Results

1. Left Atrial Volume Index during Ventricular Diastasis Assessed by Cardiac Computed Tomography is An Incremental Predictor of Adverse Events: A Matched Control Study Kevin Boczar, Mohammed Alam, Girish Dwivedi, Benjamin J Chow Department of Medicine (Cardiology), University of Ottawa Heart Institute, Canada , Results Background and Rationale • Table: Baseline characteristics • Computed tomographic (CT) coronary angiography (CTA) is increasingly being accepted as a key diagnostic modality for the non-invasive detection of coronary artery disease (CAD) • To minimize patient radiation exposure prospective-ECG gated image acquisition algorithms are being increasingly used whereby image acquisition is restricted to ventricular diastasis when cardiac motion is at a minimum. • However, this leads to the loss of left ventricular (LV) and left atrial (LA) functional information. • Previous studies have shown that assessment of LA volume index (LAVI) has incremental prognostic value in CAD patients. • However, prognostic value of LAVI during ventricular diastasis has never been investigated before. Left Atrium Objective • To determine the prognostic ability of LAVI assessed during ventricular diastasis in predicting adverse events Methods Figure : 3 dimensional volumetric method used to assess LA volume • The mean follow up duration was 20 ± 12 months. • LAVI was significantly larger in patients who experienced adverse events on follow up. • LAVI was univariable (p=0.001) as well as multivariable predictor (p=0.001) of adverse events on Cox regression analysis Patients recruited from Cardiac CT registry Database at the University of Ottawa Heart Institute • True 3 dimension reconstruction with high resolution endocardial border definition with CT allows accurate estimation of LAV not possible with other competitive techniques such as 2 dimension echocardiography. Test population: 101 patients with adverse events (all-cause mortality and troponin positive acute myocardial infarction) on follow- up constituted test population. Conclusions Discussion Control population: .A matched control list (matched according to the Morise score: the score based on clinical findings ) of 101 patients with no adverse events on follow-up was generated from the registry. • Patients experiencing adverse events (all-cause mortality and troponin positive acute myocardial infarction) on follow-up have significantly larger LAVI during ventricular diastasis . • LAVI assessed during ventricular diastasis by CT is an incremental predictor of adverse events. • This additional prognostic information from existing prospective ECG-gated CTA data sets may be provided to clinicians. • . • LA is exposed to the (diastolic) haemodynamic changes in the LV due to the close anatomical and functional coupling of these two chambers. • An enlarged LA is an independent risk factor for atrial fibrillation and other cardiovascular events such as heart failure and mortality. • Although CAD severity assessment with CTA has prognostic value, we demonstrate that other prognostic information (such as LAVI) may be available even from datasets obtained during ventricular diastasis (75% phase). LAV measured at 75% phase (mid-diastole) on CTA imaging in both groups LAV Indices (LAV indexed to body surface area) compared between test and control groups