Impact of anaemia on OAC prescription and adverse outcomes in patients with AF and chronic HF: an analysis form a real-world observational prospective study

Abstract Background Anaemia is a frequent condition that poses significant challenges in patients with atrial fibrillation (AF) and heart failure (HF). The complex interplay between AF, chronic HF, and anaemia in the real-world setting remains poorly studied and warrants further research. Purpose This study aimed to assess the impact of anaemia on oral anticoagulant (OAC) prescription and long-term clinical outcomes in patients with AF and chronic HF. Methods We used data from a prospective observational study of patients with AF. Patients were stratified according to the presence of anaemia (defined as hemoglobin Hb 12 g/dl for women and 13 g/dl for men) and the diagnosis of HF. The composite net clinical outcome (NCO) of all-cause mortality, acute coronary syndrome, thromboembolic events (TE) and hemorrhagic events was considered the primary endpoint. Results We included a total of 1,110 AF patients (median age 75 years, females 38%), divided into four groups: (1) No Anaemia/No HF = 606 (54.6%); (2) Yes Anaemia/No HF = 172 (15.5%); (3) No Anaemia/Yes HF = 220 (19.8%) and (4) Yes Anaemia/Yes HF = 112 (10.1%). At baseline, AF patients with anaemia in both groups (with and without HF) were significantly older and had a higher burden of comorbidities, including diabetes, dyslipidemia, previous TE, previous bleeding, chronic kidney disease (CKD), and cancer (all p values 0.005). Overall, the use of OAC was high (91.8%), but at the adjusted logistic regression analysis, AF patients with concomitant HF and anaemia had the lowest odds of being prescribed OAC (OR 0.11, 95% CI 0.04-0.26). During a median follow-up of 702 days, 398 (37.6%) events of the primary NCO occurred. Kaplan-Meier curves for NCO are shown in Figure 1. At the multivariable Cox regression analysis, adjusted for CHA2DS2-VA score, type of AF, CKD and use of OAC, both groups of AF patients with anaemia (both with and without HF), showed a higher risk for NCO (HR 1.44, 95% CI 1.08-1.91 for Group 2 and HR 2.32, 95% CI 1.63-3.31 for Group 4). The spline curve (Figure 2 - Panel A) highlights a non-linear relationship between Hb and NCO. The risk of NCO progressively increased for Hb values below 13 g/dL, with a plateau observed for values above this threshold (p0.001, non-linear=0.0255). Figure 2 - Panel B illustrates the interaction between Hb, modeled as a continuous variable, and HF status suggesting an increased risk of NCO in patients with HF with no significant interaction (p for interaction = 0.0733) Conclusions Anaemia is a highly prevalent condition in patients with AF and HF, complicating their clinical management and being significantly associated with a lower rate of OAC prescription. AF patients with anaemia had an increased risk of adverse events which appears to be more pronounced in patients with HF. Our findings underline the complexity of AF patients, who often present with multiple comorbidities requiring a holistic and integrated clinical management approach.Figure 1 Figure 2