Acute Kidney Injury and Subsequent Kidney Failure With Replacement Therapy Incidence in Older Adults With Advanced CKD: A Cohort Study of US Veterans

Rationale & Objective

Advanced age is a major risk factor for chronic kidney disease (CKD) development, which has high heterogeneity in disease progression. Acute kidney injury (AKI) hospitalization rates are increasing, especially among older adults. Previous AKI epidemiologic analyses have focused on hospitalized populations, which may bias results toward sicker populations. This study examined the association between AKI and incident kidney failure with replacement therapy (KFRT) while evaluating age as an effect modifier of this relationship.

Study Design

Retrospective cohort study.

Setting & Participants

24,133 Veterans at least 65 years old with incident CKD stage 4 from 2011 to 2013.

Exposures

AKI, AKI severity, and age.

Outcomes

KFRT and death.

Analytical Approach

The Fine-Gray competing risk regression was used to model AKI and incident KFRT with death as a competing risk. A Cox regression was used to model AKI severity and death.

Results

Despite a nonsignificant age interaction between AKI and KFRT, a clinically relevant combined effect of AKI and age on incident KFRT was observed. Compared with our oldest age group without AKI, those aged 65-74 years with AKI had the highest risk of KFRT (subdistribution HR [sHR], 14.9; 95% CI, 12.7-17.4), whereas those at least 85 years old with AKI had the lowest (sHR, 1.71; 95% CI, 1.22-2.39). Once Veterans underwent KFRT, their risk of death increased by 44%. A 2-fold increased risk of KFRT was observed across all AKI severity stages. However, the risk of death increased with worsening AKI severity.

Limitations

Our study lacked generalizability, was restricted to ever use of medications, and used inpatient serum creatinine laboratory results to define AKI and AKI severity.

Conclusions

In this national cohort, advanced age was protective against incident KFRT but not death. This is likely explained by the high frequency of deaths observed in this population (51.1%). Nonetheless, AKI and younger age are substantial risk factors for incident KFRT.

Effect of Intensive Blood Pressure Control on Aortic Stiffness in the SPRINT-HEART

[Figure: see text].

Impact of Intensive Blood Pressure Therapy on Concern about Falling: Longitudinal Results from the Systolic Blood Pressure Intervention Trial (SPRINT)

OBJECTIVES

Concern about falling is common among older hypertension patients and could impact decisions to intensify blood pressure therapy. Our aim was to determine whether intensive therapy targeting a systolic blood pressure (SBP) of 120 mm Hg is associated with greater changes in concern about falling when compared with standard therapy targeting an SBP of 140 mm Hg.

DESIGN

Subsample analysis of participants randomized to either intensive or standard therapy in the Systolic Blood Pressure Intervention Trial (SPRINT).

SETTING

Approximately 100 outpatient sites.

PARTICIPANTS

A total of 2313 enrollees in SPRINT; participants were all age 50 or older (mean = 69 y) and diagnosed with hypertension.

MEASUREMENTS

Concern about falling was described by the shortened version of the Falls Efficacy Scale International as measured at baseline, 6 months, 1 year, and annually thereafter.

RESULTS

Concern about falling showed a small but significant increase over time among all hypertension patients. No differences were noted, however, among those randomized to intensive vs standard therapy (P = .95). Among participants younger than 75 years, no increase in concern about falling over time was noted, but among participants aged 75 years and older, the mean falls self-efficacy score increased by .3 points per year (P < .0001). No differences were observed between the intensive and standard treatment groups when stratified by age (P = .55).

CONCLUSION

Intensive blood pressure therapy is not associated with increased concern about falling among older hypertension patients healthy enough to participate in SPRINT. J Am Geriatr Soc 68:614-618, 2020.

Implications of Early Decline in eGFR due to Intensive BP Control for Cardiovascular Outcomes in SPRINT

BACKGROUND

The Systolic BP Intervention Trial (SPRINT) found that intensive versus standard systolic BP control (targeting <120 or <140 mm Hg, respectively) reduced the risks of death and major cardiovascular events in persons with elevated cardiovascular disease risk. However, the intensive intervention was associated with an early decline in eGFR, and the clinical implications of this early decline are unclear.

METHODS

In a post hoc analysis of SPRINT, we defined change in eGFR as the percentage change in eGFR at 6 months compared with baseline. We performed causal mediation analyses to separate the overall effects of the randomized systolic BP intervention on the SPRINT primary cardiovascular composite and all-cause mortality into indirect effects (mediated by percentage change in eGFR) and direct effects (mediated through pathways other than percentage change in eGFR).

RESULTS

About 10.3% of the 4270 participants in the intensive group had a ≥20% eGFR decline versus 4.4% of the 4256 participants in the standard arm (P<0.001). After the 6-month visit, there were 591 cardiovascular composite events during 27,849 person-years of follow-up. The hazard ratios for total effect, direct effect, and indirect effect of the intervention on the cardiovascular composite were 0.67 (95% confidence interval [95% CI], 0.56 to 0.78), 0.68 (95% CI, 0.57 to 0.79), and 0.99 (95% CI, 0.95 to 1.03), respectively. All-cause mortality results were similar.

CONCLUSIONS

Although intensive systolic BP lowering resulted in greater early decline in eGFR, there was no evidence that the reduction in eGFR owing to intensive systolic BP lowering attenuated the beneficial effects of this intervention on cardiovascular events or all-cause mortality.

Excited States in Bilayer Graphene Quantum Dots

We report ground- and excited-state transport through an electrostatically defined few-hole quantum dot in bilayer graphene in both parallel and perpendicular applied magnetic fields. A remarkably clear level scheme for the two-particle spectra is found by analyzing finite bias spectroscopy data within a two-particle model including spin and valley degrees of freedom. We identify the two-hole ground state to be a spin-triplet and valley-singlet state. This spin alignment can be seen as Hund's rule for a valley-degenerate system, which is fundamentally different from quantum dots in carbon nanotubes, where the two-particle ground state is a spin-singlet state. The spin-singlet excited states are found to be valley-triplet states by tilting the magnetic field with respect to the sample plane. We quantify the exchange energy to be 0.35 meV and measure a valley and spin g factor of 36 and 2, respectively.

