Epidemiology and genetics of sudden cardiac death

Targeting MRTF/SRF in CAP2-dependent dilated cardiomyopathy delays disease onset

About one-third of dilated cardiomyopathy (DCM) cases are caused by mutations in sarcomere or cytoskeletal proteins. However, treating the cytoskeleton directly is not possible because drugs that bind to actin are not well tolerated. Mutations in the actin binding protein CAP2 can cause DCM and KO mice, either whole body (CAP2-KO) or cardiomyocyte-specific KOs (CAP2-CKO) develop DCM with cardiac conduction disease. RNA sequencing analysis of CAP2-KO hearts and isolated cardiomyocytes revealed overactivation of fetal genes, including serum response factor-regulated (SRF-regulated) genes such as Myl9 and Acta2 prior to the emergence of cardiac disease. To test if we could treat CAP2-KO mice, we synthesized and tested the SRF inhibitor CCG-1423-8u. CCG-1423-8u reduced expression of the SRF targets Myl9 and Acta2, as well as the biomarker of heart failure, Nppa. The median survival of CAP2-CKO mice was 98 days, while CCG-1423-8u-treated CKO mice survived for 116 days and also maintained normal cardiac function longer. These results suggest that some forms of sudden cardiac death and cardiac conduction disease are under cytoskeletal stress and that inhibiting signaling through SRF may benefit DCM by reducing cytoskeletal stress.

The Relation of Emergency Duties to Cardiac Death Among US Firefighters

Sudden cardiac death accounted for 42% of all firefighter duty-related fatalities over the last decade. This retrospective study analyzed available medical examiner records for duty-related firefighter fatalities among male firefighters 18 to 65 years of age that occurred between 1999 and 2014 and reported the pathoanatomic substrate for cardiac-related fatalities. Odds of duty-related cardiac death during specific duties compared with fire station duties were calculated by pathoanatomic substrate. There were 285 cardiac fatalities. Of fatalities, 80% had evidence at autopsy of coronary heart disease (CHD) and increased heart size (cardiomegaly and/or left ventricular hypertrophy). CHD alone, cardiomegaly or left ventricular hypertrophy, and causes other than CHD or increased heart size were identified in 7.7%, 6.0%, and 6.7% of fatalities, respectively. The largest proportion of deaths occurred during fire suppression (33%), although only 1% of annual occupational time was estimated to be spent performing this duty. For deaths attributed to CHD and increased heart size, fire suppression, alarm response, and physical training were associated with approximately a 112-fold, eightfold, and sevenfold increased risk of cardiac death, respectively, compared with station duties. In conclusion, the majority of firefighters who suffered a duty-related cardiac death had CHD and increased heart size, which was associated with a markedly increased risk of death during fire suppression compared with station duties. Targeted occupational medical screening for CHD and increased heart size may reduce duty-related cardiac deaths among firefighters.

A 5-year change of knowledge and willingness by sampled respondents to perform bystander cardiopulmonary resuscitation in a metropolitan city

Background

Nationwide and regional interventions can help improve bystander cardiopulmonary resuscitation (CPR) awareness, knowledge, and the willingness. Periodic community investigation will help monitor the effect. This study aimed to compare the experience of CPR education, CPR knowledge, and CPR willingness, during a 5-year interval.

Methods

This is a pre and post study. Two surveys were done in February 2012 and December 2016. National and regional intervention including legislation promoting public involvement, standardizing CPR education programs, training CPR instructors, and installing supporting organizations were done at the period. In both surveys, respondents were selected via quota sampling in Daegu Metropolitan City and answered the survey through face-to-face interview. Respondents’ general demographic characteristics, CPR educational experience, CPR knowledge and CPR willingness were questioned.

Results

Total of 2141 respondents (1000 in 2012, 1141 in 2016) were selected. The percentage of respondents who received CPR education itself and recent education were higher after intervention compared to before intervention (36.2% vs. 55.1%, 16.9% vs. 30.1%, respectively). Correct knowledge of performing CPR seems to be improved overall (1.6% vs. 11.7%, odd ratio 14.28, 95% confidence interval 5.68–35.94). However, less respondents were willing to perform CPR on strangers (54.5% vs 35.0%).

Conclusion

Nationwide and regional interventions to promote bystander CPR and CPR education were associated with increased CPR education experience and improved correct CPR knowledge in performing bystander CPR. Willingness to perform bystander CPR on family did not increase significantly and CPR willingness to strangers was decreased. Additional legal and technological measures should be implemented to promote bystander CPR.

Ozone and cardiac arrest: The role of previous hospitalizations

BACKGROUND

Several studies have reported associations between exposure to particulate matter and incidence of out-of-hospital cardiac arrest (OHCA) and some have observed associations with ozone (O₃). There are no studies investigating susceptibility based on previous disease history to short-term O₃ exposure and the risk of OHCA.

AIM

To investigate the role of previous cardiovascular-related hospitalizations in modifying the associations between the risk of OHCA and short-term increase in O₃ concentrations.

METHODS

A time-stratified case-crossover analysis of 11,923 OHCA registered in the Swedish Register for Cardiopulmonary Resuscitation from 2006 to 2014 was performed. Using personal identification numbers, OHCA were linked to all previous hospitalizations in Sweden since 1987 to create susceptible groups based on the principal diagnosis code at discharge. Susceptibility was based on hospitalization for i) acute myocardial infarction; ii) heart failure; iii) arrhythmias; iv) diabetes; v) hypertension; and vi) stroke. Moving 2 and 24-h averages for O₃, PM_2.5, PM₁₀, and NO₂ were constructed from hourly averages.

RESULTS

A 10 μg/m³ higher 2-h average O₃ concentration was associated with a 2% higher risk of OHCA (95% CI, 0% 3%). Associations were similar for 24-h average O₃ and in individuals with or without hospitalizations for AMI, heart failure, diabetes, hypertension or stroke. Individuals with previous hospitalizations for arrhythmias had a lower risk of OHCA with higher O₃. No associations were observed for other pollutants.

CONCLUSIONS

Short-term exposure to O₃ was associated with an elevated risk of OHCA, however, previous hospitalizations for cardiovascular diseases were not associated with additionally augmented risks.

Autoantibodies for Cardiac Channels and Sudden Cardiac Death and its Relationship to Autoimmune Disorders

Background:

Sudden Cardiac Death (SCD) is an unexpected death caused by heart dys-function. Autoantibodies against cardiac proteins may be potentially involved in the occurrence and progression of cardiac disease and SCD. The first report on the role of autoantibodies in idiopathic dilated cardiomyopathy appeared in the 1980s. In recent years new studies on the effects of the pres-ence of specific autoantibodies and their relationship to ventricular arrhythmias and SCD were pub-lished. The purpose of the current mini-review is to analyze the results of the research studies focused on the relationship between anti-cardiomyocyte autoantibodies and SCD with respect to autoimmune disorders.

Conclusion:

According to our analysis, more research is needed to understand the role of these auto-antibodies against cardiac proteins in the SCD pathogenesis, and potentially employ this knowledge for improving prognosis of SCD.

