Impact of an angulated aorto-septal relationship on cardio-cerebrovascular outcomes in patients undergoing hemodialysis.

Aortic and valvular calcification are well-known risk factors for cardio-cerebrovascular events in patients undergoing hemodialysis. We investigated the clinical impact of an angulated aorto-septal angle as a result of aortic elongation due to aortic calcification on cardio-cerebrovascular outcomes in patients undergoing hemodialysis. We investigated 306 patients (mean age 65.4 years, 68% male) who underwent pre-scheduled routine echocardiography between April and September 2018. The angle between the anterior wall of the aorta and the ventricular septal surface (ASA) was quantified. We determined aortic and mitral valve calcification scores based on calcified cardiac changes; the aortic and mitral valve scores ranged between 0-9 and 0-6, respectively. The primary endpoint was a composite including cardio-cerebrovascular events and cardio-cerebrovascular death. The mean duration of dialysis among the patients in this analysis was 9.6 years. The primary endpoint was observed in 54 patients during the observational period (median 1095 days). Multivariable Cox proportional hazards analyses identified left ventricular ejection fraction (per 10% increase: hazard ratio [HR] 0.67; 95% confidential interval [CI] 0.53-0.84, P = 0.001), left ventricular mass index (per 10 g/m2 increase: HR 1.14; 95% CI 1.05-1.24, P = 0.001), ASA (per 10 degree increase: HR 0.69; 95% CI 0.54-0.88; P = 0.003), and aortic valve calcification score (HR 1.15; 95% CI 1.04-1.26, P = 0.005) as independent determinants of the primary endpoint. Kaplan-Meier analysis showed a higher incidence of the primary endpoint in patients with ASA <119.4 degrees than those with ASA ≥119.4 degrees (Log-rank P < 0.001). An angulated aorto-septal angle is an independent risk factor for cardio-cerebrovascular events and cardio-cerebrovascular death in patients undergoing hemodialysis.

Non-A Blood Type Is a Risk Factor for Poor Cardio-Cerebrovascular Outcomes in Patients Undergoing Dialysis.

The clinical impact of ABO blood type on cardio-cerebrovascular outcomes in patients undergoing dialysis has not been clarified. A total of 365 hemodialysis patients participated in the current study. The primary endpoint was defined as a composite including cardio-cerebrovascular events and cardio-cerebrovascular death. The primary endpoint was observed in 73 patients during a median follow-up period of 1182 days, including 16/149 (11%) with blood type A, 22/81 (27%) with blood type B, 26/99 (26%) with blood type O, and 9/36 (25%) with blood type AB. At baseline, no difference was found in the echocardiographic parameters. Multivariable Cox regression analyses revealed that blood type (type A vs. non-A type; hazard ratio (HR): 0.46, 95% confidence interval (95% CI): 0.26-0.81, p = 0.007), age (per 10-year increase; HR: 1.47, 95% CI: 1.18-1.84), antiplatelet or anticoagulation therapy (HR: 1.91, 95% CI: 1.07-3.41), LVEF (per 10% increase; HR: 0.78, 95% CI: 0.63-0.96), and LV mass index (per 10 g/m2 increase; HR: 1.07, 95% CI: 1.01-1.13) were the independent determinants of the primary endpoint. Kaplan-Meier curves also showed a higher incidence of the primary endpoint in the non-A type than type A (Log-rank p = 0.001). Dialysis patients with blood type A developed cardio-cerebrovascular events more frequently than non-A type patients.

A nationwide analysis of renal and patient outcomes for adults with lupus nephritis in Japan.

