Incidence Rate Of Sudden Cardiac Death Research Articles

Exploring the Risk Factors of Sudden Cardiac Death Using an Electrocardiography and Medical Ultrasonography for the General Population Without a History of Coronary Artery Disease or Left Ventricular Ejection Fraction <35% and Aged >35 Years ― A Novel Point-Based Prediction Model Based on the Chin-Shan Community Cardiovascular Cohort ―

Most of the factors and prediction models of sudden cardiac death (SCD) have been developed without considering the Asia population. The purpose of this study is to construct a point-based prediction model for the general population in Asia.Methods and Results: Chin-Shan Community Cardiovascular Cohort (CCCC) is a community-based longitudinal cohort initiated between 1990 and 1991, enrolling participants aged ≥35 years and following them up until 2005. Participants with coronary artery disease (CAD) or a left ventricular ejection fraction (LVEF) of 35% were excluded from this study. The Framingham risk score function was used to derive a simple point-based prediction model. Based on bootstrapping, a novel model (CCCC-SCD-Score) was validated. A total of 2,105 participants were analyzed. The incidence rate of SCD was 0.406 per 1,000 person-years. The CCCC-SCD-Score score was calculated using age groups (maximal points=4), left ventricular hypertrophy, hypertension, left ventricular ejection fraction <40%, aortic flow rate >190 cm/s, and carotid plaque scores ≥5 (point=1 for each risk factor). The C-index of the CCCC-SCD-Score in predicting SCD risks was 0.888 (95% confidence interval: 0.807-0.969). For the general Asian population without a history of CAD or a LVEF <35% and who are aged >35 years, the novel model-based scoring system effectively identifies the risk for SCD using the clinical factors, electrocardiographic and echocardiographic data.

Risk of Sudden Death in a General Unbiased Epidemiological Cohort of Sarcoidosis.

BackgroundSarcoidosis is an inflammatory, noncaseating, granulomatous disorder of unknown cause that can affect any body system and is associated with cardiovascular disease including sudden cardiac death (SCD). Cardiac involvement in sarcoidosis is associated with higher risk of SCD, but the SCD risk in the general sarcoidosis population is unknown. We aimed to determine the risk of SCD in people with sarcoidosis versus the matched general population.Methods and ResultsA population‐based cohort of sarcoidosis and age‐ and sex‐matched comparators from January 1, 1976 to December 31, 2013 was used; presence of other comorbidities in the comparator group was not an exclusion criterion. Mortality, including time, place, and cause of death were measured and manually adjudicated for SCD events. Incidence rates are reported per 100 000 person‐years, and Cox models were used for group comparisons. Of the 345 incident cases of sarcoidosis (171 men; 50%) there were 58 reported deaths; 10 were definite/probable SCD versus 57 all‐cause and 9 SCDs in comparators. Median follow‐up was 12.9 years (interquartile range, 6.0–23.4 years) . Incidence rate of SCD in sarcoidosis was 192 (95% CI, 92–352) versus 155 (95% CI, 71–294) in comparators (hazard ratio [HR], 1.28 (95% CI, 0.52–3.17). Nocturnal deaths were more frequent in sarcoidosis 57 (95% CI, 12–168) versus 17 (95% CI, 0.4–95) (HR, 3.76 [95% CI, 0.39–36.47]). No significant differences were detected between the groups by sex, age, calendar year of diagnosis, or disease duration.ConclusionsIn a population‐based cohort of patients with sarcoidosis, the risk for SCD compared with matched comparators was not increased. There were more nocturnal deaths among patients with sarcoidosis, yet this was statistically insignificant.

