Howie JO; Centre for Heart Rhythm Disorders, University of
Adelaide, Adelaide, Australia.
Dziano JK; Ariyaratnam JP; Abbas M; Kenny GT; Evans S;
Middeldorp ME; Emami M; Sanders P; Elliott AD

Heart Rhythm. 22(12):e1137-e1145, 2025 Dec.

BACKGROUND: Heart failure with preserved ejection fraction is common in
atrial fibrillation (AF), driven by an underlying left atrial (LA)
cardiomyopathy. We hypothesize that advancing age is a key risk factor for
the development of LA cardiomyopathy and heart failure with preserved
ejection fraction in patients with AF.

OBJECTIVE: This study aimed to determine the impact of age on invasive
and noninvasive measures of LA structure and function.

METHODS: Consecutive patients with symptomatic AF with preserved left
ventricular (LV) function undergoing catheter ablation were enrolled.
During ablation, invasive hemodynamic assessment was performed to quantify
LA pressure and stiffness. Noninvasive assessment included LA reservoir
strain and indexed volumes, LV global longitudinal strain, LV
end-diastolic volume, and natriuretic peptides. Functional capacity was
determined using cardiopulmonary exercise testing, and disease-specific
patient-reported symptoms were assessed. Results were adjusted for common
risk factors.

RESULTS: Of 125 patients, advancing age was associated with increased LA
pressure (beta = 0.08, P = .05) and stiffness (beta = 0.10, P = .002).
Patients older than 65 years had greater LA stiffness (P < .001), but no
difference in LA pressure (P = .11). Noninvasive measures revealed reduced
LA reservoir strain (beta = -0.37, P < .001), increased LA minimum (beta =
0.24, P < .001) and maximum volumes (beta = 0.24, P = .007), reduced LV
end-diastolic volume (beta = -0.63, P = .005), and increased natriuretic
peptides (beta = 12.8, P = .01) with age. Age was associated with reduced
peak oxygen consumption (beta = -0.15, P = .02), but not AF (beta = -0.01,
P = .66) or heart failure symptoms (beta = -0.13, P = .49).

CONCLUSION: In patients with symptomatic AF, aging is associated with LA
hemodynamic, structural, and functional impairments, suggestive of more
advanced LA disease. These age-related changes were confirmed with
exercise intolerance but not patient-reported symptoms.