148 Sex differences in the cardiac output response to stress (cors) test in suspected and confirmed heart failure patients

IntroductionCurrently, there are limited diagnostic tools available to assist general practitioners in the diagnosis of heart failure (HF) in primary care. Moreover, the existing HF guidelines are currently based on data that reflects male response to therapies and in spite of the data suggesting sex-specific differences in the ejection fraction (EF) and left ventricular (LV) sizes criteria identifying HF reserved ejection fraction (HFrEF) and HF preserved ejection fraction (HFpEF) are sex-neutral. We have therefore developed a novel cardiac output response to stress (CORS) test, which has confirmed reproducibility, a clinical demand and feasibility in suspected HF patients. However, sex differences in the CORS test are yet to be investigated. Our aim was to evaluate the sex differences in cardiac function via the CORS test in (1) Males and females with suspected and confirmed HF, and (2) Males and females with HFrEF and HFpEF.MethodsThis single centre, prospective, observational study recruited suspected HF patients (57 male, 48 females; mean age 72±10 years) from specialised HF diagnostic clinics in secondary care. Diagnosis of HF was confirmed or refuted by a consultant cardiologist. Non-invasive bioreactance technology (Starling, Baxter, Healthcare Inc., USA) was used to assess cardiac function with the CORS test being completed in three phases (rest-supine, challenge-standing, and stress-step exercise phases).ResultsIn patients with suspected HF, both males and females (50.5±18.5 vs. 50.6±14.4 mL/beat/m2, p=0.78) had similar stroke volume index (SVI) in the rest-supine phase. However, suspected HF males had a higher but non-significant SVI compared to females during the challenge-standing (42.7±12.8 vs. 39.8±9.4 mL/beat/m2, p=0.46) and stress-step phases (59.0±15.7 vs. 56.5±17.3 mL/beat/m2, p=0.56). For confirmed HF patients, females had a higher SVI (53.1±14.7 vs. 38.5±12.3 mL/beat/m2, p