Joan-Antoni Gomez-Hospital

Lumen enlargement of the coronary segments located distal to chronic total occlusions successfully treated with drug-eluting stents at follow-up.

AIMS Chronic total occlusions (CTO) are the final stage of atherosclerosis. Occluded coronary arteries have large plaque burden and negative remodelling. The aim of this study was to assess lumen and vessel changes of segments located distal to successfully recanalised CTO. METHODS AND RESULTS Ninety-one CTO treated with drug-eluting stents underwent quantitative coronary angiography (QCA) at baseline and at 12-18 months; 31 underwent serial intravascular ultrasound (IVUS) imaging. Angiographic changes were assessed with QCA as differences in minimal, mean and maximal lumen diameter (MinLD, MeanLD and MaxLD, respectively). Vessel changes were assessed with IVUS as changes in plaque and vessel volume. At follow-up, angiographic MinLD increased 23.9% (from 0.88±0.32 to 1.09±0.35 mm; p<0.01), MeanLD 16.4% (from 1.59±0.44 to 1.85±0.45 mm; p<0.01) and MaxLD 11.7% (from 2.39±0.67 to 2.67±0.70 mm; p<0.01). Lumen enlargement was greater in non-restenotic lesions, small lumen area at the end of the index procedure and low LDL-cholesterol levels during the study. By IVUS, lumen volume increased 26.9% (from 108.1±89.2 to 137.3±115.3 mm3; p<0.01), vessel volume increased 12.1% (from 207.1±170.2 to 232.2±196.0 mm3; p<0.01) and plaque volume tended to decrease 3.9% (from 98.9±88.7 to 94.9±89.3 mm3; p=0.07). Small lumen at baseline was related to greater lumen enlargement. CONCLUSIONS Segments distal to recanalised CTO showed a notable lumen and vessel enlargement with a trend toward mild plaque regression. Low LDL-cholesterol levels increase lumen enlargement.

Five-Year Optical Coherence Tomography in Patients With ST-Segment–Elevation Myocardial Infarction Treated With Bare-Metal Versus Everolimus-Eluting Stents

Background—The main causes of late (>1 month) stent thrombosis (ST) are stent uncoverage, malapposition, and neoatherosclerosis. First-generation drug-eluting stents were associated with higher rate of late ST compared with bare-metal stents (BMS), especially in patients with ST-segment–elevation myocardial infarction. Second-generation everolimus-eluting stents (EES) have shown similar rate of late ST than BMS. The aims of the study are to compare the ratio of uncovered to total struts per cross-section ≥30% and other optical coherence tomographic findings associated with ST between EES and BMS in patients with ST-segment–elevation myocardial infarction at 5 years. Methods and Results—One hundred and sixty-nine consecutive event-free patients of the randomized EXAMINATION study (A Clinical Evaluation of Everolimus Eluting Coronary Stents in the Treatment of Patients With ST-Segment Elevation Myocardial Infarction) were screened for optical coherence tomographic imaging at 5 years. Patients with target vessel–related events or life-threatening comorbidities were excluded. Finally, 64 patients (32 EES and 32 BMS) underwent optical coherence tomographic imaging. At 5 years, uncovered struts (4.1% versus 1.0%; P<0.01), length of uncoverage (3.4 versus 1.4 mm; P=0.02), and ratio of uncovered to total struts per cross-section ≥30% (35.5% versus 9.7%; P=0.02) were larger with EES than that with BMS. Malapposed struts (1.2% versus 0.3%; P=0.02) and malapposition length (1.3 versus 0.4 mm; P=0.06) were also larger with EES. Neoatherosclerotic plaques (16.1% versus 25.8%; P=0.35) and macrophage accumulations (19.4% versus 48.4%; P=0.02) were numerically more frequent with BMS. Conclusions—Despite substantial dropout of patients, the healing pattern in event-free ST-segment–elevation myocardial infarction patients differs between EES and BMS at 5 years. EES presented with larger amount of uncovered and malapposed struts and similar rate of neoatherosclerosis as compared with BMS. The clinical relevance of these findings warrants longer follow-up. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00828087.

Clopidogrel pretreatment in primary percutaneous coronary intervention: Prevalence of high on-treatment platelet reactivity and impact on preprocedural patency of the infarct-related artery