Amiodarone Treatment in the Early Phase of Acute Myocardial Infarction Protects Against Ventricular Fibrillation in a Porcine Model

Ventricular fibrillation (VF) occurring in the first minutes to hours of acute myocardial infarction (AMI) is a frequent cause of death and treatment options are limited. The aim was to test whether early infusion of amiodarone 10 min after onset of AMI reduced the incidence of VF in a porcine model. Eighteen female Danish landrace pigs were randomized to a control and an amiodarone group. AMI was induced by ligation of the mid-left anterior descending artery for 120 min followed by 60 min of reperfusion. VF occurred in 0/8 pigs treated with amiodarone compared to 7/10 controls (P < 0.01). Amiodarone treatment prolonged RR intervals, reduced dispersion of action potential duration in the infarcted area and mean number of ectopic beats. No negative effects on cardiac output and blood pressure were observed with amiodarone. Amiodarone qualifies as a potential drug candidate to prevent VF in the first minutes to hours of AMI.

Establishment of a predictive model for inpatient sudden cardiac death in a Chinese cardiac department population

Background:

Little is known about the risk factors for sudden cardiac death (SCD) in the overall hospitalized cardiac department population. This study was conducted to investigate the risk factors and develop a predictive model for SCD in a hospitalized cardiac department population.

Methods:

We conducted a retrospective study of patients admitted to the cardiac department of the First Affiliated Hospital of Xinjiang Medical University from June 2015 to February 2017. We collected the clinical data from medical records. Multiple stepwise logistic regression analysis was carried out to confirm the risk factors for SCD and develop a predictive risk model. The risk score was assessed by the area under receiver operating characteristic (AUROC) curve and the Hosmer-Lemeshow goodness-of-fit test.

Results:

A total of 262 patients with SCD and 4485 controls were enrolled in our study. Logistic regression modeling identified eight significant risk factors for in-hospital SCD: age, main admitting diagnosis, diabetes, corrected QT interval, QRS duration, ventricular premature beat burden, left ventricular ejection fraction, and estimated glomerular filtration rate. A predictive risk score including these variables showed an AUROC curve of 0.774 (95% confidence interval: 0.744–0.805). The Hosmer-Lemeshow goodness-of-fit test showed the chi-square value was 2.527 (P = 0.640). The incidence of in-hospital SCD was 1.3%, 4.1%, and 18.6% for scores of 0 to 2, 3 to 5 and ≥6, respectively (P < 0.001).

Conclusions:

Age, main admitting diagnosis, diabetes, QTc interval, QRS duration, ventricular premature beat burden, left ventricular ejection fraction, and estimated glomerular filtration rate are factors related to in-hospital SCD in a hospitalized cardiac department population. We developed a predictive risk score including these factors that could identify patients who are predisposed to in-hospital SCD.

Sleep Apnea and Sudden Cardiac Death

Sleep plays an integral role in maintaining health and quality of life. Obstructive sleep apnea (OSA) is a prevalent sleep disorder recognized as a risk factor for cardiovascular disease (CVD) and arrhythmias. Sudden cardiac death (SCD) is a common and devastating event. Out-of-hospital SCD accounts for the majority of deaths from cardiac disease, which is the leading cause of death globally. A limited but emerging body of research have further elaborated on the link between OSA and SCD. In this article, we aim to provide a critical review of the existing evidence by addressing the following: What epidemiologic evidence exists linking OSA to SCD? What evidence exists for a pathophysiologic connection between OSA and SCD? Are there electrocardiographic markers of SCD found in patients with OSA? Does heart failure represent a major effect modifier regarding the relationship between OSA and SCD? What is the impact of sleep apnea treatment on SCD and cardiovascular outcomes? Finally, we elaborate on ongoing research to enhance our understanding of the OSA-SCD association.

Implantable Cardioverter-Defibrillators and Cardiac Resynchronization Therapy in Women

Implantable cardioverter-defibrillator and cardiac resynchronization therapy devices have been prescribed for patients with heart failure for several decades. Factors leading to increased usage include significant enhancements in technology and availability of multiple randomized clinical trials demonstrating their benefit with improved implementation of evidence-based guidelines. Despite these advances, gaps still exist in the utilization and referral of these devices, particularly among women. This article reviews the literature on these devices with a focus on gender differences and proposes reasons for why they exist.

Marriage Dissatisfaction and the Risk of Sudden Cardiac Death Among Men

Conflicts in marriage have been associated with potential risk of cardiovascular disease; however, there is lack of prospective evidence on the association between marriage satisfaction and sudden cardiac death (SCD). We aimed to assess the association between perceived level of marriage satisfaction and risk of SCD. This study employed the Kuopio Ischemic Heart Disease study, an ongoing prospective population-based study in Finland. Perceived level of marriage satisfaction was assessed in 2,262 men using a well-structured self-administered questionnaire. Multivariable adjusted Cox regression models were used to estimate hazard ratios (95% confidence interval [CI]) for SCD. During a median follow-up period of 25.9 years, 239 SCDs were recorded. The mean age of participants was 53 (SD 5.2) years. On adjustment for several conventional cardiovascular risk factors, hazard ratio (95% CI) of SCD was 1.90 (CI 1.09 to 3.32; p = 0.02) for men who were dissatisfied with their marriage, compared with men who were satisfied with their marriage. The association remained consistent on further adjustment for preexisting coronary heart disease, socioeconomic status, and years of education 1.86 (CI 1.07 to 3.25; p = 0.03). In conclusion, dissatisfied marriage is associated with an increased risk of SCD among middle-aged Caucasian men, independent of conventional cardiovascular risk factors.

A randomised controlled comparison of video versus instructor-based compression only life support training

Background and Aims:

Sudden cardiac deaths remain a major health problem worldwide. Most of these cases generally involve out of hospital cardiac arrest, making the role of bystander resuscitation very crucial. In the developing countries, illiteracy and scarcity of health professionals is a great barrier to cardiopulmonary resuscitation (CPR) training. Video-based CPR training can offer an easily accessible modality in these situations. Hence, this study was conducted with an aim to assess the efficacy of video-based training in comparison to the traditional instructor-based CPR training in layman.

Methods:

This prospective cross-over observational study included 109 undergraduate university students attending voluntary resuscitation training and were randomly divided into two groups of video-based demonstration (VBD) and instructor-based demonstration (IBD) of compression only life support (COLS). They were then assessed for psychomotor skill development (Laerdal Simpad Plus Q-CPR) and perception about the quality of training methodology as primary and secondary objectives, respectively.

Results:

Population characteristics were similar in both the groups. In the VBD, scene safety was performed by 95.2% and call for help by 97.6%, and by 76.1% each in the IBD group (P < 0.05). Response to compression time (RCT) was significantly shorter in VBD (35 ± 9 sec) as compared to IBD (54 ± 14 sec) (P < 0.001). However, the proportion of participants performing response check, correct site identification, and other parameters were comparable.

Conclusion:

Video-based COLS training significantly decreased the RCT by 35% compared to traditional instructor-based training. However, other features of high-quality CPR remain comparable.

Implantable Cardioverter-Defibrillators are the Main Link in the Modern Concept of Sudden Cardiac Death Prevention. Problems and Prospects of the Development of the Method

The article covers the development of the problem of sudden cardiac death prevention with the implantable cardioverter-defibrillators from the moment of creation of these devices to our days. The current concept of primary prevention of sudden cardiac death, based on the severity of manifestation of heart failure and left ventricular dysfunction, is not effective enough. Its practical application is difficult because it requires mass application of implantable defibrillators, with low predictive accuracy of these criteria in terms of development of life-threatening arrhythmias. The development of methods for visualizing the myocardium, allowing to assess the severity of myocardial fibrosis, as well as the possibilities of medical genetics, at the present stage, allows us to clarify indications for implantation of cardioverter-defibrillators and thereby significantly improve the concept of preventing sudden cardiac death with these instruments.

