128 - Use of Chest Ct Angiography Derived Left Atrial Size as a Predictor of Diastolic Dysfunction

Abstract

Background: We hypothesized that; (1) there will be a correlation between left atrial (LA) size measured by routine non-gated computed tomographic angiography of the chest (CTA) & echocardiography (echo); (2) CTA LA size will be larger in those with diastolic dysfunction (DD). Thus, we aimed to determine if measuring LA size in routine non-gated chest CTA would be of value in identifying underlying diastolic dysfunction. Methods: We identified 103 (46 Male & 57 female) hospitalized patients who underwent both CTA & Echo within 48 hours of each other by a retrospective chart review from July to September 2016. Exclusion criteria were a presence of mitral stenosis or regurgitation in echo. LA size in CTA (CTA LA) was measured using the maximum transverse diameter in its middle 50%. LA size in echo (Echo LA) was measured in end-systole, from leading edge of the posterior aortic wall to the leading edge of the posterior LA wall in parasternal long axis view. We divided our cohort into normal, mild and severe DD subgroups based on echocardiographic E: A & mitral valve deceleration time (DT). Normal group comprised patients with E: A 0.75–1.5, DT 180–240 ms (n = 57), Mild DD E: A < 0.75, DT >240 ms (n = 22) & severe DD E: A > 1.5, DT <180 ms (n = 11). We statistically analyzed CTA and Echo LA sizes, CTA LA vs. E: A ratio & mitral valve deceleration time (DT) using Pearson correlation. Results: There was a strong correlation between LA sizes in CTA & Echo (r = 0.749, P ≤ .05, n = 103). Statistical analysis of the general cohort showed poor correlation between CTA LA & Echo E: A, (r = 0.19, P = .07); & DT (r=-0.14, P = .09). However, in subgroup analysis moderate correlation existed between CTA LA size & echo E: A ratio (r = 0.386, P ≤ .05) in severe diastolic dysfunction group. A mild negative correlation was also seen in between CTA LA size and mitral valve deceleration time (r=-0.411, P < .05) in the same subgroup. A non-linear relationship was seen in normal and mild diastolic dysfunction subgroups. Conclusion: There is a strong correlation between LA sizes in CTA and echo. A moderate correlation exists between LA size in CTA & E: A ratio in echo in presence of severe diastolic dysfunction. A moderate negative correlation also exists between CTA LA size & mitral valve deceleration time in presence of severe diastolic dysfunction. LA size obtained from routine non-gated chest CTA can function as a potential predictor of severe diastolic dysfunction & can be clinically useful as CTA is often available in the early part of the diagnostic workup.Tabled 1Results of Pearson correlation in normal diastolic function, mild & severe DD subgroupsVariableNormalMild DDSevere DDE:A0.75–1.5<0.75>1.5Mitral valve deceleration time (DT)180–240>240<180(n)572211CTA LA vs. E:A, r0.1350.2110.386(P ≤ .05)CTA LA vs. DT, r−0.135−0.211−0.411(P≤.05) Open table in a new tab