The Benefit of Prophylactic Implantable Cardioverter Defibrillator Implantation in Asymptomatic Heart Failure Patients With a Reduced Ejection Fraction

Abstract

Recommendations for prophylactic implantable cardioverter defibrillator (ICD) implantation in asymptomatic heart failure patients with a reduced left ventricular ejection fraction (LVEF) differ between guidelines. Evidence on the risk of appropriate device therapy (ADT) and death in New York Heart Association (NYHA) class I patients is scarce. Aim of this study is to evaluate ADT and mortality in NYHA-I primary prevention ICD patients with a LVEF ≤35%. A retrospective cohort was studied, including 572 patients with LVEF ≤35% who received a prophylactic ICD with or without resynchronization therapy (CRT-D). To evaluate the incidence of ADT and mortality, NYHA-I was compared with NYHA-II-III using Cox regression analysis. During a follow-up of 4.1 § 2.4 years, 33% of the NYHA-I patients received ADT compared with 20% of the NYHA-II-III patients (hazard ratio 1.5, 95% confidence interval 1.04 to 2.31, p = 0.03). No differences in mortality were observed (hazard ratio 0.70, 95% confidence interval 0.49 to 1.07, p = 0.10). Additional analyses showed no difference in time to ADT excluding CRT patients (ICD-NYHA-I patients vs ICD-NYHA-II-III patients, p = 0.17) and comparing ischemic and nonischemic cardiomyopathy NYHA-I patients (p = 0.13). Multivariable Cox regression analyses showed that NYHA class was the strongest independent predictor of ADT. In conclusion, primary prevention NYHA-I ICD patients showed a higher incidence of ADT compared with NYHA-II-III ICD patients. These results strongly suggest that primary prevention NYHA-I patients with a LVEF ≤35% are likely to benefit from ICD therapy and should not be excluded from a potentially life-saving therapy.

Is the clinical benefit of implantable cardioverter-defibrillators in heart failure patients declining?

“…Primary prevention ICD use was associated with reduced risk of 1-year and 5-year all-cause death, and the association between ICD use and all-cause mortality was consistent in patients with versus without ischemic heart disease [2]. Furthermore, van der Lingen et al even found that primary prevention in New York Heart Association (NYHA) class I ICD patients showed a higher incidence of appropriate device therapy compared with NYHA II and III ICD patients [3]. These results strongly suggest that primary prevention NYHA I patients with a left ventricular ejection fraction 35 % are likely to benefit from ICD therapy and should not be excluded from a potentially lifesaving therapy [3].…”

“…It is well established in current literature that tremendous success has been achieved over the last decades in the management of SCD in patients with HF by the use of ICD [4]. Notably, in ischemic cardiomyopathy patients, the clinical benefit from ICD is well-stablished [2][3][4][5]. Dramatic changes in medical treatment, though, have rendered a reevaluation of the role of devices for primary prevention of SCD in patients receiving up-to-date optimal care imperative [4].…”

“…Dramatic changes in medical treatment, though, have rendered a reevaluation of the role of devices for primary prevention of SCD in patients receiving up-to-date optimal care imperative [4]. The prevalence of SCD in patients with HF with reduced ejection fraction has been declining in the last decade, not only due to better optimization of pharmacological therapy but also due to the high rate of cardiac resynchronization responders [2][3][4].…”

“…From this perspective, several authors agree that the selection of ICD patients may benefit from an extension of the current guidelines, which are based solely on the ejection fraction and New York Heart Association class. The expansion should comprise a poly-parametric patient assessment, which may selectively identify those patients who may have the highest benefit from ICD therapy [3]. Nevertheless, diverging opinions exist on the steps to perform to move in such a direction.…”

“…The DANISH trial [1] did not demonstrate a reduction of total mortality by ICD therapy in patients with HF of non-ischemic origin and severe left ventricular dysfunction with respect to non-treated ones. The inclusion of LGE in the selection criteria may ameliorate the appropriateness of ICD therapy in non-ischemic cardiomyopathy patients, by identifying patients with fibrosis (positive LGE-test), who are more prone to develop arrhythmias treatable with an ICD shock [3]. On the other hand, we are confident that further published data on LGE-CMR and other arrhythmic risk markers will allow an additional improvement in ICD appropriateness in ischemic cardiomyopathy and in HF with mild-to-moderate left ventricular dysfunction through the use of a poly-parametric approach.…”