Abstract
Background
In the Polish ICD Registry population secondary prevention recipients account for over 27%. Despite the evolution of indications for secondary prevention implantable cardioverter defibrillators (ICDs), recommendations regarding the use of ICDs for secondary prevention of sudden cardiac death (SCD) rely on information from a small number of randomized controlled trials that were performed decades ago, with mixed results. Moreover, research on the outcomes after implantations for secondary prevention of ICDs is limited. While dual-chamber devices offer theoretical advantage over single-chamber devices, dual-chamber ICDs (DC-ICDs) were announced not superior to single-chamber (SC-ICDs) in some research.
Purpose
Therefore, the aim of the study was to evaluate the all-cause mortality among patients from the Polish ICD Registry receiving either a single- or a dual-chamber device for secondary prevention in contemporary clinical practice.
Methods
All patients enrolled in the Polish ICD Registry from 1995 to 2016 were identified. Patients were included in the study if they were designated as receiving an ICD for secondary prevention of SCD after documented tachycardic arrest, sustained ventricular tachycardia (VT), or syncope. Kaplan-Meier survival analysis was used to assess all-cause mortality.
Results
In the study population of 3596 ICD recipients (mean age 69±12 years, 81% male, SC-ICD 61%, DC-ICD 39%), during mean follow-up of 79±43 months all-cause mortality rate was higher in the dual-chamber group than in the single chamber group, with a significant difference between the two groups as depicted in Kaplan-Meier curve (p<0,05). The median survival time was 98 months versus 110 months for SC and DC-ICD, respectively.
Conclusions
This study is the first to describe the characteristics of a national cohort of patients receiving a secondary prevention ICD in such a long follow-up period in contemporary practice. Implantation of a dual-chamber ICD was associated with higher all-cause mortality compared with single chamber devices.