Impact of Intensive Versus Standard Blood Pressure Management by Tertiles of Blood Pressure in SPRINT (Systolic Blood Pressure Intervention Trial)

Intensive systolic blood pressure (SBP) control improved outcomes in SPRINT (Systolic Blood Pressure Intervention Trial). Our objective was to expand on reported findings by analysis of baseline characteristics, primary outcomes, adverse events, follow-up blood pressure, and medication use differences by baseline SBP (tertile 1 [T1], <132; tertile 2 [T2], 132-145; and tertile 3 [T3], >145 mm Hg). Participants with higher baseline SBP tertile were more often women and older, had higher cardiovascular risk, and lower utilization of antihypertensive medications, statins, and aspirin. Achieved SBP in both treatment arms was slightly higher in T2 and T3 compared with T1 and fewer in the T3 groups achieved SBP targets compared with T1 and T2 groups. The primary composite outcome with intensive versus standard SBP treatment was reduced by 30% in T1, 23% in T2, and 17% in T3 with no evidence of an interaction (P=0.77). Event rates were lower in the intensive arm, and there was no evidence that this benefit differed by SBP tertile. There was no difference in the hazard for serious adverse events in any of the 3 tertiles. Medication utilization differed across the SBP tertiles at baseline with a lesser percentage of diuretics and angiotensin-converting enzyme inhibitors/angiotensin receptor blocker drugs in the higher tertiles-a finding that reversed during the trial. The beneficial effects of intensive SBP lowering were not modified by the level of baseline SBP. Within the parameters of this population, these findings add support for clinicians to treat blood pressure to goal irrespective of baseline SBP.

Gender, blood pressure, and cardiovascular and renal outcomes in adults with hypertension from the Systolic Blood Pressure Intervention Trial

BACKGROUND

To determine if the effects of intensive lowering of systolic blood pressure (goal of less than 120 mmHg) versus standard lowering (goal of less than 140 mmHg) upon cardiovascular, renal, and safety outcomes differed by gender.

METHODS

Nine thousand three hundred and sixty-one men and women aged 50 years or older with systolic blood pressure of 130 mmHg or greater, taking 0-4 antihypertensive medications, and with increased risk of cardiovascular disease, but free of diabetes, were randomly assigned to either a systolic blood pressure target of less than 120 mmHg (intensive treatment) or a target of less than 140 mmHg (standard treatment). The primary composite outcome encompassed incident myocardial infarction, heart failure, other acute coronary syndromes, stroke, or cardiovascular-related death. All-cause mortality, renal outcomes, and serious adverse events were also assessed.

RESULTS

Compared with the standard treatment group, the primary composite outcome in the intensive treatment group was reduced by 16% [hazard ratio 0.84 (0.61-1.13)] in women, and by 27% in men [hazard ratio 0.73 (0.59-0.89), P value for interaction between treatment and gender is 0.45]. Similarly, the effect of the intensive treatment on individual components of the primary composite outcome, renal outcomes, and overall serious adverse events was not significantly different according to gender.

CONCLUSION

In adults with hypertension but not with diabetes, treatment to a systolic blood pressure goal of less than 120 mmHg, compared with a goal of less than 140 mmHg, resulted in no heterogeneity of effect between men and women on cardiovascular or renal outcomes, or on rates of serious adverse events.ClinicalTrials.gov number, NCT01206062.

Clinical Outcomes by Race and Ethnicity in the Systolic Blood Pressure Intervention Trial (SPRINT): A Randomized Clinical Trial

BACKGROUND

The Systolic Blood Pressure Intervention Trial (SPRINT) showed that targeting a systolic blood pressure (SBP) of ≤ 120 mm Hg (intensive treatment) reduced cardiovascular disease (CVD) events compared to SBP of ≤ 140 mm Hg (standard treatment); however, it is unclear if this effect is similar in all racial/ethnic groups.

METHODS

We analyzed SPRINT data within non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic subgroups to address this question. High-risk nondiabetic hypertensive patients (N = 9,361; 30% NHB; 11% Hispanic) 50 years and older were randomly assigned to intensive or standard treatment. Primary outcome was a composite of the first occurrence of a myocardial infarction, acute coronary syndrome, stroke, decompensated heart failure, or CVD death.

RESULTS

Average postbaseline SBP was similar among NHW, NHB, and Hispanics in both treatment arms. Hazard ratios (HRs) (95% confidence interval) (intensive vs. standard treatment groups) for primary outcome were 0.70 (0.57–0.86), 0.71 (0.51–0.98), 0.62 (0.33–1.15) (interaction P value = 0.85) in NHW, NHB, and Hispanics. CVD mortality HRs were 0.49 (0.29–0.81), 0.77 (0.37–1.57), and 0.17 (0.01–1.08). All-cause mortality HRs were 0.61 (0.47–0.80), 0.92 (0.63–1.35), and 1.58 (0.73–3.62), respectively. A test for differences among racial/ethnic groups in the effect of treatment assignment on all-cause mortality was not significant (Hommel-adjusted P value = 0.062) after adjustment for multiple comparisons.

CONCLUSION

Targeting a SBP goal of ≤ 120 mm Hg compared to ≤ 140 mm Hg led to similar SBP control and was associated with similar benefits and risks among all racial ethnic groups, though NHBs required an average of ~0.3 more medications.

CLINICAL TRIALS REGISTRATION

Trial Number NCT01206062, ClinicalTrials.gov Identifier at https://clinicaltrials.gov/ct2/show/NCT01206062.

Effects of Intensive Blood Pressure Treatment on Acute Kidney Injury Events in the Systolic Blood Pressure Intervention Trial (SPRINT)

BACKGROUND

Treating to a lower blood pressure (BP) may increase acute kidney injury (AKI) events.

