Effect of Cardiorespiratory Fitness on Risk of Sudden Cardiac Death in Overweight/Obese Men Aged 42 to 60 Years

Physical activity and the risk of sudden cardiac death: a systematic review and meta-analysis of prospective studies

Background

Physical activity has been associated with a significant reduction in risk of sudden cardiac death in epidemiological studies, however, the strength of the association needs clarification. We conducted a systematic review and meta-analysis to summarize the available data from population-based prospective studies.

Methods

PubMed and Embase databases were searched for studies of physical activity and sudden cardiac death from inception to March 26th 2019. Prospective studies reporting adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) of sudden cardiac death associated with physical activity were included. A random effects model was used to estimate summary RRs (95% CIs).

Results

Thirteen prospective studies were included in the systematic review. Eight prospective studies with 1193 sudden cardiac deaths among 136,298 participants were included in the meta-analysis of physical activity and sudden cardiac death and the summary RR for highest vs. lowest level of physical activity was 0.52 (95% CI: 0.45–0.60, I² = 0%, p_{heterogeneity} = 0.72). The association was similar in men and women and among American and European studies. In the dose-response analysis the summary RR was 0.68 (95% CI: 0.55–0.86, I² = 44%, n = 3) per 20 MET-hours/week. Although the test for nonlinearity was not significant, p_nonlinearity = 0.18, there was no further reduction in risk beyond 20–25 MET-hours/week. The summary RR was 0.58 (95% CI: 0.41–0.81, I² = 0%, p_{heterogeneity} = 0.65, n = 2) for the highest vs. the lowest level of cardiorespiratory fitness.

Conclusion

This meta-analysis suggest that a high compared to a low level of physical activity may reduce the risk of sudden cardiac death in the general population. Further studies are needed to clarify the dose-response relationship between specific subtypes and intensities of physical activity in relation to sudden cardiac death.

Factors associated with return of spontaneous circulation after out-of-hospital cardiac arrest in Poland: a one-year retrospective study

Background

Out-of-hospital cardiac arrest (OHCA) is a common reason for calls for intervention by emergency medical teams (EMTs) in Poland. Regardless of the mechanism, OHCA is a state in which the chance of survival is dependent on rapid action from bystanders and responding health professionals in emergency medical services (EMS). We aimed to identify factors associated with return of spontaneous circulation (ROSC).

Methods

The medical records of 2137 EMS responses to OHCA in the city of Wroclaw, Poland between July 2017 and June 2018 were analyzed.

Results

The OHCA incidence rate for the year studied was 102 cases per 100,000 inhabitants. EMS were called to 2317 OHCA events of which 1167 (50.4%) did not have resuscitation attempted on EMS arrival. The difference between the number of successful and failed cardiopulmonary resuscitations (CPRs) was statistically significant (p < 0.001). Of 1150 patients in whom resuscitation was attempted, ROSC was achieved in 250 (27.8%). Rate of ROSC was significantly higher when CPR was initiated by bystanders (p < 0.001). Patients presenting with asystole or pulseless electrical activity (PEA) had a higher risk of CPR failure (86%) than those with ventricular fibrillation/ventricular tachycardia (VF/VT). Patients with VF/VT had a higher chance of ROSC (OR 2.68, 1.86–3.85) than those with asystole (p < 0.001). The chance of ROSC was 1.78 times higher when the event occurred in a public place (p < 0.001).

Conclusions

The factors associated with ROSC were occurrence in a public place, CPR initiation by witnesses, and presence of a shockable rhythm. Gender, age, and the type of EMT did not influence ROSC. Low bystander CPR rates reinforce the need for further efforts to train the public in CPR.

The role of cardiorespiratory fitness on the risk of sudden cardiac death at the population level: A systematic review and meta-analysis of the available evidence

Cardiorespiratory fitness (CRF) has been widely studied as a powerful and independent predictor of all-cause and disease-specific mortality. Sudden cardiac death (SCD) is recognized as a significant cause of mortality among the general population, including the general population without previous symptoms of any coronary heart disease (CHD). Consequently, SCD is an important public health problem, which constitutes a clinical challenge. Thus, prevention of SCD by detecting early risk factors could be a useful tool, contributing to the American Heart Association's goal of decreasing the incidence of SCD at the population level. The identification of these risk factors for CVD would facilitate the large-scale screening of those participants at higher risk of SCD. This systematic review collects information about the role of CRF on the risk of SCD at the available evidence, and analyzes the long-term influence of CRF as a risk factor and independent predictor of SCD.