Pre-participation cardiovascular screening in athletes with a focus on Asia

Pre-participation screening (PPS) in young competitive athletes aims to identify conditions associated with sudden cardiac death (SCD) in this population, with a view to appropriate management and potential mitigation of risk. A medical history questionnaire and physical examination are standard components of a PPS programme, whereas controversy still exists regarding mandatory utilisation of resting 12-lead electrocardiogram as a screening tool. Apart from a landmark study from Italy attributing the reduction of SCD rates in athletes to the implementation of a mandatory PPS programme, there remains no additional compelling evidence for similar outcomes to date. Nonetheless, comprehensive PPS programmes when carried out systematically, are efficacious in detection of cardiac pathology and cost-effective. While the incidence rate of SCD in athletes from Western countries is estimated to be around 1:50,000, comparable data in Asian athletes remain lacking. Prospective registries are much needed to accurately determine the magnitude of this issue in Asia and recent recommendations on PPS in young Asian athletes have been published to increase awareness and encourage collaboration. To further reduce SCD events, prompt recognition of sudden cardiac arrests and early defibrillation are vital components in the spectrum of SCD prevention. This review aims to outline the rationale, current status and efficacy of PPS in athletes, with a focus on Asia.

For the Evaluation of Pacific Island Athletes, an ECG and Echocardiography Are Highly Recommended

Physical exercise increases the relative risk of sudden cardiac death (SCD) in athletes when compared to a non-sporting population. Pre-participation evaluation (PPE) of athletes is thus of major importance. For Pacific Island athletes, medical guidelines recommend an echocardiography to complement a PPE including personal and family history, a physical examination and a resting twelve-lead electrocardiogram (ECG). Indeed, silent rheumatoid heart diseases found in up to 7.6% of adolescents give rise to severe valve lesions, which are the main causes of SCD in Pacific Island athletes. This short review examines the incidence rate of SCD in Pacific Island athletes and indicates how a questionnaire, physical examination, ECG and echocardiography can prevent it.

Determinants of sudden cardiac death after heart transplantation

Heart transplant recipients are at high-risk of sudden cardiac death (SCD). However, risk factors of SCD in heart recipients remained poorly described. To assess the predictors of SCD beyond the first-year post-transplant. We enrolled consecutive patients transplanted between 2004 and 2017 in two French referral centres. We excluded patients deceased during the first year. Patients underwent an evaluation at the day of transplantation and during the first year, comprising clinical, biological, histological, immunological (circulating anti-HLA DSA) and interventional (cardiac allograft vasculopathy assessment) parameters. According to the last consensus, SCD was defined as an unexpected out-of-hospital cardiac arrest without obvious non-cardiac cause, in the first hour after initiation of symptoms. A total of 913 patients were included. The median follow-up post-HT was 5.9 years (IQR = 2.9–8.5). Among the 60 parameters tested in univariate analysis, we identified 4 independent factors independently associated with sudden death after 1 year post-HT: donor age (HR = 1.55; 95% CI: 1.14–2.11; P = 0.005), recipient age (HR = 0.74; 95% CI: 0.59–0.93; P = 0.011), ventricular ejection fraction (LVEF) < 55% any time after transplantation (HR: 3.95; 95% CI: 1.95–8.02; P < 0.001), the presence of circulating anti-HLA DSA at the time of transplantation (HR: 2.18; 95% CI: 1.15–4.11; P = 0.017). The incidence rate of SCD was 2.17 per 100 person-year (95% CI: 1.42–4.60) and 1.21 per 100 person-year (95% CI: 0.80–2.58) in patients with FEVG < 55% ( n = 73) and in patients with pre-formed DSA ( n = 260), respectively ( Table 1 ). In a large multicentric and highly phenotyped cohort of heart transplant recipients, we identified four independent factors associated with SCD beyond the first year. This study provides fresh evidence of SCD assessment for improving risk stratification of HT recipients.