STUDY DESIGN

Data for AKI resulting in or during hospitalization or emergency department visits were collected as part of the serious adverse events reporting process of the Systolic Blood Pressure Intervention Trial (SPRINT).

SETTING & PARTICIPANTS

9,361 participants 50 years or older with 1 or more risk factors for cardiovascular disease.

INTERVENTIONS

Participants were randomly assigned to a systolic BP target of <120 (intensive arm) or <140mmHg (standard arm).

OUTCOMES & MEASUREMENTS

Primary outcome was the number of adjudicated AKI events. Secondary outcomes included severity of AKI and degree of recovery of kidney function after an AKI event. Baseline creatinine concentration was defined as the most recent SPRINT outpatient creatinine value before the date of the AKI event.

RESULTS

There were 179 participants with AKI events in the intensive arm and 109 in the standard arm (3.8% vs 2.3%; HR, 1.64; 95% CI, 1.30-2.10; P<0.001). Of 288 participants with an AKI event, 248 (86.1%) had a single AKI event during the trial. Based on modified KDIGO (Kidney Disease: Improving Global Outcomes) criteria for severity of AKI, the number of AKI events in the intensive versus standard arm by KDIGO stage was 128 (58.5%) versus 81 (62.8%) for AKI stage 1, 42 (19.2%) versus 18 (14.0%) for AKI stage 2, and 42 (19.2%) versus 25 (19.4%) for AKI stage 3 (P=0.5). For participants with sufficient data, complete or partial resolution of AKI was seen for 169 (90.4%) and 9 (4.8%) of 187 AKI events in the intensive arm and 86 (86.9%) and 4 (4.0%) of 99 AKI events in the standard arm, respectively.

LIMITATIONS

Trial results are not generalizable to patients with diabetes mellitus or without risk factors for cardiovascular disease.

CONCLUSIONS

More intensive BP lowering resulted in more frequent episodes of AKI. Most cases were mild and most participants had complete recovery of kidney function.

TRIAL REGISTRATION

Registered at ClinicalTrials.gov with study number NCT01206062.

Influence of Baseline Diastolic Blood Pressure on Effects of Intensive Compared With Standard Blood Pressure Control

BACKGROUND

In individuals with a low diastolic blood pressure (DBP), the potential benefits or risks of intensive systolic blood pressure (SBP) lowering are unclear.

METHODS

SPRINT (Systolic Blood Pressure Intervention Trial) was a randomized controlled trial that compared the effects of intensive (target <120 mm Hg) and standard (target <140 mm Hg) SBP control in 9361 older adults with high blood pressure at increased risk of cardiovascular disease. The primary outcome was a composite of cardiovascular disease events. All-cause death and incident chronic kidney disease were secondary outcomes. This post hoc analysis examined whether the effects of the SBP intervention differed by baseline DBP.

RESULTS

Mean baseline SBP and DBP were 139.7±15.6 and 78.1±11.9 mm Hg, respectively. Regardless of the randomized treatment, baseline DBP had a U-shaped association with the hazard of the primary cardiovascular disease outcome. However, the effects of the intensive SBP intervention on the primary outcome were not influenced by baseline DBP level (P for interaction=0.83). The primary outcome hazard ratio for intensive versus standard treatment was 0.78 (95% confidence interval, 0.57-1.07) in the lowest DBP quintile (mean baseline DBP, 61±5 mm Hg) and 0.74 (95% confidence interval, 0.61-0.90) in the upper 4 DBP quintiles (mean baseline DBP, 82±9 mm Hg), with an interaction P value of 0.78. Results were similar for all-cause death and kidney events.

CONCLUSIONS

Low baseline DBP was associated with increased risk of cardiovascular disease events, but there was no evidence that the benefit of the intensive SBP lowering differed by baseline DBP.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifier: NCT01206062.

Abstract 047: Clinical Outcomes by Race and Ethnicity in the Systolic Blood Pressure Intervention Trials (SPRINT): A Randomized Control Trial

Background: Lowering systolic blood pressure (SBP) reduces cardiovascular disease morbidity and mortality; however, appropriate SBP targets, especially by race/ethnicity remain uncertain.

Methods and Results: We examined the effects of an intensive SBP goal (<120 mm Hg) compared to the current recommendation (< 140 mmHg) on cardiovascular disease (CVD) outcomes in racial-ethnic groups in SPRINT (Systolic Blood Pressure Intervention Trial). High-risk non-diabetic patients with hypertension (N = 9,361; 30% Black; 11% Hispanic), 50 years and older were enrolled at 102 clinical sites across the U.S. and Puerto Rico. Primary outcome was a composite of the first occurrence of a myocardial infarction, acute coronary syndrome, stroke, decompensated heart failure, or CVD death. Average ± SD post-baseline SBP across race/ethnic groups ranged from 134.7±0.1 to 135.5±0.2 mmHg in the standard arm compared to 119.9±0.4 to 122.6±0.2 in the intensive arm. Intensive vs. standard arm hazard ratios [HRs] (95% CI) for the primary outcome were 0.70 (0.57-0.86), 0.71 (0.51-0.98), 0.62 (0.33-1.15) in Non-Hispanic Whites, Non-Hispanic Blacks, and Hispanics respectively. CVD mortality HRs were 0.49 (0.29-0.81), 0.77 (0.37-1.57), and 0.17 (0.01-1.08) with all-cause mortality HRs 0.61 (0.47-0.80), 0.92 (0.63-1.35), and 1.58 (0.73-3.62). Tests for interaction were not statistically significant after adjustment for multiple comparisons.

Conclusion: Regardless of racial/ethnic origin, there are cardiovascular benefits from treating to a SBP target of < 120 mmHg compared to <140 mmHg.

