Yoshinari Yasuda

Revised Equations for Estimated GFR From Serum Creatinine in Japan

BACKGROUND Estimation of glomerular filtration rate (GFR) is limited by differences in creatinine generation among ethnicities. Our previously reported GFR-estimating equations for Japanese had limitations because all participants had a GFR less than 90 mL/min/1.73 m2 and serum creatinine was assayed in different laboratories. STUDY DESIGN Diagnostic test study using a prospective cross-sectional design. New equations were developed in 413 participants and validated in 350 participants. All samples were assayed in a central laboratory. SETTING & PARTICIPANTS Hospitalized Japanese patients in 80 medical centers. Patients had not participated in the previous study. REFERENCE TEST Measured GFR (mGFR) computed from inulin clearance. INDEX TEST Estimated GFR (eGFR) by using the modified isotope dilution mass spectrometry (IDMS)-traceable 4-variable Modification of Diet in Renal Disease (MDRD) Study equation using the previous Japanese Society of Nephrology Chronic Kidney Disease Initiative (JSN-CKDI) coefficient of 0.741 (equation 1), the previous JSN-CKDI equation (equation 2), and new equations derived in the development data set: modified MDRD Study using a new Japanese coefficient (equation 3), and a 3-variable Japanese equation (equation 4). MEASUREMENTS Performance of equations was assessed by means of bias (eGFR - mGFR), accuracy (percentage of estimates within 15% or 30% of mGFR), root mean squared error, and correlation coefficient. RESULTS In the development data set, the new Japanese coefficient was 0.808 (95% confidence interval, 0.728 to 0.829) for the IDMS-MDRD Study equation (equation 3), and the 3-variable Japanese equation (equation 4) was eGFR (mL/min/1.73 m2) = 194 x Serum creatinine(-1.094) x Age(-0.287) x 0.739 (if female). In the validation data set, bias was -1.3 +/- 19.4 versus -5.9 +/- 19.0 mL/min/1.73 m2 (P = 0.002), and accuracy within 30% of mGFR was 73% versus 72% (P = 0.6) for equation 3 versus equation 1 and -2.1 +/- 19.0 versus -7.9 +/- 18.7 mL/min/1.73 m(2) (P < 0.001) and 75% versus 73% (P = 0.06) for equation 4 versus equation 2 (P = 0.06), respectively. LIMITATION Most study participants had chronic kidney disease, and some may have had changing GFRs. CONCLUSION The new Japanese coefficient for the modified IDMS-MDRD Study equation and the new Japanese equation are more accurate for the Japanese population than the previously reported equations.

Impact of renal function on coronary plaque composition

BACKGROUND Recent studies have demonstrated that patients with chronic kidney disease are at high risk of atherosclerosis. Recently it has been found that coronary plaque components can be evaluated by integrated backscatter intravascular ultrasound (IB-IVUS), and lipid-rich plaque is associated with vulnerable plaque. The aim of the study was to investigate the relationship between renal function and tissue characterization of coronary plaque composition at the target stenotic site for percutaneous coronary intervention (PCI). METHODS We prospectively performed IB-IVUS before elective PCI in 89 consecutive patients with stable angina. According to estimated glomerular filtration rate (eGFR), they were divided into two groups (eGFR <60 ml/min/ 1.73 m(2) or eGFR > or =60 ml/min/1.73 m(2)). The tissue characteristics of the coronary plaque at each target stenotic site were evaluated by three-dimensional (3D) IB-IVUS just before PCI procedure. RESULTS The patients with eGFR <60 ml/min/1.73 m(2) had higher percentage of lipid volume and lower percentage of fibrous volume compared to the patients with eGFR > or = 60 ml/min/1.73 m(2) on the 3D IB-IVUS images (36.7 +/- 10.6% versus 28.7 +/- 9.3%, P < 0.001 and 59.1 +/- 8.7% versus 66.3 +/- 8.3%, P < 0.001, respectively). eGFR showed a significant negative correlation with lipid volume and had a significant positive correlation with fibrous volume in coronary plaques (r = -0.44, P < 0.0001, and r = 0.46, P < 0.0001, respectively). CONCLUSIONS Impaired renal function was related to higher percentage of lipid volume and lower percentage of fibrous volume in coronary plaque. Our findings may explain the increasing risk of cardiovascular events in patients with renal dysfunction.