Characteristics of a novel citizen rescue system for out-of-hospital cardiac arrest in the Dutch province of Limburg: relation to incidence and survival

Background

We evaluated the characteristics of a novel text message system notifying citizen rescuers in cases of out-of-hospital circulatory arrest (OHCA) in the Dutch province of Limburg, including their relation to incidence and survival.

Methods and results

The study area comprised 2,153 km² (831 mi²) with 1.12 mio. inhabitants. During the 2‑year study period approximately 9,000 volunteers were registered, about 60% male, 59% with no experience in actual resuscitation, and 27.4% healthcare professionals. The system was not activated in 557 of 1,085 (51.3%) OHCAs, frequently because there was no resuscitation setting present yet at the time of the emergency call. Rescuers were notified on 1,076 occasions, with no resuscitation setting being present in 548 of 1,076 (50.9%) notifications. OHCA incidence rates were 67 per 100,000 inhabitants per year, 95 per 100,000 men and 39 per 100,000 women standardised for age with the European Standard Population. The mean number of notifications per volunteer was 1.3 times per year. Higher volunteer density was related to increased survival if at least one volunteer attended the cardiac arrest. If the density exceeded 0.75%, survival increased to 34.8% compared to 20.6% at a density below 0.25%.

Conclusion

In about half of OHCAs needing resuscitation the system was activated and in approximately half of the notifications resuscitation proved to be justified. Volunteers are notified 1.3 times per year on average. Survival was related to volunteer density, suggesting that further improvement can be achieved by increasing the number of citizen rescuers.

Management of Adult Patients in the Pediatric Emergency Department

Adult patients often present to the pediatric emergency department (ED) for treatment of a wide variety of diseases. However, pediatric emergency medicine physicians are primarily trained to provide specialized care for children. Studies have shown that the number of adult patients presenting to pediatric EDs has increased significantly since the introduction of the Emergency Medicine Transfer and Active Labor Act in 1986. This article discusses the management of common adult complaints presenting to the pediatric ED. The focus is on stabilization in the pediatric ED and safe transfer to a more appropriate facility.

Comparison of Continuous Versus Interrupted Chest Compressions during CPR in a Rural Community

INTRODUCTION

Cardiopulmonary resuscitation (CPR) in patients with out-of-hospital cardiac arrest (OHCA) have interruption of manual chest compressions for airway management and breathing when performed by medical personnel trained by Advanced Cardiac Life Support (ACLS) standards. This interruption likely reduces blood flow and possibly survival. Traditional CPR (30:2 compressions to ventilations) was compared with continuous chest compressions, CCC (also termed Cardiocerebral Resuscitation, CCR) in a rural community.

METHODS

A retrospective cohort analysis of three years of traditional CPR (June 2008 - May 2011) for OHCA was compared to three years of using CCC protocols (June 2011 - May 2014). Primary outcomes were survival at one and six months.

RESULTS

There were 58 0HCA patients in the six year study period (June 2008 - May 2014). Forty (69%) received CPR and 18 (31%) received CCC. Two (5%) survived at least one month with CPR and eight (44%) survived at least one month with CCC (p = 0.0007). After six months, 0/40 (0%) who received CPR had survived and 6/18 (33%) who received CCC survived (p = 0.0018). For the patient found in ventricular fibrillation or tachycardia (a shockable rhythm), 0/13 (0.0%) survived one month after CPR and 7/9 (78%) survived with CCC (p < 0.01). After six months 0/13 (0.0%) survived with CPR and 6/9 (67%) survived with CCC (p < 0.05).

CONCLUSIONS

For patients in a rural environment with OHCA, CCC had a more favorable outcome than traditional CPR. For the patient found in ventricular fibrillation or ventricular tachycardia, there was a profound survival benefit of CCC over CPR.

A Chymase Inhibitory RNA Aptamer Improves Cardiac Function and Survival after Myocardial Infarction

We have reported that mast cell chymase, an angiotensin II-generating enzyme, is important in cardiovascular tissues. Recently, we developed a new chymase-specific inhibitory RNA aptamer, HA28, and we evaluated the effects of HA28 on cardiac function and the mortality rate after myocardial infarction. Echocardiographic parameters, such as the left ventricular ejection fraction, fractional shortening, and the ratio of early to late ventricular filling velocities, were significantly improved by treatment with HA28 after myocardial infarction. The mortality rate was significantly reduced in the HA28-treated group. Cardiac chymase activity and chymase gene expression were significantly higher in the vehicle-treated myocardial infarction group, and these were markedly suppressed in the HA28-treated myocardial infarction group. The present study provides the first evidence that a single-stranded RNA aptamer that is a chymase-specific inhibitor is very effective in the treatment of acute heart failure caused by myocardial infarction. Chymase may be a new therapeutic target in post-myocardial infarction pathophysiology.

Differences in Risk of Sudden Cardiac Death Between Blacks and Whites

BACKGROUND

Prior studies have consistently demonstrated that blacks have an approximate 2-fold higher incidence of sudden cardiac death (SCD) than whites; however, these analyses have lacked individual-level sociodemographic, medical comorbidity, and behavioral health data.

OBJECTIVES

The purpose of this study was to evaluate whether racial differences in SCD incidence are attributable to differences in the prevalence of risk factors or rather to underlying susceptibility to fatal arrhythmias.

METHODS

The Reasons for Geographic and Racial Differences in Stroke study is a prospective, population-based cohort of adults from across the United States. Associations between race and SCD defined per National Heart, Lung, and Blood Institute criteria were assessed.

RESULTS

Among 22,507 participants (9,416 blacks and 13,091 whites) without a history of clinical cardiovascular disease, there were 174 SCD events (67 whites and 107 blacks) over a median follow-up of 6.1 years (interquartile range: 4.6 to 7.3 years). The age-adjusted SCD incidence rate (per 1,000 person-years) was higher in blacks (1.8; 95% confidence interval [CI]: 1.4 to 2.2) compared with whites (0.7; 95% CI: 0.6 to 0.9), with an unadjusted hazard ratio of 2.35; 95% CI: 1.74 to 3.20. The association of black race with SCD risk remained significant after adjustment for sociodemographics, comorbidities, behavioral measures of health, intervening cardiovascular events, and competing risks of non-SCD mortality (hazard ratio: 1.97; 95% CI: 1.39 to 2.77).

CONCLUSIONS

In a large biracial population of adults without a history of cardiovascular disease, SCD rates were significantly higher in blacks as compared with whites. These racial differences were not fully explained by demographics, adverse socioeconomic measures, cardiovascular risk factors, and behavioral measures of health.

Teaching Hands-Only CPR in Schools: A Program Evaluation in San José, Costa Rica

Background:

Hands-only bystander CPR increases survival from out-of-hospital cardiac arrest. Video-based CPR instruction in schools has been proposed as a means to mass-educate laypersons in Hands-only CPR™ (HOCPR), in developed as well as developing countries.

Objectives:

The purpose of this study is to determine whether a brief video- and mannequin-based instructional program, developed by the American Heart Association (AHA), is an effective strategy for teaching Costa Rican middle- and high-school age children to learn the steps of HOCPR.