BACKGROUND: The prognosis of lupus nephritis (LN) has improved following the introduction of effective immunosuppressive therapy and progress in supportive care. This study examined recent renal and patient prognosis for adults with LN in Japan. METHODS: We conducted a nationwide retrospective cohort study of LN patients who received a renal biopsy between 2007 and 2012 that were registered in the Japan Renal Biopsy Registry. Of 623 registered adults with LN from 25 institutions and their affiliated or community hospitals, 489 were eligible for this study. RESULTS: The median age at renal biopsy was 39 years, and 82.2% of patients were female. Renal biopsies were performed in 348 patients with new-onset LN, 106 with relapse LN, and 35 with refractory LN. The distribution of ISN/RPS 2003 Classes was as follows: I 1.6%; II 5.3%; III (± V) 27.0%; IV (± V) 47.0%; V 18.4%; VI 0.6%. During the median observation period of 63.8 months, 36 patients (7.3%) reached a doubling of serum creatinine or end-stage kidney disease (ESKD), and 28 patients (5.7%) died. The 5 year renal and patient survival rates were 93.9% and 94.7%, respectively. Multivariate analysis revealed body mass index (BMI) and estimated glomerular filtration rate (eGFR) were independent risk factors for a doubling of serum creatinine in ESKD. Age and eGFR were independent risk factors for death. CONCLUSION: Recent prognosis for adults with LN are relatively good in Japan. Risk factors for impaired renal function are BMI and eGFR at renal biopsy, while age and eGFR are risk factors for death.

The angiotensin II type 1 receptor blocker azilsartan can overwhelm the sympathetic nerve activation stimulated by coadministration of calcium channel blockers.

OBJECTIVE:: In our recent study, non-Gaussianity of heart rate variability (λ25s), an indicator of sympathetic nerve activity, did not change during two-day treatment with the angiotensin II type 1 receptor blocker (ARB) azilsartan. Coadministration of calcium channel blockers (CCBs) might affect the study results. METHODS:: In this subanalysis, 20 patients with chronic kidney disease (14 men; age 61±15 years) were divided into three groups: patients with coadministration of L-type CCB, patients without coadministration of CCB, and patients with coadministration of sympathoinhibitory (L/T- or L/T/N-type) CCB. λ25s was calculated separately in daytime and nighttime. RESULTS:: Daytime λ25s at baseline was higher in patients with L-type CCB coadministration (0.62±0.18, n = 5) compared with those without CCB (0.49±0.13, n = 11) and those with sympathoinhibitory CCB (0.46±0.06, n = 4). The relationship between the changes in daytime λ25s and systolic blood pressure was positive in patients with L-type CCB coadministration, whereas the relationship was inverse in the other two groups. A larger decrease in daytime λ25s was shown in patients with L-type CCB coadministration compared with those in the other two groups. CONCLUSIONS:: CCBs, as well as diuretics, are recommended as second-line antihypertensive agents. Our results suggested that ARBs can overwhelm the activation of sympathetic nerve activity stimulated by coadministration of L-type CCBs.

A case series of favorable vessel dilatation using a nitinol scoring element-equipped helical balloon catheter (AngioSculpt®).

OBJECTIVE: Although percutaneous transluminal angioplasty is an effective therapy against vascular access failure in hemodialysis patients, recurrent stenosis imposes enormous burden for hemodialysis patients. A nitinol scoring element-equipped helical balloon catheter (AngioSculpt®) has been altered the landscape for treating several vascular diseases. It is not, however, fully elucidated whether AngioSculpt for advanced vascular access stenosis, difficult to expand by conventional balloons, successfully provides bailout angioplasty. Here, we report our cases whose intradialytic venous pressure significantly improved after percutaneous transluminal angioplasty without any serious adverse complications using AngioSculpt. PATIENTS AND METHODS: Among patients undergoing hemodialysis in Masuko Memorial Hospital, 16 cases with resistant and recurrent vascular access stenosis underwent AngioSculpt (diameter 6 mm, total length 4 cm) angioplasty. We simultaneously measured the average venous pressures during hemodialysis before and after percutaneous transluminal angioplasty. RESULTS: The average outflow vessel stenosis rate was 73.0 ± 11.3% before AngioSculpt intervention. Fully enlarged vessels were observed by expanding vessels at maximum pressure of 14 atm in all cases without any complications including vascular ruptures. Their intradialytic venous pressures decreased from 181.8 ± 39.2 mmHg to 150.5 ± 39.3 mmHg ( p < 0.0001). CONCLUSION: AngioSculpt may provide a promising option for treating hemodialysis patients with severely advanced vascular access stenosis, who would otherwise need repeated vascular access surgeries and/or conventional percutaneous transluminal angioplasties.