Cilostazol Improves Long-Term Patency after Percutaneous Transluminal Angioplasty in Hemodialysis Patients with Peripheral Artery Disease

BACKGROUND AND OBJECTIVES Peripheral artery disease (PAD) is common in patients on hemodialysis (HD). Recently, cilostazol has been reported to reduce target lesion revascularization (TLR) after percutaneous transluminal angioplasty (PTA) for PAD in the general population. This study aimed to clarify the effects of cilostazol administration on long-term patency after PTA in HD patients. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Three-hundred seventy-two consecutive lesions in 193 HD patients successfully undergoing PTA were enrolled in the study and divided into two groups: patients receiving 100 mg cilostazol twice daily in conjunction with standard therapy (130 lesions in 71 patients) and those not administered cilostazol (242 lesions in 122 patients). Effects of cilostazol on preventing restenosis after PTA in these patients were investigated. RESULTS Kaplan-Meier analysis demonstrated the 5-yr patency rate was significantly higher in the cilostazol group than in the control group [52.4 versus 32.9%, hazard ratio (HR) 0.55; 95% confidence interval (CI) 0.39 to 0.77, P = 0.0005]. Cox multivariate analysis revealed that administration of cilostazol was an independent predictor of preventing restenosis (HR 0.56, 95% CI 0.36 to 0.87, P = 0.010). In 102 lesions matched after propensity score analysis, cilostazol had a beneficial effect on preventing restenosis (58.4 versus 34.7%, HR 0.47, 95% CI 0.30 to 0.75, P = 0.0017) and was an independent predictor of preventing restenosis (HR 0.50; 95% CI 0.26 to 0.87, P = 0.014) after multivariate Cox analysis. CONCLUSIONS Cilostazol administration improves long-term patency after PTA in HD patients with PAD.

Prognostic Values of C-Reactive Protein Levels on Clinical Outcome After Implantation of Sirolimus-Eluting Stents in Patients on Hemodialysis

Background—Percutaneous coronary intervention (PCI) using drug-eluting stents significantly reduces the risk of restenosis in the general population. However, in patients on hemodialysis, adverse cardiac events are frequently seen even if treated with drug-eluting stents. Recent studies suggest that C-reactive protein (CRP) reflects vascular wall inflammation and can predict adverse cardiac events. We evaluated possible prognostic values of CRP on outcomes in patients on hemodialysis undergoing PCI with drug-eluting stents. Methods and Results—A total of 167 patients undergoing PCI with sirolimus-eluting stents for stable angina (322 lesions) were enrolled. They were divided into tertiles according to serum CRP levels. We analyzed the incidence of major adverse cardiovascular events including cardiovascular death, nonfatal myocardial infarction, and target lesion revascularization after PCI as well as quantitative coronary angiographic data. The mean follow-up was 31 months (SD, 14). Major adverse cardiac events occurred in 11 patients (19.6%) of the lowest tertile, in 22 patients (39.3%) of the middle tertile, and in 28 patients (50.9%) of the highest tertile during follow-up period (P=0.0009). There was a progressive increase in neointimal growth after sirolimus-eluting stent implantation during follow-up because preprocedural CRP levels were higher, despite similar angiographic data just after PCI. Angiographic restenosis at 6 to 8 months after PCI was seen in 10.6% in the lowest tertile, 17.9% in the middle tertile, and 32.0% in the highest tertile (P=0.0007). Conclusions—Increased preprocedural serum CRP levels would predict higher major adverse cardiac events and restenosis rates after sirolimus-eluting stents implantation in patients on hemodialysis.

Two Isoforms of Npap60 (Nup50) Differentially Regulate Nuclear Protein Import

Npap60 (Nup50) is a nucleoporin that binds directly to importin α. In humans, there are two Npap60 isoforms: the long (Npap60L) and short (Npap60S) forms. Our results demonstrate that Npap60S stabilizes the binding of importin α to classical NLS-cargo, whereas Npap60L promotes the release of NLS-cargo from importin α.

Aortic Pressure Augmentation as a Marker of Cardiovascular Risk in Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with increases in cardiovascular morbidity and mortality. Vascular changes in individuals with OSAS have not been fully elucidated, however. The possible impact of OSAS on the extent of aortic pressure augmentation (AG), an indicator of cardiovascular risk, was investigated. Forty-five consecutive male patients aged 35 to 78 years (56.0±9.6 years) who were referred to the sleep clinic of Nagoya University Hospital for screening and treatment of OSAS and 71 age-matched healthy men were enrolled in the study. AG was derived from the pressure waveform measured at the radial artery by applanation tonometry. The number of apnea and hypopnea episodes per hour (apnea-hypopnea index [AHI]) was determined by standard polysomnography. AG was significantly greater in OSAS patients than in controls (9.0±4.1 vs. 6.4±3.4 mmHg, p<0.001), and it was significantly reduced in 19 OSAS patients treated with continuous positive airway pressure. AG was also significantly correlated with the AHI (r=0.562, p<0.001) and age (r=0.356, p=0.016) but not with the serum concentrations of low and high density lipoprotein-cholesterol, triglyceride, or glycosylated hemoglobin. Stepwise multiple regression analysis revealed that the AHI was the most significant contributing factor to the increased AG in OSAS patients (β=0.109, r=0.530, p<0.001). OSAS may thus have an adverse effect on vascular function that can be ameliorated by appropriate treatment.

