| 1. |
- Boushel, Robert, 1959-
(author)
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Capacity and hypoxic response of subcutaneous adipose tissue blood flow in humans
- 2014
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In: Circulation Journal. - Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 78:6, s. 1501-1506
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Journal article (peer-reviewed)abstract
- BACKGROUND:The blood flow capacity in subcutaneous adipose tissue in humans remains largely unknown, and therefore the aim of this study was to determine the physiological range of blood flow in this tissue.METHODS AND RESULTS:The subcutaneous adipose tissue blood flow (ATBF) was measured in 9 healthy young men by positron emission tomography using radiowater tracer. Subcutaneous ATBF was determined in regions adjacent to knee extensors at rest and during dynamic knee extensor exercise, and with 2 physiological perturbations: while breathing moderate systemic hypoxic air (14% O2) at rest and during exercise, and during intra-femoral artery infusion of high-dose adenosine infusion. ATBF was 1.3±0.6ml·100g(-1)·min(-1) at rest and increased with exercise (8.0±3.0ml·100g(-1)·min(-1), P<0.001) and adenosine infusion (10.5±4.9ml·100g(-1)·min(-1), P=0.001), but not when breathing moderate systemic hypoxic air (1.5±0.4ml·100g(-1)·min(-1)). ATBF was similar during exercise and adenosine infusion, but vascular conductance was lower during adenosine infusion. Finally, ATBF during exercise in moderate systemic hypoxia was reduced (6.3±2.2ml·100g(-1)·min(-1)) compared to normoxic exercise (P=0.004).CONCLUSIONS:The vasodilatation capacity of human subcutaneous adipose blood flow appears to be comparable to, or even higher, than that induced by moderate intensity exercise. Furthermore, the reduced blood flow response in subcutaneous adipose tissue during systemic hypoxia is likely to contribute, in part, to the redistribution of blood flow to exercising muscle in a condition of reduced oxygen availability.
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| 2. |
- Hatano, Masaru, et al.
(author)
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Less frequent opening of the aortic valve and a continuous flow pump are risk factors for postoperative onset of aortic insufficiency in patients with a left ventricular assist device
- 2011
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 75:5, s. 1147-1155
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Journal article (peer-reviewed)abstract
- BACKGROUND:Postoperative development of aortic insufficiency (AI) after implantation of left ventricular assist devices (LVADs) has recently been recognized, but the devices in the previous reports have been limited to the HeartMate I or II. The purposes of this study were to determine whether AI develops with other types of LVADs and to elucidate the factors associated with the development of AI.METHODS AND RESULTS:Thirty-seven patients receiving LVADs without evident abnormalities in native aortic valves were enrolled (pulsatile flow LVAD [TOYOBO]: 76%, continuous flow LVAD [EVAHEART, DuraHeart, Jarvik2000, HeartMate II]: 24%). Frequency of aortic valve opening and grade of AI were evaluated by the most recent echocardiography during LVAD support. None of the patients had more than trace AI preoperatively. During LVAD support AI >- grade 2 developed in 9 patients (24%) across all 5 types of devices. More severe grade of AI correlated with higher plasma B-type natriuretic peptide concentration (r = 0.53, P < 0.01) and with less frequent of the aortic valve (r = 0.45, P < 0.01). Multivariate analysis revealed that lower preoperative left ventricular ejection fraction and a continuous flow device type were independent risk factors for higher incidence of AI.CONCLUSIONS:AI, which is hemodynamically significant, develops after implantation of various types of LVADs. Physicians need to be more alert to the development of AI particularly with continuous flow devices.
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| 3. |
- Hori, Masatsugu, et al.