Sodium balance, circadian BP rhythm, heart rate variability, and intrarenal renin-angiotensin-aldosterone and dopaminergic systems in acute phase of ARB therapy.

We have revealed that even in humans, activated intrarenal renin-angiotensin-aldosterone system (RAAS) enhances tubular sodium reabsorption to facilitate salt sensitivity and nondipper rhythm of blood pressure (BP), and that angiotensin receptor blocker (ARB) could increase daytime urinary sodium excretion rate (UNaV) to produce lower sodium balance and restore nondipper rhythm. However, the sympathetic nervous system and intrarenal dopaminergic system can also contribute to renal sodium handling. A total of 20 patients with chronic kidney disease (61 ± 15 years) underwent 24-h ambulatory BP monitoring before and during two-day treatment with ARB, azilsartan. Urinary angiotensinogen excretion rate (UAGTV, µg/gCre) was measured as intrarenal RAAS; urinary dopamine excretion rate (UDAV, pg/gCre) as intrarenal dopaminergic system; heart rate variabilities (HRV, calculated from 24-h Holter-ECG) of non-Gaussianity index λ25s as sympathetic nerve activity; and power of high-frequency (HF) component or deceleration capacity (DC) as parasympathetic nerve activity. At baseline, glomerular filtration rate correlated inversely with UAGTV (r = -0.47, P = 0.04) and positively with UDAV (r = 0.58, P = 0.009). HF was a determinant of night/day BP ratio (ß = -0.50, F = 5.8), rather than DC or λ25s During the acute phase of ARB treatment, a lower steady sodium balance was not achieved. Increase in daytime UNaV preceded restoration of BP rhythm, accompanied by decreased UAGTV (r = -0.88, P = 0.05) and increased UDAV (r = 0.87, P = 0.05), but with no changes in HRVs. Diminished sodium excretion can cause nondipper BP rhythm. This was attributable to intrarenal RAAS and dopaminergic system and impaired parasympathetic nerve activity. During the acute phase of ARB treatment, cooperative effects of ARB and intrarenal dopaminergic system exert natriuresis to restore circadian BP rhythm.

Immunosuppressive therapy for active IgA nephropathy is effective and safe, even in "elderly" patients.

Proportions of elderly aged ≥65 and ≥75 within Japan will increase to 30 and 20 %, respectively, in 2025, when "Baby-Boom Generations" will reach the age of 75 years. Okabayashi and colleagues report that even in elderly patients with IgA nephropathy (IgAN), immunosuppressive treatment can reduce proteinuria, with no adverse events. Their findings remind us of recent finding from STOP-IgAN study; additional immunosuppressive therapy to intensive supportive care [specifically renin-angiotensin system (RAS) inhibitors (RASi)] did not improve the outcome. If STOP-IgAN makes doctors believe that immunosuppression is not necessary, many patients could lose opportunity to eliminate their kidney disease. Indeed, we have experienced patients with IgAN, who despite hematuria, could not undergo renal biopsy or immunosuppressive treatment at another facility because of low proteinuria, and exhibited advanced lesions in their renal biopsy at our institution. The discrepancy between Okabayashi's and STOP-IgAN study was derived not only from differences in population age (≥60 years vs. 18-70 years). STOP-IgAN excluded the crescentic IgAN, whereas Okabayashi et al. found active manifestations (hematuria, mesangial proliferation, and cellular/fibrocellular crescent). Therefore, immunosuppressive therapy is required even in elderly patients. In STOP-IgAN, RASi were used first, and then immunosuppressive agent was additionally used. RASi has important implications to reduce glomerular capillary pressure and to suppress the intrarenal RAS activity. However, immunosuppressant should be administered initially to cure hematuria. In fact, microscopic-hematuria was resolved in only 16 and 42 % of two-assigned groups in STOP-IgAN, respectively. Okabayashi et al. provided a timely message regarding the significance of immunosuppressive treatment of IgAN.

