Abstract 2653: Predictive Value of Left Atrial Volume and Function by MDCT for Acute Coronary Syndrome in Patients with Acute Chest Pain: ROMICAT Substudy
Background: Left atrial (LA) size is associated with coronary artery disease and shown to provide incremental prognostic value for detection of myocardial ischemia. We aim to determine whether LA volume and function as measured by MDCT is predictive of acute coronary syndrome (ACS) in patients presenting to the emergency department (ED) with chest pain.
Methods: We performed ECG-gated contrast-enhanced 64-slice coronary MDCT in 382 consecutive patients who presented to the ED with chest pain whose initial ECG and biomarkers were negative. An adjudication panel of 2 physicians determined whether patients had ACS during index hospitalization. LA volumes were derived based on threshold-based measurements. Left ventricular (LV) end-systolic and end-diastolic LA volumes (LA ESV, LA EDV) were indexed to body surface area (LA ESI, LA EDI). LA ejection fraction (LA EF) was defined as (LA ESV - LA EDV)/LA ESV x 100%.
Results: Patient characteristics were mean age 54±12 yrs, BMI 29.1±6.0 kg/m2, 140 (37%) women, and LV EF 67±10%. There were 38 (10%) patients with ACS [30 (79%) UAP, 8 (21%) MI]. Mean LA volumes and indices were significantly higher and LA EF significantly lower in those with ACS compared to those without ACS. In unadjusted analysis, subjects in the top quartile compared to the lower quartile of LA ESV and LA EDV had a 3- and 5- fold increased risk for ACS; respectively (LA ESV: 113–202 ml vs 47–78 ml and LA EDV: 66 –187 ml vs 26 – 45 ml), while subjects in the top quartile of LA EDI, LA ESI, and LA EF had not. After adjustment for gender the association was attenuated (LA ESV: OR 3.1 [95% CI 1.1–9.0], p=0.04; LA EDV: OR 3.8 [95% CI 1.2–12.1], p=0.02). There was no significant association after adjustment for age.
Conclusion: MDCT-based LA enlargement is associated with a 3–5 fold increase risk for ACS. This association is attenuated after adjustment for gender and becomes non-significant after adjustment for age. LA enlargement may have limited incremental value in the prediction of ACS.