Takeshi Shichijo

Telmisartan, an Angiotensin II Type 1 Receptor Blocker, Improves Coronary Microcirculation and Insulin Resistance among Essential Hypertensive Patients without Left Ventricular Hypertrophy

Hypertension and insulin resistance are associated with reduced coronary vasodilatory capacity, possibly caused by structural changes in the coronary resistance vessels. The goal of this study was to compare the effect of an angiotensin receptor blocker (ARB) with that of a calcium channel blocker (CCB) on coronary flow reserve and insulin resistance among essential hypertensive patients without left ventricular hypertrophy. A total of 40 consecutive essential hypertensive patients were randomized to daily 40 mg telmisartan or 20 mg nifedipine coat-core treatment. Coronary flow velocity reserve (CFVR) measurement using transthoracic Doppler echocardiography and blood tests were performed before and after 12 weeks of treatment. At baseline, blood pressure, CFVR, and homeostasis model assessment of insulin resistance (HOMA-IR) were not significantly different between the two groups. At the end of the treatment period, the telmisartan and nifedipine groups exhibited similar declines in blood pressure. CFVR was improved in the telmisartan group (2.4±0.4 to 2.9±0.4; p<0.01), but there was no difference in the nifedipine group (2.5±0.3 to 2.5±0.3; n.s.). HOMA-IR was improved in the telmisartan group (3.1±1.1 to 1.6±0.7; p<0.01), but there was no difference in the nifedipine group (2.8±1.1 to 2.4±0.7; n.s.). In conclusion, this study demonstrates that antihypertensive therapy with telmisartan, but not nifedipine, has a beneficial effect on coronary microcirculation and insulin resistance among essential hypertensive patients.

Coronary Artery Bypass Grafting with Left Inferior Epigastric Artery as Collateral

We report a case of co-existent coronary and peripheral vascular disease with collaterals to the lower extremities in a 72-year-old female. The patient had triple-vessel coronary artery disease, an occlusion of the bilateral iliac arteries, and the left internal mammary-inferior epigastric artery collateral pathway was a major route to the lower extremities. Coronary artery bypass grafting and right axillo-bifemoral bypass were performed. The well-developed left inferior epigastric artery was used as a conduit to the circumflex artery.

Successful arterial switch operation for post-Mustard pulmonary venous obstruction and secondary pulmonary hypertension

A 16-year-old girl presented with dyspnea 15 years after the Mustard operation for transposition of the great arteries with intact ventricular septum. An echocardiogram revealed secondary pulmonary hypertension due to pulmonary venous obstruction. Cardiac catheterization showed the left (pulmonary) ventricular pressure was over the systemic level. We performed a successful one-stage switch conversion. The patient is doing well 1 year after the switch conversion.

Risk factors reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum assisted circuits

OBJECTIVES Open heart surgery without homologous blood transfusion remains difficult in children. The introduction of vacuum-assisted cardiopulmonary bypass circuits to reduce priming volume for pediatric patients has improved the percentage of transfusion-free operations. We retrospectively analyzed blood transfusion risk factors to further reduce blood transfusion requirements after vacuum-assisted circuit introduction. METHODS From March 1995 to June 1996, 49 patients weighing between 5 and 20 kg underwent cardiac surgery with cardiopulmonary bypass at our institution, excluding hospital deaths. We retrospectively analyzed risk factors influencing blood use in 37 patients with no blood priming in cardiopulmonary bypass after introducing a vacuum-assisted system. Factors selected for univariate analysis were age, body weight, cyanosis, preoperative Hb, operation time, cardiopulmonary bypass time, aortic cross-clamping time, and intraoperative and postoperative bleeding volume. Correlation between total bleeding volume/body weight and cardiopulmonary bypass time was studied by regression analysis. RESULTS As risk factors, univariate analysis identified cyanotic disease, longer operation time (> 210 minutes), longer cardiopulmonary bypass time (> 90 minutes), longer aortic cross-clamping time (> 45 minutes), greater intraoperative bleeding volume/body weight (> 4 ml/kg), and greater postoperative bleeding volume/body weight (> 15 ml/kg). Regression analysis showed a significant positive correlation between total bleeding volume/body weight and cardiopulmonary bypass time. CONCLUSIONS Cyanotic disease and long bypass time are risk factors in reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum-assisted circuits. Further efforts are needed, however, to reduce blood transfusion requirements, particularly in these children.

Successful transcatheter repair of severe aortic valve stenosis with a fishhook-like calcification

An 84-year-old extreme frail woman presented with symptomatic severe aortic valve stenosis. Transthoracic echocardiography (TTE) revealed a tricuspid aortic valve with eccentric calcification. The aortic annulus area was 399 mm as observed using multidetector computed tomography (CT), which also revealed a huge fishhook-like calcification extending from the commissure between the left and right coronary cusp to the sinotubular junction through the aortic annulus and the sinus of Valsalva (Fig. 1a–c). Transcatheter aortic valve implantation (TAVI) was scheduled. The calcification was not deformed during intraoperative balloon aortic valvuloplasty, and a cineangiogram during the procedure revealed a balloon indentation on the calcified leaflet (Fig. 1d). CT re-evaluation showed a 22-mm distance between the sinus of Valsalva and the calcified commissure (Fig. 1c). Therefore, a 23-mm SAPIEN XT valve (Edwards Life-science, Irvine California) was implanted with 1 mL filling lesser than the recommended volume. A cineangiogram found that the calcification was not deformed and that the prosthetic valve was mainly expanded toward the noncoronary cusp (Fig. 1e). Postoperative CT showed that the prosthetic valve was implanted in an elliptical shape (Fig. 1f). The patient remains well 12 months after the procedure, with trivial paravalvular leakage on TTE, aortic valve mean pressure gradient of 13 mmHg, and aortic valve area of 1.5 cm.

One-stage Surgery in Patients with Ischemic Heart Combined with Occlusive Peripheral Vascular Disease.

1991年1月より5年間に10例のCABGと動脈硬化性閉塞病変の同時手術を施行した (AAA合併例は除く). 手術時年齢は平均65.8歳で, 冠動脈グラフト本数は平均2.2本で, 動脈硬化性病変の術式は内頸動脈のTEA2例, 大動脈-鎖骨下動脈バイパス2例, 大動脈-両側総腸骨動脈バイパス1例, 総腸骨動脈 interposition 1例, 大動脈-外腸骨動脈バイパス1例, F-Pバイパス3例 (4本), F-Tバイパス1例であり, 手術時間は平均428分, 体外循環時間は平均121分, 大動脈遮断時間は平均61分であった. 無輸血は4例であった. 手術死亡はPMI合併後緊急IABP挿入肢のMNMSの1例であった. 同時期に施行した待期的CABG単独施行183例と比較検討した. 手術時間, 出血量は同時手術例で多かったが, 手術死亡率, 無輸血率, 挿管日数, 術後入院日数は有意差を認めず, 手術は安全に行われた.