Methods:

This study took place in four educational centers that spanned the entire socioeconomic spectrum within the Grand Metropolitan Area of Costa Rica. Three hundred and eight students from the sixth to eleventh grades participated. The intervention included exposure to the AHA “CPR Anytime” video and practice with CPR mannequins. Before and after the intervention, students took a four-question, multiple-choice quiz that measured their knowledge of the correct steps and proper techniques of HOCPR; a separate question assessed their level of comfort “doing CPR on someone with a cardiac arrest.” Pre- and post-intervention “percent correct” scores were compared and tested for statistical significance using paired t-tests or the McNemar test as appropriate. Improvement in knowledge and comfort levels were also compared across the different educational centers and compared with similar programs implemented in the United States.

Results:

The students’ overall scores (mean percent correct) on the multiple choice questions more than doubled after training (40.9% ± 1.4% before training vs. 92.5% ± 0.9% after training, p < 0.00001). Improvements were observed in each school, regardless of geographic location or socioeconomic status. Knowledge of the appropriate steps of HOCPR doubled after training (42.2% before training vs. 92.5% after training, p < 0.000001). Post-intervention, a majority (73%) of children reported comfort with performing CPR on an individual who had suffered a cardiac arrest.

Conclusion:

This study demonstrates the effectiveness of the AHA “CPR Anytime” program in teaching HOCPR to school-age children within the Grand Metropolitan Area of Costa Rica. Additional studies are needed to measure longer-term knowledge retention and students’ ability to perform CPR in simulated cardiac arrest settings.

Teaching Hands-Only CPR in Schools: A Program Evaluation in San José, Costa Rica

BACKGROUND

Hands-only bystander CPR increases survival from out-of-hospital cardiac arrest. Video-based CPR instruction in schools has been proposed as a means to mass-educate laypersons in Hands-only CPR™ (HOCPR), in developed as well as developing countries.

OBJECTIVES

The purpose of this study is to determine whether a brief video- and mannequin-based instructional program, developed by the American Heart Association (AHA), is an effective strategy for teaching Costa Rican middle- and high-school age children to learn the steps of HOCPR.

METHODS

This study took place in four educational centers that spanned the entire socioeconomic spectrum within the Grand Metropolitan Area of Costa Rica. Three hundred and eight students from the sixth to eleventh grades participated. The intervention included exposure to the AHA "CPR Anytime" video and practice with CPR mannequins. Before and after the intervention, students took a four-question, multiple-choice quiz that measured their knowledge of the correct steps and proper techniques of HOCPR; a separate question assessed their level of comfort "doing CPR on someone with a cardiac arrest." Pre- and post-intervention "percent correct" scores were compared and tested for statistical significance using paired t-tests or the McNemar test as appropriate. Improvement in knowledge and comfort levels were also compared across the different educational centers and compared with similar programs implemented in the United States.

RESULTS

The students' overall scores (mean percent correct) on the multiple choice questions more than doubled after training (40.9% ± 1.4% before training vs. 92.5% ± 0.9% after training, p &lt; 0.00001). Improvements were observed in each school, regardless of geographic location or socioeconomic status. Knowledge of the appropriate steps of HOCPR doubled after training (42.2% before training vs. 92.5% after training, p &lt; 0.000001). Post-intervention, a majority (73%) of children reported comfort with performing CPR on an individual who had suffered a cardiac arrest.

CONCLUSION

This study demonstrates the effectiveness of the AHA "CPR Anytime" program in teaching HOCPR to school-age children within the Grand Metropolitan Area of Costa Rica. Additional studies are needed to measure longer-term knowledge retention and students' ability to perform CPR in simulated cardiac arrest settings.

Pathoanatomic Findings Associated With Duty-Related Cardiac Death in US Firefighters: A Case-Control Study

Background Sudden cardiac death accounts for the greatest proportion of duty-related deaths among US firefighters. Increased understanding of the pathoanatomic causes of sudden cardiac death and the risk associated with underlying cardiac pathologies is needed to develop evidence-based screening recommendations. Methods and Results Using autopsy data for duty-related firefighter fatalities occurring between 1999 and 2014, this retrospective case-control study compared cardiac findings of male firefighters aged 18 to 65 years who died on duty of cardiac-related causes with those who died of noncardiac trauma-related causes. Data from 276 cardiac cases and 351 noncardiac trauma controls were analyzed. Among cardiac cases, the most prevalent (82%) underlying pathoanatomic substrate was comorbid coronary heart disease and cardiomegaly/left ventricular hypertrophy. Cardiac cases had a higher prevalence of cardiomegaly (heart weight >450 g), left ventricular hypertrophy (left ventricular wall thickness ≥1.2 cm), and severe coronary artery stenosis (≥75%) than trauma controls (all P<0.001). In multivariate analyses, heart weight >450 g, coronary artery stenosis ≥75%, and evidence of a prior myocardial infarction were strong independent predictors of cardiac death, with odds ratios of 6.1 (95% confidence interval, 3.6-10.4), 9.3 (95% confidence interval, 5.3-16.1), and 6.2 (95% confidence interval, 3.4-11.3), respectively. Conclusions The majority of cardiac fatalities had evidence of both coronary heart disease and increased heart mass, and each condition was independently associated with a markedly elevated risk of cardiac death. Targeted screening for coronary heart disease, increased heart mass, and evidence of prior myocardial infarction should be considered to reduce duty-related cardiac deaths among firefighters.

Electrophysiologic Considerations After Sudden Cardiac Arrest

Background:

Sudden Cardiac Death (SCD) remains a major public health concern, accounting for more than 50% of cardiac deaths. The majority of these deaths are related to ischemic heart disease, however increasingly recognized are non-ischemic causes such as cardiac channelopathies. Bradyarrhythmias and pulseless electrical activity comprise a larger proportion of out-of-hospital arrests than previously realized, particularly in patients with more advanced heart failure or noncardiac triggers such as pulmonary embolism. Patients surviving Sudden Cardiac Arrest (SCA) have a substantial risk of recurrence, particularly within 18 months post event. The timing of tachyarrhythmias complicating acute infarction has important implications regarding the likelihood of recurrence, with those occurring within 48 hours having a more favorable long-term outcome. In the absence of a clear reversible cause, implantable cardioverter defibrillators remain the mainstay in the secondary prevention of SCD. Post defibrillation electromechanical dissociation is common in patients with cardiomyopathy and can lead to SCD despite successful defibrillation of the primary tachyarrhythmia. Antiarrhythmic agents are highly effective in preventing recurrent arrhythmias in specific diseases such as the congenital long QT syndrome.

Conclusion:

Catheter ablation is used most commonly to prevent recurrent ICD therapies in patients with structural heart disease-related ventricular arrhythmias, however recent publications have shown substantial benefit in other entities such as idiopathic ventricular fibrillation.

Efficacy and safety of Shenfu injection for patients with return of spontaneous circulation after sudden cardiac arrest: Protocol for a systematic review and meta-analysis

BACKGROUND

Sudden cardiac arrest (SCA) is one of the most common critical illnesses encountered in clinical practice. Shenfu injection (SFI) has received extensive attention as an alternative therapy that can effectively maintain the autonomic circulation function after cardiopulmonary resuscitation. However, the mechanism of SFI is not yet fully understood. In addition, there has been no systematic review or meta-analysis of SFI in the treatment of patients with return of spontaneous circulation after SCA. Herein, we describe the protocol of a proposed study based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines that aims to systematically evaluate the efficacy and safety of SFI in patients with return of spontaneous circulation after SCA.