Addition of hydrochlorothiazide to angiotensin receptor blocker therapy can achieve a lower sodium balance with no acceleration of intrarenal renin angiotensin system in patients with chronic kidney disease.

OBJECTIVE: Angiotensin receptor blockers (ARBs) produce a lower sodium (Na) balance, and the natriuretic effect is enhanced under Na deprivation, despite falls in blood pressure (BP) and glomerular filtration rate (GFR). METHODS: The effect of additional hydrochlorothiazide (HCTZ; 12.5 mg/day) to ARB treatment (valsartan; 80 mg/day) on glomerulotubular Na balance was evaluated in 23 patients with chronic kidney disease. RESULTS: Add-on HCTZ decreased GFR, tubular Na load, and tubular Na reabsorption (t(Na)), although 24-hour urinary Na excretion (U(Na)V) remained constant. Daily urinary angiotensinogen excretion (U(AGT)V, 152±10→82±17 µg/g Cre) reduced (p=0.02). Changes in tubular Na load (r(2)=0.26) and t(Na) (r(2)=0.25) correlated with baseline 24-hour U(AGT)V. Changes in filtered Na load correlated with changes in nighttime systolic BP (r(2)=0.17), but not with changes in daytime systolic BP. The change in the t(Na) to filtered Na load ratio was influenced by the change in daytime U(Na)V (ß=-0.67, F=16.8), rather than the change in nighttime U(Na)V. CONCLUSIONS: Lower Na balance was produced by add-on HCTZ to ARB treatment without an increase of intra-renal renin-angiotensin system activity, leading to restoration of nocturnal hypertension. A further study is needed to demonstrate that the reduction of U(AGT)V by additional diuretics to ARBs prevents the progression of nephropathy or cardiovascular events.

L/T-type calcium channel blocker reduces non-Gaussianity of heart rate variability in chronic kidney disease patients under preceding treatment with ARB.

INTRODUCTION: Increased sympathetic nerve activity has been suggested in patients with chronic kidney disease (CKD). Pathologic sympathetic activity can alter heart rate variability (HRV), and the altered HRV has prognostic importance, so that reducing sympathetic activity may be an important strategy. Novel nonlinear HRVs, including deceleration capacity (DC), have greater predictive power for mortality. We have recently proposed an increase in a non-Gaussianity index of HRV, λ(25s), which indicates the probability of volcanic heart rate deviations of departure from each standard deviation level, as a marker of sympathetic cardiac overdrive. L/T-type calcium channel blocker (L/T-CCB), azelnidipine, decreases sympathetic nerve activity in experimental and clinical studies. METHODS: In 43 hypertensive patients with CKD under treatment with an angiotensin receptor blocker (ARB), we investigated whether 8-week add-on L/T-CCB treatment could restore HRV. RESULTS: Means of all normal-to-normal intervals over 24 h (p<0.0001) and DC (p=0.002) increased, and λ(25s) (p=0.001) decreased regardless of gender, age, renal function or blood pressure, while no significant changes were observed in the other HRVs. CONCLUSIONS: Reduction of λ(25s) is useful to assess the effect of sympathoinhibitory treatment. Further studies are needed to investigate if the restoration of HRV is directly associated with the improvement of prognosis in patients with CKD.

Circadian rhythm of urinary potassium excretion during treatment with an angiotensin receptor blocker.