Incidence of sudden cardiac death after heart transplantation

Sudden cardiac death (SCD) is a major contributor to the rate of mortality after heart transplantation. However, little is known about the incidence of SCD in heart recipients. To assess the incidence of SCD after heart transplantation. We enrolled consecutive patients transplanted between 2004 and 2017 in two French referral centers. We defined 7 main groups of causes of deaths: SCD, cardiovascular (including Cardiac allograft vasculopathy), infection, primary graft dysfunction, graft failure (including late graft dysfunction, rejection), malignancy and others. Causes of deaths were independently adjudicated by two senior cardiologists based on the analysis of death certificates and medical records. Discrepancies were resolved by discussion until a consensus was made. SCD was defined as an unexpected out-of-hospital cardiac arrest without obvious non-cardiac cause, in the first hour after initiation of symptoms. A total of 1,363 patients were included. The median follow-up post-transplant was 3.99 years (IQR = 0.49–7.49). A total of 450 patients (33%) deceased during the first year. The leading cumulative causes of death in the first year after transplantation were infection, primary graft failure, multiple organ failure during the period in intensive car unit. Beyond the post-operative high-risk period of the first year, the leading cumulative cause of death was SCD: among the 213 deaths that occurred beyond the first year, 44 patients (21%) died from SCD. In this period, the incidence rate of SCD reached 0,82 per 100 person-year (95% CI: 0.51–2.05) ( Fig. 1 ). In a large multicentric and highly phenotyped cohort of heart transplant recipients, the leading cumulative cause of death beyond the first-year post transplant was sudden cardiac death. Our results open discussion on management of heart recipient, such as the implementation of cardioverter-defibrillators.

Determinants of sudden cardiac death after heart transplantation

Abstract Background Heart transplant recipients are at high-risk of sudden cardiac death (SCD). However, risk factors of SCD in heart recipients remained poorly described. Objective To assess the predictors of SCD beyond the first-year post-transplant. Methods We enrolled consecutive patients transplanted between 2004 and 2017 in two French referral centers. We excluded patients deceased during the first year. Patients underwent an evaluation at the day of transplantation and during the first year, comprising clinical, biological, histological, immunological (circulating anti-HLA DSA) and interventional (cardiac allograft vasculopathy assessment) parameters. Echocardiographies were routinely performed in all included patients according to a prespecified protocol. According to the last consensus, SCD was defined as an unexpected out-of-hospital cardiac arrest without obvious non-cardiac cause, in the first hour after initiation of symptoms. Cox model analysis was used to determine the parameters associated with sudden death risk. Results A total of 913 patients were included. The median follow-up post-HT was 5.9 years (IQR=2.9–8.5). Among the 213 deaths after one year, 44 patients (21%) died from SCD. In this population, the incidence rate of SCD was 0,82 per 100 person-year (95% CI: 0,51–2,05). Among the 60 parameters tested in univariate analysis, we identified 2 independent factors of sudden death after 1 year post-HT: left ventricular ejection fraction (LVEF) ≤55% any time after transplantation ( HR 4.07, 95% CI 1.94–8.53, p&amp;lt;0.001) and the presence of circulating anti-HLA DSA at the time of transplantation (HR 2.79, 95% CI 1.37–5.68, p=0.005). The incidence rate of SCD was 2.17 per 100 person-year (95% CI: 1.42; 4.60) and 1.21 per 100 person-year (95% CI: 0.80; 2.58) in patients with FEVG&amp;lt;55% (n=73) and in patients with pre-formed DSA (n=260), respectively. Conclusion In a large multicentric and highly phenotyped cohort of heart transplant recipients, we identified two independent factors associated with SCD beyond the first year. This study provides fresh evidence of SCD assessment for improving risk stratification of HT recipients. Funding Acknowledgement Type of funding source: None

2397Lesion-specific risk for sudden cardiac death or life-threatening ventricular arrhythmias in adult congenital heart disease

