Discordance in left atrial grading classifications between left atrial area and left atrial indexed volume calculations: impact of new guidelines on chamber quantification

Abstract

Introduction:Discrepancies between grading of LA size by area (LA-A) and volume (LA-V) are frequently encountered in echocardiography. Recently released guidelines on chamber quantification by American Society of Echocardiography provide new cut-offs for grading LA size.We sought to determine concordance between grading of LA size with area and volume in new guidelines compared to old guidelines. Methods: A total of 208 consecutive patients undergoing clinically indicated echocardiograms, had standardmeasures of LA size performed including calculation of LA-A and Left Atrial volume indexed to body surface area (LA-VI). Valueswere categorised into LAgrades by recommended categories (normal, mildly enlarged, moderately enlarged, and severely enlarged) for LA-VI (2005 and 2015 guidelines) and LA-A (2005 guidelines only). Comparisons of LA-A and LAVI by category were performed using weighted agreement (Cohen’s Kappa). Extreme misclassification was defined as a discrepancy greater than two categories. Results: The study cohort (n=208) showed average LA-VI of 33.1+17.9 ml/m2. Comparing LA-A and LA-VI (utilising 2005 guidelines only, n=208) showed a weighted agreement of = 0.44, with 14% major discordance (moderate-severe cohort n=72 had 42% major discordance). Comparing 2005 guidelines for LA-A and 2015 guidelines for LA-VI (n=208) showed increasedweighted agreement = 0.52with 5%major discordance (moderate-severe cohort n=39 had 20% major discordance). Conclusions: There appears to be improved concordance between grading of LA-A and LA-VI using the new guidelines. LA-Amaybe amoreuseful parameter in the assessment of LA size in conjunction with LA-VI when using cut-offs recommended by new guidelines.