Orthostatic changes in systolic blood pressure among SPRINT participants at baseline

Orthostatic changes in systolic blood pressure (SBP) impact cardiovascular outcomes. In this study, we aimed to determine the pattern of orthostatic systolic pressure changes in participants enrolled in the SBP Intervention Trial (SPRINT) at their baseline visit before randomization and sought to understand clinical factors predictive of these changes. Of the 9323 participants enrolled in SPRINT, 8662 had complete data for these analyses. The SBP after 1 minute of standing was subtracted from the mean value of the three preceding seated SBP values. At the baseline visit, medical history, medications, anthropometric measures, and standard laboratory testing were undertaken. The mean age of SPRINT participants was 68 years, two-thirds were male, with 30% black, 11% Hispanic, and 55% Caucasian. The spectrum of SBP changes on standing demonstrated that increases in SBP were as common as declines, and about 5% of participants had an increase, and 5% had a decrease of >20 mm Hg in SBP upon standing. Female sex, taller height, more advanced kidney disease, current smoking, and several drug classes were associated with larger declines in BP upon standing, while black race, higher blood levels of glucose and sodium, and heavier weight were associated with more positive values of the change in BP upon standing. Our cross-sectional results show a significant spectrum of orthostatic SBP changes, reflecting known (eg, age) and less well-known (eg, kidney function) relationships that may be important considerations in determining the optimal target blood pressure in long-term outcomes of older hypertensive patients.

Refractory Hypertension: Evidence of Heightened Sympathetic Activity as a Cause of Antihypertensive Treatment Failure

Refractory hypertension is an extreme phenotype of treatment failure defined as uncontrolled blood pressure in spite of ≥5 classes of antihypertensive agents, including chlorthalidone and a mineralocorticoid receptor antagonist. A prospective evaluation of possible mechanisms of refractory hypertension has not been done. The goal of this study was to test for evidence of heightened sympathetic tone as indicated by 24-hour urinary normetanephrine levels, clinic and ambulatory heart rate (HR), HR variability, arterial stiffness as indexed by pulse wave velocity, and systemic vascular resistance compared with patients with controlled resistant hypertension. Forty-four consecutive patients, 15 with refractory and 29 with controlled resistant hypertension, were evaluated prospectively. Refractory hypertensive patients were younger (48±13.3 versus 56.5±14.1 years; P=0.038) and more likely women (80.0 versus 51.9%; P=0.047) compared with patients with controlled resistant hypertension. They also had higher urinary normetanephrine levels (464.4±250.2 versus 309.8±147.6 µg per 24 hours; P=0.03), higher clinic HR (77.8±7.7 versus 68.8±7.6 bpm; P=0.001) and 24-hour ambulatory HR (77.8±7.7 versus 68.8±7.6; P=0.0018), higher pulse wave velocity (11.8±2.2 versus 9.4±1.5 m/s; P=0.009), reduced HR variability (4.48 versus 6.11; P=0.03), and higher systemic vascular resistance (3795±1753 versus 2382±349 dyne·s·cm(5)·m(2); P=0.008). These findings are consistent with heightened sympathetic tone being a major contributor to antihypertensive treatment failure and highlight the need for effective sympatholytic therapies in patients with refractory hypertension.

Refractory hypertension: definition, prevalence, and patient characteristics

Among patients with resistant hypertension (RHTN), there are those whose blood pressure (BP) remains uncontrolled in spite of maximal medical therapy. This retrospective analysis aims to characterize these patients with refractory hypertension. Refractory hypertension was defined as BP that remained uncontrolled after ≥3 visits to a hypertension clinic within a minimum 6-month follow-up period. Of the 304 patients referred for RHTN, 29 (9.5%) remained refractory to treatment. Patients with refractory hypertension and those with controlled RHTN had similar aldosterone levels and plasma renin activity (PRA). Patients with refractory hypertension had higher baseline BP (175±23/97±15 mm Hg vs 158±25/89±15 mm Hg; P=.001/.005) and heart rate, and higher rates of prior stroke and congestive heart failure. During follow-up, the BP of patients with refractory hypertension remained uncontrolled (168.4±14.8/93.8±17.7 mm Hg) in spite of use of an average of 6 antihypertensive medications, while those of patients with controlled RHTN decreased to 129.3±11.2/77.6±10.8 mm Hg. Spironolactone reduced the BP by 12.9±17.8/6.6±13.7 mm Hg in patients with refractory hypertension and by 24.1±16.7/9.2±12.0 mm Hg in patients with controlled RHTN. In patients with RHTN, approximately 10% remain refractory to treatment. Similar aldosterone and PRA levels and a diminished response to spironolactone suggest that aldosterone excess does not explain the treatment failure.

Both morning and evening dosing of nebivolol reduces trough mean blood pressure surge in hypertensive patients

The morning blood pressure surge (MBPS) has been shown to be an independent predictor of cardiovascular events. There is insufficient evidence on the effect of nebivolol, a vasodilating β1-receptor blocker, on the MBPS when given in the morning or the evening. This is a prospective, randomized, double-blind, crossover study designed to test morning vs. evening dosing of nebivolol in nondiabetic, hypertensive patients. Patients received nebivolol 5 mg/day (force-titrated to 10 mg/day after 1 week) in the morning or evening and corresponding placebos. Patients underwent ambulatory BP monitoring at baseline and after each treatment phase. Forty-two patients were randomized, of whom 38 completed both study periods. Both morning and evening dosed nebivolol significantly lowered daytime, nighttime, and 24-hour BP after 3 weeks of treatment. Evening (but not morning) dosing significantly reduced prewaking systolic BP from baseline (8.64 ± 26.46 mm Hg, P = .048). Nebivolol given in the morning or the evening significantly reduces 24-hour BP parameters. Evening dosed nebivolol may confer some advantage over morning dosing in reducing prewaking systolic BP.

Statin therapy is not associated with improved vascular access outcomes

BACKGROUND AND OBJECTIVES

Neointimal hyperplasia is the major cause of vascular access failure in hemodialysis patients. Statins reduce neointimal hyperplasia in experimental models, which may reduce access failure. The study presented here evaluated whether vascular access outcomes are superior in patients receiving statin therapy than in those not on statins.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A prospective computerized vascular access database was retrospectively queried to determine the access outcomes of 601 patients receiving an upper-arm fistula or graft at a single large dialysis center.

