Background:Implantable cardioverter defibrillators (ICDs) have significantly reduced the incidence of sudden cardiac death in patients with heart failure, particularly those with ischemic heart disease. However, the impact on overall mortality remains controversial, especially in non-ischemic heart failure patients. The Danish Study to Assess the Efficacy of ICDs in Patients with Non-Ischemic Systolic Heart Failure (DANISH) trial and subsequent studies have questioned the efficacy of ICDs in this population, particularly among older patients. The present study aimed to evaluate survival outcomes and predictors in a Croatian cohort of patients with an ICD or cardiac resynchronization therapy defibrillator (CRT-D) device. Methods:This retrospective cohort study analyzed data from 614 patients who received an ICD or CRT-D device at KBC Zagreb between 2009 and 2018. Patient data, including demographic information, device indication, and clinical parameters, were collected at the time of implantation. Follow-up data were systematically recorded to assess device activation and survival outcomes. Statistical analyses included a detailed descriptive analysis, Kaplan-Meier survival estimates, and Cox regression models. Results:The cohort consisted predominantly of males (83.4%), with a mean age of 58.7 years. Most had reduced left ventricular ejection fraction (mean 31.4%) and were classified as New York Heart Association (NYHA) class II or III. Over a median follow-up of 48.4 months, 36.6% of patients died. Device activation occurred in 30.3% of patients, with appropriate activation observed in 88.2% of these cases. Cox regression identified age, non-sustained ventricular tachycardia (NSVT), and decompensation history as significant survival predictors. Conclusions:This study confirmed that appropriate device activation improved survival in patients with an ICD/CRT-D. Age, NSVT, and history of decompensation were key predictors of device activation and survival outcomes. These findings underscore the need for individualized patient assessment when considering inserting ICDs, particularly in non-ischemic heart failure patients. Further research is needed to refine clinical guidelines and optimize patient selection for ICD therapy.

Implantable cardioverter-defibrillators (ICDs) reduce sudden cardiac death (SCD) in heart failure (HF) patients, especially in those with ischemic cardiomyopathy (ICM). However, the overall impact on mortality in non-ischemic cardiomyopathy (NICM) is still debated. The DANISH trial raised questions about ICD efficacy in NICM patients, particularly in older individuals, sparking concerns regarding patient selection and the risk-benefit balance. This study evaluates survival outcomes, device activation, and mortality predictors in ICM and NICM patients with implanted ICD devices. A total of 786 patients who underwent ICD (75%) or CRT-D (25%) implantation between 2009 and 2018 were included in this retrospective cohort study. The mean patient age was 58.2 ± 13.6 years, with 80.7% being male and a reduced left ventricular ejection fraction (LVEF) of 31.9 ± 12.4%. The primary outcome was all-cause mortality, and secondary outcomes included device activation (appropriate or inappropriate) and its correlation with survival. Kaplan-Meier survival estimates and Cox proportional hazard models were used, with comparisons between ischemic and non-ischemic cardiomyopathy patients and primary versus secondary prevention groups. Over follow-up period of +/-47.3 months, 35.2% died. Device activation occurred in 29.1% of patients, with 86% being appropriate. ICM patients had a higher rate of appropriate activations compared to NICM patients (28.0% vs. 23.0%), while inappropriate activations were more frequent in NICM patients (6.1% vs. 1.5%, p=0.003). Device activation was associated with a significant survival advantage (p<0.001). Mortality predictors included older age, non-sustained ventricular tachycardia (NSVT), and a history of decompensation. Cox regression analysis confirmed these as independent mortality predictors, with hazard ratios of age (HR=1.032; p<0.001), NSVT (HR=2.403; p<0.001), and decompensation (HR=1.931; p<0.001). In comparison with the DANISH trial, which reported no significant reduction in all-cause mortality in NICM patients over 70 years old, this study found similar age-dependent survival benefits. Younger patients (<70 years), (especialy with NICM), showed greater survival benefits from ICD implantation. Results emphasize the importance of careful patient selection, especially in older patients, where the benefits of ICDs must be balanced against the risks of inappropriate shocks and device complications. This study found that ICD implantation improved survival. Age, NSVT, and decompensation were key predictors of mortality and device activation, highlighting the need for individualized patient assessments. In line with the DANISH trial, our findings suggest that younger NICM patients benefit more from ICD implantation, while in older populations, the risks and benefits should be carefully weighed.

Background: This study was conducted to evaluate compliance with guideline-directed optimal medical therapy (OMT) and its association with early implantable cardioverter-defibrillator (ICD) activation in patients with heart failure and reduced ejection fraction (HFrEF). Methods: Retrospective data from 307 patients who underwent ICD implantation for primary prevention from 2011 to 2017 were collected and analyzed. Results: Among the study participants, only 23.8% received the maximum tolerated dose of OMT prior to ICD implantation, with 59.0% receiving all three OMT medication groups. No significant difference in OMT compliance was found between patients with ischemic cardiomyopathy (ICM) and those with non-ischemic dilated cardiomyopathy (DCM). However, DCM patients received ICDs more frequently at the time of diagnosis than ICM patients (13.8% vs. 0.7%). Early ICD activation (within 3 months) occurred in only one patient who had not received appropriate OMT, representing 0.7% of all ICM patients. Furthermore, early activation was also infrequent in patients who received OMT (2.9% of ICM patients and 2.6% of DCM patients). Echocardiography follow-up data revealed that 20.4% of ICM patients and 29.8% of DCM patients who did not receive OMT before ICD implantation showed improvement in the left ventricular ejection fraction (EF) to 35% or more. Conclusions: This study found suboptimal compliance with OMT prior to ICD implantation in HFrEF patients. The results showed that early ICD activation was rare in all patient groups, especially those who did not receive the prescribed 3 months of OMT. More research is needed to investigate longer waiting periods for the evaluation of potential EF improvement, and to better evaluate the eligibility of HFrEF patients for ICD. The current findings have potential implications for clinical practice and patient outcomes.

