Background-Although clopidogrel reduces the risk of cardiovascular episodes after coronary events and stenting, a substantial number of incidents continue to occur. Methods and Results-The antiplatelet effect of clopidogrel was studied prospectively in 60 consecutive patients who underwent primary angioplasty (percutaneous coronary intervention [PCI]) with stenting for acute ST-segmentelevation myocardial infarction (STEMI) to determine whether variability in response to clopidogrel affects clinical outcomes. Patients were stratified into 4 quartiles according to the percentage reduction of ADP-induced platelet aggregation. Although patients in the first quartile were resistant to the effects of clopidogrel (ADP-induced platelet aggregation at day 6, 103Ϯ8% of baseline), ADP-induced aggregation was reduced to 69Ϯ3%, 58Ϯ7%, and 33Ϯ12% of baseline, respectively, in patients in quartiles 2 through 4 (PϽ0.01 for all). In addition, epinephrine-induced platelet aggregation and platelet aggregation under flow conditions, assessed by the cone-and-plate(let) analyzer method, were reduced significantly less in the first quartile than in quartiles 2 through 4. Whereas 40% of patients in the first quartile sustained a recurrent cardiovascular event during a 6-month follow-up, only 1 patient (6.7%) in the second quartile and none in the third and fourth quartiles suffered a cardiovascular event (Pϭ0.007). Conclusions-Up to 25% of STEMI patients undergoing primary PCI with stenting are resistant to clopidogrel and therefore may be at increased risk for recurrent cardiovascular events.

Background-The measurement of late gadolinium enhanced MRI (LGE-MRI) intensity in arbitrary units (au), limits the objectivity of thresholds for focal scar detection and inter-patient comparisons of scar burden.

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Aims To estimate the prevalence, incidence, mortality, and risk factors for atrial fibrillation (AF) in 195 countries and territories from 1990 to 2017. Methods and Results Following the methodologies used in the Global Burden of Disease study 2017, the prevalence, incidence, and mortality of AF were analyzed by age, sex, year, socio-demographic index (SDI), and location. The percentage contributions of major risk factors to age-standardised AF deaths were measured by population attributable fractions. In 2017, there were 37.57 million [95% uncertainty interval (UI) 32.55 to 42.59] prevalent cases and 3.05 million (95% UI 2.61 to 3.51) incident cases of AF globally, contributing to 287,241 (95% UI 276,355 to 304,759) deaths. The age-standardised rates of prevalent cases, incident cases, and deaths of AF in 2017 and their temporal trends from 1990 to 2017 varied significantly by SDI quintile and location. High systolic blood pressure was the leading risk factor for AF age-standardised deaths [34.3% (95% UI 27.4 to 41.5)] in 2017, followed by high body-mass index [20.7% (95% UI 11.5 to 32.2)] and alcohol use [9.4% (95% UI 7.0 to 12.2)]. Conclusion Our study has systematically and globally assessed the temporal trends of AF, which remains a major public heath challenge. Although AF mainly occurred in developed countries, the unfavorable trend in countries with lower SDI also deserves particular attention. More effective prevention and treatment strategies aimed at counteracting the increase in AF burden should be established in some countries.