Abstract 13677: Left Atrial Structure and Function in Relation to Incident Stroke/TIA and Dementia: The Multi-ethnic Study of Atherosclerosis
Introduction: Increased left atrial (LA) size and reduced LA function are known predictors of atrial fibrillation (AF). Evidence also links increased LA size and stroke. We sought to examine the association of LA function, measured with cardiac magnetic resonance imaging (CMR) and incident stroke/TIA and dementia.
Methods: This case-cohort study compared LA size and function in 180 MESA participants with incident Stroke/TIA and 95 with incident dementia, over a median follow up of 10.7 years, to 550 participants randomly selected from the whole MESA cohort. All individuals were free of clinical cardiovascular and major valvular heart disease. Phasic LA volumes, LA emptying fractions (LAEF) and peak strain were quantified in sinus rhythm using tissue-tracking CMR. Vascular neurologists adjudicated stroke events by medical record review. Dementia cases were identified using ICD9 codes from hospital records. Modified Cox proportional hazard models weighted for the stratified case-cohort sampling design was used to examine the associations.
Results: Incident Stroke/TIA (age 67 ± 9 years, 45% male) and dementia cases (age 74 ± 6 years, 58% male) were older than the subcohort population (age: 61 ± 10, 49% male). In multivariable analysis adjusted for standard cardiovascular risk factors and left ventricular ejection fraction, lower peak LA strain and passive LAEF were associated with both incident stroke/TIA and dementia. After further adjustment for incident AF, the associations were attenuated for peak LA strain but remained significant for passive LAEF (HR for incident Stroke/TIA: 0.72 per SD 95% CI: 0.55-0.93, p=0.013 and for incident dementia: 0.59 per SD 95% CI: 0.37-0.95, p=0.031).
Conclusions: Reduced LA conduit function was associated with incident Stroke/TIA and dementia independent of other cardiovascular risk factors and incident AF. Assessment of LA function may add further information in risk stratifying individuals at risk for stroke and dementia.
Author Disclosures: M. Habibi: None. M. Zareian: None. B. Ambale Venkatesh: None. S. Samiei: None. E. Chamera: None. K. Rezzadeh: None. C. Wu: None. L.J. Launer: None. A. Diez Roux: None. S. Shea: None. S.R. Heckbert: None. D.A. Bluemke: None. J.A. Lima: None.
- © 2015 by American Heart Association, Inc.