Sex Differences in Out-of-Hospital Cardiac Arrest: Commotio Cordis and More

By Jeremy Towns, MD, on behalf of the SAEM Sex and Gender in Emergency Medicine Interest Group

The recently televised medical tragedy that struck NFL Buffalo Bills safety Damar Hamlin has put cardiac arrest at the forefront of current national health care conversations — and that conversation should include the sex differences seen in out-of-hospital cardiac arrest and cardiac arrest outcomes.

Commotio cordis specifically has been documented overwhelmingly in adolescent boys and young men. The predominance of males may be partially explained by more significant numbers of males involved in sports where commotio cordis is a risk; however, it has also been speculated that there may be sex-related genetic susceptibility related to cardiac ion channel differences and/or sex hormone influence

Significant sex differences have been noted in other types of out-of-hospital cardiac arrest as well. A study published in Circulation, which included only patients successfully resuscitated, found that women were more likely to present in nonshockable rhythms, pulseless electrical activity and asystole, as compared to men. Despite this, women were more likely than men to experience return of spontaneous circulation with resuscitative efforts. Unfortunately, however, women are less likely to receive bystander resuscitative measures, such as CPR. Researchers have theorized that this gender-related discrepancy may be influenced by bystanders shying away from chest compressions because of social stigma or fear associated with touching a woman’s breasts.

With regard to outcomes, even when women are adequately resuscitated, they are less likely to survive to hospital discharge when compared to their male counterparts. This may be due to women being less likely to receive post-arrest guideline appropriate therapies such as coronary angiography and targeted temperature management. Women are also more likely to have a “Do Not Resuscitate” or “Withhold Life Sustaining Therapy” order placed. These sexspecific differences in treatment and outcome may be, in part, due to female cardiac arrest victims typically being older than their male counterparts, which may confer additional comorbidities and fragility.

Certainly, more sex-specific research is needed to better understand the observed differences in all types of out-of-hospital cardiac arrest. A better understanding of the sociocultural, biological, and genetic variables which may be impacting etiology and outcomes could influence prehospital and emergency postarrest care. A better understanding of the sex differences in out-of-hospital cardiac arrest could have profound implications on neurologic survival outcomes for men and women.

ABOUT THE AUTHOR

Dr. Towns is a third-year emergency medicine resident at the University of Alabama at Birmingham.