P1464A question of gender equality. Sex-related differences in survival after primary prevention implantable cardioverter-defibrillator implantation for dilated cardiomyopathy An analysis from POLKARD

OnBehalf

POLKARD Polish ICD Registry

Background

The protective effects of implantable cardioverter defibrillators (ICDs) in the primary prevention of sudden cardiac death of patients presenting with left ventricular (LV) systolic dysfunction are unequivocal. Nevertheless, female underrepresentation has been a consistent finding in all randomized controlled primary prevention ICD trials. Surprisingly, there is a vast body of literature on female primary prevention ICD patients exhibit a lower overall mortality.

Purpose

Therefore, we analyzed data from a large, nationwide POLKARD registry to evaluate the effect of sex on survival after primary prevention cardioverter-defibrillator implantation for dilated cardiomyopathy.

Methods

All patients enrolled in the Polish ICD Registry from 2008 to 2014 were identified. Patients were included in the study if they were designated as receiving an ICD for primary prevention of SCD after documented non-ischeamic cardiomyopathy. Kaplan-Meier survival analysis was used to assess all-cause mortality.

Results

Of the 964 ICD recipients, 241 (25%) were women (mean age of 64± 0,45 years). During a mean follow-up of 5,53 ± 2,48 years 32% of women and 42% of men died. Kaplan-Meier curve depicted a significantly lower mortality for women than for men (p = 0,05). The median survival time was 6,73 years (55 deaths per 1000 person-years) versus 6,37 years (78 deaths per 1000 person-years) for women and men, respectively.

Conclusions

In agreement with previous studies, our data indicate that primary prevention implantation rates for dilated cardiomyopathy are lower in women. However, the reasons are not entirely understood.

P1463Regional variation in survival rates among primary prevention implantable cardioverter-defibrillator recipients in Eastern and Northern Europe POLKARD Polish ICD Registry perspective

Funding Acknowledgements

None.

OnBehalf

POLKARD Polish ICD Registry

Objective

The findings of Danish Study to assess the efficiency of ICD in patients with non ischemic heart failure has recently raised questions about the current strategy of ICD implantation for the primary prevention of sudden cardiac death. POLKARD - Polish ICD Registry is a prospective, non-randomised, central registry of patients who are referred for an implantation of an ICD in Poland. The Registry contains prospectively collected follow-up data including mortality.

Purpose

To compare survival rates between Polish and Danish ‘real-world’ non-ischemic primary prevention cohorts.

Methods

Retrospective analysis of clinical characteristics and long-term follow-up of patients referred for primary prophylactic implantable cardioverter defibrillator (ICD) implantation in Poland between April 2008 and November 2014 was performed. The primary outcome of the trial was all-cause mortality. Results: The polish study cohort was large (964) as compared to Danish population randomized to receive ICD therapy (556). The median follow-up time in DANISH Study and Polish ICD Registry was 67,6 and 77 months, respectively. Compared with patients enrolled in the DANISH Study, patients in the Polish ICD Registry were age-similar. However, the polish study population was male-dominated. What is more, male gender was identified as a risk factor for long-term mortality in polish study population (p = 0.005). In the matched cohorts, there was difference in survival between DANISH Study and Polish ICD Registry patients (all-cause mortality rates: 21,6% - 44 events per 1000 person-years and 39,3% - 72 events per 1000 person-years, respectively).

Conclusions

Our findings imply that survival among patients who receive a primary prevention ICD for non-ischemic cardiomyopathy in clinical practice in Central Europe is different from Northern Europe.

P990Assessment of clinical risk factors for all-cause mortality among hypertrophic cardiomyopathy patients with ICDs

Introduction

According to the literature, the annual mortality rate of hypertrophic cardiomyopathy (HCM) patients is estimated to 1–2%. Sudden cardiac death (SCD), heart failure and thromboembolism are the main causes of death among this population. Patients at high risk for SCD, identified using HCM risk score, are qualified for ICD implantation. Unfortunately for clinicians, there is no validated model or statistical tool for assessment of the risk of mortality within the HCM patients with ICDs.

Purpose

The aim of this study was to determine the main risk factors of all- cause mortality in HCM patients with ICDs.

Methods

The long-term follow-up of group of 104 consecutive patients with HCM, who had the ICD implanted between 1996 and 2006 in tertiary reference clinical unit was performed. Twenty patients who died during observation were the subject of the current analysis. ICD was implanted for primary (n=16) and secondary (n=4) prevention of SCD within this subpopulation. Analysis were performed for mentioned below potential risk factors: age at the time of implantation, syncopes, family history of SCD, atrial fibrillation/supraventricular tachycardia, decreased left ventricular ejection fraction (LVEF), non-sustained ventricular tachycardia (nsVT), maximum left ventricular wall thickness, abnormal exercise blood pressure response, left ventricular outflow tract obstruction.

Results

The average time of survival since ICD implantation was 8,5±4,6 years. Decreased LVEF (Wald chi2 4,57; p=0,033), secondary prevention (Wald chi2 8,57; p=0,003), family history of SCD (Wald chi2 4,93; p=0,026) and episodes of nsVT (Wald chi2 3,49; p=0,062) are the clinical risk factors that significantly affect the time of survival. The probability of death, expressed as Hazard Ratio, was 27-fold higher in secondary prevention group (HR=27,18), almost 10-fold higher in patients with positive family history of SCD (HR=9,74) and 3,7-fold higher when nsVT was detected. The cause of death was established in 16/20 patients. In 15 cases, these were deaths from cardiovascular causes: end-stage heart failure (8), complications of heart transplantation or circulatory support (4), SCD (1) and other cardiovascular (2).

Conclusion

Secondary prevention, positive family history of SCD, nsVT and decreased LVEF seem to be the most significant risk factors associated with all- cause mortality in HCM patients with ICDs. Despite the ICD implantation, subpopulation studied had poor prognosis with high incidence of progression to end-stage heart failure. Further studies to create validated model for assessment of death risk in long-term observation of patients with HCM after ICD implantation are required.

P2878Higher all-cause mortality in patients with implanted dual-chamber cardioverter-defibrillators for secondary prevention: an analysis from the Polish ICD Registry

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.

Improved robust T-wave alternans detectors

New statistical and spectral detectors, the modified matched pairs t test, the extended spectral method and the modified spectral method, were proposed for T-wave alternans (TWA) detection gaining robustness according to trend and single-frequency interferences. They were compared to classic detectors such as matched pairs t test, unpaired t test, spectral method, generalized likelihood ratio test and estimated TWA amplitude within a simulation framework and applied to real data. The optimal detection threshold was selected by using a full Monte-Carlo simulation where signals, with and without alternans episodes, were corrupted by Gaussian noise with different power and single-frequency interferences with different tones. All the combinations of noise and frequency were selected and repeated 500 times in order to compute probability of detection ([Formula: see text]) and the false alarm probability ([Formula: see text]), providing ROC curves. The study group consisted of 50 patients with implantable cardioverter-defibrillator (age: [Formula: see text]; LVEF: [Formula: see text]), who were paced (ventricular pacing) at 100 bpm. Two-minute recordings were analyzed. The XYZ orthogonal lead system was used. The best performance was reached by using the modified matched pairs t test (in comparison with the spectral method and other reference methods).

Resolution of an aortic mobile mass with anticoagulation without evidence of arterial embolism

The prognostic significance of aortic mobile debris detected by transesophageal echocardiography (TEE) in patients without history of embolism has not been established. A mobile aortic arch mass was found by TEE in a 59-year-old man with coronary artery disease, and with rheumatic mitral valve disease, and with no embolic symptoms. The patient was anticoagulated for 6 weeks and the mass was no longer seen on repeated TEE. He had no embolic symptoms during 9 months of follow-up. Different therapeutic approaches to mobile aortic debris are discussed and anticoagulant treatment of asymptomatic cases is advocated.

[Treatment of 3 patients with arrhythmias using "radiofrequency" ablation]

In 3 patients radiofrequency (RF) ablation of AV node (n = 2) and left sided accessory pathway (n = 1) was performed because of intractable tachyarrhythmias. RF ablation was made in the first patient (ablation of AV node) using 135 Watts during 72 sec., in the second patient (AV node ablation) 331 Watts during 185 sec., and in the last patient 883 Watts during 695 sec. In the last patient ablation of accessory pathway was unsuccessful and the patient has been successfully operated. AV conduction was interrupted in 2 cases. No complications were noted. General anesthesia was not required. All the patients were discharged in a good state.

Promotion of neuronal survival in vitro by thermal proteins and poly(dicarboxylic)amino acids

Evaluating molecules for their ability to promote survival and growth of neurons, we tested thermal proteins on cultures of dissociated fetal rat forebrain neurons. (Thermal proteins are polyamino acids formed when mixtures of amino acids with minimal proportions of glutamic or aspartic acid are heated.) Thermal proteins, added to low-density cultures in serum-free medium, stimulated neurite outgrowth and induced the formation of neuronal networks which survived for 6-10 days. Neurons in control cultures failed to grow and degenerated completely within 2-4 days. Effective concentrations (EC50) of thermal proteins ranged from 3 to 100 micrograms/ml. They were equally effective when present in the medium during the culture time or after precoating of the culture dishes. A single preparation which contained only aspartic and glutamic acid was effective, and similar survival promoting actions were then found for polyglutamic acid and mixed polyamino acids containing glutamic or aspartic acid. Thermal proteins and polyglutamic acid acted in a specific manner since, under the same experimental conditions, many control peptides, proteins and growth hormones failed to promote survival of neurons. Furthermore, their effects were antagonized by heparin, but not heparan sulfate nor chondroitin sulfate. These findings suggest that sequences of successive dicarboxylic amino acid residues are able to promote survival and neurite elongation of cultured neurons and that such sequences are responsible for the survival promoting action of thermal proteins. They invite the speculation that sequences of successive dicarboxylic amino acids, while occur in many proteins and show a high degree of evolutionary conservation, may have functional role in molecular recognition processes during neuronal development.

Carbon monoxide effect on the membrane potential of cells in nervous tissue cultures

The effects of carbon monoxide (CO) on the membrane potential of neurons and glial cells were investigated using organotropic cultures of the cerebellum of newborn rats in two experimental groups. Group I comprised cultures maintained during 2, 3 and 4 weeks and exposed only once to CO during 30 minutes. In group II 3-week cultures were exposed twice to CO with a 30-minute interval between exposures. The gaseous environment of the cultures contained air with 10% of CO. The results of measurements of membrane potentials carried out immediately after exposure and 24 hours later were subjected to conventional statistical analysis. After one exposure to CO the membrane potential of the neurons and glial cells decreased, and after 24 hours it rose, without, however, reaching the value observed in the cells kept in standard cultures. Immediately after two exposures of 30 minutes each a significant fall of the membrane potential was observed in the neurons and glial cells, while 24 hours later the measurements of the resting potential in all cells showed zero value. The experiments with two exposures to CO for 10 minutes each demonstrated a fall in the membrane potential of neurons and glia, and after 24 hours this potential rose only in glial cells. The results of these investigations are compared with those reported in the literature and the mechanism of disturbances of cell membrane polarization during cytotoxic hypoxia is discussed.

Discharge pattern of single neuronal units in cortical projection area of vagus nerve during successive episodes of hypoxia

For an analysis of discharge pattern of single neuronal units in the cortical projection area of the vagus nerve during successive episodes of hypoxia their action potentials were recorded extracellularly. Changes in the discharge pattern were assessed by means of histograms of interimpulse intervals. It was found that the reaction of neurons to repeated exposure to hypoxia includes: a) increased frequency of discharges, b) decreased activity, or c) habituation, i.e. reduction in the degree of neuronal activity changes during successive exposures to hypoxia.

Anoxia-induced changes in the resting potential of the cerebellar cells in tissue culture

Membrane potentials of Purkynĕ cells, granular cells, astrocyte cells and oligodendrocyte cells were measured in the cerebral tissue culture under normal conditions and after anoxia. An increment of the membrane potential value with age of culture was found. After anoxia the resting potential decreased with exception of 2-week Purkynĕ cells and granular cells. The highest anoxia-induced decrease of the membrane potential of all the cells studied was observed in 3-week tissue culture.