METHODS

Two researchers will search 9 electronic databases (PubMed, Medline, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, Chinese VIP Information, Wanfang, and Chinese Biomedical Database) to identify all studies that meet the inclusion criteria and were published before July 2018. After information extraction and methodological quality evaluation, we will use Stata 13.0 software (STATA Corporation, College Station, TX, USA) to synthesize the data. The primary outcomes will be the survival rate and Glasgow Coma Scale.

RESULTS

The data synthesis results will objectively illustrate the efficacy and safety of SFI in patients with return of spontaneous circulation after SCA.

CONCLUSION

The findings will provide a reference for the use of SFI in the treatment of patients with return of spontaneous circulation after SCA.

REGISTRATION

PROSPERO (registration number: CRD42018104230).

Neighborhood food environment, dietary fatty acid biomarkers, and cardiac arrest risk

We explored links between food environments, dietary intake biomarkers, and sudden cardiac arrest in a population-based longitudinal study using cases and controls accruing between 1990 and 2010 in King County, WA. Surprisingly, presence of more unhealthy food sources near home was associated with a lower 18:1 trans-fatty acid concentration (-0.05% per standard deviation higher count of unhealthy food sources, 95% Confidence Interval [CI]: 0.01, 0.09). However, presence of more unhealthy food sources was associated with higher odds of cardiac arrest (Odds Ratio [OR]: 2.29, 95% CI: 1.19, 4.41 per standard deviation in unhealthy food outlets). While unhealthy food outlets were associated with higher cardiac arrest risk, circulating 18:1 trans fats did not explain the association.

Genetic Counselors' Approach To Postmortem Genetic Testing After Sudden Death: An Exploratory Study

A significant portion of sudden death cases result from an underlying genetic etiology, which may be determined through postmortem genetic testing. The National Association of Medical Examiners (NAME) recommends that an appropriate postmortem sample is saved on all sudden death cases under the age of 40. Genetic counselors (GCs) play an important role in this process by working with medical examiners and coroners (ME/Cs) to recommend and interpret specific testing and to guide family members. A survey sent to the National Society of Genetic Counselors was designed and implemented to learn more about the experiences of genetic counselors who had considered or ordered postmortem genetic testing. Results showed that cardiovascular GCs were significantly more willing to recommend genetic testing in younger age decedents (ages 10, 18, 30, 40, and 50) compared to other specialty GCs (p<0.05, Chi-square). Thirty-seven percent (7 of 19) of GCs reported insurance covering some portion of genetic testing. Participants also reported highest success for DNA extractions with fresh and frozen blood, reinforcing NAME recommendations for appropriate sample collection for postmortem genetic testing. Overall, participating GCs demonstrated a very good understanding for the appropriate use of postmortem genetic testing and did identify suspected barriers of cost and lack of insurance coverage as deterrents. With the rapid decrease in costs for diagnostic genetic testing, ME/C awareness of NAME recommendations for sample collection and storage remain important to facilitate postmortem genetic testing.

Primary Ventricular Fibrillation in the Primary Percutaneous Coronary Intervention ST-Segment Elevation Myocardial Infarction Era (from the "Codi IAM" Multicenter Registry)

Primary ventricular fibrillation (PVF) is a dreadful complication of ST segment elevation myocardial infarction (STEMI). Scarce data are available regarding PVF prognosis since primary percutaneous coronary intervention (PPCI) became routine practice in STEMI. Our aim was to compare 30-day and 1-year mortality for patients with and without PVF (including out-of-hospital and in-hospital PVF) within a regional registry of PPCI-treated STEMI patients. This prospective multicenter registry included all consecutive STEMI patients treated with PPCI from January 2010 to December 2014. Patients were classified as non-PVF or PVF, with further subdivision into out-of-hospital and in-hospital PVF. We analyzed 30-day and 1-year all-cause mortality in groups. The registry included 10,965 patients. PVF occurred in 949 patients (8.65%), including 74.2% out-of-hospital and 25.8% in-hospital PVF. Compared with the non-PVF group, PVF patients were younger; less commonly diabetic; more frequently had anterior wall STEMI, higher Killip-Kimball class, and left main disease; and showed significantly higher 24-hour (5.1% vs 1.1%), 30-day (18.5% vs 4.7%), and 1-year mortality (23.2% vs 7.9%) (all p <0.001). Mortality did not differ in out-of-hospital versus in-hospital PVF. After multivariable adjustment, PVF remained associated with all-cause 30-day (2.32, 95% CI: 1.91 to 2.82, p <0.001) and 1-year (HR: 1.59, 95% CI: 1.13 to 2.24, p = 0.008) mortality. In conclusion, we present the largest registry of PVF patients in the era of routine PPCI in STEMI. Although overall STEMI mortality has declined, PVF emerged as a predictor of both 30-day and 1-year mortality. These data warrant prospective validation and proper identification and protection of high-risk patients.

Long-term use of the wearable cardioverter defibrillator in patients with explanted ICD

OBJECTIVES

To evaluate the effectiveness of wearable cardioverter defibrillator (WCD) use in protecting patients from sudden cardiac arrest (SCA) while they were treated in nonhospital settings until re-implantation of an Implantable cardioverter-defibrillator (ICD) was feasible. We sought to determine whether the WCD could be successfully utilized long term (≥1 year) after ICD extraction in patients at continued risk of SCD in which ICD re-implantation was not practical.

BACKGROUND

ICDs have proven to improve mortality in patients for both secondary and primary prevention of SCA. Increased ICD implantation in older patients with comorbid conditions has resulted in higher rates of cardiac device infections. Currently, a wearable cardioverter defibrillator (WCD) is an alternative management for SCA prevention in specific cases.

METHODS

This a retrospective analysis based on consecutive WCD patients who underwent ICD explant due to device-related infections or mechanical reasons between April 2007 and July 2014. A total of 102 patients were identified from the national database maintained by ZOLL (Pittsburgh, PA, USA). We analyzed the reason for WCD use, demographic information, device data, compliance and duration of WCD use, detected arrhythmias and therapies, and reason for discontinuing WCD use.

RESULTS

In these long term WCD users, average length of WCD use was 638 ± 361 days. Nine patients (8.8%) had a sustained ventricular arrhythmia that was successfully resuscitated by the WCD. Six patients (5.8%) experienced inappropriate shocks. Two patients (1.9%) died of asystole events while wearing the WCD and an additional 10 patients died while not monitored by the WCD. Thirty-nine patients (38.2%) ended WCD use when a new ICD was implanted and 15 patients (14.7%) were still wearing the WCD at the time of analysis.

CONCLUSIONS

We found that extending use of the WCD to ≥1 year is a safe and effective alternative treatment for patients with explanted ICDs who are not pacemaker dependent.

A genetic variant near adaptor-related protein complex 2 alpha 2 subunit gene is associated with coronary artery disease in a Chinese population

Background

Adaptor-related protein complex 2 alpha 2 subunit (AP2A2) gene encodes a protein-a subunit of the AP-2 adaptor protein complex. Evidence has revealed that benzodiazepine receptor-associated protein 1 (BZRAP1) is abundant in the hippocampus with potential effects on brain diseases. Recently, an epidemiological study reported that two variants (rs7396366 and rs2526378) closest to the AP2A2 and BZRAP1 genes are associated with higher plasma lipids and Alzheimer’s disease. Whether the two single nucleotide polymorphisms (SNPs) are actually relevant to coronary artery disease (CAD) and CAD severity remains elusive. Our aim was to assess whether these two SNPs are relevant to CAD and its severity in a Chinese population.

