P910 Can left ventricular volume and diastolic flow reversal in descending aorta be useful to rule in or rule out severe chronic aortic regurgitation?

Funding Acknowledgements The study was financed by grants from the Swedish state under the agreement between the Swedish government and the county councils, the ALF¬-agreement Background and Purpose Grading severity of chronic aortic regurgitation (AR) by echocardiography may be challenging in cases with few feasible parameters leading to diagnostic uncertainty. The aim of the present study was to transform left ventricular (LV) volume and diastolic flow reversal to quantitative parameters using cardiovascular magnetic resonance (CMR) as reference. Methods Patients (n = 120) were recruited either prospectively (n= 45, CMR performed < 4 hours) or retrospectively (n = 75, CMR performed < 21 days (median)). The latter comprised patients with echocardiographic uncertainty. LV end-diastolic volume index (LVEDVI) by Simpson biplane method and end-diastolic flow velocity (EDFV) in the proximal descending aorta were assessed. The patients were randomised to either a derivation (n = 60) or a test group (n = 60). Results Severe AR (regurgitant fraction by CMR > 33%) was present in 51% of the patients. In the derivation group, the area under the ROC curves for LVEDVI was 0.80 (95% CI 0.67-0.93) and for EDFV was 0.83 (95% CI 0.71-0.94). LVEDVI > 99 ml/m2 and ≤ 75 ml/m2 were useful to rule in and rule out severe AR, respectively. The corresponding for EDFV were > 17 cm/s and ≤ 10 cm/s. The diagnostic performances of the cut off values in the test group are presented in the Table. Conclusions LVEDVI and EDFV are useful quantitative parameters to rule in and rule out severe chronic AR in patients with diagnostic ambiguity. Combination of LVEDVI > 99 ml/m2 and EDFV > 17 cm/s is the most useful to rule in severe AR. Sensitivity (%) (95% CI) Specificity (%) (95% CI) Positive likelihood ratio (95% CI) Negative likelihood ration (95% CI) Rule in severe AR LVEDVI (> 99 ml/ m2) 48 (29-67) 95 (77-99) 10.0 (1.4-71) 0.55 (0.37-0.82) Rule out severe AR LVEDVI (≤ 75 ml/m2) 91 (73-98) 62 (41-79) 2.4 (1.4-4.2) 0.14 (0.04-0.55) Rule in severe AR EDFV (> 17 cm/s) 44 (28-63) 96 (79-99) 10.2 (1.4-73) 0.58 (0.41-0.82) Rule out severe AR EDFV (≤ 10 cm/s) 96 (82-99) 48 (29-67) 1.9 (1.2-2.8) 0.08 (0.01-0.56) Rule in severe AR > 99 ml/m2 + > 17 cm/s 36 (20-57) 100 (82-100) - 0.64 (0.46-0.87) Rule out severe AR ≤ 75 ml/m2 + ≤ 10 cm/s 91 (72-98) 29 (13-53) 1.3 (0.92-1.8) 0.31 (0.07-1.4)