Potential clinical impact of cardiovascular magnetic resonance assessment of ejection fraction on eligibility for cardioverter defibrillator implantation.

Subodh B Joshi,Andrew M Crean,Mark Hansen,Graham A Wright,Howard Leong-Poi,Andrew T Yan,Abdul Al-Hesayen,Laura Jimenez-Juan,Anish Kirpalani,Kim A Connelly,Paul Dorian,Iqwal Mangat

doi:10.1186/1532-429x-14-69

Abstract

BackgroundFor the primary prevention of sudden cardiac death, guidelines provide left ventricular ejection fraction (EF) criteria for implantable cardioverter defibrillator (ICD) placement without specifying the technique by which it should be measured. We sought to investigate the potential impact of performing cardiovascular magnetic resonance (CMR) for EF on ICD eligibility.MethodsThe study population consisted of patients being considered for ICD implantation who were referred for EF assessment by CMR. Patients who underwent CMR within 30 days of echocardiography were included. Echocardiographic EF was determined by Simpson’s biplane method and CMR EF was measured by Simpson’s summation of discs method.ResultsFifty-two patients (age 62±15 years, 81% male) had a mean EF of 38 ± 14% by echocardiography and 35 ± 14% by CMR. CMR had greater reproducibility than echocardiography for both intra-observer (ICC, 0.98 vs 0.94) and inter-observer comparisons (ICC 0.99 vs 0.93). The limits of agreement comparing CMR and echocardiographic EF were – 16 to +10 percentage points. CMR resulted in 11 of 52 (21%) and 5 of 52 (10%) of patients being reclassified regarding ICD eligibility at the EF thresholds of 35 and 30% respectively. Among patients with an echocardiographic EF of between 25 and 40%, 9 of 22 (41%) were reclassified by CMR at either the 35 or 30% threshold. Echocardiography identified only 1 of the 6 patients with left ventricular thrombus noted incidentally on CMR.ConclusionsCMR resulted in 21% of patients being reclassified regarding ICD eligibility when strict EF criteria were used. In addition, CMR detected unexpected left ventricular thrombus in almost 10% of patients. Our findings suggest that the use of CMR for EF assessment may have a substantial impact on management in patients being considered for ICD implantation.

Highlights

For the primary prevention of sudden cardiac death, guidelines provide left ventricular ejection fraction (EF) criteria for implantable cardioverter defibrillator (ICD) placement without specifying the technique by which it should be measured
Guidelines recommend ICD implantation for primary prevention in patients with left ventricular ejection fraction (EF) below 30% or 35% depending on etiology and symptoms [1,2,3]
When strict EF thresholds are used for primary prevention ICD placement, it is unknown whether differences between modalities would alter clinical decisions

Summary

Introduction

For the primary prevention of sudden cardiac death, guidelines provide left ventricular ejection fraction (EF) criteria for implantable cardioverter defibrillator (ICD) placement without specifying the technique by which it should be measured. We sought to investigate the potential impact of performing cardiovascular magnetic resonance (CMR) for EF on ICD eligibility. Implantable cardioverter defibrillator (ICD) placement has been shown to reduce the risk of sudden cardiac death in patients with severe left ventricular dysfunction [1,2,3]. Guidelines recommend ICD implantation for primary prevention in patients with left ventricular ejection fraction (EF) below 30% or 35% depending on etiology and symptoms [1,2,3]. We sought to investigate the potential clinical impact of performing CMR for EF in patients being evaluated for ICD therapy

Methods

Results

Conclusion