Methods

Three hundred and thirty-five patients with documented CAD (282 stable CAD, 28 non-ST-segment elevation myocardial infarction, 25 ST-segment elevation myocardial infarction), and 372 non-CAD controls were included in the study. The participants were divided into two groups according to coronary angiography results. CAD patients were further demarcated into subgroups with one-, two-, or three-vessel stenosis. Genotypes at rs7396366 and rs2526378 were examined using polymerase chain reaction-ligase detection reaction. The association between these two SNPs with CAD and its severity were analyzed.

Results

The frequency of the rs7396366 TT genotype was significantly higher in CAD patients than in controls (13.7% vs. 7.8%, 95% CI: 1.15–3.07, P = 0.014). Subjects with a variant genotype T allele had an increased risk of CAD compared with G allele carriers (additive model: 95% CI: 1.21–3.35, P = 0.008). After adjustment for traditional cardiovascular risk factors, analysis of the dominant models involving rs7396366 also showed that T allele carriers had a significantly higher risk for CAD than G allele carriers had (dominant model: OR 1.48, 95% CI: 1.03–2.14, P = 0.035). Age, sex, type 2 diabetes mellitus, fasting plasma glucose, and the TT genotype in rs7396366 were significantly associated with three-vessel lesions. Despite these significant outcomes of rs7396366, information on rs2526378 showed no significant difference between CAD patients and non-CAD controls.

Conclusion

Our results show that the T allele and TT genotype in rs7396366, closest to the AP2A2 gene, are linked to an increased risk of CAD and its severity in a Chinese population.

Electronic supplementary material

The online version of this article (10.1186/s12872-018-0905-2) contains supplementary material, which is available to authorized users.

Association between mitochondrial DNA copy number and sudden cardiac death: findings from the Atherosclerosis Risk in Communities study (ARIC)

Aims

Sudden cardiac death (SCD) is a major public health burden. Mitochondrial dysfunction has been implicated in a wide range of cardiovascular diseases including cardiomyopathy, heart failure, and arrhythmias, but it is unknown if it also contributes to SCD risk. We sought to examine the prospective association between mtDNA copy number (mtDNA-CN), a surrogate marker of mitochondrial function, and SCD risk.

Methods and results

We measured baseline mtDNA-CN in 11 093 participants from the Atherosclerosis Risk in Communities (ARIC) study. mtDNA copy number was calculated from probe intensities of mitochondrial single nucleotide polymorphisms (SNP) on the Affymetrix Genome-Wide Human SNP Array 6.0. Sudden cardiac death was defined as a sudden pulseless condition presumed due to a ventricular tachyarrhythmia in a previously stable individual without evidence of a non-cardiac cause of cardiac arrest. Sudden cardiac death cases were reviewed and adjudicated by an expert committee. During a median follow-up of 20.4 years, we observed 361 SCD cases. After adjusting for age, race, sex, and centre, the hazard ratio for SCD comparing the 1st to the 5th quintiles of mtDNA-CN was 2.24 (95% confidence interval 1.58-3.19; P-trend <0.001). When further adjusting for traditional cardiovascular disease risk factors, prevalent coronary heart disease, heart rate, QT interval, and QRS duration, the association remained statistically significant. Spline regression models showed that the association was approximately linear over the range of mtDNA-CN values. No apparent interaction by race or by sex was detected.

Conclusion

In this community-based prospective study, mtDNA-CN in peripheral blood was inversely associated with the risk of SCD.

Cardiomyopathies and Related Changes in Contractility of Human Heart Muscle

About half of hypertrophic and dilated cardiomyopathies cases have been recognized as genetic diseases with mutations in sarcomeric proteins. The sarcomeric proteins are involved in cardiomyocyte contractility and its regulation, and play a structural role. Mutations in non-sarcomeric proteins may induce changes in cell signaling pathways that modify contractile response of heart muscle. These facts strongly suggest that contractile dysfunction plays a central role in initiation and progression of cardiomyopathies. In fact, abnormalities in contractile mechanics of myofibrils have been discovered. However, it has not been revealed how these mutations increase risk for cardiomyopathy and cause the disease. Much research has been done and still much is being done to understand how the mechanism works. Here, we review the facts of cardiac myofilament contractility in patients with cardiomyopathy and heart failure.

Race, ethnicity, and the risk of sudden death<sup/>

Sudden cardiac death (SCD) is a major cause of death worldwide, with an estimated U.S. annual incidence of 350,000 [1]. This review will examine the influence of race and ethnicity on SCD burden and risk factors, and review the available literature on resuscitation outcomes and primary prevention of SCD. An improved understanding of associations between race, ethnicity, and SCD may provide clues to mechanisms, lead to improved prevention of SCD, and ultimately reduce racial and ethnic disparities in the burden of SCD.

Effectiveness of high rate and delayed detection ICD programming by race: A MADIT-RIT substudy

INTRODUCTION

Data on inappropriate and appropriate ICD therapy, and efficacy of ICD programing strategies by race are limited.

METHODS

In MADIT-RIT, we evaluated the risk of ICD therapy by race, and the efficacy of high rate cut-off ventricular tachycardia (VT) zone ≥200 beats per minute (bpm) (Arm B), or 60 seconds delay in VT zone 170-199 bpm (Arm C), compared to 2.5 seconds delay at 170 bpm (Arm A) among black and white patients.

RESULTS

MADIT-RIT enrolled 272 (20%) black and 1119 (80%) white patients. The risk of inappropriate therapy was similar among blacks and whites, HR 1.25, 95% CI (0.82-1.93), P  =  0.30. High rate cut-off or delayed VT therapy was associated with significant reductions in inappropriate therapy among whites, Arm B versus Arm A, HR 0.15, 95% CI (0.08-0.29), P < 0.0001, Arm C versus Arm A, HR 0.19, 95% CI (0.11-0.33), P < 0.001, and black individuals Arm B versus Arm A, HR 0.24, 95% CI (0.01-0.56), P  =  0.0001, Arm C versus Arm A, HR 0.30, 95% CI (0.13-0.68), P  =  0.004, P interaction > 0.10). However, delayed VT therapy was associated with a trend toward greater reduction in appropriate therapy in black individuals, HR 0.08, 95% CI (0.03-0.27), P < 0.0001 relative to white individuals, HR 0.27, 95% CI (0.16-0.43), P < 0.0001, P interaction  =  0.077.

CONCLUSION

In MADIT-RIT, high rate and delayed detection ICD programming provided similar benefit with reductions in both inappropriate therapy and unnecessary appropriate therapy among black and white individuals. CLINICALTRIALS.

GOV IDENTIFIER

NCT00947310.

Ventricular pro-arrhythmic phenotype, arrhythmic substrate, ageing and mitochondrial dysfunction in peroxisome proliferator activated receptor-γ coactivator-1β deficient (Pgc-1β-/-) murine hearts

INTRODUCTION

Ageing and age-related bioenergetic conditions including obesity, diabetes mellitus and heart failure constitute clinical ventricular arrhythmic risk factors.

MATERIALS AND METHODS

Pro-arrhythmic properties in electrocardiographic and intracellular recordings were compared in young and aged, peroxisome proliferator-activated receptor-γ coactivator-1β knockout (Pgc-1β-/-) and wild type (WT), Langendorff-perfused murine hearts, during regular and programmed stimulation (PES), comparing results by two-way ANOVA.

