Comparative assessment of ascending aortic aneurysms in Marfan patients using ECG-gated computerized tomographic angiography versus trans-thoracic echocardiography.

BACKGROUND: Contrast-enhanced computed tomography (CT) is routinely used as a complementary technique to trans-thoracic echocardiography (TTE) for assessing thoracic aortic aneurysms (TAA). However different measures can be obtained on CT and there are no recommendations on which to use. The objective was to determine which CT measurements most closely match reference TTE measurements in Marfan patients with TAA. METHODS: TTE measurements were obtained using the leading edge-to-leading edge technique in end-diastole on the parasternal longitudinal view. ECG-gated CT measurements were obtained, using the inner-to-inner technique in end-diastole by double oblique reconstruction: on three-cavity view (3C), left ventricle-aorta view (LVAo), and strict transverse plane passing through the maximal diameter "cusp to commissure" and "cusp to cusp" for each cusp. CT and TTE were performed within one month. RESULTS: 44 Marfan patients (39 ± 19 years, 48% men) were included. Dilatation of the ascending aorta was maximal at the level of the sinuses (TTE diameters: mean 47.5 ± 5.3 mm). TTE diameters were similar to 3C, LVAo (mean differences: 2.2 and -0.1 mm, p=NS) and to the three "cusp to cusp" diameters (mean differences ranging from 0 to 1.1mm, p=NS), whereas "cusp to commissure" diameters were all statistically smaller than TTE (3.6 mm, 2.9 mm and 3.7 mm, p ≤ 0.01). CONCLUSIONS: Inner-to-inner "cusp to cusp" diameter measured on an ECG-gated CT should be used for comparison with 2D TTE aortic diameter at the level of the sinuses of Valsalva in patients with thoracic aortic aneurysms.

A randomized comparison of high clopidogrel loading doses in patients with non-ST-segment elevation acute coronary syndromes: the ALBION (Assessment of the Best Loading Dose of Clopidogrel to Blunt Platelet Activation, Inflammation and Ongoing Necrosis) trial.

OBJECTIVES: We sought to compare the antiplatelet effects of three clopidogrel loading doses (LDs). BACKGROUND: Administration of a 300-mg clopidogrel LD is beneficial in situations requiring rapid platelet inhibition. Whether higher LDs can provide further benefits remains unknown. METHODS: Patients (n = 103) with non-ST-segment elevation acute coronary syndromes were randomized to receive a 300-mg, 600-mg, or 900-mg clopidogrel LD, given on top of other standard therapy (including acetylsalicylic acid). The main outcome measure was inhibition of adenosine diphosphate-induced inhibition of platelet aggregation (IPA); inhibition of platelet activation, inflammatory markers, troponin I release, and major adverse cardiac events also were evaluated; all measures were blindly evaluated. RESULTS: Compared with the 300-mg LD, greater doses were associated with significantly greater platelet inhibition, with dose-effect relationships observed for onset of action, maximal plateau, 24-h areas under the curves of IPA, and rates of low IPA (<10% at 6 h), using 20 micromol/l major adverse cardiac events. A significant dose-response was also observed for the vasodilator-stimulated phosphoprotein index, a measure of P2Y(12) receptor inhibition. Similar but nonsignificant trends were observed for troponin release and major adverse cardiac events. Bleeding rates were similar in each group. CONCLUSIONS: In low-to-moderate risk patients with non-ST-elevation acute coronary syndromes, clopidogrel LDs >300 mg provide a faster onset of action, a higher IPA plateau, and greater reductions in platelet activation during the first 24 h. A 900-mg LD may induce a greater antiplatelet effect than 600 mg, when compared with the standard 300-mg regimen. These findings require further clinical confirmation.