3D Echocardiography May Affect Decision to Implant an ICD in Subset of Patients

Assessment of left ventricular ejection fraction (LVEF) by 3-dimensional echocardiography (3DE) may change the decision to implant an implantable cardioverter-defibrillator (ICD) in patients with left ventricular (LV) dysfunction, according to a study published in JACC: Cardiovascular Imaging.

Investigators sought to determine the optimal imaging modality to assess LVEF. The investigators examined 172 patients with ischemic or nonischemic LV dysfunction (LVEF<50%) that were being considered for ICD implantation and compared assessments for LVEF done with 2DE versus 3DE.

Major arrhythmic events such as sudden cardiac death (SCD), aborted cardiac arrest, and appropriate ICD therapy were the outcomes for evaluation. Patients were followed for 18 to 65 months (median=56).

In regards to selection for ICD implantation, the study showed that when using 2DE LVEF, 69 (40%) patients underwent an ICD implant for the prevention of SCD. When 3DE LVEF was used for these same patients, the results made reclassification necessary for 34 (20% overall) patients.

Major arrhythmic events occurred in 30% of the patients. Assessment using 3DE LVEF changed the assignment above and below LVEF thresholds for implementation of ICD in 20% of patients, with the majority having 2DE LVEFs within ±10% from the threshold.

The 3DE LVEF predictive value was particularly strong, with a 31% decrease in the risk of major arrhythmic events per each 5% increase in LVEF. Age (hazard ratio [HR], 1.030; 95% CI, 1.008-1.050 per year; P =.007) and 3DE LVEF (HR, 0.69; 95% CI, 0.52-0.96 per 5% increase; P =.02) remained the only significant predictors of the occurrence of major arrhythmic events.

LVEF values measured with 3DE were stronger predictors of major arrhythmic events than the same values calculated with 2DE.

The study is limited by its observational design, the lack of assessments done with contrast for the 2DE, and a high prevalence of ischemic heart disease with resting wall motion abnormalities among the study population.

The results from this study may provide a basis for future clinical trials assessing LVEF for selection of ICD implementation.

Disclosures: Two authors declare possible conflicts of interest. Please refer to original reference for a full list of authors’ disclosures.

Reference

Rodríguez-Zanella H, Muraru D, Secco E, et al. Added value of 3- versus 2-dimensional echocardiography left ventricular ejection fraction to predict arrhythmic risk in patients with left ventricular dysfunction [published online September 12, 2018]. JACC Cardiovasc Imaging. doi: 10.1016/j.jcmg.2018.07.011