Intravascular ultrasound assessment of minimum lumen area and intimal hyperplasia in in-stent restenosis after drug-eluting or bare-metal stent implantation. The Nordic Intravascular Ultrasound Study (NIVUS).

INTRODUCTION: Drug-eluting stents (DES) reduce the risk of restenosis after percutaneous coronary intervention. The aim of the study was to evaluate, by intravascular ultrasound (IVUS), the minimum lumen area site in the stented segment and the distribution of intimal hyperplasia in patients presenting with a DES or bare-metal stent (BMS) in-stent restenosis. METHODS: The "Nordic Intravascular Ultrasound Study (NIVUS)" study was conducted in Nordic and Baltic countries as a prospective multicenter registry. Two hundred nine patients (DES n=121 and BMS n=88) with in-stent restenosis were enrolled. RESULTS: At the minimum lumen area site in the stented segment, the stent area (5.8±2.2mm2 vs. 7.6±2.4mm2, p<0.001) and intimal hyperplasia area (2.6±2.0mm2 vs. 5.0±2.2mm2, p<0.001) were significantly lower in patients treated with DES compared to BMS. The percentage of stents that did not have a minimum stent area of at least 5.0mm2 (under expansion) was higher in DES (58.7% vs. 37.7%, p=0.008) compared to BMS. Intimal hyperplasia covered 55.4±33.3% of the stent length in the DES compared to 90.7±17.4% in the BMS group, p<0.001. Focal in-stent restenosis was more often seen in DES treated patients compared to BMS treated patients (DES n=84 (59.9%) vs. BMS n=15 (17.0%), p<0.001). CONCLUSION: Stent underexpansion was more often seen in DES than BMS in-stent restenosis. DES more often had focal in-stent restenosis with less intimal hyperplasia.

Culprit lesion thrombus burden after manual thrombectomy or percutaneous coronary intervention-alone in ST-segment elevation myocardial infarction: the optical coherence tomography sub-study of the TOTAL (ThrOmbecTomy versus PCI ALone) trial.

AIMS: Manual thrombectomy has been proposed as a strategy to reduce thrombus burden during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). However, the effectiveness of manual thrombectomy in reducing thrombus burden is uncertain. In this substudy of the TOTAL (ThrOmbecTomy versus PCI ALone) trial, we compared the thrombus burden at the culprit lesion using optical coherence tomography (OCT) in patients treated with thrombectomy vs. PCI-alone. METHODS AND RESULTS: The TOTAL trial (N = 10 732) was an international, multicentre, randomized trial of thrombectomy (using the Export catheter, Medtronic Cardiovascular, Santa Rosa, CA, USA) in STEMI patients treated with primary PCI. The OCT substudy prospectively enrolled 214 patients from 13 sites in 5 countries. Optical coherence tomography was performed immediately after thrombectomy or PCI-alone and then repeated after stent deployment. Thrombus quantification was performed by an independent core laboratory blinded to treatment assignment. The primary outcome of pre-stent thrombus burden as a percentage of segment analysed was 2.36% (95% CI: 1.73-3.22) in the thrombectomy group and 2.88% (95% CI: 2.12-3.90) in the PCI-alone group (P = 0.373). Absolute pre-stent thrombus volume was not different (2.99 vs. 3.74 mm(3), P = 0.329). Other secondary outcomes of pre-stent quadrants of thrombus, post-stent atherothrombotic burden, and post-stent atherothrombotic volume were not different between groups. CONCLUSION: Manual thrombectomy did not reduce pre-stent thrombus burden at the culprit lesion compared with PCI-alone. Both strategies were associated with low thrombus burden at the lesion site after the initial intervention to restore flow.