INTRODUCTION: We have reported that the circadian rhythm of urinary potassium excretion (U(K)V) is determined by the rhythm of urinary sodium excretion (U(Na)V) in patients with chronic kidney disease (CKD). We also reported that treatment with an angiotensin receptor blocker (ARB) increased the U(Na)V during the daytime, and restored the non-dipper blood pressure (BP) rhythm into a dipper pattern. However, the circadian rhythm of U(K)V during ARB treatment has not been reported. MATERIALS AND METHODS: Circadian rhythms of U(Na)V and U(K)V were examined in 44 patients with CKD undergoing treatment with ARB. RESULTS: Whole-day U(Na)V was not altered by ARB whereas whole-day U(K)V decreased. Even during the ARB treatment, the significant relationship persisted between the night/day ratios of U(Na)V and U(K)V (r=0.56, p<0.0001). Whole-day U(K)V/U(Na)V ratio (p=0.0007) and trans-tubular potassium concentration gradient (p=0.002) were attenuated but their night/day ratios remained unchanged. The change in the night/day U(K)V ratio correlated directly with the change in night/day U(Na)V ratio (F=20.4) rather than with the changes in aldosterone, BP or creatinine clearance. CONCLUSIONS: The circadian rhythm of U(K)V was determined by the rhythm of UNaV even during ARB treatment. Changes in the circadian U(K)V rhythm were not determined by aldosterone but by U(Na)V.

Diuretics-assisted treatment of chronic laxative abuse.

Hypopotassemia with acid-base imbalance caused by laxative abuse is one of the disorders that nephrologists can be consulted for. Although laxatives are not supposed to form psychological dependence in themselves and their abuse should be cured theoretically by just finishing the overdose, the patients often resist treatment due to unpleasant symptoms such as edema and worsening constipation. Thus, chronic laxative abuse is often regarded as a drug addiction. We report a successfully treated case of chronic laxative abuse, where drastic reduction of laxatives was achieved by applying diuretics. After drastic reduction of laxatives, diuretics were added until they eased edema and bloating so that the patient could feel them to be tolerable, paying attention to lab data such as potassium and renal function. The diuretics, which substituted for laxatives in fluid control, could be tapered off over 3 months without any withdrawal symptoms or a need of additional laxatives. Our experience of simple but successful treatment of chronic laxative abuse emphasizes importance of physical management and suggests that there are cases where the two different kinds of drugs, laxatives and diuretics, can practically be regarded as swappable in the treatment of laxative abuse. This presentation should contribute to accumulation of knowledge in how to treat chronic laxative abuse where no standardized method is established yet.

Identification of chromosome 3q28 and ALPK1 as susceptibility loci for chronic kidney disease in Japanese individuals by a genome-wide association study.

BACKGROUND: Although genome-wide association studies (GWASs) have implicated several genes in the predisposition to chronic kidney disease (CKD) in Caucasian or African American populations, the genes that confer susceptibility to CKD in Asian populations remain to be identified definitively. We performed a GWAS to identify genetic variants that confer susceptibility to CKD in Japanese individuals. METHODS: 3851 Japanese individuals from three independent subject panels were examined. Subject panels A, B, and C comprised 252, 910, and 190 individuals with CKD and 249, 838, and 1412 controls, respectively. A GWAS for CKD was performed in subject panel A. RESULTS: Five single nucleotide polymorphisms (SNPs) at chromosome 3q28, ALPK1, FAM78B, and UMODL1 were significantly (false discovery rate<0.05) associated with CKD by the GWAS. The relation of these five SNPs and of an additional 22 SNPs at these loci to CKD was examined in subject panel B, revealing that rs9846911 at 3q28 was significantly associated with CKD in all individuals and that rs2074381 and rs2074380 in ALPK1 were associated with CKD in individuals with diabetes mellitus. These three SNPs were further examined in subject panel C, revealing that rs2074381 and rs2074380 were significantly associated with CKD. For subject panels B and C combined, rs9846911 was significantly associated with CKD in all individuals and rs2074381 and rs2074380 were associated with CKD in diabetic individuals. CONCLUSIONS: Chromosome 3q28 may be a susceptibility locus for CKD in Japanese individuals, and ALPK1 may be a susceptibility gene for CKD in such individuals with diabetes mellitus.

Angiotensin receptor blockers regulate the synchronization of circadian rhythms in heart rate and blood pressure.

