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- Imamura, Teruhiko, et al.
(author)
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A case with recovery of response to tolvaptan associated with remission of acute kidney injury and increased urine osmolality
- 2013
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 54:2, s. 115-118
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Journal article (peer-reviewed)abstract
- Tolvaptan (TLV), a vasopressin type 2 receptor antagonist, has been demonstrated to be effective in patients with decompensated heart failure (HF) refractory to incremental doses of diuretics, but the responsiveness has not always been predictable. We have recently proposed that urine osmolality (U-OSM) is a valuable parameter for the prediction of responses to TLV, because U-OSM reflects the activity of the collecting ducts, where TLV plays its unique role. Acute kidney injury (AKI) is often associated with severe tubular dysfunction, including the collecting ducts, and in such cases a response to TLV may not be expected. We here experienced a patient with HF and AKI in whom TLV was not effective during AKI. We also observed recovery of responsiveness to TLV along with remission of AKI as well as increased U-OSM later on. We believe that this is the first report on the reversibility of the TLV response in relation to U-OSM.
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- Imamura, Teruhiko, et al.
(author)
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Correction of hyponatremia by tolvaptan before left ventricular assist device implantation
- 2012
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 53:6, s. 391-393
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Journal article (peer-reviewed)abstract
- Hypervolemic hyponatremia is often complicated with advanced heart failure together with increased excretion of sodium by diuretics. Tolvaptan, an oral vasopressin-2-receptor antagonist, has been previously reported to improve congestion and correct hyponatremia through increased excretion of free water. However, there is little evidence concerning the administration of tolvaptan in patients with stage D heart failure. We experienced 2 patients with stage D heart failure who received 3.75 mg/day of tolvaptan to correct hyponatremia before ventricular assist device implantation. It may be useful, even for patients with stage D heart failure, to administer a low dose of tolvaptan to treat hyponatremia before ventricular assist device implantation to avoid a drastic alteration in serum sodium concentration perioperatively.
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- Imamura, Teruhiko, et al.
(author)
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Everolimus-incorporated immunosuppressant strategy improves renal dysfunction while maintaining low rejection rates after heart transplantation in Japanese patients
- 2013
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 54:4, s. 222-227
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Journal article (peer-reviewed)abstract
- The long-term survival of heart transplantation (HTx) recipients has increased significantly in recent years, however, the nephrotoxic adverse effects of calcineurin inhibitors (CNIs) are still a major concern. Recently, an inhibitor of mammalian target of rapamycin, everolimus (EVL), has emerged as an alternative immunosuppressant drug that may allow CM dosage reduction and thereby spare renal function. Data were collected from 20 HTx recipients who had received EVL (target trough level 3-8 ng/mL) along with a dose reduction of CNIs and/or mycophenolate mophetil (MMF) and had been followed for 1 year. Estimated glomerular filtration rate increased significantly with a reduction in the CM dosage in a dose-dependent manner (P less than 0.001, r = -0.807). Neutrophil count increased significantly (P less than 0.05) with a reduction in the dosage of MMF (P = 0.009, r = -0.671). Cytomegalovirus antigenemia remained negative after EVL administration among all candidates without any antiviral agents (P = 0.001). There were no significant increases in the acute rejection rates among recipients with EVL compared to those without EVL (P = 0.132). An immunosuppressant strategy incorporating EVL could reduce the CM and MMF dosages, which resulted in improvements in renal dysfunction and neutropenia while maintaining low rejection rates among HTx recipients.
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5. |
- Imamura, Teruhiko, et al.
