Sex differences in Cardiorenal Syndrome: Insights from CARDIOREN Registry.

Purpose of the work: Although sex-specific differences in heart failure (HF) or kidney disease (KD) have been analyzed separately, the predominant cardiorenal phenotype by sex has not been described. This study aims to explore the sex-related differences in cardiorenal syndrome (CRS) in a contemporary cohort of outpatients with HF.

Findings: An analysis of the Cardiorenal Spanish registry (CARDIOREN) was performed. CARDIOREN Registry is a prospective multicenter observational registry including 1107 chronic ambulatory HF patients (37% females) from 13 Spanish HF clinics. Estimated Glomerular Filtration Rate (eGFR) < 60 ml/min/1.73 m² was present in 59.1% of the overall HF population, being this prevalence higher in the female population (63.2% vs. 56.6%, p = 0.032, median age: 81 years old, IQR:74-86). Among those with kidney dysfunction, women displayed higher odds of showing HF with preserved ejection fraction (HFpEF) (odds ratio [OR] = 4.07; confidence interval [CI] 95%: 2.65-6.25, p < 0.001), prior valvular heart disease (OR = 1.76; CI 95%:1.13-2.75, p = 0.014), anemia (OR: 2.02; CI 95%:1.30-3.14, p = 0.002), more advanced kidney disease (OR for CKD stage 3: 1.81; CI 95%:1.04-3.13, p = 0.034; OR for CKD stage 4: 2.49, CI 95%:1.31-4.70, p = 0.004) and clinical features of congestion (OR:1.51; CI 95%: 1.02-2.25, p = 0.039). On the contrary, males with cardiorenal disease showed higher odds of presenting HF with reduced ejection fraction (HFrEF) (OR:3.13; CI 95%: 1.90-5.16, p < 0.005), ischemic cardiomyopathy (OR:2.17; CI 95%: 1.31-3.61, p = 0.003), hypertension (OR = 2.11; CI 95%:1.18-3.78, p = 0.009), atrial fibrillation (OR:1.71; CI 95%: 1.06-2.75, p = 0.025), and hyperkalemia (OR:2.43, CI 95%: 1.31-4.50, p = 0.005). In this contemporary registry of chronic ambulatory HF patients, we observed sex-related differences in patients with combined heart and kidney disease. The emerging cardiorenal phenotype characterized by advanced CKD, congestion, and HFpEF was predominantly observed in women, whereas HFrEF, ischemic etiology, hypertension, hyperkalemia, and atrial fibrillation were more frequently observed in men.