Sex-specific syncope characteristics in the early diagnosis of cardiac syncope

Background The Lancet women and cardiovascular disease commission requested evaluating sex-specific approaches in the diagnosis and management of acute cardiovascular disease. Purpose We aimed to explore 1) the utility of sex-specific syncope characteristics in the early diagnosis of cardiac syncope 2) sex-related differences in the management and outcomes of patients with a cardiac syncope. Methods Thirty-one syncope characteristics were prospectively assessed in women and men presenting with syncope to the emergency department (ED) in an international multicenter study. The final diagnosis of cardiac syncope was centrally adjudicated by two independent cardiologists. Sex-specific differences in the prevalence of syncope characteristics and their positive likelihood ratio (pLR) for cardiac syncope were the primary diagnostic endpoints. Sex-specific differences in hospital admission, diagnostic procedures performed in patients with a cardiac syncope and adverse events in patients directly discharged from the ED during one-year follow-up were secondary endpoints. Results Among 2661 patients (median age 71 years, 1099 women and 1562 men), 14.6% of women and 18.2% of men (p=0.02) were adjudicated to have a cardiac syncope. Eleven syncope characteristics showed diagnostic utility (statistically significant pLRs) in assessing cardiac syncope in the overall population. However, none of the syncope characteristics demonstrated significant sex interaction. Women adjudicated as having a cardiac syncope were as likely to be hospitalized as men (OR 1.12; 95% CI: 0.61-2.08, p=0.7) and to receive telemetry (40% vs 41%, p=0.9), ergometry (3.1% vs 6.3%, p=0.4), a holter (21% vs 17%, p=0.3), a loop recorder (0.6% vs 3.9%, p=0.06) and an echocardiogram (69% vs 65%, p=0.4). Among the 591 women and 796 men directly discharged from the ED, 18 women (3%) and 36 men (5%) were finally adjudicated as cardiac syncope. Noteworthy, within this cardiac syncope subgroup, 28% of women experienced major adverse cardiac events (MACE) during the 365-day follow-up period, in comparison to 67% men (OR 0.20; 95% CI: 0.06-0.68, p=0.011, Figure). Conclusion Syncope characteristics contributed to the early diagnosis of cardiac syncope, however, none had a significant sex interaction. Women with a cardiac syncope had a similar likelihood of being hospitalized and receiving diagnostic testing. Compard to men, women had a significantly decreased risk of MACE when not hospitalized after a cardiac syncope.