Advanced Interatrial Block Linked with AFib in Older Patients: BAYES Registry

A new analysis of the BAYES registry suggests that advanced interatrial block (IAB) is associated with the development of atrial fibrillation (AFib) and stroke in older patients with structural heart disease.

“Advanced interatrial block is an unrecognized surrogate of atrial dysfunction and a trigger of atrial dysrhythmias, mainly AFib,” the authors wrote in their abstract. “Our aim was to prospectively assess whether advanced IAB in sinus rhythm is associated with AFib and stroke in elderly outpatients with structural heart disease, a group not previously studied.”

The BAYES registry was a prospective, observational registry consisting of outpatients aged ≥70 years with structural heart disease and no previous AFib diagnosis. The study researchers divided the patients into groups with normal P-wave duration (<120 ms; n=223), partial IAB (P-wave duration ≥120 ms, positive in the inferior leads; n=196), and advanced IAB [P-wave duration ≥120 ms, biphasic (+/-) morphology in the inferior leads; n=137]. Following a median follow-up of 694 days, 93 patients (16.7%) developed AFib, 30 developed stroke, and 34 patients died.

The results indicated that advanced IAB was associated independently with AFib (HR=2.9; 95% CI, 1.7 to 5.1; P<0.001), with stroke (HR=3.8; 95% CI, 1.4 10.7; P=0.10) , and with AFib/stroke (HR=2.6; 95% CI, 1.5 to 4.4; P=0.001). The authors also reported that P-wave duration (in ms) was interdependently linked with AFib (Hr=1.05; 95% CI, 1.03 to 1.07; P<0.001), AFib/stroke (HR=1.04; 95% CI, 1.02 to 1.06, P<0.001), and mortality (HR=1.04; 95% CI, 1.00 to 1.08; P=0.021).

“The presence of advanced IAB in sinus rhythm is independently associated with AFib and stroke in an elderly population with structural heart disease and no previous diagnosis of AFib,” the authors wrote. “P-wave duration was also associated with all-cause mortality.”

The study was published in EP Europace.