Abstract Background Risk models for primary prevention strategies in adult congenital heart disease (ACHD) must incorporate the heterogeneous risk for sudden cardiac death (SCD) and life-threatening ventricular arrhythmias (LTVA) as stratified by underlying lesion. Objectives To determine lesion-specific risk for SCD and LTVA in ACHD. Methods We analyzed 3311 ACHD patients (50% males) prospectively followed-up for 37510 person/years. SCD cases were confirmed by means of the Spanish National Death Registry. In addition, we identified all cases of resuscitated cardiac arrest or ventricular tachycardia requiring cardioversion. According to the incidence rate of the composite end-point of SCD and LTVA, lesions were stratified into four groups of risk. Cumulative freedom from SCD or LTVA in patients at high, moderate, low and very low risk were compared by using Cox regression model with left truncation. The c-index of this lesion-specific risk stratification was calculated by using the β-coefficients. The discriminative ability of this lesion-specific risk stratification was also tested in an external cohort of 203 SCD-LTVA cases and 2287 controls from 20 different centers. Results 71 patients experienced an event (53 SCD, 18 LTVA). Patients at highest risk (incidence rate &gt;1%) were those with Rastelli procedure, severe coronary abnormalities, complex Fallot and cyanotic patients, either Eisenmenger or non-Eisenmenger; at moderate risk (incidence rate 0.25–1.0%) non-complex Fallot, Mustard/Senning repair, Fontan procedures and congenitally corrected transposition; at low risk (incidence rate 0.1–0.25%) Ebstein anomaly and left heart lesions; and at very low risk (incidence rate &lt;0.1%) left-to-right shunts and right ventricular outflow lesions. The discriminative ability in a multicenter external cohort was excellent (c-index ranged from 0.748 to 0.819 by center). Lesion-specific risk and C-index Conclusions A lesion-specific risk stratification based on the incidence rate of SCD and LTVA was performed and validated. This approach could result in a more individualized risk assessment. Acknowledgement/Funding Instituto de Salud Carlos III, Ministerio de Economía y Competividad, Spain (Exp PI14/02099 and PI17/01327) and co-financed by FEDER

Screening for heart problems in young athletes

Physical training has several cardiovascular benefits. However, in rare cases, intensive exercise may be associated with sudden cardiac death (SCD). Although rare, SCD is the leading medical cause of death in the young athletes. The incidence rate of SCD is widely debated and largely unknown - the probable incidence range of SCD is between 1 and 2.5 per 100 000 athletes. The American Heart Association (AHA) estimates the prevalence of an underlying cardiovascular disorder in young athletes that predisposes to SCD as 0.3%.

Genotype-phenotype relationship and risk stratification in loss-of-function SCN5A mutation carriers.

Loss-of-function (LoF) mutations in the SCN5A gene cause multiple phenotypes including Brugada Syndrome (BrS) and a diffuse cardiac conduction defect. Markers of increased risk for sudden cardiac death (SCD) in LoF SCN5A mutation carriers are ill defined. We hypothesized that late potentials and fragmented QRS would be more prevalent in SCN5A mutation carriers compared to SCN5A-negative BrS patients and evaluated risk markers for SCD in SCN5A mutation carriers. We included all SCN5A loss-of-function mutation carriers and SCN5A-negative BrS patients from our center. A combined arrhythmic endpoint was defined as appropriate ICD shock or SCD. Late potentials were more prevalent in 79 SCN5A mutation carriers compared to 39 SCN5A-negative BrS patients (66% versus 44%, p=.021), while there was no difference in the prevalence of fragmented QRS. PR interval prolongation was the only parameter that predicted the presence of a SCN5A mutation in BrS (OR 1.08; p<.001). Four SCN5A mutation carriers, of whom three did not have a diagnostic type 1 ECG either spontaneously or after provocation with a sodium channel blocker, reached the combined arrhythmic endpoint during a follow-up of 44±52months resulting in an annual incidence rate of 1.37%. LP were more frequently observed in SCN5A mutation carriers, while fQRS was not. In SCN5A mutation carriers, the annual incidence rate of SCD was non-negligible, even in the absence of a spontaneous or induced type 1 ECG. Therefore, proper follow-up of SCN5A mutation carriers without Brugada syndrome phenotype is warranted.

Incidence and predictors of sudden cardiac death after heart transplantation: A systematic review and meta-analysis.

Sudden cardiac death (SCD) is an important post-transplant problem being responsible for ~10% of deaths. We conducted a systematic review and meta-analysis to evaluate incidence and predictors of post-heart transplant SCD and the use of implantable cardiac defibrillator (ICD). Citations were identified in electronic databases and references of included studies. Observational studies on adults reporting on incidence and predictors of post-transplant SCD and ICD use were selected. We meta-analyzed SCD in person-years using random effects models. We qualitatively summarized predictors. This study includes 55 studies encompassing 47901 recipients. The pooled incidence rate of SCD was 1.30 per 100 person-years (95% CI: 1.08-1.52). Cardiac allograft vasculopathy (CAV) was associated with higher SCD risk (2.40 per 100 patient-years, 95% CI: 1.46-3.34). Independent predictors of SCD identified by two moderate-quality studies were older donor age, younger recipient age, non-Caucasian race, reduced left ventricular ejection fraction, rejection, infection, and cancer. Authors rarely reported on ICD use. This meta-analysis found that post-transplant SCD risk in heart transplant recipients is higher than that in the general population. CAV was associated with increased SCD risk. Observational studies reporting on absolute risk of SCD are needed to better identify populations at a clinically significant increased risk.

