Predicting Atrial Fibrillation Risk in Hypertrophic Cardiomyopathy Patients: Left Atrial Phasic Function and Strain Mechanics.

BACKGROUND: To evaluate whether the left atrium (LA) phasic function and myocardial deformation by cardiovascular magnetic resonance (CMR) in hypertrophic cardiomyopathy (HCM) patients is a predictor of atrial fibrillation (AF) development. METHODS: The baseline CMRs of HCM patients who later developed AF (n = 140; mean age = 61 ± 12 years; male = 86) were compared with those of HCM patients who did not develop AF (n = 70; mean ag e= 58 ± 11 years; male patients = 48). This case-control study was conducted at our quaternary referral centre between January 2001 and June 2021. The univariate and multivariable Cox proportional hazards model was used to assess the correlation between clinical and imaging parameters vs the likelihood of developing AF. RESULTS: Compared to the non-AF cohort, HCM patients with AF had larger baseline LA volumes and lower LA strain and LA strain rates. Maximum left ventricular (LV) wall thickness, absolute and indexed LV mass, and indexed LV end-diastolic volume were larger in patients with AF vs the non-AF group. LV ejection fraction assessed by CMR along with late gadolinium enhancement prevalence and pattern was similar between patients with vs without AF.LA booster strain (5.8 ± 3.4 in the AF group vs 11.4 ± 4.2 in the non-AF group, P < 0.00001) and total LA ejection fraction (32.9 ± 12.8 in the AF group vs 44.0 ± 9.3 in the non-AF group, P < 0.00001) were significantly worse at baseline in the AF group. No significant relationship was present between markers of LV disease burden and AF. CONCLUSIONS: LA booster strain and total LA ejection fraction at baseline CMR correlated with AF development in HCM patients.