Fumihiko Saeki

Effects of competitive blood flow on arterial graft patency and diameter: Medium-term postoperative follow-up

To identify predictors of arterial graft patency, we followed up 30 internal thoracic arterial grafts and 23 right gastroepiploic arterial grafts in situ with patency documented during postoperative angiography. After 24 months of follow-up on average, repeat angiography detected that one internal thoracic artery and two gastroepiploic arteries were anatomically occluded and that the other three gastroepiploic arteries were nonfunctioning. The logistic regression model identified a relationship between graft patency and competitive flow, which was detected as stenosis in the recipient coronary arteries (coefficients, p < 0.05; model, Hosmer-Lemeshow chi2 statistic 3.59, p = 0.89). The linear regression model demonstrated that changes in graft luminal diameter correlated with competitive flow (p < 0.01), smoking history (p < 0.05), and type of arterial grafts (p < 0.001) (R2 = 0.40, adjusted R2 = 0.36). The findings suggest a temporal relationship between competitive flow and prognosis of arterial graft.

Heart Rate Recovery After Exercise Is a Predictor of Silent Myocardial Ischemia in Patients With Type 2 Diabetes

OBJECTIVE Slow heart rate recovery (HRR) predicts all-cause mortality. This study investigated the relationship between silent myocardial ischemia (SMI) and HRR in type 2 diabetes. RESEARCH DESIGN AND METHODS The study enrolled 87 consecutive patients with type 2 diabetes and no chest symptoms. They underwent treadmill exercise testing and single-photon emission computed tomography imaging with thallium scintigraphy. Patients with abnormal myocardial perfusion images also underwent coronary angiography. RESULTS SMI was diagnosed in 41 patients (47%). The SMI group showed slower HRR than the non–SMI group (18 ± 6 vs. 30 ± 12 bpm; P < 0.0001). HRR was significantly associated with SMI (odds ratio 0.83 [95% CI 0.75–0.92]; P = 0.0006), even after adjustment for maximal exercise workload, resting heart rate, maximum heart rate, rate pressure product, HbA1c, use of sulfonamides, and a history of cardiovascular disease. CONCLUSIONS HRR can predict SMI in patients with type 2 diabetes.

Relation of coronary plaque composition determined by 64-slice multidetector computed tomography in patients with suspected coronary heart disease.

Sixty-four-slice multidetector row computed tomography is a noninvasive method of assessing coronary artery stenosis and plaque composition. The aim of this study was to clarify the relation between plaque composition and coronary heart disease. Three hundred sixty consecutive patients and 1,085 plaques were evaluated using 64-slice multidetector row computed tomography. On axial or cross-sectional multiplanar reconstruction images, 3 regions of interest were randomly selected within each plaque. Soft plaques and calcified plaques were defined as having computed tomographic densities <50 and >130 Hounsfield units, respectively. The association between coronary risk factors and plaque composition was analyzed. The number of plaques and the mean computed tomographic density of plaques were significantly higher in men than in women (p = 0.002 and p = 0.04, respectively). Coronary plaques were more frequent in patients with stroke, diabetes, hypertension, and dyslipidemia than in patients without these conditions (all p values <0.001). Calcified plaques were more frequent in patients with hypertension (p = 0.02), and patients with calcified plaques also had significantly lower low-density lipoprotein cholesterol levels (p <0.001). Soft plaques were more frequent in patients with dyslipidemia (p <0.001). Patients with soft plaques had significantly higher low-density lipoprotein cholesterol levels (p = 0.02) and lower high-density lipoprotein cholesterol levels (p <0.001) than those without soft plaques. In conclusion, 64-slice multidetector row computed tomography is a useful noninvasive method for quantifying coronary plaques.