Modified Haller Index is inversely associated with asymptomatic status in atrial fibrillation patients undergoing electrical cardioversion: a preliminary observation.

Background: No previous study evaluated the possible influence of chest wall conformation on symptoms perception in atrial fibrillation (AF) patients candidates for electrical cardioversion (ECV). We aimed at evaluating the anthropometric and clinical characteristics of patients with persistent AF undergoing ECV, categorized according to the presence or absence of symptoms.

Methods: This study retrospectively analyzed a series of persistent AF patients scheduled for early ECV who underwent pre-procedural clinical evaluation, MHI (the ratio of chest transverse diameter over the distance between sternum and spine) assessment, transthoracic and transesophageal echocardiography implemented with strain analysis of both left atrium and left atrial appendage. Thromboembolic risk and burden of comorbidities were assessed by CHA2DS2-VASc Score and Charlson Comorbidity Index (CCI), respectively. The independent predictors of "asymptomatic AF" were assessed.

Results: A total of 25 asymptomatic and 90 symptomatic AF patients were retrospectively examined. Compared to symptomatic AF patients, those asymptomatic were significantly older (78.4±3.8 vs. 71.0±7.7 years, P<0.001), predominantly males (84 vs. 44.4%, P<0.001), with significantly lower MHI (2.0±0.1 vs. 2.4±0.1, P<0.001), higher CHA2DS2-VASc Score (5.8±1.1 vs. 3.6±1.1, P<0.001) and CCI (6.8±1.4 vs. 2.3±0.9, P<0.001), and greater impairment in biventricular systolic function and atrio-auricolar myocardial strain indices. On multivariate logistic regression analysis, CHA2DS2-VASc Score (OR=2.65, 95% CI: 1.53-4.60) and CCI (OR=2.36, 95% CI: 1.16-4.66) were linearly associated with the endpoint "asymptomatic AF," whereas MHI (OR 0.76, 95% CI 0.59-0.97) was inversely associated with the asymptomatic status. A MHI <2.2 was the best cut-off for detecting asymptomatic AF patients.

Conclusions: MHI is inversely associated with asymptomatic status in persistent AF patients undergoing ECV. MHI assessment might represent an innovative practical approach to AF patients.