IntroductionCoronavirus disease 2019 (COVID-19) pandemic has influenced health-care organization worldwide, including management of non-communicable diseases. The aim of this study was to determine the impact of COVID-19 pandemic on cardiac implantable electronic devices' (CIEDs) implantation rates in Croatia.MethodsA retrospective, observational, national study was conducted. The data on CIEDs' implantation rates from 20 Croatian implantation centres, between January 2018 and June 2021, were extracted from the national Health Insurance Fund registry. Implantation rates before and after COVID-19 pandemic started, were compared.ResultsThe overall numbers of CIED implantations in Croatia during COVID-19 pandemic were not different in comparison to 2 years pre-COVID-19 time (2618 vs. 2807, p = .081). The pacemaker implantation rates decreased significantly (by 45%) during April (122 vs. 223, p < .001) and May 2020 (135 vs. 244, p = .001), as well as during November 2020 (177 vs. 264, p = .003), but significantly increased during summer months 2020 comparing to 2018 and 2019 (737 vs. 497, p<0.001). The ICD implantation rates decreased significantly by 59% in April 2020 (26 vs. 64, p = .048).ConclusionTo the authors best knowledge this is a first study including complete national data on CIED implantation rates and COVID-19 pandemic impact. A significant reduction in number of both pacemaker and ICD implants during specific months of the COVID-19 pandemic was determined. However, afterwards compensation in implants resulted in similar total number when the complete year was evaluated.

Introduction : The dosing strategies for cryoballon (CB) ablation rely on adequate real time (RT) visualization of pulmonary vein potentials. In order to improve incidence of RT recordings Cryoballoon Advance Short-tip was designed, but soon withdrawn from the market due to technical problems with the catheter. Recently, Artic Front Advanced Pro (AFA-Pro) was introduced, with the tip that is 5.5 mm shorter than its predecessor. Ideally, a shorter tip should permit an improved visualization of real-time recordings in the pulmonary vein (PV) due to a more proximal positioning of the inner lumen mapping catheter. We sought to compare the incidence of visualization of real-time recordings in patients having undergone ablation with the AFA-Pro with patients having received older second generation device (AFA).

Four thousand cardiac implantable electronic devices (CIED) are implanted yearly in Croatia with constant increase. General anesthesia and surgery carry some specific risk for the patients with implanted CIEDs. Since most of the surgical procedures are performed in institutions without reprogramming devices available, or in the periods when they are unavailable, these guidelines aim to standardize the protocol for perioperative management of these patients. With this protocol, most of the procedures can be performed easily and, more importantly, safely in the majority of surgical patients.

ORcid: Mislav Puljević, https://orcid.org/0000-0003-1477-2581 • Ivica Šafradin, https://orcid.org/0000-0003-4519-5940 Borka Pezo Nikolić, https://orcid.org/0000-0002-0504-5238 • Richard Matasić, https://orcid.org/0000-0003-1289-1704 Vedran Velagić, https://orcid.org/0000-0001-5425-5840 • Martina Lovrić Benčić, https://orcid.org/0000-0001-8446-6120 Miroslav Krpan, https://orcid.org/0000-0002-0639-953X • Davor Puljević, https://orcid.org/0000-0003-3603-2242

Uvod: Uobičajeno se ventrikulska elektroda postavlja u apeks desne klijetke. Ovaj pristup ima nekoliko prednosti. Ponajprije, apeks desne klijetke se lako lokalizira fluoroskopijom i elektroda se u većini slučajeva lako postavlja. Rizik pomaka elektrode je minimalan i dobiju se pouzdani parametri. Ali budući da impuls elektrostimulatora srca započinje od apeksa desne klijetke, nastaje jatrogeni kompletni blok lijeve grane. Posljedica je nastanak interventrikulske i intraventrikulske disinhronije (rana aktivacija desne klijetke i interventrikulskog septuma i kasna aktivacija lateralne stijenke lijeve klijetke. Većina bolesnika navedeno podnosi dosta dobro određeno vrijeme. Kod nekih bolesnika i pogotovo onih koji zahtijevaju stalnu stimulaciju klijetki, mogu nastati dilatacija i remodeliranje lijeve klijetke, pad ejekcijske frakcije lijevog klijetke pa čak i kongestivno srčano popuštanje1,2. Stimulacija putem Hisovog snopa, aktivira klijetke putem nativnog His-Purkinje sustava što dovodi do prirodnije elektrostimulacije srca. Budući da aktivacija nastaje putem normalnog provodnog sustava srca, nema ni intraventrikulske ni interventrikulske disinhronije. Zbog toga nema negativnih učinaka na dimenzije i funkciji klijetki3.