[Early and late results and problems of coronary artery bypass grafting in patients over 80-year-old].

This study evaluated the validity of coronary artery bypass grafting (CABG) in patients over 80-year-old investigating the early and late result, patient's opinion to the surgery, and change of activities of daily living scale. From July 1993 to September 2002, consecutive 94 patients over 80-year-old were performed CABG in our institution. The group consisted of 43 female patients, and mean age of 82.6 years. Of these patients, 36 were operated conventional CABG (CABG group) and 58 patients were operated with off-pump CABG (OPCAB) group. There were no significant differences between 2 groups in preoperative characteristics except for anemia and hypertension. Operative results, including mortality, number of distal anastomoses, operative time had no significant differences between 2 groups. But maximum CK-MB fraction was higher in CABG group. There were 4 operative deaths, indicating operative mortality was 4.3%. Late results showed overall survival rate at 3 years was 81.1% and cardiac event free survival rate at 3 years was 88.8%. Questionnaire revealed over 80% patients were satisfied with the surgery but less than 40% patients felt activities of daily living (ADL) scale was improved. Operative results of CABG in octogenarians were satisfied, but more efforts to remain patient's high ADL were mandatory.

A rat model of dilated cardiomyopathy to investigate partial left ventriculectomy.

BACKGROUND: This study is the first to assess a small animal model of dilated cardiomyopathy (DCM) for evaluation of partial left ventriculectomy. METHOD: Eighteen Dahl salt-sensitive (DS) rats were divided into three groups. Six rats were fed an 8% high-salt diet from the age of 7 weeks (Group 1), and similarly six rats from 8 weeks (Group 2) and six from 9 weeks (Group 3). Blood pressure (BP) was measured by the tail-cuff method and left ventricular (LV) dimensions by echocardiography. RESULTS: In Groups 1 and 2, systolic BP rose and reached 200 mmHg by the 10th to 11th week, when all rats died within a week without signs of heart failure. However, in Group 3, systolic BP gradually rose to 196+/-15 mmHg (mean +/- SD) at the age of 14 weeks, when LV end-diastolic diameter (EDD) was 6.2+/-0.4 mm (control 5.1+/-0.7 mm) and LV fractional shortening (FS) was 77+/-3% (control 68+/-3%). At the age of 25 to 30 weeks, all rats in Group 3 showed signs of congestive heart failure, systolic BP remained high, EDD markedly increased (8.7+/-0.6 mm), and LVFS decreased (38.9+/-8.1%). From this stage, rats survived for 13.7+/-5.9 days. We employed the Group 3 model for our pilot PLV study. Eight rats had PLV with a beating heart by plicating the LV area between the papillary muscle bases. Two rats died perioperatively but the rest survived (60% survival 3 weeks after PLV). Postoperatively, the rats' LVEDD decreased and FS improved significantly. CONCLUSIONS: Using DS rats, we developed a DCM model for investigating PLV. The model may contribute to scientific investigation of PLV.

VCAM-1 expression precedes macrophage infiltration into subendothelium of vein grafts interposed into carotid arteries in hypercholesterolemic rabbits--a potential role in vein graft atherosclerosis.

Intimal hyperplasia and atherosclerosis are major causes of late vein graft failure after coronary artery bypass surgery. Hypercholesterolemia appears to be a key risk factor for atherosclerosis in vein grafts as well as in native arteries. We used a rabbit model of interposition jugular vein graft to the carotid artery and compared intimal thickening, macrophage accumulation, and VCAM-1 expression between hypercholesterolemic (H group) and normocholesterolemic (N group) rabbits. Fifty-nine rabbits were divided into H and N groups. Intimal thickening in vein grafts was approximately three times more prominent in the H group than in the N group. Macrophage accumulation progressively increased with time in H group vein grafts, although it was negligible in the N group. In the H group, moreover, macrophages were initially more abundant in deep intima, and subsequently accumulated in subendothelium of the grafted vein. VCAM-1 expression in luminal endothelial cells of the grafted veins was time-dependently increased after the vein graft surgery in both the H and N groups, and was more prominent in the H group. Comparison of the time-courses between macrophage accumulation and VCAM-1 expression revealed that VCAM-1 expression in luminal endothelium preceded subendothelial accumulation of macrophages. VCAM-1 expression and macrophage accumulation may be key factors which regulate progression of vein graft atherosclerosis.

