Prediction of severity of isolated aortic regurgitation by echocardiography: an aortic regurgitation index study.
BACKGROUND
No single precise qualitative method is recommended for evaluating the severity of aortic regurgitation (AR). Quantitative methods for AR assessment are, typically, cumbersome and time-consuming. The purpose of this study was to develop a more comprehensive method for predicting the severity of AR.


METHODS
In all, 79 patients with normal left ventricular systolic function and at least mild AR were included in this prospective study. The standard references for evaluating AR severity were quantitative methods. The AR index consisted of 5 echocardiographic parameters: jet width ratio, vena contracta width, pressure half-time, jet density, and diastolic flow reversal in the descending aorta. Each parameter was scored on a 3-point scale from 1 to 3. The AR index was calculated as the sum of each score divided by the number of parameters. Thus, an increasing AR index score from 1 to 3 was indicative of increasing regurgitation.


RESULTS
The study demonstrated that the numeric value of AR index increased proportionately to the quantitative grading of AR severity, and proved to be an accurate predictor for AR severity. A 1.8 threshold for the AR index offered a high level of sensitivity and negative predictive value for severe AR. The possibility of missing severe AR was low with AR index less than 1.8. A 2.6 threshold for the AR index provided high specificity and positive predictive value for severe AR. The possibility of diagnosing severe AR was extremely high with AR index of 2.6 or more.


CONCLUSIONS
AR index provided a more comprehensive method for predicting the degree of AR severity in this study. We suggest that the AR index should be considered for any evaluation of the severity of AR.
Chin
Chih-Hui
CH
Division of Cardiology and Cardiac Surgery, Cathay General Hospital, Taipei, Taiwan.
Chen
Chung-Huo
CH
Chen
Chin-Chien
CC
Chen
Thay-Hsiung
TH
Chang
Mei-Ling
ML
Chiou
Herng-Cheng
HC
D000368:Aged; D001022:Aortic Valve Insufficiency / Q000145:classification / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000145:classification / Q000150:complications / Q000000981:diagnostic imaging*; D011379:Prognosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D014463:Ultrasonography; D018487:Ventricular Dysfunction, Left / Q000145:classification / Q000000981:diagnostic imaging* / Q000209:etiology