Changes in Follow-Up Left Ventricular Ejection Fraction Associated With Outcomes in Primary Prevention Implantable Cardioverter-Defibrillator and Cardiac Resynchronization Therapy Device Recipients. 

<br/><br/>Available online from MWHC library: 1995 - present, Available in print through MWHC library:1999-2007 
<br/><br/> BACKGROUND: Heart failure patients with primary prevention implantable cardioverter-defibrillators (ICD) may experience an improvement in left ventricular ejection fraction (LVEF) over time. However, it is unclear how LVEF improvement affects subsequent risk for mortality and sudden cardiac death.  CONCLUSIONS: Among primary prevention ICD patients, 40.0% had an improved LVEF during follow-up and 25% had LVEF improved to >35%. changes in LVEF were inversely associated with all-cause mortality and appropriate shocks for ventricular tachyarrhythmias. In patients whose follow-up LVEF improved to >35%, the risk of an appropriate shock remained but was markedly decreased.Copyright � 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.  METHODS: We conducted a prospective cohort study of 538 patients with repeated LVEF assessments after ICD implantation for primary prevention of sudden cardiac death. The primary endpoint was appropriate ICD shock defined as a shock for ventricular tachyarrhythmias. The secondary endpoint was all-cause mortality.  OBJECTIVES: This study sought to assess changes in LVEF after ICD implantation and the implication of these changes on subsequent mortality and ICD shocks.  RESULTS: Over a mean follow-up of 4.9 years, LVEF decreased in 13.0%, improved in 40.0%, and was unchanged in 47.0% of the patients. In the multivariate Cox models comparing patients with an improved LVEF with those with an unchanged LVEF, the hazard ratios were 0.33 (95% confidence interval: 0.18 to 0.59) for mortality and 0.29 (95% confidence interval: 0.11 to 0.78) for appropriate shock. During follow-up, 25% of patients showed an improvement in LVEF to >35% and their risk of appropriate shock decreased but was not eliminated. 
<br/><br/><br/>English 
<br/><br/><label>ISSN: </label>0735-1097 
<br/><br/><label>Subjects--Topical Terms: </label><br/>*Cardiac Resynchronization Therapy<br/>*Death, Sudden, Cardiac<br/>*Electric Countershock<br/>*Heart Failure<br/>*Ventricular Dysfunction, Left<br/>Aged<br/>Cardiac Resynchronization Therapy/mt [Methods]<br/>Cardiac Resynchronization Therapy/sn [Statistics & Numerical Data]<br/>Cohort Studies<br/>Death, Sudden, Cardiac/ep [Epidemiology]<br/>Death, Sudden, Cardiac/et [Etiology]<br/>Death, Sudden, Cardiac/pc [Prevention & Control]<br/>Defibrillators, Implantable<br/>Electric Countershock/is [Instrumentation]<br/>Electric Countershock/mt [Methods]<br/>Female<br/>Heart Failure/co [Complications]<br/>Heart Failure/th [Therapy]<br/>Humans<br/>Incidence<br/>Male<br/>Middle Aged<br/>Proportional Hazards Models<br/>Prospective Studies<br/>Risk Assessment<br/>Severity of Illness Index<br/>Stroke Volume<br/>United States/ep [Epidemiology]<br/>Ventricular Dysfunction, Left/di [Diagnosis]<br/>Ventricular Dysfunction, Left/et [Etiology]<br/>Ventricular Dysfunction, Left/mo [Mortality]
<br/><br/><label>Subjects--Geographic Terms: </label><br/>MedStar Heart & Vascular Institute
<br/><br/><label>Index Terms--Function: </label><br/>Journal Article<br/>Multicenter Study<br/>Research Support, N.I.H., Extramural<br/>Research Support, Non-U.S. Gov't