It is unclear whether dissemination of automated external defibrillators (AEDs) in public places can improve the rate of survival among patients who have had an out-of-hospital cardiac arrest.

Rationale:: Despite a recent decline of in-hospital mortality attributable to acute myocardial infarction (AMI), the incidence of ischemic heart failure (HF) in post-AMI patients is increasing. Although various microRNAs have been proposed as diagnostic indicators for AMI, no microRNAs have been established as predictors of ischemic HF that develops after AMI. Objective:: We attempted to identify circulating microRNAs that can serve as reliable predictors of ischemic HF in post-AMI patients. Methods and Results:: Using sera collected a median of 18 days after AMI onset, we screened microRNAs in 21 patients who experienced development of HF within 1 year after AMI and in 65 matched controls without subsequent cardiovascular events after discharge. Among the 377 examined microRNAs, the serum level of only miR-192 was significantly upregulated in AMI patients with development of ischemic HF. Because miR-192 is reported to be p53-responsive, the serum levels of 2 other p53-responsive microRNAs, miR-194 and miR-34a, also were investigated. Interestingly, both microRNAs were coordinately increased with miR-192, particularly in exosomes, suggesting that these microRNAs function as circulating regulators of HF development via the p53 pathway. Furthermore, miR-194 and miR-34a expression levels were significantly correlated with left ventricular end-diastolic dimension 1 year after AMI. Conclusions:: In the sera of post-AMI patients who experienced development of de-novo HF within 1 year of AMI onset, the levels of 3 p53-responsive microRNAs had been elevated by the early convalescent stage of AMI. Further investigations are warranted to confirm the usefulness of these circulating microRNAs for predicting the risk of development of ischemic HF after AMI.

Background—: Little is known about the nationwide trend in the survival of out-of-hospital cardiac arrest (OHCA) in Japan and the differences in incidence and survival by age group and origin of arrest. Methods and Results—: A nationwide, prospective, population-based observation covering the whole population of Japan and involving consecutive OHCA patients with resuscitation attempts was conducted from January 2005 to December 2009. The main outcome measure was 1-month survival with favorable neurological outcome. The nationwide trends in OHCA incidence and outcome by age and origin of arrest were assessed. Multiple logistic regression analysis for bystander-witnessed OHCA was used to adjust for factors that were potentially associated with favorable neurological outcome. During 5 years, 547 153 overall OHCAs and 169 360 bystander-witnessed OHCAs were enrolled. The annual incidence significantly increased among overall OHCAs and bystander-witnessed OHCAs. Neurologically favorable survival significantly increased from 1.6% (1676/102 737) in 2005 to 2.8% (3280/115 250) in 2009 ( P <0.001), from 2.1% (638/30 556) to 4.3% (1558/36 361) ( P <0.001), and from 9.8% (437/4461) to 20.6% (1215/5906) ( P <0.001) among overall OHCA, bystander-witnessed OHCA, and bystander-witnessed ventricular fibrillation OHCA, respectively. Public-access automated external defibrillator use, either bystander-initiated chest compression–only cardiopulmonary resuscitation or conventional cardiopulmonary resuscitation, and earlier emergency medical services response time were associated with a better neurological outcome. Favorable neurological outcome among adult OHCA subjects significantly improved, but the outcome among younger children and very elderly subjects did not improve and was poor irrespective of origin of OHCA. Conclusions—: Nationwide improvements of favorable neurological outcome from OHCA were observed in Japan and differed by age group and origin of OHCA.

Early defibrillation plays a key role in improving survival in patients with out-of-hospital cardiac arrests due to ventricular fibrillation (ventricular-fibrillation cardiac arrests), and the use of publicly accessible automated external defibrillators (AEDs) can help to reduce the time to defibrillation for such patients. However, the effect of dissemination of public-access AEDs for ventricular-fibrillation cardiac arrest at the population level has not been extensively investigated.

Background—: The best cardiopulmonary resuscitation (CPR) technique for survival after out-of-hospital cardiac arrests (OHCAs) has been intensively discussed in the recent few years. However, most analyses focused on comparison at the individual level. How well the dissemination of bystander-initiated chest compression–only CPR (CCCPR) increases survival after OHCAs at the population level remains unclear. We therefore evaluated the impact of nationwide dissemination of bystander-initiated CCCPR on survival after OHCA. Methods and Results—: A nationwide, prospective, population-based, observational study covering the whole population of Japan and involving consecutive OHCA patients with resuscitation attempts was conducted from January 2005 through December 2012. The main outcome measure was 1-month survival with favorable neurological outcome. The incidence of survival with favorable neurological outcome attributed to types of bystander CPR (CCCPR and conventional CPR with rescue breathing) was estimated. Among 816 385 people experiencing OHCAs before emergency medical services arrival, 249 970 (30.6%) received CCCPR, 100 469 (12.3%) received conventional CPR, and 465 946 (57.1%) received no CPR. The proportion of OHCA patients receiving CCCPR or any CPR (either CCCPR or conventional CPR) by bystanders increased from 17.4% to 39.3% ( P for trend <0.001) and from 34.6% to 47.3% ( P for trend <0.001), respectively. The incidence of survival with favorable neurological outcome attributed to CCCPR per 10 million population significantly increased from 0.6 to 28.3 ( P for trend=0.010), and that by any bystander-initiated CPR significantly increased from 9.0 to 43.6 ( P for trend=0.003). Conclusion—: Nationwide dissemination of CCCPR for lay-rescuers was associated with the increase in the incidence of survival with favorable neurological outcome after OHCAs in Japan.