A cohort study revealed that subclinical atrial fibrillation (AF) was common in heart failure (HF) patients with preserved ejection fraction (HFpEF) and mildly reduced ejection fraction (HFmrEF). The study included 367 patients with cardiac monitoring data at baseline and follow-up in a randomized clinical trial of atrial shunt therapy. The median patch monitoring time was 6 and 125 days at baseline and over a 12-month follow-up, respectively. 194 (53%) patients had a history of AF or atrial flutter (AFL), and median baseline AF burden was 0.012%. After multivariable adjustment, baseline AF burden ≥0.012% was significantly associated with HF events (HR: 2.00) regardless of a history of AF or AFL. Adjustment for left atrial reservoir strain attenuated the baseline AF burden-HF event association (HR: 1.71). 141 (38%) patients had patch-detected AF during follow-up without a history of AF or AFL. Atrial shunt therapy did not reduce the total rate of HF events or improve health status, it did not change AF incidence or burden during follow-up either. The findings indicate that subclinical AF is common in patients with HFpEF and HFmrEF and baseline AF burden is associated with HF events. Source: https://www.jacc.org/; https://www.thelancet.com/
