Gruber N

Indices of aortic distensibility and coronary flow velocity reserve in patients with different grades of aortic atherosclerosis.

Objective: The purpose of this study was to evaluate the correlation of the elastic properties of the descending aorta, the coronary flow velocity reserve (CFR) and the grade of aortic atherosclerosis (AA) in patients who have undergone coronary angiography. Methods: A total of 113 consecutive patients (77 men and 36 women, aged 31–80 years) underwent stress transoesophageal echocardiographic (STEE) assessment of the CFR. The grade of AA and the indices of aortic distensibility were evaluated during the same session of STEE. All patients had chest pain without previous myocardial infarction. Coronary angiography was performed in all cases. Results: The resting systolic and diastolic coronary flow velocities increased, while the coronary flow velocities measured at the peak of stress and the ratio Smax/Srest decreased in parallel with the aortic grade. The CFR and mean CFR were impaired in patients who exhibited aortic intimal thickening, but no further decrease was found in the event of aortic plaque. The elastic moduli E(p) and E(s) increased in parallel with the grade of AA. The occurance of a negative coronary angiogram was more common in patients without AA, but significant left anterior descending coronary artery disease or multivessel disease were more frequent at a higher grade of AA (in cases with aortic plaque). Conclusions: The CFR was decreased in patients with aortic intimal thickening, but no further decrease was observed in the presence of aortic plaque. The indices of aortic distensibility increased continuously in parallel with the aortic grade.

Prospective evaluation of thallium-201 reinjection in single-vessel coronary patients undergoing coronary bypass surgery

Twenty-two patients with single-vessel left anterior descending coronary artery disease were investigated by means of dipyridamole stress thallium-201 myocardial perfusion scintigraphy, using single photon emission tomography (SPET), 1 week before and 2–5 weeks after coronary bypass surgery. The dose of dipyridamole was 0.56 mg/kg, and the injected activity of 201T1 was 74 MBq. Before surgery, and after completion of the redistribution study, a further 37 MBq of 201T1 was injected. Ten minutes and 1 h later, repeated SPET imaging were performed. SPET images were evaluated both subjectively and semiquantitatively, using a five-grade segmental defect score system, with higher scores for more severe perfusion defects. Before surgery, the 3-h redistribution images revealed complete or partial persistence of the perfusion defects in all patients. On the images taken 10 min after reinjection, these defects were completely filled in four cases, and partially filled in ten cases. Further positive changes were observed on the 1-h post-reinjection images in four cases. Three of the 1-h post-reinjection images exhibited a paradox redistribution. The stress images after surgery corresponded well to the 201T1 distribution on the preoperative 1-h post-reinjection images in 11 cases. The average of the segmental defect severity scores was 17.0 after stress, 10.1 at rest, 7.1 10 min after reinjection and 6.4 1 h after reinjection. After surgery, the average of both the post-stress and the 3-h redistribution scores was 3.1. The correlation coefficients between the segmental scores of the postoperative resting study and the preoperative 3-h resting and the 10-min and 1-h post-reinjection studies were 0.72, 0.69 and 0.78, respectively. It is concluded that post-reinjection 201T1 images before surgery are good predictors of myocardial perfusion after revascularization. The best results are obtained if imaging is performed 1 h after reinjection.