INCIDENCE RATE, CIRCUMSTANCES, AND CARDIAC SYMPTOMS PRECEDING SUDDEN CARDIAC DEATH CAUSED BY HYPERTROPHIC CARDIOMYOPATHY

Hypertrophic cardiomyopathy (HCM) is believed to be a leading cause of sudden cardiac death (SCD) in younger persons. Estimates of the incidence of SCD in patients with HCM vary widely, usually cited as 0.5-1%/year. Few prior studies have included autopsy and systematically sought details on preceding circumstances of death and prior history. Using the comprehensive Chief Coroner of Ontario database, encompasing all deaths attended by the coroner in Ontario, we identified all cases of SCD determined to be caused by HCM in individuals aged 10-65, between 2011-2016. EMS records, in-hospital information, death certificates, available medical records, coroner’s investigation statement, toxicology and post-mortem reports were reviewed. We identified 65 SCDs considered be caused by HCM over a 6-year period. Individuals older than 45 years comprised the vast majority of cases (64.6%). An autopsy was performed in all cases except for 8 cases with clinically diagnosed HCM. Based on a population of 10,125,401 Ontarians aged 10-65 (60,752,406 person years) and an estimated prevalence of HCM of 1:500, this corresponds to an estimated annual sudden death rate from HCM of 0.53/1,000 person years, and 0.37/1,000 person years amongst individuals ≤45 years (based on a population of 6,245,643 ; 37,473,858 person years). Males comprised 74.6% of the cases. Twenty-one individuals (31.8%) had a prior diagnosis of HCM. Eighty percent (53) of SCD events occurred at rest, 10.6% (6) during light activity (including walking and driving), 7.6%(5) during moderate exercise (including swimming, biking and fitness activities) and only 1.5% (1) during competitive sport. In 2 cases the circumstances could not be determined. Information about prior symptoms was available in 39 cases; 22 experienced symptoms during the week prior to SCD. In a validation data set, we reviewed all 911 attended cardiac arrests in the Greater Toronto Area (population of 4,128,570; 16,514,280 person years), ages 10-45, over a 4-year period and matched the EMS records with coroners files (89.1% matched) and autopsy information (82% matched). We identified 9 SCD from HCM, corresponding to an estimated incidence of 0.27/1000 person-years. The estimated incidence rate of SCD caused by HCM in ages 10-65 in Ontario is considerably lower than previously reported and is estimated at 0.05% per year amongst persons with HCM. The vast majority of events occurred during rest or light activity. Further studies are needed to assess the incidence and circumstances of SCDs in HCM.

Sudden cardiac death in non-dialysis chronic kidney disease patients

BackgroundA relatively high proportion of deaths in dialysis patients occur suddenly and unexpectedly. The incidence of sudden cardiac death (SCD) in non-dialysis advanced chronic kidney disease (CKD) stages has been less well investigated. ObjectiveThis study aims to determine the incidence and predictors of SCD in a cohort of 1078 patients with CKD not yet on dialysis. MethodsProspective observational cohort study, which included patients with advanced CKD not yet on dialysis (stage 4–5). The association between baseline variables and SCD was assessed using Cox and competing-risk (Fine and Gray) regression models. Demographic, clinical information, medication use, and baseline biochemical parameters of potential interest were included as covariates. ResultsDuring the study period (median follow-up time 12 months), 210 patients died (19%), and SCD occurred in 34 cases (16% of total deaths). All-cause mortality and SCD incidence rates were 113 (95% CI: 99–128), and 18 (95% CI: 13–26) events per 1000patient-years respectively. By Cox regression analysis, covariates significantly associated with SCD were: Age, comorbidity index, and treatment with antiplatelet drugs. This latter covariate showed a beneficial effect over the development of SCD. By competing-risk regression, in which the competing event was non-sudden death from any cause, only age and comorbidity index remained significantly associated with SCD. ConclusionsSCD is relatively common in non-dialysis advanced CKD patients. SCD was closely related to age and comorbidity, and some indirect data from this study suggest that unrecognized or undertreated cardiovascular disease may predispose to a higher risk of SCD.

