with a previous stent implantation in the culprit coronary artery were excluded. Also patients in whom successful wiring of the culprit artery and TIMI ≥1 flow allowed angiographic visualisation of a very high thrombus load were excluded. Furthermore International Journal of Cardiology 167 (2013) 656–663 ⁎ Corresponding author at: Thoraxcenter, Ba-585, Dr. Molewaterplein 40, 3015 RD Rotterdam, The Netherlands. Tel.: +31 10 4635260(33348); fax: +31 10 4369154. E-mail address: r.vangeuns@erasmusmc.nl (R.J. van Geuns). 0167-5273/$ – see front matter © 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ijcard.2012.03.073 Contents lists available at SciVerse ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard