For Whom the Bell Tolls: Refining Risk Assessment for Sudden Cardiac Death

[(LV)EF is a poor predictor of sudden cardiac death : Pro/Contra]

For more than two decades the left ventricular ejection fraction (LVEF) has been utilized with practically uncritical absolutism for the risk stratification of patients with ischemic and, historically, also nonischemic cardiomyopathy, in order to identify patients who could be threatened by sudden cardiac death. Based on historical data and in the absence of other better predictive parameters, the LVEF continues to appear in the guidelines unchanged, with cut-off values that lie in the region of the measurement accuracy of LVEF as determined by echocardiography. The basic identification of high-risk patients who then really benefit from an implantable cardioverter defibrillator (ICD) must be re-evaluated under the aspect of a meaningfully altered interventional and pharmaceutical treatment of heart failure.

Trends in the Prevalence of Infiltrative Cardiomyopathy Among Patients With in-Hospital Cardiac Arrest

Sarcoidosis, amyloidosis, hemochromatosis and scleroderma are the most forms of infiltrative/nonischemic cardiomyopathy (NICM) associated with sudden cardiac death. In patients who undergo in-hospital cardiac arrest, a high index of suspicion is required to rule out NICM as an underlying contributor. We aimed to analyze the prevalence of NICM among patients with in-hospital cardiac arrest and identify factors associated with increased mortality. We analyzed data from the National Inpatient Sample, and identified patients who were hospitalized across 10 years from 2010 to 2019 with a diagnosis of cardiac arrest and NICM. The total number of patients with in-hospital cardiac arrest was 19,34,260. The total number with NICM was 14,803 (0.77%). Mean age was 63 years. Overall prevalence of NICM across the years ranged between 0.75% to 0.9%, with a significant temporal increase (P < 0.01). Incidence of in-hospital mortality ranged between 61% to 76% for females and 30% to 38% for males. The following comorbidities were more prevalent in patients with NICM than those without: heart failure, chronic obstructive pulmonary disease (COPD), chronic kidney disease, anemia, malignancy, coagulopathy, ventricular tachycardia, acute kidney injury and stroke. The following factors were independent predictors of in-hospital mortality-age, female gender, Hispanic race, history of COPD and presence of malignancy (P = 0.042). The prevalence of infiltrative cardiomyopathy in patients with in-hospital cardiac arrest is increasing. Females, older patients and Hispanic population are at an increased risk of mortality. Sex and race-based disparities in the prevalence of NICM in patients with in-hospital cardiac arrest is an area of further research.

A Review of the Commercially Available ECG Detection and Transmission Systems-The Fuzzy Logic Approach in the Prevention of Sudden Cardiac Arrest

Sudden cardiac death (SCD) constitutes a major clinical and public health problem, whose death burden is comparable to the current worldwide pandemic. This comprehensive review encompasses the following topics: available rescue systems, wearable electrocardiograms (ECG), detection and transmission technology, and a newly developed fuzzy logic algorithm (FA) for heart rhythm classification which is state-of-the art in the field of SCD prevention. Project "PROTECTOR", the Polish Rapid Transtelephonic ECG to Obtain Resuscitation for development of a rapid rescue system for patients at risk of sudden cardiac arrest (SCA), is presented. If a lethal arrhythmia is detected on the basis of FA, the system produces an alarm signal audible for bystanders and transmits the alarm message along with location to the emergency medical center. Phone guided resuscitation can be started immediately because an automated external defibrillator (AED) localization map is available. An automatic, very fast diagnosis is a unique feature of the PROTECTOR prototype. The rapid detection of SCA is based on a processor characterized by 100% sensitivity and 97.8% specificity (as measured in the pilot studies). An integrated circuit which implements FA has already been designed and a diagnosis is made within few seconds, which is extremely important in ischemic brain damage prophylaxis. This circuit could be implemented in smart implants (Sis).

Mind the gap: Knowledge deficits in evaluating young sudden cardiac death

Sudden cardiac arrest affects around half a million people aged under 50 years old annually, with a 90% mortality rate. Despite high patient numbers and clear clinical need to improve outcomes, many gaps exist in the evidence underpinning patients' management. Domains identifying the greatest barriers to conducting trials are the prehospital and forensic settings, which also provide care to the majority of patients. Addressing gaps in evidence along each point of the cardiac arrest trajectory is a key clinical priority.

Elevated plasma levels of asymmetric dimethylarginine and the risk for arrhythmic death in ischemic and non-ischemic, dilated cardiomyopathy - A prospective, controlled long-term study

INTRODUCTION

Elevated plasma levels of asymmetric dimethylarginine (ADMA), an inhibitor of NO synthase, are associated with adverse outcome. There is no data available, whether ADMA levels are associated with arrhythmic death (AD) in patients with ischemic cardiomyopathy (ICM) or non-ischemic, dilated cardiomyopathy (DCM).

METHODS AND RESULTS

A total of 110 ICM, 52 DCM and 30 control patients were included. Primary outcome parameter of this prospective study was arrhythmic death (AD) or resuscitated cardiac arrest (RCA). Plasma levels of ADMA were significantly higher in ICM (p < 0.001) and in DCM (p < 0.001) patients compared to controls. During a median follow-up of 7.0 years, 62 (32.3%) patients died. AD occurred in 26 patients and RCA was observed in 22 patients. Plasma levels of ADMA were not associated with a significantly increased risk of AD or RCA in ICM (hazard ratio (HR) = 1.37, p = 0.109) or in DCM (HR = 1.06, p = 0.848) patients. No significant association was found with overall mortality in ICM (HR = 1.39, p = 0.079) or DCM (HR = 1.10, p = 0.666) patients. Stratified Kaplan-Meier curves for ADMA levels in the upper tertile (>0.715 µmol/l) or the two lower tertiles (≤0.715 µmol/l) did not show a higher risk for AD or RCA (p = 0.221) or overall mortality (p = 0.548). In patients with left ventricular ejection fraction ≤ 35%, ADMA was not associated with AD or RCA (HR = 1.35, p = 0.084) or with overall mortality (HR = 1.24, p = 0.162).

CONCLUSIONS

Plasma levels of ADMA were elevated in patients with ICM or DCM as compared to controls, but were not significantly predictive for overall mortality or the risk for arrhythmic death.