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

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.

Clinical Impact of Cardiac Magnetic Resonance Imaging Versus Echocardiography-Guided Patient Selection for Primary Prevention Implantable Cardioverter Defibrillator Therapy

“…The present study demonstrated that 19% of 149 patients were not eligible for ICD therapy if LVEF assessment was based on 2DE. These findings confirm the results obtained by Joshi et al 11 , who found a reclassification of 21% regarding device eligibility when cardiac MRI was used for LVEF evaluation. In patients with 2DE-LVEF 30-35% specifically, this reclassification increased to 41% of the patients and usually was in favour of ICD implantation.…”

“…6-13;19 Although conflicting results have been published regarding LVEF differences, most studies report an overestimation of LVEF by 2DE in patients with impaired LVEF when taking cardiac MRI as a reference standard. 6;7;10-12 Consistent with the results from this study, Joshi et al 11 and Gruszczynska et al 10 reported a significant overestimation of LVEF by 2DE ranging from 3 to 5% compared with cardiac MRI. Furthermore, comparable to most of these studies, this discrepancy becomes more substantial in patients with more severely reduced LVEF.…”

“…5 Previous studies comparing LVEF assessment by 2DE and cardiac MRI showed that they are not interchangeable. [6][7][8][9][10][11][12][13] Especially in patients with impaired LVEF, most studies demonstrate that LVEF values as assessed using cardiac MRI are 3-7% lower when compared with LVEF assessed by 2DE, resulting in a substantial reclassification of patients with regard to ICD eligibility. 7; 10;11 Consequently, cardiac MRI-based LVEF assessment might lead to an increase of patients eligible for ICD implantation, which may have important clinical consequences for the benefit of primary prevention ICD therapy.…”

Echocardiography vs Cardiac Magnetic Resonance Imaging for the Diagnosis of Left Ventricular Thrombus: A Systematic Review

“…However, it is important to note that none of the studies showed that an alternate modality or sequence was superior to LE-CMR imaging in the detection of thrombi. Second, there was only 1 study that exclusively used surgical or pathological evidence of LV thrombus as the gold 24 Yes No Yes Weinsaft et al 25 Yes Yes Yes Weinsaft et al 26 Yes Yes Yes Joshi et al 27 Yes No No Delewi et al 28 Yes Unknown No standard. 24 In this study the authors concluded that LE-CMR imaging was the most accurate sequence compared with this standard.…”

Highlights of the 16th annual scientific sessions of the Society for Cardiovascular Magnetic Resonance

“…Florian Andre presented data from a cohort of more than a 1000 patients showing that measuring left ventricular ejection fraction by CMR reclassified many patients into different risk groups when compared to echocardiography [37]. Others have shown the potential clinical impact of more accurate measurement of ejection fraction by CMR on selecting patients who might benefit from defibrillator implantation [38]. Recently, it has been demonstrated that the addition of late gadolinium enhancement CMR adds further prognostic value over echocardiography alone [39].…”