RESULTS

Primary fistula failure was observed in 37% of patients on statin therapy versus 38% not on statin therapy. Primary graft failure occurred in 20% of patients on statin therapy versus 14% not on statin therapy. A multiple variable logistic regression analysis including statin use, diabetes, coronary artery disease, peripheral artery disease, sex, and age found that only sex predicted primary fistula failure and graft failure. After excluding primary failures, cumulative fistula survival was similar for patients with or without statin therapy (hazard ratio [HR] 1.26; 95% confidence interval [CI] 0.76 to 2.16). Likewise, cumulative graft survival was similar for statin therapy versus no statin therapy (HR 0.88; 95% CI 0.59 to 1.32). Using a multivariable survival analysis model to predict cumulative fistula survival, only age predicted fistula failure (HR 1.21 per decade; 95% CI 1.02 to 1.44). None of the variables in this model predicted cumulative graft survival.

CONCLUSIONS

Statin therapy is not associated with improved fistula or graft outcomes in patients with chronic kidney disease.

Current options for the treatment of resistant hypertension

Patients with resistant hypertension are those who have uncontrolled blood pressure despite use of three or more antihypertensive medications, or those who require four or more medications to achieve control. When evaluating resistant hypertension it is important to rule out pseudoresistant hypertension that may result from factors including poor blood pressure measurement technique and the white coat effect. Potential contributing factors should be identified and reversed if possible, including obesity, excess alcohol intake and use of interfering medications such as NSAIDS, sympathomimetics and oral contraceptives. Modification of lifestyle factors such as weight loss, sodium restriction and physical activity is paramount for treatment success. Secondary causes of hypertension are common in this patient group and, therefore, appropriate screening tests should be carried out as necessary. Pharmacologic therapy is centered on combination therapy of medications from different mechanisms of action, especially diuretics, which are essential in maximizing antihypertensive effects. The role of mineralocorticoid antagonists is expanding, especially in patients with obstructive sleep apnea and obesity where aldosterone excess may be implicated. Finally, when appropriate, specialist referral may facilitate blood pressure reduction and the ability to meet target blood pressure goals.

The epidemiology of severe acute kidney injury: from BEST to PICARD, in acute kidney injury: new concepts

Various definitions of acute kidney injury (AKI) exist, making comparisons among studies difficult. Despite this, significant changes have occurred in the epidemiology of AKI during the last decade. Recent studies, including PICARD and BEST, have examined the epidemiology of ICU-related AKI in the USA and worldwide, respectively, and found that AKI remains a major cause of morbidity and mortality. The incidence of AKI has increased, most likely due to a trend toward older, more severely and chronically ill patients admitted to the hospital. Sepsis and multi-organ system failure continue to be strongly associated with AKI, as well as pre-morbid chronic kidney disease. The proportion of patients with AKI requiring dialysis is high. The mortality of ICU-related AKI, although still very elevated, may be decreasing. Understanding these changes, in the context of standardized definitions, will be essential for the design of successful interventional studies.

Symptoms of depression, prescription of benzodiazepines, and the risk of death in hemodialysis patients in Japan

Many hemodialysis patients in Japan have symptoms of depression, but whether those patients are treated appropriately is unknown. As part of the Dialysis Outcomes and Practice Patterns Study, data on symptoms of depression, physician-diagnosed depression, prescribed medications, and death were collected prospectively in cohorts in Japan (n=1603) and 11 other countries (n=5872). Symptoms of depression were as prevalent in Japan as elsewhere, but in Japan a much smaller percentage of patients had physician-diagnosed depression: only 2% in Japan vs 17% elsewhere. Antidepressants were much less commonly prescribed in Japan: only 1% in Japan vs 17% elsewhere for patients with many and frequent symptoms of depression, and 16% in Japan vs 34% elsewhere for patients with physician-diagnosed depression. In Japan, symptoms of depression were associated with prescription of benzodiazepines (without antidepressants), and patients with physician-diagnosed depression were twice as likely to be given benzodiazepines: 32% in Japan vs 16% elsewhere. Benzodiazepine monotherapy was associated with death (relative risk 1.56, 95% confidence interval (CI), 1.25-1.94), even after adjustments for 13 likely confounders (relative risk 1.27, 95% CI, 1.01-1.59). Hemodialysis patients in Japan with symptoms of depression are given not antidepressants but benzodiazepines, a practice associated with higher mortality.

[The Dialysis Outcomes and Practice Patterns Study (DOPPS): results of the Italian cohort]

BACKGROUND

The Dialysis Outcomes and Practice Patterns Study (DOPPS) is an international prospective, longitudinal, observational study examining the relationship between dialysis unit practices and outcomes for hemodialysis (HD) patients in seven developed countries France, Germany, Italy, Spain, United Kingdom, Japan and the United States. Results of the DOPPS in Italy are the subject of this report.

METHODS

A national representative sample of 20 dialysis units (21 in Germany) was randomly selected in each of the European DOPPS countries (Euro-DOPPS). In these units, the HD in-center patients were included on a facility census, and their survival rates continuously monitored. A representative sample of incident (269 in Italy, 1553 in the Euro-DOPPS) and prevalent (600 in Italy, 3038 in the Euro-DOPPS) patients was randomly selected from the census for more detailed longitudinal investigation with regard to medical history, laboratory values and hospital admission.

RESULTS

Comparing the Italian and Euro-DOPPS cohorts we found comparable mean age for prevalent patients (61.4 vs. 59.5 yrs), but incident patients were older in Italy. Italian prevalent patients had less cardiovascular disease, more satisfactory nutritional status and more frequent use of native vascular access. These data were associated with a comparable mortality (15.7 vs. 16.3 deaths/100 patient yrs), but morbidity was lower in Italy. Kt/V levels were comparable in the two cohorts (1.32 vs. 1.37), but 35% of Italian patients showed a Kt/V below the recommended target. Moreover, hemoglobin levels were below 11 g/dL in 60% of Italian patients.