OBJECTIVE: The sympathetic nervous system plays an important role in blood pressure regulation even in the early stages of chronic kidney disease (CKD). METHODS: To understand the role of the sympathetic system, we examined the relationship between day/night ratios of both heart rate (HR) and mean arterial pressure (MAP) as well as HR variability (HRV, SD) before and during an 8-week treatment with the angiotensin II receptor blocker (ARB), olmesartan, in 45 patients with CKD. RESULTS: The day/night HR ratio strongly correlated with the day/night MAP ratio before and during ARB treatment. The ratio of [day/night HR ratio] over [day/night MAP ratio] was increased as renal function deteriorated at baseline (r = -0.31, P = 0.04), and it was attenuated (1.10 ±â€Š0.10 to 1.06 ±â€Š0.10; P = 0.04) and became independent of renal function during ARB treatment (r = -0.04, P = 0.8). ARB increased both the day/night HR ratio (1.17 ±â€Š0.09 to 1.21 ±â€Š0.13; P = 0.04) and HRV (10.6 ±â€Š2.9 to 11.7 ±â€Š4.2; P = 0.04), which were lower when baseline renal function deteriorated. CONCLUSION: The present study indicates that there exists a close correlation in circadian rhythms between HR and MAP in CKD. Synchronization between the two rhythms was progressively lost as renal function deteriorated, and ARB partly restored the synchronization. These findings suggest that the sympathetic nervous system is activated as renal function deteriorates, and ARB may suppress its activation.

Duration until nighttime blood pressure fall indicates excess sodium retention.

Impaired renal sodium excretion causes sodium retention, which prevents the nocturnal dip in blood pressure (BP); thus, high BP persists until excess sodium is excreted. The authors defined "dipping time" (DT) as the duration until the nocturnal BP falls below 90% of the daytime average. Diuretic (e.g., hydrochlorothiazide [HCTZ]) and angiotensin receptor blocker (ARB) are able to eliminate sodium retention and restore the non-dipper BP rhythm. Reanalysis of two previous studies demonstrate that HCTZ and ARB shortened the DT. Shortening DT correlated directly with the increase in daytime urinary sodium excretion (Study 2). DT can be used as a preliminary indicator of sodium retention.

Circadian rhythm of urinary potassium excretion in patients with CKD.

AIMS: We previously reported in patients with chronic kidney disease (CKD) that the circadian rhythms of blood pressure (BP) and urinary sodium excretion were both impaired into non-dipper pattern as renal function deteriorated. However, the circadian rhythm of urinary potassium excretion has not been studied in relation to renal dysfunction. METHODS: BP and urinary excretion rates of sodium (UNaV) and potassium (UKV) were evaluated for daytime and nighttime to estimate their circadian rhythms in 83 subjects with CKD. RESULTS: As renal function deteriorated, night/day ratios of UNaV and UKV were both increased. Night/day ratio of UKV was positively correlated with night/day ratio of UNaV (r = 0.60, p < 0.0001). Multiple regression analysis (R2 = 0.37, p < 0.0001) revealed that night/day ratio of UKV was determined independently by the night/day ratio of UNaV (r = -0.55, p < 0.0001), rather than renal function or night/day ratio of BP. CONCLUSIONS: Circadian rhythm of natriuresis was regulated by renal function and night/day ratio of BP. On the other hand, the circadian rhythm of urinary potassium excretion was primarily determined by neither renal function nor BP, but was correlated with that of urinary sodium excretion.

Salt sensitivity and nondippers in chronic kidney disease.

High salt-sensitivity and nondipper blood pressure (BP) rhythm are highly associated with each other, because both are caused by impaired renal sodium excretion capability. We proposed that nocturnal hypertension and resultant pressure natriuresis could compensate for daytime sodium retention. If so, high BP may continue until sodium is sufficiently excreted at night. In fact, it takes longer for the night-time BP to fall in patients with more severe renal dysfunction. The time appears to be an essential component of the nondipper BP rhythm and, therefore, we defined the duration as the dipping time. Also, renal function was the sole determinant of a nocturnal BP dip other than age, sex, or BMI. Furthermore, we reported that diuretic therapy or dietary salt restriction, which can prevent sodium retention, restored the circadian BP rhythm into a dipper pattern. Large-scale studies are needed to explore whether these interventions can decrease the risks.