Background
Left atrial (LA) geometry has been associated with the development of atrial fibrillation (AF). However, the comparative predictive value of different LA geometric parameters has not been investigated in a large contemporary cohort with cardiovascular disease and long-term follow-up. The aim of this study was to assess the predictive value of LA morphological parameters for incident AF across the HF spectrum and to evaluate the predictive value compared to established AF risk prediction scores, such as the Cohorts for Heart and Aging Research in Genomic Epidemiology for Atrial Fibrillation Score (CHARGE-AF-score).
Methods
Individuals from the prospective MyoVasc study (N=3,289; NCT04064450) were investigated in a highly standardized setting. Echocardiography was performed according to standard operating procedures based on guideline recommendations. LA morphological parameters were assessed in apical two- and four-chamber view using an iE33 Philips Ultrasound machine in individuals with sinus rhythm and without history of atrial fibrillation. Incidental AF was documented during structured follow-up visits by resting ECG, Holter-ECG, medical history, and adjudicated hospital records. Multiple Cox regression models were used to assess the predictive value of LA morphological parameters for incident AF after adjustment for age, sex, and cardiovascular risk factors.
Results
LA morphological measures were available in 1,908 individuals (median age 64 years (interquartile range [IQR] 55 – 72 years), 38.8% women). During a follow-up of 7 years, incidental AF was observed in 170 participants. LA area (Hazard Ratio per standard deviation [HR] 1.144, 95% Confidence Interval [CI] 1.080-1.210, p=0.0000037), LA circumference (HR: 1.382, 95%CI: 1.212-1.576, p=0.0000013), LA volume (HR: 1.030, 95%CI: 1.016-1.043, p=0.0000085), LA apical-basal diameter (HR: 2.250, 95%CI: 1.611-3.143, p=0.0000020) and LA septal-lateral diameter (HR: 2.491, 95%CI: 1.513-4.102, p=0.00033) were predictors for incidental AF after adjusting for age, sex and cardiovascular risk factors. LA area (HR: 1.063, 95%CI: 1.001-1.129, p=0.046), circumference (HR: 1.173, 95%CI: 1.024-1.345, p=0.022) and apical-basal diameter (HR: 1.520, 95%CI: 1.079-2.140, p=0.017) remained independently associated with new onset AF after additional adjustment for the clinical profile and NT-proBNP. All associations were consistent across HF phenotypes. Among all LA measures, the LA apical-basal diameter provided the strongest predictive role and remained independently associated with incident AF after additional adjustment for the CHARGE-AF score for incident AF (HR: 1.50, 95%CI: 1.06-2.12, p=0.021).
Conclusions
LA geometry predicted incidental AF independent of the clinical profile and NT-proBNP across the HF spectrum. Among all LA parameters, LA apical-basal diameter showed the highest predictive value and improved AF risk prediction beyond the established CHARGE-AF score.
