Ascertainment of silent myocardial infarction in patients undergoing percutaneous coronary intervention (from the GLOBAL LEADERS Trial)

Abstract: Q-wave myocardial infarction (QWMI) comprises 2 entities. First, a clinically evident MI, which can occur spontaneously or be related to a coronary procedure. Second, silent MI which is incidentally detected on serial electrocardiographic (ECG) assessment. The prevalence of silent MI after percutaneous coronary intervention (PCI) in the drug-eluting stent era has not been fully investigated. The GLOBAL LEADERS is an all-comers multicenter trial which randomized 15,991 patients who underwent PCI to 2 antiplatelet treatment strategies. The primary end point was a composite of all-cause death or nonfatal new QWMI at 2-years follow-up. ECGs were collected at discharge, 3-month and 2-year visits, and analyzed by an independent ECG core laboratory following the Minnesota code. All new QWMI were further reviewed by a blinded independent cardiologist to identify a potential clinical correlate by reviewing clinical information. Of 15,968 participants, ECG information was complete in 14,829 (92.9%) at 2 years. A new QWMI was confirmed in 186 (1.16%) patients. Transient new Q-waves were observed in 28.5% (53 of 186) of them during the follow-up. The majority of new QWMI (78%, 146 of 186) were classified as silent MI due to the absence of a clinical correlate. Silent MI accounted for 22.1% (146 of 660) of all MI events. The prevalence of silent MI did not differ significantly between treatment strategies (experimental vs reference: 0.88% vs 0.98%, p = 0.5027). In conclusion, we document the prevalence of silent MI in an all-comers population undergoing PCI in this large-scale randomized trial. (AU)

Clinical, Angiographic, and Procedural Correlates of Very Late Absorb Scaffold Thrombosis: Multistudy Registry Results

OBJECTIVES: The aim of this study was to identify independent correlates of very late scaffold thrombosis (VLST) from an analysis of consecutively treated patients from 15 multicenter studies. BACKGROUND: Recent analyses suggest an increased risk for VLST with the Absorb Bioresorbable Vascular Scaffold compared with drug-eluting stents, but insights as to correlates of risk are limited. METHODS: A total of 55 patients were identified with scaffold thrombosis. They were matched 2:1 with control subjects selected randomly from patients without thrombosis from the same study. Quantitative coronary angiography was available for 96.4% of patients. Multiple logistic and Cox regression analysis were used to identify significant independent outcome correlates from 6 pre-specified characteristics. RESULTS: Patients had scaffold thrombosis at a median of 20 months (interquartile range: 17 to 27 months). Control subjects were followed for 36 months (interquartile range: 24 to 38 months). For the combined groups, reference vessel diameter (RVD) was 2.84 0.50 mm, scaffold length was 26 16 mm, and post-dilatation was performed in56%. Univariate correlates of thrombosis were smaller nominal scaffold/RVD ratio (linear p»0.001; ratio<1.18:1; odds ratio: 7.5; p»0.002) and larger RVD (linear p»0.001;>2.72 mm; odds ratio: 3.4; p»0.001). Post-dilatation at$16 atm, post-dilatation balloon/scaffold ratio, final percentage stenosis, and dual antiplatelet therapy were not correlated with VLST. Only scaffold/RVD ratio remained a significant independent correlate of VLST (p»0.001), as smaller ratio was correlated with RVD (p<0.001). Post hoc analysis of 8 other potential covariates revealed no other correlates of outcome. CONCLUSIONS: In the present analysis, the largest to date of its type, relative scaffold undersizing was the strongest determinant of VLST. Given current understanding of "scaffold dismantling," this finding likely has ramifications for all bioresorbable scaffolds.

Clinical, angiographic, and procedural correlates of acute, subacute, and late absorb scaffold thrombosis

OBJECTIVES: The authors sought to identify and verify independent correlates of device thrombosis from an analysis of multicenter trials and registries. BACKGROUND: Recent analyses suggest an increased risk of device thrombosis with Absorb bioresorbable vascular scaffold (Abbott Vascular, Santa Clara, California) implantation compared with metallic drug-eluting stents, and data from moderate size studies suggest a risk relationship to vessel size and technique. METHODS: From 8,771 consecutively treated patients, 105 patients (1.2%) were identified with scaffold thrombosis within 1 year of implantation. They were matched 2:1 with controls selected randomly from nonthrombosis patients. Data-restricted multiple logistic analysis was used to identify significant independent covariates of the outcome. RESULTS: Early (within 1 month) scaffold thrombosis occurred in 69 patients and late (1 to 12 months) thrombosis occurred in 36 patients. Modelling found significant correlations of thrombosis to be final minimal lumen diameter 1.1:1 balloon/scaffold ratio (OR: 2.3; p = 0.022), and reference vessel diameter <2.40 mm (OR: 2.1; p = 0.036).CONCLUSIONS:Suboptimal vessel sizing, procedural technique, angiographic outcomes, and dual antiplatelet therapy discontinuation appear to be the principal determinants of Absorb scaffold thrombosis risk through 12 months after implantation.