CONCLUSIONS

The DOPPS results bring to light several positive aspects and the opportunity for further possible improvements for Italian patients, but at the same time highlight some critical points that could represent a risk for dialysis quality.

Diverse effects of increasing lisinopril doses on lipid abnormalities in chronic nephropathies

BACKGROUND

Dyslipidemia frequently complicates chronic nephropathies and increases the risk of renal and cardiovascular events. This might be ameliorated by drugs, such as angiotensin-converting enzyme inhibitors, which effectively reduce proteinuria.

METHODS AND RESULTS

In this longitudinal study, we evaluated the extent to which uptitration of the ACE inhibitor lisinopril to maximum tolerated doses (median [range]: 30 [10 to 40] mg/d) ameliorated proteinuria and dyslipidemia in 28 patients with nondiabetic chronic nephropathies. Maximum lisinopril doses significantly and safely reduced proteinuria, serum total, LDL cholesterol, and triglycerides without substantially affecting serum HDL and renal hemodynamics. Proteinuria already decreased at 10 mg/d. Serum lipids progressively and dose-dependently decreased during uptitration to maximum doses. Reduction in total and LDL cholesterol correlated with increases in serum albumin/total protein concentration and oncotic pressure, peaked at lisinopril maximum doses, and persisted after treatment withdrawal. Despite less proteinuria reduction, hypercholesterolemia decreased more (and reflected the increase in serum albumin) in hypoalbuminemic than in normoalbuminemic patients who, despite more proteinuria reduction, had less decrease in cholesterol and no changes in serum albumin. Changes in serum triglycerides were independent of changes in serum proteins, were strongly correlated with lisinopril doses (r=-0.89, P=0.003) and recovered promptly after treatment withdrawal. Lisinopril was well tolerated, did not affect renal hemodynamics, and caused symptomatic, reversible hypotension in only two patients.

CONCLUSIONS

In chronic nephropathies, angiotensin converting enzyme inhibitor uptitration to maximum tolerated doses safely ameliorated hypertriglyceridemia by a direct, dose-dependent effect, and hypercholesterolemia through amelioration of the nephrotic syndrome, particularly in patients with more severe hypoalbuminemia.

Effect of high dose ramipril with or without indomethacin on glomerular selectivity

BACKGROUND

Despite the accumulating evidence of their efficacy, angiotensin-converting enzyme inhibitors (ACEi) still provide imperfect renoprotection. Up-titration above conventional doses and combined therapy with other antiproteinuric agents may serve to achieve renoprotection in patients at risk of rapid disease progression.

METHODS

The effect of maximum tolerated ACEi doses (ramipril 15 mg/day, range 5 to 20) alone or combined with indomethacin (75 mg x 2/day) on urinary protein excretion (UPE) and glomerular barrier size-selective function was evaluated in 19 patients with chronic non-diabetic nephropathies and persistent proteinuria.

RESULTS

Maximum ramipril doses decreased UPE more effectively than non-ACEi therapy. Proteinuria reduction was associated with significant reduction (>50%) of the non-selective glomerular membrane shunt, but did not correlate with concomitant changes in arterial pressure and renal hemodynamics, nor was it influenced by treatment duration. The reduction in UPE and sieving coefficient of the largest neutral dextrans exceeded by twofold the reduction achieved by conventional ACEi doses in historical controls with similar renal dysfunction and proteinuria, previously studied under identical experimental conditions. Indomethacin did not influence renal effects of maximum ramipril doses and was prematurely withdrawn in six patients because of reversible side effects. Serum potassium significantly increased only in combination with indomethacin and never required treatment withdrawal.

CONCLUSIONS

Up-titration to maximally tolerated doses safely increases ACEi antiproteinuric effect and may serve to achieve maximum renoprotection in the long-term. Combination with indomethacin is poorly tolerated and ineffective. Innovative approaches are needed to use ACEi more effectively.

Inhibitors of the renin-angiotensin system reduce the rate of GFR decline and end-stage renal disease in patients with severe renal insufficiency

Drugs that inhibit the renin-angiotensin system (RAS) are of proven benefit in the treatment of hypertension, congestive heart failure, or acute myocardial infarction. In the last decade, several clinical trials have shown that RAS inhibitors also offer significant renoprotection in both diabetic and non-diabetic nephropathy. However, patients with advanced renal insufficiency did not take part in these trials because of the risk of acute renal failure (ARF) and hyperkalemia, and, for the same reason, most physicians do not offer these drugs to patients with impaired renal function. Recently, a post-hoc analysis of the Ramipril Efficacy In Nephropathy (REIN) study which included patients with severe renal insufficiency, showed that RAS inhibition slows glomerular filtration rate (GFR) decline over time and progression to end-stage renal disease (ESRD) in a safe way in patients quite close to ESRD (basal GFR, 10 to 30 ml/min/1.73m2). These beneficial effects have also been shown in the Reduction of Endpoints in NIDDM with the All Antagonist Losartan (RENAAL) study, in patients with type 2 diabetes mellitus, clinical proteinuria, and renal insufficiency, where RAS inhibition therapy significantly reduced the risk of ESRD once doubling of baseline serum creatinine levels had been achieved as compared to non-RAS anti-hypertensive treatment. Thus, these data suggest that RAS inhibition therapy should be given to all patients with proteinuric chronic nephropathy, independently of the level of renal function.

Mechanisms of progression of chronic renal disease

Many patients with proteinuric chronic nephropathies progress relentlessly to end-stage renal failure (ESRF). Research in animal and human models has helped to identify the mechanisms involved in this progression and to indicate effective intervention. We review the main factors associated with the progression of chronic renal diseases including systemic and intra-glomerular hypertension, glomerular hypertrophy, proteinuria, hyperlipidemia, and intrarenal precipitation of calcium phosphate. We also describe a therapeutic strategy aimed at achieving maximal reno-protection.

