Acute Declines in Renal Function during Intensive BP Lowering: Implications for Future ESRD Risk

Comparative effectiveness of first-line antihypertensive drug classes on the maintenance of estimated glomerular filtration rate (eGFR) in real world primary care

Renin-angiotensin system inhibitors (RASi), particularly angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II receptor blockers (ARBs), are commonly used in the treatment of hypertension and are recommended for kidney protection. Uncertainty remains about the effectiveness of RASi being used as first-line antihypertensive therapy on eGFR maintenance compared to its alternatives, especially for those with no or early-stage chronic kidney disease (CKD). We conducted a retrospective cohort study of 19,499 individuals (mean age 64.1, 43.5% males) from primary care in Singapore with 4.5 median follow-up years. The study cohort included newly diagnosed individuals with hypertension (whose eGFR was mainly in CKD stages G1-G2) and initiated on ACEIs, ARBs, beta-blockers (BBs), calcium channel blockers (CCBs) or diuretics (Ds) as first-line antihypertensive monotherapy. We compared the estimated glomerular filtration rate (eGFR) curve before/after the drug initiation over time of patients under different drug classes and analyzed the time to declining to a more advanced stage CKD. Inverse probability of treatment weighting (IPTW) was used to adjust for baseline confounding factors. Two key findings were observed. First, after initiating antihypertensive drugs, the eGFR almost maintained the same as the baseline in the first follow-up year, compared with dropping 3 mL/min/1.73 m2 per year before drug initiation. Second, ARBs were observed to be slightly inferior to ACEIs (HR = 1.14, 95% CI = (1.04, 1.23)) and other antihypertensive agents (HR = 1.10, 95% CI = (1.01, 1.20)) in delaying eGFR decline to a more advanced CKD stage in the study population. Our results showed that initiating antihypertensive agents can significantly maintain eGFR for those newly diagnosed patients with hypertension. However, RASi may not be superior to other antihypertensive agents in maintaining eGFR levels for non-CKD or early stages CKD patients.

Acute Declines in Estimated GFR in Blood Pressure Target Trials and Risk of Adverse Outcomes

RATIONALE & OBJECTIVE

Acute decreases in glomerular filtration rate (GFR) occur commonly during intensive blood pressure (BP) lowering. Our objective was to determine the relationship between acute decreases in estimated GFR and patient outcomes.

STUDY DESIGN

Retrospective observational study.

SETTING & PARTICIPANTS

Participants from 4 randomized controlled trials of intensive BP lowering in chronic kidney disease (Modification of Diet in Renal Disease study, African American Study of Kidney Disease and Hypertension, Systolic Blood Pressure Intervention Trial, and Action to Control Cardiovascular Risk in Diabetes trial).

EXPOSURE

A 4-category exposure defined by the level of acute decrease in estimated GFR (defined as>15% vs≤15% between baseline and month 4) and the randomization to intensive versus usual BP control.

OUTCOMES

Risk of kidney replacement therapy (primary outcome), defined as the need for dialysis or transplant except in the Action to Control Cardiovascular Risk in Diabetes trial, which defined its kidney outcome as a composite occurrence of serum creatinine concentration>3.3mg/dL, kidney failure, or kidney replacement therapy.

ANALYTICAL APPROACH

Multivariable Cox models.

RESULTS

We included 4,473 individuals randomly assigned to intensive versus usual BP control who had a total of 351 kidney outcomes and 304 deaths during median follow-up durations of 22 and 24 months, respectively. Approximately 14% of participants exhibited an acute decrease in eGFR, 11.0% in the usual BP treatment arm and 17.8% in the intensive BP treatment arm. In adjusted models, compared with a≤15% eGFR decrease in the usual BP arm, a≤15% eGFR decrease in the intensive BP control arm was associated with lower risk of the kidney outcome (HR, 0.75; 95% CI, 0.57-0.98). In contrast, a>15% decrease in eGFR was associated with a higher risk of the kidney outcome in the usual (HR, 2.47; 95% CI, 1.80-3.38) and intensive BP treatment arms (HR, 1.99; 95% CI, 1.45-2.73) compared with a≤15% decrease in the usual BP arm.

