Guideline-Directed Medications for Heart Failure Before ICD

Study Questions:

What is the utilization of guideline-directed medical therapy (GDMT) for systolic heart failure (HF) prior to implantation of a primary implantable cardioverter-defibrillator (ICD)?


The study authors merged data from a 40% random sample of Medicare administrative data (Master Beneficiary Summary File) with that from the National Cardiovascular Data Registry (NCDR) and then examined the prescription fills for recipients of primary prevention ICD for the time period between 2007 and 2011. They analyzed overall GDMT (defined as one or more prescription fill for an HF beta-blocker and any renin-angiotensin inhibitor) and for each US hospital referral region. They identified characteristics with GDMT and the association with 1-year mortality. They used descriptive statistics to assess characteristics of the cohort overall and across subgroups defined by pre-ICD implant GDMT use. They used Poisson regression to model the association between receipt of both any or adequate pre-implant GDMT and 1-year mortality adjusted for patient characteristics and HF severity.


The study cohort included 19,773 systolic HF (left ventricular ejection fraction [LVEF] <40%) patients (mean age, 74.9 ± 6.2 years; 35.4% female) with primary prevention ICD. Based on ICD registry data, 74.4% of patients had ischemic cardiomyopathy and 62% had nonischemic dilated cardiomyopathy, and in some, both were reported. In this cohort, they found that 61.1% filled any prescription prior to implant. Across hospital referral region, the application of GDMT occurred in 44-76% (51-71% for 5th-95th percentile). The proportion of patients with an adequate supply was much lower, ranging from 16-49% (5th-95th percentile: 19-38%). The strongest predictors of GDMT included absence of chronic renal disease, or nonsustained ventricular tachycardia, low-income prescription benefits subsidy, and less recent LVEF evaluation. LVEF, New York Heart Association functional class, diabetes, dementia, or race were not associated with receipt of GDMT. They found that the 1-year mortality with ICD implant was lower in those receiving pre-implant GDMT (11.1% vs. 16.2%, adjusted relative risk [RR], 0.80; 95% confidence interval [CI], 0.73-0.87), even after adjusting for comorbidities such as LVEF and functional HF class. Mortality within 1 year after implantation was also less common for patients with adequate GDMT (9.4% vs. 14.6%, adjusted RR, 0.80; 95% CI, 0.72-0.89).


The authors concluded that in systolic HF patients prior to ICD implantation, the rate of GDMT was lower.


This is an important study because it supports the fact that compliance with GDMT reduces mortality. To improve compliance, implantation of an ICD should probably be considered only after documentation of adherence to GDMT is available. Conducting prospective studies that determine adherence to GDMT and more importantly with tools to improve compliance, is the next step.

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