RESULTS AND DISCUSSION

Young and aged Pgc-1β-/- showed higher frequencies and durations of arrhythmic episodes through wider PES coupling-interval ranges than WT. Both young and old, regularly-paced, Pgc-1β-/- hearts showed slowed maximum action potential (AP) upstrokes, (dV/dt)max (∼157 vs. 120-130 V s-1), prolonged AP latencies (by ∼20%) and shortened refractory periods (∼58 vs. 51 ms) but similar AP durations (∼50 ms at 90% recovery) compared to WT. However, Pgc-1β-/- genotype and age each influenced extrasystolic AP latencies during PES. Young and aged WT ventricles displayed distinct, but Pgc-1β-/- ventricles displayed similar dependences of AP latency upon (dV/dt)max resembling aged WT. They also independently increased myocardial fibrosis. AP wavelengths combining activation and recovery terms paralleled contrasting arrhythmic incidences in Pgc-1β-/- and WT hearts. Mitochondrial dysfunction thus causes pro-arrhythmic Pgc-1β-/- phenotypes by altering AP conduction through reducing (dV/dt)max and causing age-dependent fibrotic change.

Feasibility of analysis of the SCN5A gene in paraffin embedded samples in sudden infant death cases at the Pretoria Medico-Legal Laboratory, South Africa

To determine variations in the SCN5A gene linked to inherited cardiac arrhythmogenic disorders in sudden, unexplained infant death (SUID) cases examined at the Pretoria Medico-Legal Laboratory, South Africa. A retrospective study was conducted on SUID cases and controls, analyzing DNA extracted from archived formalin-fixed, paraffin-embedded (FFPE) myocardial tissue samples as well as blood samples. A total of 48 FFPE tissue samples (cases), 10 control FFPE tissue samples and nine control blood samples were included. DNA extracted from all samples was used to test for variations in the SCN5A gene by using high resolution melt (HRM) real-time PCR and sequencing. Genetic analysis showed 31 different single nucleotide variants in the entire study population (n = 67). Five previously reported variants of known pathogenic significance, and 14 variants of benign clinical significance, were identified. The study found 12 different variants in the cases that were not published in any database or literature and were considered novel. Of these novel variants, two were predicted as "probably damaging" with a high level of certainty (found in four case samples), one (identified in another case sample) was predicted to be "possibly damaging" with a 50% chance of being disease-causing, and nine were predicted to be benign. This study shows the significant added value of using genetic testing in determining the cause of death in South African SUID cases. Considering the high heritability of these arrhythmic disorders, post mortem genetic testing could play an important role in the understanding of the pathogenesis thereof and could also aid in the diagnosis and treatment of family members at risk, ultimately preventing similar future cases.

Current Status of Knowledge about Cardiopulmonary Resuscitation among the University Students in the Northern Region of Saudi Arabia

Background

Sudden cardiac arrest is a major public health problem in the world. Immediate initiation of high-quality cardiopulmonary resuscitation (CPR) significantly increased patient survival rate. Therefore, it is very important to train young people and increase public awareness of CPR for the long-term benefit of the community.

Objective

We aimed at estimating the level of knowledge and attitude towards cardiopulmonary resuscitation (CPR) among the university students in the northern region of Saudi Arabia.

Methodology

A cross-sectional, prospective study was conducted among the students of four northern region universities of Saudi Arabia (Jouf, Hail, Northern Borders, and Tabuk) between March and November 2017. A self-administered questionnaire was prepared in both Arabic and English languages and distributed to all the participants. All the data were collected and analyzed by using SPSS version 21.

Results

A total of 947 students from four universities completed the questionnaire: Jouf (57%), Hail (15%), Northern Borders (13%), and Tabuk (15%). Although 72% of students have previous knowledge about CPR, 49% of them lack knowledge about a medical emergency. Moreover, 59% failed to answer regarding CPR where only 41% wrote the ABC steps in the correct sequence. However, 67% of the participants had very poor knowledge, 89% of participants desired to receive additional CPR training course, and 49% of the students thought that CPR training should be a mandatory graduation requirement for all universities. There were no significant differences between male and female students. Students from medicine-related colleges have significantly (p < 0.001) more knowledge and scored better compared with non-medicine-related colleges. Tabuk University scored better compared to the others, but the overall knowledge and attitude scored were low.

Conclusions

Overall knowledge about CPR among the university students was not satisfactory; however, attitude towards CRP training was very positive. Our results suggested that there is a need for improvement of CPR education among Saudi university students, which will help to reduce the cardiac arrest mortality rate among the community.

Abnormal Repolarization Duration During Everyday Emotional Arousal in Long QT Syndrome and Coronary Artery Disease

BACKGROUND

Rare, high-arousal negative emotions are known triggers of sudden death in individuals with preexisting heart disease. Whether everyday fluctuations in emotional arousal influence arrhythmia risk is unknown.

METHODS

We studied 160 patients with the congenital long QT syndrome, 199 patients with coronary artery disease, and 2 groups of matched healthy volunteers (n = 52 and 50, respectively). Three-day home visits including a 12-hour Holter recording each day were completed. Subjects engaged in typical daily activities and were paged 10 times per day. On each occasion, subjects rated the intensity of 16 different emotions during the 5 minutes preceding the page. Holter data over those 5-minute epochs were analyzed for heart rate and QT interval corrected for heart rate (QTc). Analyses focused on within-subject covariation of momentary emotion and QTc.

RESULTS

In patients with long QT syndrome, activated positive affect and activated negative affect were associated with QTc shortening, whereas low arousal positive affect (calm and relaxed) was associated with QTc lengthening, which at times exceeded 500 msec. Findings were not affected by beta-blocker status or observed in younger healthy subjects. Findings were 3 to 8 times stronger in the LQT2 genotype, known to be prone to emotion-induced events, relative to the LQT1 genotype. Findings in patients with long QT syndrome for activated positive affect and low arousal positive affect were replicated in patients with coronary artery disease relative to older healthy subjects.

CONCLUSION

These findings suggest that even subtle changes in emotional arousal may alter repolarization reserve and contribute to sudden death risk in vulnerable individuals.

Cardiac abnormalities in Parkinson's disease and Parkinsonism

OBJECTIVES

Though there is increasing evidence for primary cardiac disease in Parkinson's disease (PD) and Parkinsonism (PS), this evidence is hardly included in the general management of these patients.

METHODS

Literature review.

RESULTS

PD is one of the most common age-related neurodegenerative disorders. Epidemiological studies have shown that PD is accompanied by high rates of premature death compared with the general population. In general, death in PD/PS is usually caused by determinant factors such as pneumonia, cerebrovascular, and cardiovascular disease. There is a significant body of literature demonstrating involvement of the heart in PD/PS. Cardiac involvement in PD/PS includes cardiac autonomic dysfunction, cardiomyopathy, coronary heart disease, arrhythmias, conduction defects, and sudden cardiac death (SCD), and sudden unexpected death in Parkinson's disease (SUDPAR).

CONCLUSIONS

Cardiac abnormalities found in PD/PS are manifold but the most prominent is cardiac autonomic dysfunction. The frequency of coronary heart disease in PD is a matter of debate. Only rarely reported in PD/PS are cardiomyopathies, arrhythmias, and sudden cardiac death, and SUDPAR. It is particularly recommended that PD/PS patients are more intensively investigated cardiologically as soon as the diagnosis is established. Early recognition of cardiac involvement is important for preventing SCD and SUDPAR.

