Neurogenic regulation of basal tone of coronary artery with mild atherosclerosis in humans: observation using two-dimensional intravascular ultrasound

The purpose of this study was to assess the role of the autonomic nervous system in the regulation of basal coronary artery tone in normal and atherosclerotic plaque segments by using intravascular ultrasound in humans. In each of 21 patients, a short-axis image at one site of coronary artery was imaged by means of a 3.2F, 30-MHz intravascular ultrasound before and after intracoronary administration of 2 mg isosorbide dinitrate (ISDN). The authors identified the perimeters of the vessel wall segments with normal or atherosclerotic plaque on ultrasound images and evaluated the basal tone in each segment as a percent increase in each perimeter produced by ISDN. Using heart rate variability analysis for 512 seconds recorded immediately before ISDN administration, they evaluated cardiac sympathetic and vagal activities at rest as the integrated power of fast Fourier transform (FFT) spectrum for the low-frequency (LF: 0.04 to 0.15 Hz), and high-frequency (HF: 0.15 to 0.4 Hz) components, respectively. Of 29 segments examined by ultrasound, 16 were normal and 13 were atherosclerotic plaque. In all 29 segments, ISDN produced an increase in the perimeter of the vessel wall. At the normal 16 segments, the increase in perimeter by ISDN exhibited a significant correlation to the power of HF (r = 0.749, p = 0.0008) but no significant correlation to LF. At 13 plaque segments, however, no significant correlation between the response to ISDN and autonomic nerve activity was observed. In conclusion, the basal tone of normal coronary arterial wall segment is closely related to parasympathetic nerve, whereas the relation is impaired in mild atherosclerotic segments.     

Effects of valsartan and amlodipine on home blood pressure and cardiovascular events in Japanese hypertensive patients: a subanalysis of the VART

The Valsartan Amlodipine Randomized Trial (VART) was performed to compare the beneficial effects of valsartan and amlodipine on cardiovascular events in Japanese hypertensive patients. In this subanalysis of the VART, we assessed the relationship between home blood pressure (HBP) levels and cardiovascular events in the enrolled patients. We enrolled 1021 patients with mild-to-moderate hypertension in the VART. The participants were allocated randomly to either the valsartan group or the amlodipine group. The primary end point was a composite of all-cause death, sudden death, cerebrovascular events, cardiac events, vascular events and renal events. A total of 621 patients (valsartan group: 305 and amlodipine group: 316) completed the measurements of HBP (morning and evening) throughout the trial. Both the agents evenly and significantly lowered morning HBP and evening HBP throughout the trial. There was no significant difference in the primary end point between the two groups. However, we observed significant decreases in the left ventricular mass index and urinary albumin to creatinine ratio in the valsartan group but not in the amlodipine group. There were no significant differences in HBP levels and the main outcome of the cardiovascular events between the valsartan and amlodipine groups. However, in the valsartan group, significant improvements in left ventricular hypertrophy and microalbuminuria were observed.     

The relationship between HIV testing and CD4 counts at HIV diagnosis among newly diagnosed HIV-1 patients in Japan

The aim of this study was to investigate the factors relating to CD4 level at HIV diagnosis and HIV testing behaviour. Participants were newly diagnosed patients (n = 654) in Japan from 2000 to 2005. Around 75% of participants were diagnosed at hospital and clinics. Mean CD4 counts at diagnosis through voluntary HIV testing, screening tests and testing due to concomitant sexually transmitted infection (STI) were 368, 336 and 316 cells/μL, respectively. In contrast, the mean CD4 count where testing was due to the presence of HIV-related clinical symptoms was 151 cells/μL (P < 0.0001). Compared with those diagnosed at their first HIV test, those who had undertaken multiple HIV tests prior to diagnosis showed CD4 counts that increased significantly (P < 0.0001) in relation to the number of tests undertaken: CD4 count at first test was 232 cells/μL, second test 346 cells/μL and third or additional tests 439 cells/μL. According to our results, HIV testing policy that promotes HIV testing in medical settings and among STI patients is needed to facilitate earlier HIV diagnosis in Japan.