To date, there is limited data on levels of platelet inhibition achieved in patients with ST-elevation myocardial infarction (STEMI) who are loaded with clopidogrel and aspirin (ASA) prior to undergoing primary percutaneous coronary intervention (P-PCI). The aim of this investigation was to evaluate the percentage of STEMI patients with high on-treatment platelet reactivity (HPR) to clopidogrel at the time of initiating P-PCI and its association with the initial patency of the infarct-related artery (IRA). This prospective pharmacodynamic study included 50 STEMI patients, previously naïve to oral antiplatelet agents, who received 500-mg ASA and 600-mg clopidogrel loading doses prior to P-PCI. Platelet function assessment was performed at the beginning of the procedure using various assays, including VerifyNow™ system (primary endpoint), light transmission aggregometry and multiple electrode aggregometry. The percentage of patients with suboptimal response to clopidogrel and ASA assessed with the VerifyNow™ system was 88.0% and 28.6%, respectively. Similar results were obtained with the other assays used. A higher percentage of patients with initial patency of the IRA was observed among those patients without HPR compared with those with HPR to clopidogrel (66.7% vs 15.9%; p=0.013), while no differences were observed regarding postprocedural angiographic or electrocardiographic outcomes. In conclusion, this study shows that a high percentage of STEMI patients have inadequate levels of clopidogrel-induced and, to a lesser extent, aspirin-mediated platelet inhibition when starting a P-PCI procedure, and suggests that a poor response to clopidogrel might be associated with impaired initial TIMI flow in the IRA.

Preserved endothelial vasomotor function after everolimus-eluting stent implantation

AIMS To compare the degree of endothelial dysfunction (ED) in patients treated with everolimus-eluting stent (EES) versus bare metal stent (BMS) implantation. METHODS AND RESULTS This is an observational study. A total of 30 elective patients (15 treated with EES and 15 with BMS) were recruited. All patients underwent coronary angiography and intracoronary acetylcholine (Ach) test at different doses at six months after stent implantation. Quantitative coronary angiography analysis was performed to evaluate the changes in mean luminal diameter (MLD) of the segments distal to the distal stent edge after increasing doses of Ach. Both EES and BMS groups had similar baseline characteristics except for stent length (18.6±2.5 vs. 16.5±2.5 mm; p=0.033) and diameter (3.1±0.2 vs. 3.4±0.3 mm; p=0.007). The vasomotion test showed that EES had 3.14% of MLD decrease after Ach infusion and BMS had 2.35% of vasoconstriction (p=0.62). After adjustment for baseline characteristics, no statistical difference was observed between groups. CONCLUSIONS In our study EES implantation was associated with a low degree of ED and had a similar vasomotion response as compared to BMS. Prospective randomised investigations are warranted to confirm these findings.

IVUS-guided treatment strategies for definite late and very late stent thrombosis

AIMS Our aim was to describe the intravascular ultrasound (IVUS) findings of patients with late stent thrombosis (ST) undergoing percutaneous intervention, and to compare the pre- and post-intervention IVUS findings of patients treated with balloon angioplasty (BA) vs. additional stent implantation (ASI). METHODS AND RESULTS A total of 117 patients with late ST imaged with IVUS were included (51.2% had drug-eluting stent ST). Treatment was left to the operators discretion: BA was performed in 53.8% and ASI in 46.2%. Pre-intervention, incomplete stent apposition (ISA) was observed in 69.8% vs. 63.0% (p=0.43), underexpansion in 33.3% vs. 18.5% (p=0.07) and restenosis in 15.9% vs. 27.8% (p=0.12), respectively. Post-intervention, persistent ISA was observed in 37.2% vs. 60.9% (p=0.03) and malapposition volume decreased by 43.6% vs. 2.6% (p=0.03). Persistent underexpansion was observed in 9.3% vs. 17.4% (p=0.26); however, the stent expansion index was largely increased with BA (from 0.75 to 0.88) compared to ASI (from 0.80 to 0.82); p=0.046. At two years, recurrent ST was observed in one (1.7%) vs. four (7.7%) patients, respectively; p=0.09. CONCLUSIONS Non-optimal IVUS criteria of stent implantation are often observed in patients with late ST. Treatment of late ST with BA leads to a larger reduction of malapposition and underexpansion with respect to ASI and is associated with favourable outcomes.

Rationale and study design of the RESERVOIR trial: A randomized trial comparing reservoir‐based polymer‐free amphilimus‐eluting stents versus everolimus‐eluting stents with durable polymer in patients with diabetes mellitus

Patients with diabetes mellitus (DM) remain at high risk for stent restenosis and adverse cardiovascular events in the drug‐eluting stent era. The amphilimus‐eluting stent (AES) is a third generation reservoir‐based polymer‐free drug‐eluting stent that has shown promising preliminary results in patients with DM. It has been suggested that the formulation of the drug with fatty acids could not only modulate the drug release in a timely manner but also achieve convenient levels of drug concentration in diabetic cardiac cells. The aim of this trial is to assess the efficacy of the AES in patients with DM compared with the cobalt chromium everolimus‐eluting stent with non‐erodible polymer (EES).

TIcaGrEloR and Absorb bioresorbable vascular scaffold implantation for recovery of vascular function after successful chronic total occlusion recanalization (TIGER‐BVS trial): Rationale and study design

To explore the role of ticagrelor versus clopidogrel in coronary blood flow normalization immediately after chronic coronary total occlusion (CTO) recanalization.