Survival after out-of-hospital cardiac arrest in relation to sex: A nationwide registry-based study

Association of Bystander and First‐Responder Efforts and Outcomes According to Sex: Results From the North Carolina HeartRescue Statewide Quality Improvement Initiative

“…In particular, our results may have implications for how to address sex‐related differences in order to increase survival for both men and women. It has previously been suggested that lower rates of survival in women could be attributable to lower rates of bystander CPR, which our study does not support 2, 12. The limited increase in overall survival in women compared with men despite the significant increase in bystander CPR and the combination of bystander CPR and first‐responder defibrillation may be partly attributable to the substantial proportion of female patients with nonshockable heart rhythm.…”

“…The vast majority of men suffer cardiac arrest because of coronary artery disease and acute myocardial infarction, whereas women are more likely to have other underlying pathophysiology such as cardiomyopathies 9. The mechanism of cardiac arrest in the absence of an acute myocardial infarction is believed to be an electric event caused by ventricular arrhythmia in the setting of a chronically diseased heart, which is more likely to occur among women who are typically older and have more comorbidities 2. This is supported by our finding that even among those with an initial shockable heart rhythm, the increase in survival was more limited for women compared with men (although this difference was not statistically significant).…”

“…Multiple studies highlight differences in care between women and men treated for cardiac arrest, with evidence suggesting that women have poorer outcomes 2, 3, 4, 5, 6, 7…”

“…For example, women with out‐of‐hospital cardiac arrest are more likely to have advanced age, chronic health comorbidities, noncardiac etiology, unwitnessed cardiac arrest, and initial nonshockable heart rhythm, and to live alone, all of which have been associated with worse outcomes 2, 5, 8, 9, 10, 11. While these characteristics are important to understand differences in outcomes, they are unlikely to be modifiable.…”

“…In contrast, sex‐related differences in interventions that may highly impact survival, such as bystander or first‐responder resuscitation efforts, are presumably modifiable. Recent European studies found that female sex was associated with lower rates of bystander cardiopulmonary resuscitation (CPR) and early defibrillation, even among witnessed cardiac arrests 2, 5, 12, 13. It is unclear whether such differences also exist in contemporary US cardiac arrest populations.…”