(author)
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Efficacy and Safety of Dabigatran vs. Warfarin in Patients With Atrial Fibrillation - Sub-Analysis in Japanese Population in RE-LY Trial
- 2011
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In: Circulation Journal. - 1346-9843 .- 1347-4820. ; 75:4, s. 800-805
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Journal article (peer-reviewed)abstract
- Background: RE-LY (Randomized Evaluation of Long-term Anticoagulation Therapy) is an international multi-center study (18,113 patients from 967 centers in 44 countries) that demonstrated the ability of dabigatran to reduce the occurrence of both stroke and hemorrhage in patients who had atrial fibrillation (AF) with high risks of stroke compared with patients who received warfarin. From Japan, 326 patients were randomized in RE-LY. Methods and Results: RE-LY was designed to compare 2 fixed doses (110 mg or 150 mg, twice daily) of dabigatran, each administered in a blinded manner, with open-label use of warfarin. There were no major differences in patient demographic information among the overall study population and Japanese patients. However. in Japanese patients, the proportion of prior stroke was higher but prior myocardial infarction was lower than in the overall. The yearly rate for the primary endpoints (stroke and systemic embolism) was 1.38, 0.67 and 2.65%/year for 110 mg and 150 mg dabigatran twice daily and warfarin, respectively. These results were similar to the overall results (1.54, 1.11 and 1.71%/year for each group, respectively). For any bleeding, the relative risk of dabigatran at 110 mg and 150 mg twice daily over warfarin was 0.79 and 1.06, respectively, which was similar to the findings overall (dabigatran 110 mg twice daily: 0.78; 150 mg twice daily: 0.91). Conclusions: In RE-LY, the efficacy and safety profiles of dabigatran for Japanese AF patients at high risk of stroke were essentially the same as for the study population overall.
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| 4. |
- Imamura, Teruhiko, et al.
(author)
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Late-onset right ventricular failure in patients with preoperative small left ventricle after implantation of continuous flow left ventricular assist device
- 2014
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 78:3, s. 625-633
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Journal article (peer-reviewed)abstract
- Background: The continuous flow (CF) left ventricular assist device (LVAD) has replaced the pulsatile flow (PF) LVAD because of its advantages of better patient survival and higher quality of life. However, "late-onset right ventricular failure (RVF)" after CF LVAD implantation has emerged as an increasing concern, but little is known about the mechanism. Methods and Results: We retrospectively analyzed the 3-month hemodynamic and echocardiographic data from 38 consecutive patients who had received CF LVADs, and from 22 patients who had received PF LVADs. Late-onset RVF was defined as persistent right ventricular stroke work index (RVSWI) less than4.0 g/m(2) at any rotation speed and after saline infusion test at 5 weeks after implantation of CF LVAD. Patients with late-onset RVF had significantly impaired exercise tolerance indicated by shorter 6-min walking distance and lower peak (V) over dot O-2, and worsened tricuspid regurgitation, together with enlargement of the RV under CF LVAD treatment (all Pless than0.05). Univariable analyses demonstrated that preoperative smaller LV diastolic diameter (LVDd) was the risk factor for late-onset RVF with a cutoff value of 64 mm calculated by ROC analysis (area under curve, 0.925). In contrast, there was no correlation between preoperative LVDd and postoperative RVSWI in the PF LVAD group, though their preoperative background was worse than that of the CF group. Conclusions: In the setting of preoperative small LVDd, CF LVAD may cause late-onset RVF by leftward shift of the interventricular septum.
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| 5. |
- Imamura, Teruhiko, et al.
(author)
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Novel criteria of urine osmolality effectively predict response to tolvaptan in decompensated heart failure patients--association between non-responders and chronic kidney disease
- 2013
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 77:2, s. 397-404
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Journal article (peer-reviewed)abstract
- BACKGROUND:A newly-developed vasopressin type 2 receptor antagonist, tolvaptan (TLV), has a unique feature of diuresis, but the response to this drug can be unpredictable.METHODS AND RESULTS:Data were collected from hospitalized patients with decompensated congestive heart failure who were administered TLV at 3.75-15 mg/day (n=61). A responder/non-responder to TLV was determined as having any increase/decrease in urine volume (UV) during the next 24h after TLV treatment on the first day. Logistic regression analyses for increases in UV were performed, and independent predictors of the responder were the following: C1, baseline urine osmolality (U-OSM) >352 mOsm/L; and C2, %decrease in U-OSM >26% at 4-6h after TLV administration. Criteria consisting of C1 and C2 had a good predictability for responders by receiver-operating characteristic analysis (area under the curve=0.960). Kidneys of the non-responders no longer had diluting ability (%decrease of U-OSM at 4-6h=2.7 ± 14.6%*), but also barely kept concentrating ability (baseline U-OSM=296.4 ± 68.7*mOsm/L) with markedly reduced estimated glomerular filtration ratio (35.5 ± 29.4 m l · min(-1) · 1.73 m(-2)*) (*P<0.05 vs. patients who had at least 1 positive condition [n=42]).CONCLUSIONS:More than 26% decrease in U-OSM from a baseline >352 mOsm/L for the first 4-6h predicts responders to TLV. Unresponsiveness to TLV is attributable to nephrogenic diabetes insipidus complicated by chronic renal disease.
