{'fraction_non_alphanumeric': 0.07318348144276006, 'fraction_numerical': 0.03293256664924203, 'mean_word_length': 5.056962025316456, 'pattern_counts': {'":': 0, '<': 10, '<?xml version=': 0, '>': 3, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Quantification of left atrial function and geometry by cardiac magnetic resonance imaging in patients with severe aortic stenosis


 Purpose: The study sought to evaluate the role of CMR in characterizing LA geometry and function in patients with severe aortic stenosis (AS). Left atrial (LA) enlargement and dysfunction are closely related to AS progression, however, a CMR-based approach has not been yet appraised.Method: We prospectively evaluated 70 patients with severe AS and 70 age and gender-matched healthy volunteers. LA morphology, function and geometry were determined using CMR. A composite outcome (cardiac death, ventricular tachyarrhythmias, and heart failure hospitalization) was evaluated over a median of 31 months. Time-to-event outcomes were analyzed using Kaplan-Meier method.Results: LA volumes (LAV) were significantly increased, and LA sphericity index (LASI) was decreased (all p<.001), while LA phasic functions and strains were also considerably defective in patients with AS (all p<.001). Moreover, LA volumes were closely associated with LA atrial booster function and LA strains (all p<.0001), while LASI mostly related to LA total and active strain (p<.0001). Furthermore, LV mass (LVM), end-diastolic (LVEDV) and end-systolic volumes (LVESV) were significantly associated with all LA strains (p<.0001). In prognosis prediction, LA total (LA-et), passive (LA-ep) and active (LA-ea) strain, along with LASI were independently associated with increased risk of outcome (p<.001). Time-to-event analysis showed significantly higher risk to reach the composite outcome for LA-et>31.1 ml/m2 [HR=5.94; p=.0002)], LA-ep >14.5% [HR=4.04; p<.0009)], LA-ea<21.2% [HR=2.25; p<.04], LASI>0.5 [HR=2.24; p<.04)].Conclusion: Patients with severe AS and impaired LA geometry and function at CMR have increased risk of outcomes. LAVmin, LASI, LAPF and LA-ep were independent predictors for outcome.