Time in the therapeutic range during warfarin therapy in Japanese patients with non-valvular atrial fibrillation. - A multicenter study of its status and infuential factors-.

BACKGROUND: Time in the therapeutic range (TTR) assesses the appropriateness of international normalized ratio of prothrombin time (PT-INR) control during warfarin therapy. We examined the status of and the factors influencing TTR in Japanese patients with non-valvular atrial fibrillation (AF). METHODS AND RESULTS: We enrolled 501 AF patients (mean age, 70 ± 10 years; males 66%; mean CHADS2 score 2.0 ± 1.2) taking warfarin for ≥ 2 years from 5 prefectures. The PT-INR therapeutic range was set up according to the 2008 Japanese Guideline. TTR was 64 ± 25% for all patients and varied from 56% to 74% with the institution. Time below and above TTR was 31 ± 26% and 5 ± 7%, respectively. TTR was not affected by gender or antiplatelet co-administration. TTR in patients < 70 and ≥ 70 years old was 46 ± 23% and 77 ± 17%, respectively (P < 0.0001). TTR in patients with CHADS2 score ≤ 1 and ≥ 2 was 59 ± 27% and 68 ± 23%, respectively (P < 0.0001). TTR in patients with warfarin doses < 2.0, 2.0-4.9, and ≥ 5.0 mg/day was 72 ± 22%, 63 ± 25% and 48 ± 24%, respectively (all P < 0.001). Multivariate analysis revealed age and warfarin dose as independent predictors of TTR. CONCLUSIONS: TTR is generally high in Japan, although it varies with institutions. Most of the time spent out of therapeutic range is below the range. TTR is influenced by age presumably because of the low range recommendation for elderly patients, and by warfarin dose presumably because of physicians' anxiety about the hemorrhage risk.

Novel pro-atherogenic molecule coupling factor 6 is elevated in patients with stroke: a possible linkage to homocysteine.

BACKGROUND AND PURPOSE: Homocysteine (Hcy) is an independent predictor of stroke. Coupling factor 6 (CF6) is regulated by nuclear factor kappa B (NF-kappaB) signaling which is activated by Hcy. We tested the hypothesis that CF6 is elevated with Hcy in stroke. We also examined the effect of vitamin treatment on CF6 and Hcy levels. METHODS AND RESULTS: The 59 Japanese patients with a recent history of stroke were randomly assigned to a group without vitamin treatment (Group 1, n = 29) and to a group with treatment with both folic acid and vitamin B(12) for 2 months (Group 2, n = 30). The CF6 level was elevated in the patients with stroke compared with that in controls (n = 64) at admission. In a multiple regression model, the plasma CF6 level was weakly correlated to the total Hcy (tHcy) level. In Group 1, the plasma tHcy and CF6 levels were unchanged. In Group 2, however, they were both decreased, and there was a weak positive correlation between the decreases in plasma levels of CF6 and tHcy. CONCLUSION: CF6 is elevated in patients with stroke independently of risk factors. Since Hcy and vitamin treatment affect CF6 levels in stroke, CF6 appears to be a novel molecule for the pathogenesis and treatment of stroke.

Effect of losartan on nocturnal blood pressure in patients with stroke: comparison with angiotensin converting enzyme inhibitor.

BACKGROUND: Treatment of nocturnal hypertension has been reported to be beneficial for primary and secondary prevention of stroke. We compared the effects of angiotensin II antagonist (losartan) and angiotensin converting enzyme inhibitor (quinapril) on nocturnal blood pressure (BP) and sympathetic nervous activity in patients with hypertension and stroke. METHODS: According to a prospective, randomized, cross-over design, 30 hypertensive patients with a previous history of stroke (25 hemorrhage, 5 infarction) were assigned randomly to receive losartan (50 mg) or quinapril (10 mg) once daily for 4 weeks. The patients were switched to the alternative regimen for an additional 4-week period. In the last week of each treatment, 24-h ambulatory BP monitoring was performed every 30 min, and 24-h urine was collected for the measurement of catecholamine. RESULTS: Neither systolic nor diastolic BP during daytime differed between losartan and quinapril treatments, but those during nighttime were lower with losartan treatment than with quinapril treatment. The nocturnal decreases in systolic and diastolic BP were both greater with losartan treatment than with quinapril treatment (systolic BP: 6.1% +/- 5.9% v 2.5% +/- 6.9%, diastolic BP: 6.4% +/- 6.5% v 3.3% +/- 7.8%, both P <.05). The nocturnal decrease in urinary norepinephrine excretion was greater with losartan treatment than with quinapril treatment (52.8% +/- 9.7% v 42.8% +/- 17.2%, P <.05). CONCLUSIONS: Losartan enhances the nocturnal decrease in ambulatory BP compared with that of quinapril in patients with a previous history of stroke presumably by way of the suppression of nocturnal sympathetic nervous activity.