Muerte súbita en pacientes con enfermedad renal crónica avanzada

BackgroundA relatively high proportion of deaths in dialysis patients occur suddenly and unexpectedly. The incidence of sudden cardiac death (SCD) in non-dialysis advanced chronic kidney disease (CKD) stages has been less well investigated. ObjectiveThis study aims to determine the incidence and predictors of SCD in a cohort of 1078 patients with CKD not yet on dialysis. MethodsProspective observational cohort study, which included patients with advanced CKD not yet on dialysis (stage 4–5). The association between baseline variables and SCD was assessed using Cox and competing-risk (Fine and Grey) regression models. Demographic, clinical information, medication use, and baseline biochemical parameters of potential interest were included as covariates. ResultsDuring the study period (median follow-up time 12 months), 210 patients died (19%), and SCD occurred in 34 cases (16% of total deaths). All-cause mortality and SCD incidence rates were 113 (95% CI: 99–128), and 18 (95% CI: 13–26) events per 1000 patients/year, respectively. By Cox regression analysis, covariates significantly associated with SCD were: Age, comorbidity index, and treatment with antiplatelet drugs. This latter covariate showed a beneficial effect over the development of SCD. By competing-risk regression, in which the competing event was non-sudden death from any cause, only age and comorbidity index remained significantly associated with SCD. ConclusionsSCD is relatively common in non-dialysis advanced CKD patients. SCD was closely related to age and comorbidity, and some indirect data from this study suggest that unrecognised or undertreated cardiovascular disease may predispose to a higher risk of SCD.

0235: Incidence of sudden cardiac death in sub-Saharan Africa: the DoualaSCD registry

A population-based incidence estimates of Sudden Cardiac Death (SCD) in sub-Saharan Africa (SSA) is unknown. We sought to determine the epidemiology of SCD in Douala, Cameroon. During 12 months, 4 districts were randomly chosen to monitor all deaths. The COSA ("comité de santé") of each area registered every death, and a postgraduate fellow recorded detailed demographic and medical data for victims of natural death. A senior physician studied every case of suspected sudden death, either cardiac or extra-cardiac. For optimal exhaustiveness, surrounding hospital mortuaries were checked simultaneously to match identities of victims. Established SCD was defined as rapid witnessed collapses leading to death within 1h after the onset of symptoms, and probable SCD as unexpected death within 24h without obvious extra-cardiac cause. Our registry numbered 240 000 people and 2304 deaths. The overall mortality rate was 11.2/1000 inhabitants/year. Four (0.3%) were sudden extra-cardiac death, and 58 (2.5%) SCD of which 41.4% were established and 48.3% had <40 year-old. The incidence rate of SCD was 24.2/100 000 person-year. Coronary artery disease or dilated cardiomyopathy was able to be diagnosed in 13.8% cases. Out-of-hospital cardiac arrest (OHCA) occurred in 58.6% victims, of which 35.3% at home, and 58.8% in a cab, on the way towards hospital. Witness cardiac arrest was reported in 86.2% cases, but only 7.4% of victims experienced cardiopulmonary resuscitation attempts. Although not negligible, the SCD incidence in this SSA population is lower than that reported in most of western countries. However, as the vast majority of cases are witnessed cardiac arrests, the absence of CPR attempts raises the question of educating populations in providing basic life support rescue to tackle this potential reversible fatal outcome.