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| 6. |
- Imamura, Teruhiko, et al.
(author)
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Novel risk scoring system with preoperative objective parameters gives a good prediction of 1-year mortality in patients with a left ventricular assist device.
- 2012
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 76:8, s. 1895-1903
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Journal article (peer-reviewed)abstract
- BACKGROUND:As we have previously reported, the preoperative profile defined by INTERMACS is a good predictor for the prognosis after left ventricular assist device (LVAD) implantation, but is largely dependent on the physician's decision. Several other risk stratification systems including objective parameters (eg, Leitz-Miller, Columbia, Seattle Heart Failure Model, APACHE II) have been proposed to estimate patient's mortality after LVAD implantation.METHODS AND RESULTS:According to the preoperative data from 59 patients who received LVAD (10 implantable, 49 extracorporeal) since 2002 through 2010, we performed a logistic analysis and constructed a new scoring system (ie, the TODAI VAD score (TVAD score), assigning 8 points to serum albumin <3.2mg/dl (odds ratio [OR] 8.475), 7 points to serum total bilirubin >4.8mg/dl (OR 7.300), 6 points to left ventricular end-diastolic diameter <55mm (OR 5.917), 5 points to central venous pressure >11mmHg (OR 5.128)). The receiver-operating characteristic analysis showed that the area under the curve of our new scoring system (0.864) was significantly larger than any of the abovementioned 5 scoring methods (all P<0.05). With the TVAD score, low (0-8 points), intermediate (9-17 points), and high (18-26 points) risk strata had significantly different 1-year survival rates of 95%, 54%, and 14%, respectively (all P<0.001).CONCLUSIONS:The TVAD score can predict the prognosis after LVAD implantation much better than the previously known methods.
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| 7. |
- Imamura, Teruhiko, et al.
(author)
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Preoperative Levels of Bilirubin or Creatinine Adjusted by Age Can Predict Their Reversibility After Implantation of Left Ventricular Assist Device
- 2013
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 77:1, s. 96-104
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Journal article (peer-reviewed)abstract
- Background: It is often difficult to predict reversibility of liver or renal function after left ventricular assist device (LVAD) implantation in patients with stage D heart failure. Methods and Results: Data were obtained for 69 patients who had received a LVAD (18 continuous-flow, 51 pulsatile). Persistent hepatic or renal dysfunction was defined as levels of total bilirubin (TB) or creatinine (Cre) greater than1.5 mg/dl at 6 months after LVAD implantation. TB score or Cre score was calculated: 0.15 x age+ 1.1x (preoperative TB) or 0.2 x age + 3.6 x (preoperative Cre), in which coefficients were determined on the basis of odds ratios for persistent hepatic or renal dysfunction, respectively. Receiver-operating characteristics analyses showed good predictabilities for persistent end-organ dysfunction (area under curve: 0.794 for TB score and 0.839 for Cre score). High-risk strata of TB score (greater than11.0 points) or Cre score (greater than14.1 points) were associated with persistently higher levels of TB or Cre (TB, 1.32 +/- 0.51; Cre, 1.23 +/- 0.41 mg/dl; both Pless than0.001 vs. low-risk strata). Conclusions: Reversibility of end-organ function with LVAD implantation can be well predicted by our new risk scoring system that consists of the preoperative TB or Cre level adjusted by the patients age. The scoring system would be beneficial, especially in considering the indication of a bridge to candidacy.
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| 8. |
- Imamura, Teruhiko, et al.
