Noninvasive Radioablation of Ventricular Tachycardia.

Ventricular tachycardia (VT) occurs most commonly in the presence of structural heart disease or myocardial scarring from prior infarction. It is associated with increased mortality, especially when it results in cardiac arrest outside of a hospital. When not due to reversible causes (such as acute ischemia/infarction), placement of an implantable cardioverter-defibrillator for prevention of future sudden death is indicated. The current standard of care for recurrent VT is medical management with antiarrhythmic agents followed by invasive catheter ablation for VT that persists despite appropriate medical therapy. Stereotactic arrhythmia radioablation (STAR) is a novel, noninvasive method of treating VT that has been shown to reduce VT burden for patients who are refractory to medical therapy and/or catheter ablation, or who are unable to tolerate catheter ablation. STAR is the term applied to the use of stereotactic body radiation therapy for the treatment of arrhythmogenic cardiac tissue and requires collaboration between an electrophysiologist and a radiation oncologist. The process involves identification of VT substrate through a combination of electroanatomic mapping and diagnostic imaging (computed tomography, magnetic resonance imaging, positron emission tomography) followed by carefully guided radiation therapy. In this article, we review currently available literature describing the utilization, efficacy, safety profile, and potential future applications of STAR for the management of VT.

Use of Statins for Primary Prevention: Selection of Risk Threshold and Implications Across Race and Gender.

BACKGROUND: The 2016 U.S. Preventive Services Task Force (USPSTF) guidelines for primary prevention statin therapy are more restrictive than the 2013 American College of Cardiology/American Heart Association (ACC/AHA) guidelines. There are important differences in how application of the risk thresholds from these guidelines would impact particular segments of the U.S. METHODS: Data from the National Health and Nutrition Examination Survey (2005-14) were used to determine statin eligibility across age, gender, and racial or ethnic group using criteria from the 2013 ACC/AHA and 2016 USPSTF guidelines. Proportions of the study population eligible for statins under the ACC/AHA 5% and 7.5% risk thresholds were compared with those eligible under the 2016 USPSTF 10% guidelines. RESULTS: Of the 5388 study participants, 34% were eligible for statin therapy under the USPSTF guideline compared with 43% under the Class I (7.5%) ACC/AHA treatment threshold and 53% under the Class IIa (5%) ACC/AHA treatment threshold. Moving from the USPSTF 10% threshold to the ACC/AHA 5% threshold increased statin eligibility for males ages 40-59 from 26%-48% (whites), from 19%-43% (Hispanics), and from 33%-74% (blacks). A similar disproportionate but less pronounced effect was seen when different risk thresholds were used for statin eligibility among women ages 40-59 across differing races and ethnicities. CONCLUSIONS: In this sample of U.S. adults from the National Health and Nutrition Examination Survey database, full implementation of the higher USPSTF statin treatment threshold could lead to less overall statin use and disproportionately lower statin use among non-Hispanic blacks.