Sex-related differences among patients with reflex neurally mediated syncope

Few studies have evaluated the effect of sex in patients with reflex neurally mediated syncope. The aim of our study was to describe the sex-related differences in clinical characteristics and responses to HUTT among a large population with syncope. 1845 consecutive patients who underwent HUTT for suspected or established reflex syncope were evaluated. The study population was dichotomized according to sex. The clinical characteristics, the HUTT positivity rate and responses were compared between the groups. The trends of blood pressure (BP) and heart rate (HR) and the HUTT positivity rate were analyzed across different age groups according to sex. 1845 patients (45 ± 20 years) were included; 938 were females. Females showed lower values of systolic BP with higher values of HR compared to males up to 49 years. The HUTT positivity rate was significantly lower in females compared to males (61.1% vs 66%; p = 0.03). After adjusting for age decades, females had a higher positivity rate than males until the age of 29 years. Females showed an overall significantly lower rate of cardioinhibitory response compared with males (22.2% vs 29.3%; p = 0.0005). Female patients with suspected reflex neurally mediated syncope showed a different hemodynamic profile characterized by lower BP values and higher HR values than males until the age of 49 years. The overall HUTT positivity rate was lower in females than in males; however, females had a higher positivity rate until the age of 29 years. The prevalence of cardioinhibitory response was lower in females.