Inter-atrial block as a predictor of adverse outcomes in patients with HFpEF

Aims: Inter-atrial block (IAB), a marker of electrical atrial dysfunction, is associated with an increased risk of atrial fibrillation (AF) and adverse events in various populations. The prognostic impact of IAB in heart failure (HF) with preserved ejection fraction (HFpEF) remains unknown. The aim of this study is to determine the prevalence of IAB and the association of IAB and AF with adverse events in HFpEF across different healthcare settings. Methods and results: To identify electrical atrial dysfunction, baseline ECG's and medical history were analysed in HFpEF patients in an ambulatory setting and after recent HF hospitalisation. Patients were categorised into (i) HFpEF, (ii) HFpEF, or (iii) HFpEF. Adverse events included HF hospitalisation, cardiac/sudden death and a composite of both. The ambulatory cohort included 372 patients [mean age 75 ± 7 years, 252 (68%) females]. The recently hospitalised cohort included 132 patients [mean age 81 ± 10 years, 80 (61%) females]. Ambulatory patients included 17 (4%) HFpEF, 114 (31%) HFpEF and 241 (65%) HFpEF, while recently hospitalised patients included 31 (23%), 73 (55%) and 28 (21%), respectively. After 33 months of follow-up of ambulatory patients, composite endpoints occurred in 0 (0%) HFpEF, 12 (11%) HFpEF [HR 4.1 (95% CI 0.5-522.6)] and 59 (24%) HFpEF patients [HR 10.1 (95% CI 1.5-1270.4), P < 0.001]. Recently hospitalised patients showed a similar trend, with composite endpoints in 10 (32%) HFpEF, 31 (42%) HFpEF (HR 1.5 [95% CI 0.7-3.1]) and 22 (79%) HFpEF (HR 3.8 [95% CI 1.8-8.1], P < 0.001). Conclusions: Progressive stages of electrical atrial dysfunction appeared to be prognostic markers of adverse outcomes in ambulatory and recently hospitalised patients with HFpEF. Ambulatory patients with HFpEF and no early stages of electrical atrial dysfunction showed to be at very low risk for adverse outcomes. Whether such patients benefit less strict management remains to be investigated.