Incidence and other epidemiological characteristics of sudden cardiac death in northwest Greece

Incidence of sudden cardiac death in the young: a systematic review

OBJECTIVE

To summarise studies describing incidence of sudden cardiac death in a general population of young individuals to inform screening policy.

DESIGN

Systematic review.

DATA SOURCES

Database searches of MEDLINE, EMBASE and the Cochrane library (all inception to current) on 29 April 2019 (updated 16 November 2019), and forward/backward citation tracking of eligible studies.

STUDY ELIGIBILITY CRITERIA

All studies that reported incidence of sudden cardiac death in young individuals (12-39 years) in a general population, with no restriction on language or date. Planned subgroups were incidence by age, sex, race and athletic status (including military personnel).

DATA EXTRACTION

Two reviewers independently assessed study eligibility, extracted study data and assessed risk of bias using the Joanna Briggs Institute critical appraisal checklist for prevalence studies.

ANALYSIS

Reported incidence of sudden cardiac death in the young per 100 000 person-years.

RESULTS

38 studies that reported incidence across five continents. We identified substantial heterogeneity in population, sudden cardiac death definition, and case ascertainment methods, precluding meta-analysis. Median reported follow-up years was 6.97 million (IQR 2.34 million-23.70 million) and number of sudden cardiac death cases was 64 (IQR 40-251). In the general population, the median of reported incidence was 1.7 sudden cardiac death per 100 000 person-years (IQR 1.3-2.6, range 0.75-11.9). Most studies (n=14, 54%) reported an incidence between one and two cases per 100 000 person-years. Incidence was higher in males and older individuals.

CONCLUSIONS

This systematic review identified variability in the reported incidence of sudden cardiac death in the young across studies. Most studies reported an incidence between one and two cases per 100 000 person-years.

PROSPERO REGISTRATION NUMBER

CRD42019120563.

Smoking cessation is associated with reduced long-term mortality and the need for repeat interventions after coronary artery bypass grafting

DESIGN

A prospective study.

METHODS

We estimated the impact of smoking cessation on long-term mortality and the need for a revascularization procedure in 1027 patients undergoing a first-ever coronary artery bypass-grafting.

RESULTS AND DISCUSSION

Of the 640 active smokers, 44.7% continued smoking after CABG ('current smokers'), and 55.3% quit. During a 5310 patient-years follow-up, with never smokers as the reference group, current smokers (but not quitters) experienced a significant increase in total mortality (hazard ratio 2.6, 95% confidence interval 1.0-6.6) mainly owing to increased cardiovascular mortality (hazard ratio 4.8, 95% confidence interval 1.1-21.4), as well as increased need for a repeat revascularization procedure (hazard ratio 1.7, 95% confidence interval 1.0-2.9).

Characteristics and short-term survival of individuals with out-of-hospital cardiac arrests in the East Bohemian region

AIM

We describe survival after admission to hospital from out-of-hospital cardiac arrest (OHCA) in the East Bohemian region, according to the Utstein Style guidelines and have identified the main diagnosis including in those who died and had an autopsy.

PATIENT GROUP

Over a period of 29 months we used a questionnaire supplied to 24 rescue stations, to identify 718 individuals (511 men and 207 women, aged 16-97 years) with confirmed cardiac arrest who were considered for resuscitation.

RESULTS

Out of 560 patients in whom cardiopulmonary resuscitation for OHCA of confirmed cardiac aetiology was attempted, 350 patients (62.5%) died in the field and 61 (10.9%) died during transport. Hospital admission was achieved in 149 cases (26.6%) and, of these, 96 patients died. Fifty-three patients (9.5%) were discharged home alive, 36 (6.4%) with an intact CNS. The first monitored rhythm showed asystole in 264 cases (47.1%) followed by ventricular fibrillation in 227 cases (40.5%). The main diagnosis of coronary heart disease (CHD) was established clinically in 467 cases (83.4%). In 175 autopsy reports this diagnosis was noted in 152 cases (86.9%).