(author)
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Urine osmolality estimated using urine urea nitrogen, sodium and creatinine can effectively predict response to tolvaptan in decompensated heart failure patients
- 2013
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 77:5, s. 1208-1213
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Journal article (peer-reviewed)abstract
- BACKGROUND:Urine osmolality (U-OSM) is valuable to predict response to tolvaptan (TLV) in decompensated heart failure patients, but measurement of U-OSM is not always available on site.METHODS AND RESULTS:Data were collected from 66 hospitalized patients with decompensated heart failure who had received TLV at 3.75-15 mg/day. U-OSM, which was estimated using the following formula: 1.07×{2×[(urine sodium (mEq/L)]+[urine urea nitrogen (mg/dl)]/2.8+[urine creatinine (mg/dl)]×2/3}+16, was well correlated with the actual measurement (r=0.938, P<0.001). Criteria consisting of C1 (estimated baseline U-OSM>358 mOsm/L) and C2 (%decrease in estimated U-OSM>24% at 4-6 h after the first TLV dose) significantly discriminated responders from non-responders (P<0.05).CONCLUSIONS:Response to TLV can be predicted using U-OSM, which can be estimated using urine urea nitrogen, sodium, and creatinine concentration data.
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| 9. |
- Kato, Naoko, et al.
(author)
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Quality of life as an independent predictor for cardiac events and death in patients with heart failure
- 2011
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 75:7, s. 1661-1669
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Journal article (peer-reviewed)abstract
- BACKGROUND:Little is known about health-related quality of life (QOL) in Japanese patients with heart failure. The purpose of this study was to identify factors related to QOL using a disease-specific QOL instrument, and to clarify whether QOL independently predicts clinical outcomes among Japanese patients with heart failure.METHODS AND RESULTS:A total of 114 outpatients with heart failure were enrolled (mean age 64.7 ± 15.8 years; 73.7% males). The Minnesota Living with Heart Failure Questionnaire (MLHFQ) to assess patient's QOL was used. At baseline, depressive symptoms and chronic kidney disease were significantly associated with worse QOL in multiple regression analysis. During a 2-year follow up, patients with a MLHFQ score ≥ 26, indicating worse QOL, had a higher incidence of the combined endpoint of cardiac death or hospitalization for heart failure, and a higher all-cause mortality than those with a score < 26 (25.3% vs. 7.5%, P = 0.011; 18.5% vs. 6.4%, P = 0.018; respectively). Multivariate Cox proportional hazard models demonstrated that a higher MLHFQ score was significantly associated with increased risks of cardiac events (hazard ratio, 1.02, 95% confidential interval, 1.001-1.05, P = 0.038) and of all-cause death (hazard ratio, 1.04, 95% confidential interval, 1.02-1.07, P = 0.001).CONCLUSIONS:Depressive symptoms and chronic kidney disease are major determinants of impaired QOL, and the MLHFQ score is an independent predictor of both cardiac events and death among Japanese patients with heart failure.
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| 10. |
- Kato, Naoko, et al.
(author)
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Trend of clinical outcome and surrogate markers during titration of β-blocker in heart failure patients with reduced ejection fraction : relevance of achieved heart rate and β-blocker dose
- 2013
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In: Circulation Journal. - : Japanese Circulation Society. - 1346-9843 .- 1347-4820. ; 77:4, s. 1001-1008
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Journal article (peer-reviewed)abstract
- BACKGROUND:The aim of this study was to examine trends of clinical outcome and to clarify surrogate markers when titrating β-blocker in heart failure patients with reduced left ventricular ejection fraction (HFrEF, LVEF <50%).METHODS AND RESULTS:Consecutive HFrEF patients starting on β-blocker were divided into 2 groups according to time of dose fixation attainment: before 31 December 2005 (group 1, n=108) or after 1 January 2006 (group 2, n=119). There were no significant differences in patient characteristics between the 2 groups at baseline. Beta-blocker fixed dose was higher with lower resting heart rate in group 2 (6.2±5.7mg/day vs. 9.5±9.1mg/day in carvedilol equivalent dose, P=0.001; 74.2±11.1beats/min vs. 70.2±9.7beats/min, P=0.004). The rate of HF hospitalization and/or all-cause death after 36 months was lower in group 2 than in group 1 (22% vs. 38%, P=0.011; hazard ratio, 0.90; P=0.012). Cox regression analysis showed that β-blocker ≥10mg/day and achieved heart rate ≤71beats/min predicted a better outcome (both P<0.05).CONCLUSIONS:Recent improvement of clinical outcome among HFrEF patients may be attributable to the up-titration policy accompanying lowered heart rate. Resting heart rate ≤71beats/min and β-blocker ≥10mg/day (ie, 50% of the target dose for Japanese patients) could be surrogate markers when titrating β-blocker.
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