Reduced total left atrial emptying fractions (LAEF) was a potential independent biomarker for predicting incident ischemic cerebrovascular events (CVEs) in older adults who were free of clinical cardiovascular disease, according to study results published in JACC Cardiovascular Imaging.
A total of 4261 participants from the Multi-Ethnic Study of Atherosclerosis (MESA) who had phasic left atrial volumes; total, passive and active LAEF; and peak longitudinal left atrial strain measurements taken during the study were included in the analysis (patient age, 61±10). At baseline, all participants were free of clinical cardiovascular disease.
During 11.6±3.5 years of follow-up, individuals were contacted by telephone every 9 months to record data regarding new hospital admissions, cardiovascular outpatient diagnoses, and death. The analysis was focused on the diagnosis of incident ischemic CVE, comprised of ischemic stroke or transient ischemic attack (TIA), during follow-up.
The researchers recorded a total of 193 ischemic CVEs (1.26 per 1000 person-years) during follow-up, represented by 134 ischemic strokes and 59 TIAs. Compared with participants without CVEs, individuals who developed CVEs during follow-up had larger left atrial volumes and lower passive, active, and total LAEF at baseline. Of the participants with incident ischemic CVE, 34 (17.6%) were diagnosed with atrial fibrillation (AF) prior to or at the time of ischemic CVE and 24 (12.4%) were diagnosed with AF after incident ischemic CVE, while 135 (70.0%) participants did not develop clinically recognized AF during the follow-up.
Total LAEF was associated with incident CVE in the multivariable analysis adjusted for known cerebrovascular risk factors, interim AF, and left ventricular mass (hazard ratio [HR], 0.85; 95% CI, 0.74-0.98; P =.027). The adjusted HR for the lowest total LAEF tertile vs the highest LAEF tertile was 1.47 (95% CI, 1.04-2.05; P =.031).
A model consisting of known clinical risk factors for CVE and left ventricular mass that was capable of predicting incident ischemic CVE was improved with the addition of total LAEF (C statistics, 0.76 vs 0.73; P =.039).
Limitations of the study were the inclusion of participants from only 6 communities in the United States and the reliance on CMR imaging data that were acquired between 2000 and 2002.
“Our findings suggest possible value of [left atrial] functional parameters in stratification of individuals at risk of ischemic CVE especially those with no clear evidence of AF,” concluded the researchers.
Habibi M, Zareian M, Ambale Venkatesh B, et al. Left atrial mechanical function and incident ischemic cerebrovascular events independent of AF [published online April 10, 2019]. JACC Cardiovasc Imaging. doi:10.1016/j.jcmg.2019.02.021