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In the setting of prior myocardial infarction, the oral antiplatelet ticagrelor added to aspirin reduced the risk of recurrent ischemic events, especially, in those with diabetes mellitus. Patients with stable coronary disease and diabetes are also at elevated risk and might benefit from dual antiplatelet therapy. The Effect of Ticagrelor on Health Outcomes in diabEtes Mellitus patients Intervention Study (THEMIS, NCT01991795) is a Phase 3b randomized, double-blinded, placebo-controlled trial of ticagrelor vs placebo, on top of low dose aspirin. Patients ≥50 years with type 2 diabetes receiving anti-diabetic medications for at least 6 months with stable coronary artery disease as determined by a history of previous percutaneous coronary intervention, bypass grafting, or angiographic stenosis of ≥50% of at least one coronary artery were enrolled. Patients with known prior myocardial infarction (MI) or stroke were excluded. The primary efficacy endpoint is a composite of cardiovascular death, myocardial infarction, or stroke. The primary safety endpoint is Thrombolysis in Myocardial Infarction major bleeding. A total of 19 220 patients worldwide have been randomized and at least 1385 adjudicated primary efficacy endpoint events are expected to be available for analysis, with an expected average follow-up of 40 months (maximum 58 months). Most of the exposure is on a 60 mg twice daily dose, as the dose was lowered from 90 mg twice daily partway into the study. The results may revise the boundaries of efficacy for dual antiplatelet therapy and whether it has a role outside acute coronary syndromes, prior myocardial infarction, or percutaneous coronary intervention. ispartof: CLINICAL CARDIOLOGY vol:42 issue:5 pages:498-505 ispartof: location:United States status: published

ObjectivesCHARISMA was a landmark randomized clinical trial that failed to demonstrate a benefit of dual antiplatelet therapy (DAPT) over aspirin alone for preventing cardiovascular events. However, subgroup analyses of the trial found fewer major adverse cardiovascular events (MACEs) for patients with established cardiovascular disease but more MACEs for patients with multiple risk factors without established cardiovascular disease. Our objective was to examine DAPT use in contemporary clinical practice after publication of CHARISMA results.Study designRetrospective analysis of a large clinical registry of outpatient cardiovascular visits to over 1000 physicians that collected data on patient clinical history, symptoms, vital signs, and medications.MethodsClinical characteristics and prescription rates of aspirin and clopidogrel were compared for patients with established cardiovascular disease and for patients with only multiple cardiovascular risk factors. Prescription of DAPT by calendar quarter was evaluated from 2008 to 2011 using multivariable Poisson regression models.ResultsOf 167,839 patients with established cardiovascular disease, 20.5% were prescribed both aspirin and clopidogrel. Of 20,478 patients with multiple risk factors but no known cardiovascular disease, 3.5% were prescribed both aspirin and clopidogrel. Across 14 calendar quarters, prescription rates of DAPT did not change significantly for patients with established CVD but decreased for patients with multiple risk factors with an incidence rate ratio of 0.77.ConclusionsUse of DAPT is modest in patients with established cardiovascular disease, for whom the CHARISMA trial suggested decreased MACEs, and prescription rates have remained stable over time. Use of DAPT in patients with multiple risk factors only, for whom CHARISMA suggested that DAPT may lead to increased MACE, was low and decreased over time.

The purpose of this study was to describe radiation exposure from cardiac imaging procedures over time in a general population.Cardiac imaging procedures frequently expose patients to ionizing radiation, but their contribution to effective doses of radiation in the general population is unknown.We used administrative claims to identify cardiac imaging procedures performed from 2005 to 2007 in 952,420 nonelderly insured adults in 5 U.S. health care markets. We estimated 3-year cumulative effective doses of radiation in millisieverts from these procedures We then calculated population-based annual rates of radiation exposure to effective dosesor =3 mSv/year (background level of radiation from natural sources),3 to 20 mSv/year, or20 mSv/year (upper annual limit for occupational exposure averaged over 5 years).A total of 90,121 (9.5%) individuals underwent at least 1 cardiac imaging procedure using radiation. Among patients who underwentor =1 cardiac imaging procedures, the mean cumulative effective dose over 3 years was 23.1 mSv (range 1.5 to 543.7 mSv). Myocardial perfusion imaging accounted for 74% of the cumulative effective dose. Overall, 47.8% of cardiac imaging procedures were performed in physician offices; this proportion was higher for myocardial perfusion imaging (74.8%) and cardiac computed tomography studies (76.5%). The annual population-based rate of receiving an effective dose of3 to 20 mSv/year was 89.0 per 1,000; and 3.3 per 1,000 for cumulative doses20 mSv/year. Annual effective doses increased with age and were generally higher among men.Cardiac imaging procedures lead to substantial radiation exposure and effective doses for many patients in the U.S.