64-slice multidetector computed tomography (MDCT) for detection of aortic regurgitation and quantification of severity.

BACKGROUND

Recent advances in 64-slice multidetector computed tomography (MDCT) provide an opportunity to assess coronary artery disease, left ventricular function and, potentially, valvular heart disease.

OBJECTIVE

To determine the ability of 64-MDCT to both detect and to quantify the severity of aortic regurgitation (AR), as compared with transthoracic echocardiography (TTE).

METHODS

We evaluated a total of 64 patients (43 males, mean age 63+/-11 years), 30 with varying severities of AR as assessed by TTE and 34 matched controls. The severity of AR by TTE was determined using the vena contracta, the ratio of jet to left ventricular outflow tract (LVOT) height, and the ratio of the jet to LVOT cross-sectional area. AR by MDCT was defined as a lack of coaptation of the aortic valve leaflets in diastole and, if detected, the maximum anatomic aortic regurgitant orifice was determined.

RESULTS

All 34 control patients without AR were correctly identified by MDCT. There were 14 patients with mild AR, 10 with moderate AR, and 6 with severe AR by TTE. Of these patients, MDCT correctly identified 21 patients with AR (sensitivity 70%, specificity 100%, positive predictive value [PPV] 100%, and negative predictive value [NPV] 79%). Anatomic regurgitant orifice area measured by MDCT correlated well with the TTE-derived vena contracta (r=0.79, P<0.001), ratio of jet to LVOT height (r=0.79, P<0.001), and ratio of jet to LVOT cross-sectional area (r=0.75, P<0.001).

CONCLUSIONS

Direct planimetric measurement of the aortic valve anatomic regurgitant orifice area on 64-MDCT provides an accurate, noninvasive technique for detecting and quantifying AR.