Sex and the CT: an evolving story of the heart

Gender-specific research for emergency diagnosis and management of ischemic heart disease: proceedings from the 2014 Academic Emergency Medicine Consensus Conference Cardiovascular Research Workgroup

Coronary artery disease (CAD) is the most common cause of death for both men and women. However, over the years, emergency physicians, cardiologists, and other health care practitioners have observed varying outcomes in men and women with symptomatic CAD. Women in general are 10 to 15 years older than men when they develop CAD, but suffer worse postinfarction outcomes compared to age-matched men. This article was developed by the cardiovascular workgroup at the 2014 Academic Emergency Medicine (AEM) consensus conference to identify sex- and gender-specific gaps in the key themes and research questions related to emergency cardiac ischemia care. The workgroup had diverse stakeholder representation from emergency medicine, cardiology, critical care, nursing, emergency medical services, patients, and major policy-makers in government, academia, and patient care. We implemented the nominal group technique to identify and prioritize themes and research questions using electronic mail, monthly conference calls, in-person meetings, and Web-based surveys between June 2013 and May 2014. Through three rounds of nomination and refinement, followed by an in-person meeting on May 13, 2014, we achieved consensus on five priority themes and 30 research questions. The overarching themes were as follows: 1) the full spectrum of sex-specific risk as well as presentation of cardiac ischemia may not be captured by our standard definition of CAD and needs to incorporate other forms of ischemic heart disease (IHD); 2) diagnosis is further challenged by sex/gender differences in presentation and variable sensitivity of cardiac biomarkers, imaging, and risk scores; 3) sex-specific pathophysiology of cardiac ischemia extends beyond conventional obstructive CAD to include other causes such as microvascular dysfunction, takotsubo, and coronary artery dissection, better recognized as IHD; 4) treatment and prognosis are influenced by sex-specific variations in biology, as well as patient-provider communication; and 5) the changing definitions of pathophysiology call for looking beyond conventionally defined cardiovascular outcomes to patient-centered outcomes. These emergency care priorities should guide future clinical and basic science research and extramural funding in an area that greatly influences patient outcomes.

Differential survival for men and women from out-of-hospital cardiac arrest varies by age: results from the OPALS study

BACKGROUND

The effect of sex on survival in out-of-hospital cardiac arrest (OHCA) is controversial. Some studies report more favorable outcomes in women, while others suggest the opposite, citing disparities in care. Whether sex predicts differential age-specific survival is still uncertain.

OBJECTIVES

The objective was to study the sex-associated variation in survival to hospital discharge in OHCA patients as well as the relationship between age and sex for predicting survival.

METHODS

The Ontario Prehospital Advanced Life Support (OPALS) registry, collected in a large study of rapid defibrillation and advanced life support programs, is Utstein-compliant and has data on OHCA patients (1994 to 2002) from 20 communities in Ontario, Canada. All adult OHCAs not witnessed by emergency medical services (EMS) and treated during one of the three main OPALS phases were included. Clinically significant variables were chosen a priori (age, sex, witnessed arrest, initial cardiopulmonary resuscitation [CPR], shockable rhythm, EMS response interval, and OPALS study phase) and entered into a multivariable logistic regression model with survival to hospital discharge as the outcome, with sex and age as the primary risk factors. Fractional polynomials were used to explore the relationship between age and survival by sex.

RESULTS

A total of 11,479 (out of 20,695) OPALS cases met inclusion criteria and 10,862 (94.6%) had complete data for regression analysis. As a group, women were older than men (median age = 74 years vs. 69 years, p < 0.01), had fewer witnessed arrests (43% vs. 49%; p < 0.01), had fewer initial ventricular fibrillation/ventricular tachycardia rhythms (24% vs. 42%; p < 0.01), had a lower rate of bystander CPR (12% vs. 17%; p < 0.01), and had lower survival (1.7% vs. 3.2%; p < 0.01). Survival to hospital admission and return of spontaneous circulation did not differ between women and men (p > 0.05). The relationship between age, sex, and survival to hospital discharge could not be analyzed in a single regression model, as age did not have a linear relationship with survival for men, but did for women. Thus, age was kept as a continuous variable for women but was transformed for men using fractional polynomials [ln(age) + age(3) ]. In sex-stratified regression models, the adjusted probability of survival for women decreased as age increased (adjusted odds ratio = 0.88, 95% confidence interval = 0.81 to 0.96, per 5-year increase in age) while for men, the probability of survival initially increased with age until age 65 years and then decreased with increasing age. Women had a higher probability of survival until age 47 years, after which men maintained a higher probability of survival.

CONCLUSIONS

Overall OHCA survival for women was lower than for men in the OPALS study. Factors related to the sex differences in survival (rates of bystander CPR and shockable rhythms) may be modifiable. The probability of survival differed across age for men and women in a nonlinear fashion. This differential influence of age on survival for men and women should be considered in future studies evaluating survival by sex in OHCA population.