Drug-induced thrombotic microangiopathy: incidence, prevention and management

The term thrombotic microangiopathy (TMA) describes syndromes characterised by microangiopathic haemolytic anaemia, thrombocytopenia and variable signs of organ damage due to platelet thrombi in the microcirculation. In children, infections with Shigella dysenteriae type 1 or particular strains of Escherichia coli are the most common cause of TMA; in adults, a variety of underlying causes have been identified, such as bacterial and viral infections, bone marrow and organ transplantation, pregnancy, immune disorders and certain drugs. Although drug-induced TMA is a rare condition, it causes significant morbidity and mortality. Antineoplastic therapy may induce TMA. Most of the cases reported are associated with mitomycin. TMA has also been associated with cyclosporin, tacrolimus, muromonab-CD3 (OKT3) and other drugs such as interferon, anti-aggregating agents (ticlopidine, clopidogrel) and quinine. The early diagnosis of drug-induced TMA may be vital. Strict monitoring of renal function, urine and blood abnormalities, and arterial pressure has to be performed in patients undergoing therapy with potentially toxic drugs. The drug must be discontinued immediately in the case of suspected TMA. Treatment modalities sometimes effective in other forms of TMA have been used empirically. Although plasma exchange therapy seems to be of value, the effectiveness of this approach has yet to be proved in multicentre, randomised clinical studies.

Renoprotective therapy in patients with nondiabetic nephropathies

End-stage renal failure (ESRF) represents a major health problem. Early diagnosis and effective measures to slow or to stop renal damage are essential goals for nephrologists to prevent or delay progression to ESRF. Identifying mechanisms of progressive parenchymal injury is instrumental in developing renoprotective strategies. Protein traffic through the glomerular barrier is an important determinant of progression in chronic nephropathies and proteinuria is the best predictor of renal outcome. At the moment, ACE inhibition is the most effective treatment in patients with chronic nondiabetic proteinuric nephropathies, reducing protein traffic, urinary protein excretion rate and progression to ESRF more effectively than conventional treatment. Low sodium diet and/or diuretic treatment may help to increase the antiproteinuric effect of ACE inhibitors by maximally activating the renin-angiotensin system. Intensified blood pressure control, whatever treatment is employed, also enhances the antiproteinuric response to ACE inhibitors. However, since this is not always sufficient to normalise urinary proteins and fully prevent renal damage, additional treatments may be needed in patients poorly or not responding to ACE inhibitors. These may include angiotensin II receptor antagonists, non-dihydropyridine calcium antagonists and perhaps low doses of nonsteroidal anti-inflammatory drugs. Preliminary data on multidrug treatments including these additional antiproteinuric agents are encouraging, but additional studies in larger patient numbers are needed to better define the risk/benefit profile of this innovative approach.

Pretreatment blood pressure reliably predicts progression of chronic nephropathies. GISEN Group

BACKGROUND

Random, nontimed blood pressure (BP) measurements in the outpatient clinic may fail to provide reliable information on actual daily BP control in renal patients on chronic antihypertensive therapy.

METHODS

In a cohort of 163 patients with proteinuric chronic nephropathies followed prospectively with repeated BP and glomerular filtration rate (GFR) measurements, we compared baseline and follow-up pretreatment, morning ("trough," measured by standard procedures, and "0 minutes," measured by an automatic device) and post-treatment (120 minutes) measurements, with BP monitored up to 600 minutes after treatment administration. We then evaluated which BP value most reliably predicted GFR decline (delta GFR) and progression to end-stage renal failure (ESRF) over a median (interquartile range) follow-up of 20 (9 to 25) months.

RESULTS

GFR decline was more reliably predicted by systolic as compared with diastolic BP and by pretreatment as compared to post-treatment BP, regardless of the timing and method of measurement, respectively. In particular, at the 120-minute baseline and follow-up measurements, systolic BP had no predictive value in patients with less severe renal insufficiency and baseline diastolic BP, regardless of the level of renal dysfunction. The BP predictive value was remarkably higher in ramipril than in conventionally treated patients. All follow-up-but no baseline-measurements reliably predicted the risk of ESRF in the entire study group.

CONCLUSIONS

In patients with progressive chronic nephropathies, systolic BP and pretreatment morning BP measurements are the most reliable predictors of disease outcome and may serve to guide antihypertensive therapy in routine clinical activities and in prospective controlled trials, particularly in patients on angiotensin-converting enzyme inhibitor therapy. Reliability and relevance of single measurements taken at different times after treatment administration are questionable.

Thrombotic microangiopathy

The term 'thrombotic microangiopathy' (TMA) describes syndromes of microangiopathic hemolytic anemia, thrombocytopenia, and variable signs of organ impairment, due to platelet aggregation in the microcirculation. The term 'hemolytic uremic syndrome' (HUS) has entered clinical use to describe childhood cases of TMA dominated by renal impairment, while the term 'thrombotic thrombocytopenic purpura' (TTP) refers to adult cases of TMA with predominant neurological abnormalities. HUS and TTP show the same histological lesion characterized by widening of the subendothelial space and microvascular thrombosis and their different manifestations are secondary to the different distribution of the microvascular lesions. Available evidence orients towards endothelial injury as an important factor in the sequence of events leading to the microangiopathic process. Here we provide an overview of the pathophysiology, epidemiology, clinical manifestations, and management of TMA.

How much must blood pressure be reduced in order to obtain the remission of chronic renal disease?