Effects of oral cilostazol 100 mg BID on long-term patency after percutaneous transluminal angioplasty in patients with femoropopliteal disease undergoing hemodialysis: a retrospective chart review in Japanese patients.

BACKGROUND Percutaneous transluminal angioplasty (PTA) for femoropopliteal lesions in peripheral artery disease has been performed in patients undergoing hemodialysis as well as in the general population. Cilostazol, a selective inhibitor of phosphodiesterase 3, has been reported to reduce target lesion revascularization after PTA for femoropopliteal lesions in the general population. OBJECTIVE This study investigated the effects of cilostazol use on long-term patency after PTA in patients with femoropopliteal disease undergoing hemodialysis. METHODS In this retrospective study, data from patients undergoing hemodialysis who underwent successful PTA for femoropopliteal disease, defined as a final luminal diameter stenosis <30% without angiographically visual arterial dissection and no in-hospital complications, were included. One study group received long-term treatment with oral cilostazol 100 mg BID after PTA; the control group did not. The duration of follow-up was <or=6 years. The primary outcome of interest was cumulative patency, as measured by the event-free rate 6 years after PTA, with event defined as restenosis of >50% of the vessel diameter in femoropopliteal lesions. Data on baseline characteristics, patency, and covariates (diabetes, hypertension, hyperlipidemia, smoking, coronary artery disease, critical limb ischemia, TransAtlantic Inter-Society Consensus classification, and stenting) were obtained from electronic medical records and telephone interviews with patients. To minimize the effects of selection bias for cilostazol administration, a propensity-matched analysis using Cox univariate and multivariate models including the previously mentioned covariates was conducted. The propensity scores of the 2 groups were matched 1:1 (AUC = 0.69 [receiving operating characteristics analysis]). Data were obtained from electronic medical records and telephone interviews with patients by trained personnel who were blinded to treatment assignment. RESULTS A total of 358 consecutive lesions of 174 patients undergoing hemodialysis were included (103 men, 71 women; mean [SD] age, 66 [11] years; cilostazol group, 61 patients, 121 lesions; control group, 113 patients, 237 lesions). The mean duration of follow-up was 37 (27) months. The 6-year event-free rate of restenosis of >50% of the vessel diameter was significantly higher in the cilostazol group than in the control group (72/121 [59.5%] vs 120/237 [50.6%]; P = 0.005 [logrank test]; hazard ratio [HR] = 0.63; 95% CI, 0.45-0.88; P = 0.008 [Cox univariate analysis]). Also, event-free rates of target lesion revascularization and limb amputation were significantly higher in the cilostazol group than in the control group (40/61 [65.6%] vs 57/113 [50.4%]; P = 0.013 [log-rank test] and 54/61 [88.5%] vs 90/113 [79.6%]; P = 0.047 [logrank test], respectively). On propensity score matching (105 lesions), the baseline characteristics were comparable between the 2 groups. The 6-year eventfree rate of restenosis was significantly higher in the cilostazol group than in the control group (66/105 [62.9%] vs 52/105 [49.5%]; HR = 0.58; 95% CI, 0.38-0.88; P = 0.012 [Cox univariate analysis]). On propensity-matched (Cox multivariate) analysis, cilostazol (HR = 0.51; 95% CI, 0.27-0.84; P = 0.008), age (HR = 1.01; 95% CI, 1.01-1.04; P = 0.031), and critical limb ischemia (HR = 2.21; 95% CI, 1.39-3.53; P = 0.001) were independent predictors of restenosis. None of the patients in the cilostazol group discontinued cilostazol treatment during the follow-up period. Four patients (6.6%) experienced mild headache. CONCLUSION This study found that in these patients with femoropopliteal lesions in peripheral artery disease who were undergoing hemodialysis, those treated with cilostazol 100 mg BID after PTA had a higher mean rate of cumulative patency after PTA than those in the control group.