Non-invasive and invasive evaluation of aortic valve area in 100 patients with severe aortic valve stenosis: comparison of cardiac computed tomography with ECHO (transesophageal/transthoracic) and catheter examination.

BACKGROUND: Current guidelines place emphasis on the determination of aortic valve area (AVA) for defining an appropriate treatment strategy. Invasive and non-invasive modalities are used to perform planimetric [transesophageal echocardiography (TEE) and cardiac multidetector computed tomography (MDCT)] and calculated [catheter examination (CE), transthoracic echocardiography (TTE)] AVA measurements. PURPOSE AND METHODS: We investigated 100 patients admitted to evaluate the AVA using cardiac MDCT (CT), TEE/TTE as well as invasive CE. RESULTS: In all 100 patients we calculated a mean AVA of 0.79±0.29cm(2) (female 50/100, 0.70±0.19cm(2), male 0.9±0.21cm(2)) determined by all investigated examinations (mean±SEM). AVA measurements determined by CT were significantly greater (0.86±0.25cm(2)) than those determined by CE: 0.75±0.18cm(2), p=0.01. Echocardiographically determined AVA was comparable to CE (statistically not significant). Similar results were seen in all patients regardless of gender, presence of atrial fibrillation, and heart rate. We calculated a mean AVA for each patient and evaluated the variance of the AVA determined through investigated specific examinations as the bias. Overall, we found for CT 0.13±0.1cm(2), CE 0.13±0.11cm(2), TEE 0.16±0.09cm(2), and for TTE 0.16±0.08cm(2) a specific statistical non-significant variance. On subgroups: sinus rhythm, atrial fibrillation, females, males or combination, we found no further significant relevance for the specific variance. CONCLUSION: Our data suggest the feasibility of cardiac MDCT to evaluate the correct AVA regardless of rhythm, heart rate, and sex. The planimetric concept to determine the AVA with CT displaces the "gold-standard" CE with respect to elucidating the potencies for complications, i.e. cerebral stroke. Regardless of CT's accessing of AVA measurement the TTE examination should remain the primary method of screening for aortic valve pathologies.