286Cardiac magnetic resonance for primary prevention implantable cardioverter debrillator therapy international registry: results of the derivate study

Abstract

BACKGROUND: Sudden cardiac death (SCD) is the most common cause of cardiovascular death in ischemic cardiomyopathy (ICM) and non-ischemic dilated cardiomyopathy (NICM) patients. To date, guidelines indicate LVEF of 35% and New York Heart Association (NYHA) class the only parameters in primary prevention ICD implantation decision making. However, up to one-fourth of patients with an ICD experience inappropriate shocks while, on the other hand, patients with normal to moderately depressed LVEF incur in SCD. In light of this, additional prognostic stratification should be desirable to better identify patients who really need an ICD implantation. Recently, cardiac magnetic resonance (CMR) imaging has emerged as the gold standard technique for morphologic and functional evaluation, with the added benefit of providing tissue characterization. PURPOSE: The aim of this study was to determine the prognostic benefit of CMR over standard of care in a wide cohort of NICM patients evaluated for primary ICD therapy. METHODS: DERIVATE is an international, multicenter, prospective, observational registry including consecutive patients with chronic heart failure (HF) with reduced LVEF (<50%) who undergo clinical evaluation, TTE and CMR. The registry included 2419 patients from n. 20 sites in Europe and the United States. The present analysis concerns 1496 patients affected by NIDM of which 1000 [mean age: 56.7 ± 14.2 yrs, male: 686 (68.6%)] included in the derivation cohort and 496 in the validation cohort enrolled in the period between January 2007 and October 2017. All patients were followed-up for all cause of mortality as primary endpoint and major adverse cardiac events (MACE) defined as combined endpoint SCD, aborted SCD and sustained ventricular tachicardia as secondary endpoint RESULTS: During a median follow-up of 959 [559.5-1590] days all-cause mortality and combined MACE occurred in 74 (11.9%) and 134 (21.5%) patients respectively. On multivariate analysis, age and number of segments with LGE middlewall >3 were significant independent predictors of mortality. Differently, gender, CMR LVEDV > 120.5 ml/m2, and number of segments with LGE middlewall >2 remained independent predictors of MACE when added to a model only based on clinical and TTE data. Moreover, adding CMR data to the model based only on clinical and TTE data provided a net reclassification improvement of 45% (24.6%-65.4%; p < 0.001). In order to estimate the performance of the integrated clinical, TTE and CMR score for MACE in the validation cohort (496 idiopathic pts), K-M survival curves were sorted out on the basis of quantiles of the CMR integrated scores showing different event free rates (P = 0.001). CONCLUSIONS: This International Study showed that CMR provides additional prognostic stratification as compared to standard of care, which may have direct impact on the indication of ICD implantation.