(author)
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Successful Conversion From Thiazide to Tolvaptan in a Patient With Stage D Heart Failure and Chronic Kidney Disease Before Heart Transplantation
- 2013
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 54:1, s. 48-50
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Journal article (peer-reviewed)abstract
- Chronic kidney disease (CKD) is often complicated with advanced heart failure because of not only renal congestion and decreased renal perfusion but also prolonged use of diuretics at higher doses, which sometimes results in hyponatremia. Preoperative CKD is known to be associated with poor prognosis after heart transplantation (HTx). We experienced a stage D heart failure patient with CKD and hyponatremia who was switched from trichlormethiazide to tolvaptan. His hyponatremia was normalized, and his renal function was improved after conversion to tolvaptan. In patients with stage D heart failure, it may be useful to administer tolvaptan with a concomitant reduction in the dose of diuretics in order to preserve renal function and avoid hyponatremia before HTx.
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- Imamura, Teruhiko, et al.
(author)
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Successful conversion to everolimus after cytomegalovirus infection in a heart transplant recipient
- 2012
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 53:3, s. 199-201
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Journal article (peer-reviewed)abstract
- Cytomegalovirus (CMV) infection remains a major problem in recipients with heart transplantation (HTx), because it may play a significant role in the development of cardiac allograft vasculopathy, which is one of the major causes of death after HTx. Valganciclovir (VGC) is effective for the treatment of CM V infection, but is often associated with neutropenia, especially when used with mycophenolate mophetil (MMF). We experienced an HTx recipient with positive CMV antigenemia who suffered progressive neutropenia after administration of VGC. We switched MMF to everolimus (EVL) and assay for CM V antigenemia was constantly negative even after discontinuation of VGC. In all other 14 HTx recipients who received EVL for any reason, we found that assay for CMV antigenemia remained negative throughout the period of EVL administration. Considering the prophylactic effect on CMV, EVL can not only be an alternative to rescue from comorbidity, but might also be indicated earlier especially in CMV-seronegative HTx recipients.
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7. |
- Imamura, Teruhiko, et al.
(author)
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Successful treatment of hemodynamic compromise caused by antibody-mediated and cellular rejection in a recipient 12 years after heart transplantation
- 2013
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 54:5, s. 328-331
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Journal article (peer-reviewed)abstract
- Heart transplantation (HTx) is an established therapy for stage D heart failure due to recent advances in immunosuppressive regimens. However, antibody-mediated rejection remains an unsolved problem because of its refractoriness to standard immunosuppressive therapy with high mortality and graft loss. We experienced a 16-year old patient with hemodynamic compromise caused by both cellular and antibody-mediated rejection 12 years after HTx. The rejection was refractory to repeated steroid pulse treatment, intravenous immunoglobulin administration, and intensifying immunosuppression including addition of everolimus. Eventually, she was successfully treated with repeated plasma exchange accompanied by a single administration of the anti-CD20 monoclonal antibody rituximab.
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8. |
- Imamura, Teruhiko, et al.
(author)
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Tolvaptan Can Improve Clinical Course in Responders Validation Analysis for the Definition of Responsiveness by Urine Volume
- 2013
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 54:6, s. 377-381
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Journal article (peer-reviewed)abstract
- We previously defined "responders" as patients with increases in urine volume (UV) on day 1 after the administration of tolvaptan (TLV), and demonstrated that responders to TLV could be predicted with considerable accuracy by urine osmolality (U-OSM) levels. Responders and non-responders to TLV should be associated with different clinical courses after a certain time following TLV administration. Therefore, the aim of the present study was to validate our definition of responders by clinical parameters 1 week after administration of TLV. Data (n = 85) were obtained from in-hospital patients with decompensated heart failure (HF) who had received TLV at 3.75-15 mg daily, and clinical data at 1 week after the administration of Thy were compared with those of baseline. Sixty patients (70.6%) were "responders", in whom UV on day 1 increased after the administration of TLV compared with day 0. "Non-responders" were older, and had higher serum creatinine concentration and lower baseline U-OSM than "responders". Serum creatinine concentration increased significantly in "non-responders", but was unchanged in "responders". Body weight, plasma B-type natriuretic peptide concentration, and HF symptom score decreased significantly in "responders", but remained unchanged in "non-responders". Increases in UV after the first administration of TLV were closely correlated with improvement of congestive HF after 1 week of TLV treatment, which verified our definition of "responders" to TLV.