Combined effect of renal function and serum potassium level in sudden cardiac death in aging hypertensive subjects

In patients with chronic kidney disease, serum potassium level is a factor influencing sudden cardiac death (SCD). The aim of our analysis was to study the combined effect of serum potassium level and renal function on the onset of SCD in elderly hypertensive subjects. Data from the 3620 hypertensive patients aged over 70 years were extracted from three randomized clinical trials included in the INDANA database. During a mean follow up of 4.5 years, 81 patients (2.24%) died from SCD. Mean serum potassium levels and prevalence of chronic kidney disease were not different in patients who died from SCD. In addition to serum potassium and creatinine levels, 14 clinical and biological variables linked to cardiovascular diseases recorded at baseline were analyzed using a Bayesian network. The area under the receiver operating characteristic curve of the Bayesian model reached 0.91. Bayesian inference was used to simulate the combined effects of serum potassium and creatinine levels on SCD. Our analysis, using simulated data from Bayesian model, showed that the estimated probabilities of SCD was significantly increased in case of hyperkalemia (>5.0 mmol/l) and in case of hypokalemia (<3.5 mmol/l) and in case of chronic kidney disease. Combined effects of serum potassium level and renal function revealed that chronic kidney disease increased the probability of SCD whatever the serum potassium level. Our results using a Bayesian model confirm the deleterious effects of hypokalemia, hyperkalemia and chronic kidney disease on SCD in elderly hypertensive patients.

Comparative Safety of Sulfonylureas and the Risk of Sudden Cardiac Arrest and Ventricular Arrhythmia

OBJECTIVE

To examine the association between individual antidiabetic sulfonylureas and outpatient-originating sudden cardiac arrest and ventricular arrhythmia (SCA/VA).

RESEARCH DESIGN AND METHODS

We conducted a retrospective cohort study using 1999-2010 U.S. Medicaid claims from five large states. Exposures were determined by incident use of glyburide, glimepiride, or glipizide. Glipizide served as the reference exposure, as its effects are believed to be highly pancreas specific. Outcomes were ascertained by a validated ICD-9-based algorithm indicative of SCA/VA (positive predictive value ∼85%). Potential confounding was addressed by adjustment for multinomial high-dimensional propensity scores included as continuous variables in a Cox proportional hazards model.

RESULTS

Of sulfonylurea users under study (N = 519,272), 60.3% were female and 34.9% non-Hispanic Caucasian, and the median age was 58.0 years. In 176,889 person-years of sulfonylurea exposure, we identified 632 SCA/VA events (50.5% were immediately fatal) for a crude incidence rate of 3.6 per 1,000 person-years. Compared with glipizide, propensity score-adjusted hazard ratios for SCA/VA were 0.82 (95% CI 0.69-0.98) for glyburide and 1.10 (0.89-1.36) for glimepiride. Numerous secondary analyses showed a very similar effect estimate for glyburide; yet, not all CIs excluded the null.

CONCLUSIONS

Glyburide may be associated with a lower risk of SCA/VA than glipizide, consistent with a very small clinical trial suggesting that glyburide may reduce ventricular tachycardia and isolated ventricular premature complexes. This potential benefit must be contextualized by considering putative effects of different sulfonylureas on other cardiovascular end points, cerebrovascular end points, all-cause death, and hypoglycemia.

Prophylactic implantable cardioverter defibrillator in heart failure: the growing evidence for all or Primum non nocere for some?

Heart failure (HF) is a common health problem and has reached epidemic in many western countries. Despite the current era of HF treatment, the risk of sudden cardiac death (SCD) in HF remains significant. Implantable cardioverter defibrillator (ICD) support has been shown to reduce the risk of SCD in patients with HF and impaired left ventricular function. Prophylactic ICD implantation in HF patients seems a logical step to reduce mortality through a reduction in SCD. However, ICD implantation is an invasive procedure, and both short- and long-term complications can occur. This needs to be carefully considered when evaluating the risk-benefit ratio of ICD implantation for individual patients. As the severity of HF increases, the proportion of SCD compared with HF-related deaths decreases. The challenge lies in identifying patients with HF who are at significant risk of SCD and who would most benefit from an ICD in addition to other anti-arrhythmic strategies. This review offers insight on the applicability and practicability of ICD for this growing population.

Role of copy number variants in sudden cardiac death and related diseases: genetic analysis and translation into clinical practice

Several studies have identified copy number variants (CNVs) as responsible for cardiac diseases associated with sudden cardiac death (SCD), but very few exhaustive analyses in large cohorts of patients have been performed, and they have been generally focused on a specific SCD-related disease. The aim of the present study was to screen for CNVs the most prevalent genes associated with SCD in a large cohort of patients who suffered sudden unexplained death or had an inherited cardiac disease (cardiomyopathy or channelopathy). A total of 1765 European patients were analyzed with a homemade algorithm for the assessment of CNVs using high-throughput sequencing data. Thirty-six CNVs were identified (2%), and most of them appeared to have a pathogenic role. The frequency of CNVs among cases of sudden unexplained death, patients with a cardiomyopathy or a channelopathy was 1.4% (8/587), 2.3% (20/874), and 2.6% (8/304), respectively. Detection rates were particularly high for arrhythmogenic cardiomyopathy (5.1%), long QT syndrome (4.7%), and dilated cardiomyopathy (4.4%). As such large genomic rearrangements underlie a non-neglectable portion of cases, we consider that their analysis should be performed as part of the routine genetic testing of sudden unexpected death cases and patients with SCD-related diseases.

Prognostic value of T-wave morphology parameters in coronary artery disease in current treatment era

BACKGROUND

The prognostic value of T-wave morphology parameters in coronary artery disease in the current treatment era is not well established.

METHODS

The Innovation to reduce Cardiovascular Complications of Diabetes at the Intersection (ARTEMIS) study included 1,946 patients with angiographically verified coronary artery disease (CAD). The study patients underwent thorough examinations including 12-lead digital electrocardiogram (ECG) at baseline.

RESULTS

During a follow-up period of 73 ± 22 months, a total of 201 (10.3%) patients died. Of the study patients, 95 (4.9%) experienced cardiac death (CD) consisting of 44 (2.3%) sudden cardiac deaths (SCD) and 51 (2.6%) nonsudden cardiac deaths (NSCD), and 106 (5.4%) patients experienced noncardiac death (NCD). T-wave morphology dispersion (TMD), T-wave area dispersion (TWAD), and total cosine R-to-T (TCRT) had a significant association with CD even after adjustment with relevant clinical risk markers in the Cox regression analysis (multivariate HRs: 1.015, 95% CI 1.007-1.023, p = .0003; 0.474, 95% CI 0.305-0.737, p = .0009; 0.598, 95% CI 0.412-0.866, p = .006, respectively). When including these parameters to the clinical risk model for CD, the C-index increased from 0.810 to 0.823 improving the discrimination significantly (integrated discrimination index [IDI] = 0.0118, 95% CI 0.0028-0.0208, p = .01). These parameters were more closely associated with NSCD (multivariate p-values from .016 to .001) than with SCD (univariate/multivariate p-values for TMD .015/.197 and for TCRT .012/.43).

CONCLUSION

T-wave morphology parameters describing repolarization heterogeneity improve the predictive power of the clinical risk model for CD in patients with CAD in the current treatment era.