P266 SUBCUTANEOUS DEFIBRILLATOR USE LIMITATION IN PATIENT AFFECT BY ARRHITMOGENIC CARDIOMYOPATHY IN REAL WORLD

Abstract

Abstract Introduction The prevention of sudden cardiac death (SCD) through the implantation of a defibrillator (ICD) represents one of the fundamental milestones in the management of arrhythmogenic cardiomyopathy (ACM). Individual characteristics of the patient and of the disease can help in the selection of the device [transvenous (TV) or subcutaneous (S–ICD) defibrillator]. The objective of this study is to evaluate the major factors limiting S–ICD implantation in a real–world ACM patient population. Methods This multicenter retrospective observational study enrolled consecutive patients undergoing ICD implantation in primary or secondary prevention for ACM at the participating centers. The population was subdivided according to the execution of the preimplant S–ICD screening test and its result. Baseline clinical and instrumental data were analyzed to identify predictors of passing the screening test. Results 21 ACM patients (67% men) who underwent 24 S–ICD or TV–ICD implant procedures were enrolled. 70.8% of patients (N=17) were screened for S–ICD. Screening was not performed in 4 patients (17%): in one case due to an indication for resynchronization therapy and in three patients because they were implanted in the pre–S–ICD era. Screening failed in 53% of cases. The cause of the failures were the low voltages of the QRS (100% of the failures) and a poor stability of the trace in the different positions tested for significant variation of the QRS/T ratio (37.5% of the failures). No significant difference was noted between the clinical and instrumental characteristics of the two subgroups (Table 1), although the patients who passed the screening showed a trend towards a greater QRS amplitude in DI (0.52±0.29 vs 0.28±0.17 mV – P= 0.07) and to present a positive QRS in DI (100% vs 50%; P=0.08 – Table 2). Conclusions The use of the S–ICD in patients with ACM could be limited by some intrinsic characteristics of the disease. In a real–world cohort of patients affected by ACM, the presence of low QRS voltages on the surface ECG and positional morphology variations allowed S–ICD use in half of the patient candidates.