Predictive value of left and right atrial strain for the detection of atrial fibrillation in patients with cryptogenic stroke and implant of loop recorder

FUNDING ACKNOWLEDGEMENTS: Type of funding sources: None. BACKGROUND: Structural and functional remodeling of left and right atrium (LA-RA) are predictors of the risk of hospitalization and mortality. These are chronic and complex processes, dependent on an adaptive response implemented by the atrial myocytes against stressors of an electrical, mechanical and metabolic nature. Atrial fibrillation (AF) is the most common condition associated with remodeling of both atria, of which it can be cause and effect at the same time: atrial enlargement, interstitial fibrosis and myocardial distension. Often the first manifestation of AF is cryptogenic stroke (CS) which is associated with a high rate of recurrence and adverse long-term follow-up outcomes, mainly due to its unknown etiology often leading to secondary prevention ineffective. Asymptomatic (AF) may play an important pathophysiological role to detect CS. Evidence has demonstrated the efficacy of AF ablation in restoring the structure of the LA and, consequently, in favoring the maintenance of sinus rhythm. However, little is known regarding the evaluation of RA remodeling and its variation over time in patients with FA. AIM OF THE STUDY: Evaluate the relationship between echocardiographic parameters of LA and RA function, and the occurrence of AF revealed by continuous ECG monitoring through insertable cardiac monitors (ICM) implant in a cohort of patients with CS METHODS: Single-center retrospective study. A total of 204 patients who suffered from cryptogenic stroke underwent ICM between May 2013 and July 2022. All detected AF episodes lasting more than 30 seconds were considered, according to Guidelines. All patients underwent to Transthoracic Echocardiography (TTE) to study on LA and RA function, including both standard and longitudinal strain-derived parameters. Transesophageal Echocardiography (TEE) was also performed to exclude embolic sources. RESULTS: During a median follow-up period of 15.3 months (interquartile range, 7.4 / 23.5), continuous ECG monitoring revealed AF in 96 patients (47.0%). Many echocardiographic parameters, such as LA maximum and minimal volume were significantly associated with the occurrence of AF, suggesting the worst atrial function in the AF group. Furthermore, multivariable regression analysis revealed that peak atrial contraction strain of both atria were independently associated with AF (p < 0.001,respectively). CONCLUSION: In patients with cryptogenic CS, LA and RA strain analysis are strong and independent predictors of the occurrence of AF despite clinical and morpho-functional echocardiographic parameters. [Figure: see text] [Figure: see text]