Most chronic nephropathies are characterized by a progressive decline in glomerular filtration rate (GFR) that may lead to renal function replacement by dialysis or transplant. Hypertension has an extremely important role among the various mechanisms contributing to renal function deterioration. High blood pressure levels are associated with increased urinary excretion of proteins and the decrease of systemic and glomerular hypertension reduces urinary excretion of proteins and preserves renal function deterioration. Moreover, recent studies found that an intensified blood pressure control (less than 130/80 mmHg) can slow the progression of diabetic and non diabetic renal disease even more than conventional blood pressure control. The Ramipril Efficacy in Nephropathy (REIN) Study showed that ramipril, an ACE-inhibitor, slowed the rate of GFR decline and halved the combined risk of doubling serum creatinine or end stage renal failure (ESRF) in patients with nephrotic range proteinuria as compared to conventional antihypertensive therapy, at comparable levels of blood pressure control. In these patients, prolonged enough treatment (at least 36 months) with ramipril, lowered the velocity of GFR decline and reduced the risk of dialysis. Thus, both tight blood pressure control and ACE-inhibitors may have a renoprotective effect. It will be interesting to evaluate whether the two combined approaches may have sinergistic effects.

How to convert from traditional cyclosporine to the microemulsion formulation in stable renal transplant patients?

How to convert from traditional cyclosporine (CsA) to the microemulsion formulation in stable renal transplant patients is still a matter of debate. The present study was designed to evaluate the effects of changeover from traditional Sandimmune to Neoral formulation at two dose-ratio conversions on CsA pharmacokinetics, safety and tolerability particularly in terms of renal function. Thirty outpatients regularly followed at our Clinical Research Center were randomized to 1:1 or 1:0.75 dose-ratio conversion and assigned to the two groups according to a comparable renal function and time post-transplant. Patients underwent CsA pharmacokinetic evaluation and renal function measurements (GFR and RPF) before, at day 15, and at month 6 after conversion to Neoral formulation. More consistent CsA concentration-time profiles with Neoral than traditional formulation were obtained at the two time points of evaluation after conversion. At 1:1 dose-ratio conversion an increased absorption rate, reflected by a shorter time to maximum blood CsA concentration (Tmax), and a greater bioavailability, as shown by an increase in the peak CsA concentration (Cmax) and the 12-h exposure to drug defined by the area under the time-concentration curve (AUC0-->12 h) was found 15 d and 6 months after conversion to Neoral formulation. A similar AUC as compared with traditional Sandimmune was observed in those patients randomized to receive a 25% lower dose of Neoral formulation. All of patients defined as 'low' absorbers became 'high' absorbers as early as 15 d after conversion to Neoral formulation at 1:1 or 0.75 dose-ratio regimen. Overall mean GFR was unchanged in both conversion regimens during the 6 months of follow-up. However, there was a tendency to lower GFR even in some patients randomized to 1:0.75 conversion but mostly in those with 1:1 conversion. A limited sampling strategy utilizing three blood samples (0, 1, 3 h post-dosing of Neoral formulation) provided an excellent correlation with actual drug exposure (r = 0.977). Enhanced CsA absorption with the microemulsion formulation results in increased drug exposure that may reduce GFR in some patients who undergo 1:1 dose-ratio conversion. The Neoral formulation that permits a more effective, consistent, and predictable absorption of CsA may represent a great advantage in order to prevent acute and possibly chronic rejections. Efforts have to be made to find optimal therapeutic range and dosing schedule for this new formulation, which may be facilitated by using the limited sampling approach to predict AUC after only three-point sampling.

Urinary protein excretion rate is the best independent predictor of ESRF in non-diabetic proteinuric chronic nephropathies. "Gruppo Italiano di Studi Epidemiologici in Nefrologia" (GISEN)

We investigated the predictors of the rate of glomerular filtration rate decline (delta GFR) and progression to end-stage renal failure (ESRF) in the 352 patients with proteinuric non-diabetic chronic nephropathies [urinary protein excretion rate (UProt) > or = 1 g/24 hr, creatinine clearance 20 to 70 ml/min/1.73 m2] enrolled in the Ramipril Efficacy In Nephropathy (REIN) study. Overall the GFR declined linearly by 0.46 +/- 0.05 ml/min/1.73 m2/month (mean rate +/- SEM) over a median follow-up of 23 months (range 3 to 64 months), and progression to ESRF was 17.3%. Using multivariate analysis, higher UProt and mean arterial pressure (MAP) independently correlated with a faster delta GFR (P = 0.0001 and P = 0.0002, respectively) and progression to ESRF (P = 0.0001 and P = 0.003, respectively). Mean UProt and systolic blood pressure during follow-up were the only time-dependent covariates that significantly correlated with delta GFR (P = 0.005 and P = 0.003, respectively) and ESRF (P = 0.006 and P = 0.0001, respectively). After stratification for baseline UProt, patients in the lowest tertile (UProt < 1.9 g/24 hr) had the slowest delta GFR (0.16 +/- 0.07 ml/min/1.73 m2/month) and progression to ESRF (4.3%) as compared with patients in the middle tertile (UProt 2.0 to 3.8 g/24hr; delta GFR, 0.55 +/- 0.09 ml/min/1.73 m2/month, P = 0.0002; ESRF, 15.3%, P = 0.0001) and in the highest tertile (UProt 3.9 to 18.8 g/24 hr; delta GFR, 0.70 +/- 0.11 ml/min/1.73 m2/month, P = 0.0001; ESRF, 32.5%, P = 0.0001). Both delta GFR (P = 0.01) and progression to ESRF (P = 0.01) significantly differed even between the middle and the highest tertiles. On the contrary, stratification in tertiles of baseline MAP failed to segregate subgroups of patients into different risk levels. Patients with the highest proteinuria and blood pressure were those with the fastest progression (delta GFR, 0.91 +/- 0.23; ESRF 34.7%). Of interest, at each level of baseline MAP, a higher proteinuria was associated with a faster delta GFR and progression to ESRF. On the other hand, at each level of proteinuria, a faster delta GFR was associated with MAP only in the highest tertile (> 112 mm Hg) and the risk of ESRF was independent of the MAP. Thus, in chronic nephropathies proteinuria is the best independent predictor of both disease progression and ESRF. Arterial hypertension may contribute to the acceleration of renal injury associated with enhanced traffic of plasma proteins. Antihypertensive drugs that most effectively limit protein traffic at comparable levels of blood pressure are those that most effectively slow disease progression and delay or prevent ESRF in proteinuric chronic nephropathies.