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9. |
- Imamura, Teruhiko, et al.
(author)
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Urine sodium excretion after tolvaptan administration is dependent upon baseline serum sodium levels : a possible explanation for the improvement of hyponatremia with scarce chance of hypernatremia by a vasopressin receptor antagonist
- 2014
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 55:2, s. 131-137
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Journal article (peer-reviewed)abstract
- Several studies have demonstrated that tolvaptan (TLV) can improve hyponatremia in advanced heart failure (BF) patients with rare chance of hypernatremia. However, changes in serum sodium concentrations (S-Na) in patients with or without hyponatremia during TLV treatment have not been analyzed. Ninety-seven in-hospital patients with decompensated HF who had received TLV at 3.75-15 mg/day for 1 week were enrolled. Among 68 "responders", who had achieved any increases in urine volume (UV) during the first day, urinary sodium excretion during 24 hours (U-NaEx(24)) increased significantly during one week of TLV treatment along with higher baseline S-Na (P less than 0.05 and r = 0.325). Considering a cut-off value (S-Na, 132 mEq/L; AUC, 0.711) for any increases in U-NaEx(24), we defined "hyponatremia" as S-Na less than 132 mEq/L. In hyponatremic responders (n = 25), S-Na increased significantly, although 1 week was not sufficient for normalization (125.8 +/- 5.0 versus 128.9 +/- 4.3 mEq/L, P less than 0.05), along with unchanged U-NaEx(24) (2767 +/- 2703 versus 2972 +/- 2950 mg/day, NS). In contrast, in normonatremic responders (n = 43), S-Na remained unchanged (136.6 +/- 3.1 versus 137.4 +/- 2.9 mEq/L, NS) along with increased U-NaEx(24) (2201 +/- 1644 versus 4198 +/- 3550 mg/day, P less than 0.05). TLV increased S-Na only in hyponatemic responders by way of pure aquaresis, but increased U-NaEx(24) only in nonnonatremic responders, which explains the scarcity of hypernatremia. Epithelial Na-channels in the distal nephrons, whose repression by TLV increases urinary sodium excretion, may be attenuated by reduced ATP-supply in worse hemodynamics under hyponatremia.
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10. |
- Kato, Naoko, et al.
(author)
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Development and psychometric properties of the Japanese heart failure knowledge scale
- 2013
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In: International Heart Journal. - : International Heart Journal Association. - 1349-2365 .- 1349-3299. ; 54:4, s. 228-233
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Journal article (peer-reviewed)abstract
- Knowledge about their own condition is important for patients with heart failure (HF). No valid, reliable, and easily administered instrument is available to measure this knowledge in clinical practice. In this study, a HF knowledge scale was developed, and its psychometric properties were tested. Items related to knowledge about HF were extracted from relevant guidelines. Content validity of the items was confirmed by an expert panel including a cardiologist and nurses specialized in treatment and care of patients with HF. A self-administered questionnaire was then distributed to 187 patients with BY (64.0 +/- 12.1 years, males 69%). In 62% patients, a left ventricular ejection fraction of less than 50% was identified. Exploratory factor analysis demonstrated the one-dimensionality of the 15-item HF knowledge scale. Mean score was 10.7 +/- 3.0 (range, 0-15). Known-group validity testing revealed a significant difference in HF knowledge score between patients newly diagnosed with HF and patients experienced with HF (9.4 +/- 3.2 versus 10.8 +/- 2.9, P = 0.043). In addition, HF knowledge scale scores were correlated with HF self-care scores assessed by the European Heart Failure Self-Care Behavior Scale for evaluation of criterion validity (rho = 0.304, P less than 0.001). Cronbachs alpha was 0.79, and item-total correlation was 0.22-0.51, thereby suggesting that the reliability of the scale was acceptable. Acceptable validity and reliability were demonstrated for the HF knowledge scale developed in this study. This instrument could be useful in evaluation of patient knowledge about HF.
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