Akihiro Hata

Angiographic findings of Takayasu arteritis: New classification

Having proposed a new classification on angiographic findings of patients with Takayasu arteritis, we evaluated the angiographic findings of 80 Japanese patients and 102 Indian patients according to this classification. Japanese patients showed a higher frequency of involvement of the ascending aorta, aortic arch and its branches than did the Indians (P < 0.01). On the other hand, the frequency of involvement of the abdominal aorta and/or renal arteries was higher in Indian patients (P < 0.01). Type III cases of the new classification which involves the thoracic descending aorta, abdominal aorta and/or renal arteries were observed in 3% of the Indian patients, but not at all in the Japanese. In conclusion, in Japanese patients, vascular lesions tend to occur primarily in the ascending aorta, aortic arch and/or its branches and extend into the abdominal aorta. On the other hand, in Indian patients, the tendency is primarily in the abdominal aorta including renal arteries and extending into the thoracic aorta.

Magnetic resonance imaging of vascular changes in Takayasu arteritis

We studied the thoracic aorta in 42 female patients with Takayasu arteritis by magnetic resonance imaging (MRI) with a 1.5-T superconducting instrument and compared the findings with those in 10 healthy female controls. Images in the transaxial and oblique sagittal planes were acquired by cardiac gating using a spin-echo pulse sequence. Images in the oblique plane were also obtained with cine MRI. Vascular changes were found in 41 (98%) of the patients. Dilatation of the ascending aorta was observed in 20 patients (48%), while stenotic changes were more characteristic in the descending aorta (16 patients, 38%). Moderate signal-intensity masses on the aortic wall were encountered in 21 patients (50%), suggesting mural thrombi. Turbulent blood flow was observed around all masses by cine MRI. HLA analysis revealed that patients carrying HLA-B52 typing showed these masses more frequently than those without this typing (P < 0.05). Cine MRI demonstrated aortic regurgitation in 20 patients (48%), all of whom showed dilated ascending aorta; furthermore, 14 (70%) of them were confirmed as carrying HLA-B52. Thus, MRI was a useful non-invasive tool not only for the evaluation of the morphological changes in the aorta and its branches, and of the hemodynamic disturbance in Takayasu arteritis, but also for follow-up of the morbid condition.

Four years follow-up study in patients with Takayasu arteritis and severe aortic regurgitation; assessment by echocardiography

We prospectively performed the follow-up study in 11 female patients with Takayasu arteritis and severe aortic regurgitation by echocardiography. A mean follow-up period was 4 years. The inflammatory state was controlled in all patients. Antihypertensive agents including beta-blocker were administered in nine patients. Heart failure did not progress in all patients except one. No candidate for cardiac surgery appeared during the follow-up period. Aortic root diameter, left atrial, left ventricular end-diastolic and end-systolic dimensions, wall thickness, left ventricular mass, and percent fractional shortening of the left ventricle showed no significant change in echocardiography. These data indicate that left ventricular disturbance might be slowly progressive in patients with Takayasu arteritis and severe aortic regurgitation. Systemic hypertension and the inflammatory state should be well controlled in managing the patients. beta-blocker might be useful in some patients with Takayasu arteritis and severe aortic regurgitation. Further follow-up is necessary for the decision of the cardiac surgical indication.

What Effect Does Controlling Platelets Have on Atherosclerosis

Platelets play important roles for hemostasis with activated platelets adhering to the injured vessel wall to initiate platelet aggregation. At the same time, our study revealed the cytotoxic effect on endothelial cells characterized by an increase of intracellular Ca++ and a decrease of EDRF production, which may cause plasmal infiltration including blood cells and lipids. Our clinical survey using a small dose of aspirin as an antiplatelet therapy clearly demonstrated its suppressive effect on platelet aggregation and its favorable effect on fibrinolysis. These data suggest that the therapeutic effect of aspirin in vascular disease could be applied to the prevention of thrombus formation and the protection of endothelial cells from the cytotoxic effect of activated platelets.

Concentric Left Ventricular Hypertrophy in Patients with Takayasu Arteritis

Although aortic regurgitation (AR) in patients with Takayasu arteritis (TA) is believed to be caused by dilatation of the aortic ring or thickening of the aortic cusps, the pattern of left ventricular hypertrophy (LVH) in these patients has not been described. To clarify the geometry of the LV in patients with TA that had been documented both echocardiographically and hemodynamically, the authors evaluated 22 patients with TA and severe AR (group 1), 10 with TA and systemic hypertension (group 2), and 17 with isolated severe AR of other etiolo gies (group 3). M-mode echocardiography showed that LV dimensions were smaller in groups 1 and 2 than in group 3 and that wall thickness was greater in group 1 than in group 3. The concentric hypertrophic ratio (CHR = wall thick ness/LV end-diastolic dimension + wall thickness) was larger than group 1 (p < 0.001) and group 2 (p < 0.01) than in group 3. CHR was similar in groups 1 and 2. Systolic blood pressure was significantly increased in group 2 and showed a tendency to increase in group 1 as compared with group 3. The results confirmed the presence of concentric LVH related to a pressure overload in patients with TA, even when TA was complicated by severe AR.

Transesophageal Echocardiographic Recognition of a Fistula Between a Coronary Artery and the Left Atrium

A 58-year-old woman with a prosthetic mitral valve and an anomalous single coronary artery received transesophageal echocardiography and was found to have a coronary artery--to--left atrium fistula. Because of its superior imaging quality, transesophageal color Doppler method is a useful diagnostic procedure.