[Two successful cases of coronary artery bypass grafting followed by transluminal carotid angioplasty with stenting].

In coronary artery bypass grafting (CABG), carotid artery disease is an important factor that affects the incidence of perioperative stroke. The incidence of stroke following cardiac surgery is about 5 times higher in patients with carotid lesions than in patients without them. However, therapeutic strategies for those cases have not established in recent years. We report 2 successful cases of CABG following transluminal carotid angioplasty with stenting (TCAS) for concomitant coronary and carotid artery disease. The first case was a 71-year-old male who had left main trunk (LMT) and three-vessel coronary artery disease (CAD) and a 90% stenosis of the right internal carotid artery (ICA). One month after TCAS, triple CABG with cardiopulmonary bypass (CPB) was performed. The second case was a 75-year-old male who had LMT and single vessel CAD and a 99.9% stenosis of the lt. ICA. Considering his poor general conditions, combined strategy of off-pump CABG and PTCA was performed following TCAS. During and after cardiac surgery, they had no cerebral complications. Postoperative myocardial scintigraphy showed improved imaging in both cases. Preoperative TCAS is a safe and minimally invasive procedure for the patients with carotid artery stenosis who need CABG.

Differences in arousal response between aged and middle-aged patients with obstructive sleep apnea syndrome.

The aim of this study is to show the clinical significance of the differences in arousal response at a termination of apnea/hypopnea between aged and middle-aged patients with obstructive sleep apnea syndrome (OSAS). We polygraphically assessed electrocardiographic (ECG) and electroencephalographic (EEG) arousal. Electrocardiographic arousal was defined as an abrupt increase in heart rate at a termination of apnea/hypopnea. Our findings showed that EEG and ECG arousal at a termination of apnea/hypopnea were significantly suppressed in aged patients with OSAS, which might provide useful information on the pathophysiology, of OSAS.

Natriuretic peptide receptors in human artery and vein and rabbit vein graft.

Natriuretic peptides elicit their biological effects by elevation of cGMP through activation of two biologically active receptors: natriuretic peptide A receptor, which shows high affinity to atrial and brain natriuretic peptides, and natriuretic peptide B receptor, which is specific to C-type natriuretic peptide. To elucidate the implications of the natriuretic peptide system in arteries and veins, we examined the cGMP production in response to atrial and C-type natriuretic peptide and gene expressions of biologically active natriuretic peptide receptors in human gastroepiploic artery, internal mammary artery, and saphenous vein. Atrial natriuretic peptide augmented cGMP production more potently by one order of magnitude in arteries than in veins. C-type natriuretic peptide stimulated cGMP production weakly and equally in these vessels. Analyzed by reverse transcription-polymerase chain reaction, gene expression of natriuretic peptide A receptor was four times more abundant in arteries than in veins. Gene expression of natriuretic peptide B receptor was approximately the same between these vessels. We also studied the responsiveness to atrial and C-type natriuretic peptide in rabbit jugular vein grafted into carotid artery. In arterialized vein grafts 4 weeks after operation, the effects of atrial and C-type natriuretic peptides on cGMP production did not change from those in jugular veins. In conclusion, atrial natriuretic peptide stimulates cGMP production more potently in arteries than in veins due to the preferential expression of natriuretic peptide A receptor in arteries. These observations support the distinct roles of natriuretic peptides in cardiovascular homeostasis.

New surgical technique for repair of ventricular septal perforation.

We describe a technique for repairing the ventricular septal perforation using porcine pericardium tailored in a conical shape. This technique may allow a good operating view and facilitate suturing to the left ventricular cavity.

[Perioperative management for type A acute aortic dissection].

Twenty nine cases of type A acute aortic dissection were subjected to a retrospective study concerning perioperative management. Two keys pointed out for the management were as follow; (1) An optimal control of blood pressure is the most important measure to avoid advance of aortic dissection or rupture of dissecting aneurysm. Both pericardiac tamponade and aortic valve insufficiency should be taken care of from their onset, since they are often complicated after aortic dissections and their onset is fatal. (2) Separated brain perfusion and profound hypothermia with total circulatory arrest might involve a high risk of inducing postoperative brain damage and mortality, especially for old patients.