Transaortic flow velocity from dual-source MDCT for the diagnosis of aortic stenosis severity.

OBJECTIVES: To describe a method for the estimation of transaortic flow from multidetector computer tomography (MDCT). BACKGROUND: Cardiac MDCT may not allow instantaneous flow measurement yet the components of flow, namely, volume change over time and lumenal area are recorded. METHODS: In 36 patients, the transaortic flow velocity was determined on transthoracic echocardiography and also with cardiac MDCT as follows: On MDCT an axial orientation through the aortic root was obtained so that the nadir of all three aortic leaflets could be seen simultaneously in one axial image. Aortic valve area (AVA) was determined by planimetry and left ventricular volumes by endocardial border mapping at every 5% increment of the RR intervals. Flow velocity was then calculated as the incremental ejection volume ÷ duration of the increment ÷ AVA. RESULTS: The transthoracic echocardiography (TTE) peak velocity and MDCT peak velocity were highly correlated (r = 0.75, P < 0.01). Transaortic peak velocity was higher when measured by MDCT as compared to TTE, with respectively a median [IQ-range] of 4.5 [2.9-5.3] and 4.0 [3.0-4.6], P < 0.01. For the diagnosis of severe aortic stenosis greater concordance with TTE peak velocity was seen with MDCT peak velocity (sensitivity 100%, specificity 76%) than with MDCT AVA (sensitivity 74%, specificity 76%). CONCLUSIONS: We show for the first time that transaortic flow velocity can be estimated by dual-source MDCT and has a better sensitivity for the detection of severe aortic stenosis than AVA planimetry when compared to the gold standard of TTE peak flow velocity.

[Survival and disorders after percutaneous aortic valve replacement]. / Overleving en klachten na percutane aortaklepvervanging.

OBJECTIVE: Description of the characteristics of patients with aortic valve stenosis and high surgical risk considered suitable for percutaneous aortic valve replacement (PAVR) and investigation of the effect of this treatment on survival and the occurrence of complications. DESIGN: Prospective observational single center cohort study. METHOD: Patients with aortic valve stenosis and high surgical risk received a special consultation, after which the heart team decided whether they were considered suitable for PAVR or for surgical valve replacement (AVR). Deaths and complications in the 30 day period after PAVR were registered. The study period was September 2005-January 2009. The EuroSCORE system was used to summarise the patient characteristics, survival was determined by using the Kaplan Meier method, and the subjective health status defined following the New York Heart Association (NYHA) classification. RESULTS: In the study period 166 patients were referred for PAVR of whom 91 (55%) actually underwent PAVR, 16 (10%) underwent surgical valve replacement (AVR), 39 (23%) were rejected for AVR/PAVR and 20 patients (12%) declined surgical treatment. The mean EuroSCORE (SD) for PAVR was 17% (8), for AVR 12% (7) , for patients unsuitable for surgery 19% (12) and for those declining surgery 25% (14). The mortality and risk of stroke 30 days after PAVR were respectively 12 and 13%. Survival at 1 year after PAVR was 73%. This was associated with a significant improvement of the functional class: before PAVR 15% of patients had NYHA class ≤ 2, and afterwards 72%. CONCLUSION: PAVR was associated with a substantial risk of mortality and stroke. The subjective health status of patients did improve substantially after PAVR. In the absence of randomised studies, the authors are of the opinion that PAVR should be restricted to patients who are not considered suitable for surgical valve replacement.

Three dimensional evaluation of the aortic annulus using multislice computer tomography: are manufacturer's guidelines for sizing for percutaneous aortic valve replacement helpful?

AIMS: To evaluate the effects of applying current sizing guidelines to different multislice computer tomography (MSCT) aortic annulus measurements on Corevalve (CRS) size selection. METHODS AND RESULTS: Multislice computer tomography annulus diameters [minimum: D(min); maximum: D(max); mean: D(mean) = (D(min) + D(max))/2; mean from circumference: D(circ); mean from surface area: D(CSA)] were measured in 75 patients referred for percutaneous valve replacement. Fifty patients subsequently received a CRS (26 mm: n = 22; 29 mm: n = 28). D(min) and D(max) differed substantially [mean difference (95% CI) = 6.5 mm (5.7-7.2), P < 0.001]. If D(min) were used for sizing 26% of 75 patients would be ineligible (annulus too small in 23%, too large in 3%), 48% would receive a 26 mm and 12% a 29 mm CRS. If D(max) were used, 39% would be ineligible (all annuli too large), 4% would receive a 26 mm, and 52% a 29 mm CRS. Using D(mean), D(circ), or D(CSA) most patients would receive a 29 mm CRS and 11, 16, and 9% would be ineligible. In 50 patients who received a CRS operator choice corresponded best with sizing based on D(CSA) and D(mean) (76%, 74%), but undersizing occurred in 20 and 22% of which half were ineligible (annulus too large). CONCLUSION: Eligibility varied substantially depending on the sizing criterion. In clinical practice both under- and oversizing were common. Industry guidelines should recognize the oval shape of the aortic annulus.