Associations of Integrated Left Ventricular Myocardial Strain Metrics and Incident Atrial Fibrillation

Data on associations between left ventricular (LV) strain metrics and incident atrial fibrillation (AF) remains limited, particularly regarding integrated effects of multi-directional strains. This study aimed to investigate the associations of LV global longitudinal strain (GLS), radial strain (GRS) and circumferential strain (GCS) measured by cardiac magnetic resonance with incident AF.

This prospective cohort study included 36,876 AF-free UK Biobank participants (52.5% female; median age 64.0 years). Incident AF was ascertained via ICD-10 codes. Impaired strain metrics were defined as the absolute value of lower 5%. Cox proportional hazards regression (adjusting for demographic characteristics, lifestyle factors, cardiac imaging indices, and clinical features) was performed to assess the associations of LV strain metrics and incident AF.

Over 6.88 ± 1.63 years, 862 incident AF events occurred. GLS (HR 1.22, 95%CI 1.13-1.31), GRS (0.88, 0.80-0.96), and GCS (1.27, 1.15-1.40) were independently associated with AF (all P < 0.01), with J-shaped (GLS/GCS) and reverse J-shaped (GRS) nonlinearity. AF risk increased with the number of impaired strain metrics (P _trend < 0.001), more pronounced in ≥ 60 years (HR 1.45 for single, 1.87 for two, 3.36 for three impairments), while <60 years only showed significance with all three impaired (HR 4.09, 95%CI 1.35-12.36).

LV GLS, GRS, and GCS are linked to incident AF. Combined strain impairment improves AF risk stratification, especially in adults ≥ 60 years.