CONCLUSION

Of patients resuscitated for OHCA of cardiac aetiology, 9.5% survived to leave the acute hospital. CHD was the principle diagnosis in the entire group and this correlated with the same finding in the group of patients who received an autopsy.

An epidemiologic study of acute coronary syndromes in northwestern Greece

Acute coronary syndromes (ACS) represent the most common cause of morbidity and mortality in the Western world. Relative epidemiologic data for Greece, a Mediterranean country, are sparse. The aim of the study was to determine the incidence and the clinical presentations of ACS. Over a 1-year period we conducted a prospective, population-based survey of ACS cases in an isolated area of northwestern (NW) Greece with 170,000 inhabitants. Every patient living in the study area, aged <80 years, without history of coronary artery disease, who presented with symptoms suspicious for ACS and was hospitalized for at least 24 hours was eligible for inclusion in the study. For sudden cardiac deaths, relative information was obtained from the autopsy report or the physician who documented death. Additional information regarding timing and associated conditions was obtained from relatives. The diagnosis and classification of the studied cases was performed according to World Health Organization and European Society of Cardiology criteria. The authors identified 352 patients (265 men, 87 women, mean age 62.5 +/-10 and 68 +/-9.5 years, respectively) with first-appeared ACS (174 non-ST elevation, 105 ST elevation, 73 sudden cardiac deaths). Fifty-six patients with other forms of ischemic heart disease (stable angina, heart failure, and silent ischemia) were not included in the analysis. Moreover, 154 patients with chest pain and normal appearing EGG at rest, normal values for enzymes (CK, troponin), and negative exercise testing, as well as 77 patients with normal findings from coronary angiography studies, were also excluded. The annual incidence for the age group of 30-79 was 39/10,000 inhabitants (60.6 for men and 19 for women). The incidence of ACS increased with age in both sexes and was higher in men even after the age of 70. About one third of the ACS and half of the sudden cardiac deaths occurred in the age group of 70-79. Only 3 patients were successfully resuscitated. ACS are common in this area of NW Greece and the majority of them present in a form amenable to therapeutic manipulations. Twenty percent of patients died suddenly, and a very small percentage of these were successfully resuscitated. Preventive measures and acute management facilities need to be improved, even in a Mediterranean country where the incidence of ischemic heart disease is relatively lower than in northern European countries.

Clinical characteristics of unexplained sudden cardiac death in Korea

In Western countries, sudden cardiac death (SCD) is closely related to coronary artery disease, but in Korea the clinical characteristics of SCD are not well determined. Over a 4-year period (June 1995 to May 1999), 186 cases of SCD, ranging in age from 16 to 75 years, were admitted to the Chonnam National University Hospital. In 82 (44.1%) of these, neither symptoms nor evidence of structural heart disease was found and so their clinical characteristics were investigated. There were 66 (80.5%) men and 16 (19.5%) women (male/female ratio = 4.1:1). The mean age was 50 +/- 14 years: 19 (23.2%) were in their 40s, 21 (25.6%) in their 50s, and 17 (20.7%) in their 60s. The time of circulatory collapse witnessed in 68 cases of SCD showed 2 peaks: between midnight and 03.00h (n=16, 23.5%) and between 09.00h and midday (n=15, 22.1%). Unexplained SCD occurred at home in 48 (64.9%) cases and on the street in 12 (16.2%); it occurred during normal daily routine activity in 23 (39.6%) and during sleep in 15 (25.9%). Thirty-three patients (40.2%) experienced various prodromal symptoms, including chest discomfort (n=13, 15.9%) and dyspnea (n=8, 9.8%). The electrocardiogram taken on arrival recorded asystole in 65 (79.3%) and ventricular fibrillation in 17 (20.7%). Idiopathic ventricular fibrillation was diagnosed in 14 (10 men, 4 women; 45 +/- 11 years) of 21 patients who recovered spontaneous circulation. Five (6.1%) patients were discharged alive, and an implantable cardioverter-defibrillator was implanted in 2. Unexplained SCD is common in Korea and develops predominantly in middle-aged males around midnight or in the late morning usually with no prodromal symptoms (59.8%). Idiopathic ventricular fibrillation is thought to be one of the important causes.