Abstract 19577: Race and Sudden Cardiac Death: Findings From the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

Introduction: Blacks, as compared to whites, have a higher burden of cardiovascular disease (CVD) risk factors and CVD. Recent studies have reported a higher burden of sudden cardiac death (SCD) in blacks; however, it remains unclear whether this elevation in SCD risk is independent of racial differences in risk factor profiles and prevalent CVD. Methods: We examined the association between black race and SCD in participants with and without a history of CVD at baseline in the REGARDS study, a prospective, longitudinal cohort of 29,695 participants ≥45 years (55% women, 41% black) from across the United States. SCD was defined as sudden pulselessness from a presumed cardiac origin that occurred out of hospital or in the emergency room. Results: Over a median [IQR] of 6.0 [4.5-7.3] years of follow-up, 388 SCD events occurred. Compared to whites, blacks had less education, lower income and a higher burden of CVD risk factors. In the entire population, the age-adjusted SCD incidence rates per 1000 person-years were 2.6 (95% CI, 2.3-3.0) for blacks versus 1.7 (95% CI, 1.4-1.9) for whites, (HR=1.47; 95% CI 1.20-1.79). This elevated risk was attenuated after controlling for CVD risk factors and became non-significant after controlling for prevalent CVD (Table 1). Among the subgroup of 22,507 participants without CVD at baseline, SCD risk remained elevated in blacks (HR=1.90; 1.35-2.68) even after controlling for CVD risk factors and medication use (Table 1). In contrast, there was no elevation in SCD risk among the participants with prevalent CVD at baseline. The association between black race and SCD was stronger in those without compared to those with a history of CVD (p=0.001). Conclusions: The higher risk of SCD risk associated with black race, compared to whites, is partially explained by the higher prevalence of CVD and its risk factors in blacks. However, there remains a higher SCD risk associated with black race among those without CVD not explained by standard CVD risk factors.

Sudden cardiac death in young adults with previous hospital-based psychiatric inpatient and outpatient treatment: a nationwide cohort study from Denmark.

Psychiatric patients have premature mortality compared to the general population. The incidence of sudden cardiac death (SCD) in psychiatric patients is unknown in a nationwide setting. The aim of this study was to compare nationwide SCD incidence rates in young individuals with and without previous psychiatric disease. Nationwide, retrospective cohort study including all deaths in people aged 18-35 years in 2000-2006 in Denmark. The unique Danish death certificates and autopsy reports were used to identify SCD cases. Psychiatric disease was defined as a previous psychiatric hospital contact and was identified using The Danish Psychiatric Central Research Register. All diagnoses in Danish registries are coded according to ICD-8 or ICD-10. All hospital records were retrieved manually. Among 5,178 deaths, 395 were due to SCD and autopsies were performed on 262 (66%). In 77 SCD cases, a previous psychiatric hospital contact was identified. The SCD incidence rate in psychiatric patients was 14.8 (95% CI, 11.7-18.5) per 100,000 person-years versus 3.8 (95% CI, 3.4-4.3) per 100,000 person-years in individuals without psychiatric hospital contact (incidence rate ratio = 3.9; 95% CI, 3.0-5.0; P < .01). Incidence rates per 100,000 persons-years were the highest in patients with schizophrenia-spectrum disorders (38.9; 95% CI, 26.4-55.2) and substance-related disorders (31.6; 95% CI, 19.3-48.8). SCDs in psychiatric patients compared to nonpsychiatric patients were more often unexplained (65% vs 40%, P = .02), and cardiac symptoms were reported prior to death in 46% of psychiatric patients. Patients with prior psychiatric hospital contact have a 4-fold increased risk of SCD. Since almost 50% had possible cardiac symptoms prior to death, cardiovascular risk monitoring and management in the mentally ill are essential.

Sudden death in athletes: Preventable or inevitable?

