Stroke is an important cause of disability and the third leading cause of death.

Approximately 30 to 40 % of all strokes are estimated to be cryptogenic (i.e. no cause can be found). There have been few previous studies regarding risk stratification for stroke recurrence in patients with cryptogenic stroke.

Recent studies have suggested that left atrial (LA) function is an important determinant of stroke risk. However, most studies focus on volume indices and LA dimensions, we also want to investigate other echocardiographic parameters. The aim of this study is to assess the predictive value of left atrial function for the risk of stroke recurrence and/or atrial fibrillation by transthoracic echocardiography in cryptogenic stroke patients with no proven atrial fibrillation (AF) and no indication for anticoagulants.

Study design and population The investigators used a retrospective mono-centric case-control design and analyzed all patients admitted for cerebrovascular accident (CVA) or transient ischemic attack (TIA) between 2011 and 2014. The investigators searched for patients who had a recurrent CVA/TIA and/or who were diagnosed with newly documented AF during the study duration. Clinical, demographic and laboratory parameters were assessed. Echocardiographic parameters, measured on first admission, were analyzed using EchoPAC version 112.

Statistical analysis Univariate analysis was performed for all covariates using the Cox proportional hazards model. Likelihood ratio tests were used to determine significance for all parameters.

If covariates were significant at the 25% significance level, they were used in the multivariate model.

Multivariate analysis was performed using the Cox proportional hazards model with backward elimination model selection. The Wald Chi-Square test was used to determine significance at 5% significance level. The program used for analysis is SAS version 9.4.

Inclusion Criteria:

• CVA
• TIA

Exclusion Criteria:

• proven AF or atrial flutter
• prior ablation for AF
• valvular disease
• artificial heart valves
• endocarditis
• presence of an atrial septum defect or moderate to large patent foramen ovale
• LV akinesia
• moderate to severe carotid stenosis
• prior surgery for carotid artery stenosis
• total occlusion of the internal carotid artery
• carotid artery dissection
• vertebral artery dissection
• massive aortic atheromatosis
• temporal arteritis
• basilar artery aneurysm
• ascending aortic aneurysm
• subclavian steal
• prior CVA/TIA
• intracerebral hemorrhage
• lacunar infarction
• clotting disorder
• on anticoagulants
• CVA/TIA as a procedural complication
• hyperthyroidism
• patients who died in hospital after first admission for CVA/TIA

Patients with Cryptogenic Stroke