Sudden cardiac death (SCD) is a tragic and devastating complication of a number of underlying cardiovascular diseases. In people younger than 35 years, genetic heart diseases such as inherited cardiomyopathies, namely, hypertrophic cardiomyopathy (HCM), and primary arrhythmogenic disorders, including familial long QT syndrome, represent an important cause of SCD. In those younger than 35 years, coronary artery disease and myocardial infarction together comprise over 90% of SCD cases. Understanding the causes and arrhythmogenic substrates underpinning SCD and elucidating what specific factors may trigger malignant arrhythmias represent key foundations for the development of treatment and prevention strategies to reduce SCD in our communities. In this issue of HeartRhythm, Risgaard et al present findings from a retrospective nationwide study of SCD in Denmark, with data from SCD cases collected over a 3-year period from 2007 to 2009. The main focus was on SCD cases aged 12–49 years and specifically to compare SCD incidence rates between competitive and noncompetitive athletes, so-called sports-related SCD cases. Of 881 SCD cases aged 12–49 years over the study period, 44 sports-related SCD cases were identified (0.54 per 100,000 person-years). Significantly, in the age group of 12–35 years, there was no difference in the incidence of SCD between competitive (0.47 per 100,000 athlete person-years) and noncompetitive (0.43 per 100,000 athlete person-years) athletes. The incidence of sports-related SCD in those aged 36–49 years was significantly increased in both competitive and noncompetitive athletes. Importantly, the overall incidence of SCD in the general population was found to be much more prevalent than that of sports-related SCD in all age groups. The authors are to be congratulated for the rigorous and dedicated efforts to collect this important data set. These

Burden of Sudden Cardiac Death in Persons Aged 1 to 49 Years

Background— Knowledge of the burden and causes of sudden cardiac death (SCD) is sparse in persons aged &lt;50 years; better understanding is needed to lower the risk of SCD. The aim of this study was to report SCD incidence rates and autopsy findings in persons aged 1 to 49 years. Methods and Results— All deaths in persons aged 1 to 49 years were included in 2007 to 2009. Death certificates were reviewed by 2 physicians. History of previous admissions to hospital was assessed, and discharge summaries were read. Sudden unexpected death cases were identified and autopsy reports were collected. In the 3-year study period, there were 7849 deaths of which we identified 893 (11%) SCD cases. The annual incidence rate per 100 000 persons increased from 2.3 (95% confidence interval, 2.0–2.7) to 21.7 (95% confidence interval, 20.2–23.4) in persons aged 1 to 35 and 36 to 49 years, respectively. Coronary artery disease was the most common cause of death and was found in 158 (36%) autopsied cases, followed by 135 (31%) cases of sudden unexplained death. Conclusions— In a nationwide cohort of persons aged &lt;50 years, the annual incidence rate of SCD was ≈10× higher in persons aged 36 to 49 years than in persons aged 1 to 35 years. Notably, coronary artery disease was the most common cause of SCD, followed by unexplained deaths. These findings may help in developing strategies to prevent SCD in the future.

Risk Factors for Sudden Cardiac Death in Post-Menopausal Women

The aim of this study was to estimate the annual incidence rate of sudden cardiac death (SCD) and to identify risk factors for SCD in post-menopausal women. With the aging U.S. population, post-menopausal women now have the greatest population burden of cardiovascular disease including SCD. We examined 161,808 women who participated in the Women's Health Initiative clinical trials and observational study. The women were recruited at 40 clinical sites across the United States, enrolled between 1993 and 1998, and followed until August 2009. Our primary endpoint is incident SCD, defined as death occurring within 1 h of symptom onset or within 1 h after the participant was last seen without symptoms and death that occurred in the absence of a potentially lethal non-coronary disease process. Four hundred eighteen women experienced adjudicated SCD. The incidence rate of SCD was 2.4/10,000 women/year (95% confidence interval: 2.2 to 2.7). We identified the following independent risk factors for SCD: older age, African-American race, tobacco use, higher pulse, higher waist-to-hip ratio, elevated white blood cell count, history of heart failure, diabetes, history of myocardial infarction, previous carotid artery disease, and hypertension. Population-attributable fractions were greatest for hypertension, waist-to-hip ratio, and myocardial infarction. Besides traditional risk factors for coronary heart disease, risk factors for sudden cardiac death in post-menopausal women include African-American race, higher pulse, higher waist-to-hip ratio, elevated white blood cell count, and heart failure. Nearly one-half of women who experienced sudden cardiac death had no previous diagnosis of coronary heart disease.