LIMITATIONS

Observational study, residual confounding.

CONCLUSIONS

Decreases in eGFR of>15% in the usual and intensive BP treatment arms were associated with a higher risk of kidney outcomes compared with a≤15% decrease in the usual BP arm and may be a harbinger of adverse outcomes.

Association of acute increases in serum creatinine with subsequent outcomes in patients with type 2 diabetes mellitus treated with sodium-glucose cotransporter 2 inhibitor or dipeptidyl peptidase-4 inhibitor

AIMS

The frequency of an acute increase in serum creatinine (sCr) of >30%, following treatment of sodium-glucose cotransporter-2 inhibitors (SGLT2i) and its clinical implications in patients with type 2 diabetes remains unclear.

METHODS AND RESULTS

We used medical data from a multicenter health care provider in Taiwan and recruited 11,657 and 8,117 diabetic patients with baseline/follow-up sCr data available within 12 weeks of SGLT2i and dipeptidyl peptidase-4 inhibitor (DPP4i) treatment from June 1, 2016, to December 31, 2018. Participants receiving SGLT2i or DPP4i were categorized by initial sCr change into three groups:>30% sCr increase, 0-30% increase, or no-sCr increase. Participants receiving SGLT2i was associated with a higher proportion of sCr increase of 0-30% (52.7% vs. 42.6%) but a lower proportion of sCr increase of >30% (5.9% vs. 9.6%) when compared with DPP4i. In contrast to DPP4i, the mean estimated glomerular filtration rate over time became stable after 24 weeks in three categories of sCr increase following SGLT2i initiation. Compared with no sCr increase, an initial sCr increase of >30% was associated with a higher risk of major adverse cardiovascular events (adjusted hazard ratio [aHR]:2.91, [95% confidence interval [CI]:1.37-6.17]), heart failure hospitalization (HHF) (aHR:1.91,[95%CI:1.08-3.40]), and composite renal outcome (aHR:1.53,[95%CI:1.05-2.25]) in SGLT2i group; an initial sCr increase of >30% associated with a higher risk of HHF and composite renal outcome in DPP4i group after multivariate adjustment. Overall, participants receiving SGLT2i was associated with a lower risk of HHF (aHR:0.64,[95%CI:0.48-0.85]) and composite renal outcomes (aHR:0.40,[95%CI:0.34-0.48]) compared with DPP4i after multivariate adjustment, and the treatment benefit was persistent across three categories of sCr increase (P interaction>.05).

CONCLUSIONS

A modest increase in serum creatinine (<30%) was common following SGLT2i initiation, and was not associated with worse clinical outcomes, therefore should not stop therapy prematurely, but a larger increase in creatinine following drug therapy was not typical and should raise concern and review of the patient.

The association of SBP with mortality in patients with stage 1-4 chronic kidney disease

OBJECTIVES

Hypertension is a risk factor for chronic kidney disease (CKD) progression and mortality. However, the optimal blood pressure associated with decreased mortality in each stage of CKD remains uncertain.

METHODS

In this retrospective cohort study, we included 13 414 individuals with CKD stages 1-4 from NHANES general population datasets from 1999 to 2004 followed to 31 December 2010. Multivariate analysis and Kaplan--Meier curves were used to assess SBP and risk factors associated with overall mortality in each CKD stage.

RESULTS

In these individuals with death rates of 9, 12, 30 and 54% in baseline CKD stages 1 through 4, respectively, SBP less than 100 mmHg was associated with significantly increased mortality adjusted for age, sex and race in stages 2,3,4. After excluding less than 100 mmHg, as a continuous variable, higher SBP is associated with fully adjusted increased mortality risk in those on or not on antihypertensive medication (hazard ratio 1.006, P = 0.0006 and hazard ratio 1.006 per mmHg, P < 0.0001, respectively). In those on antihypertensive medication, SBP less than 100 mmHg or in each 20 mmHg categorical group more than 120 mmHg is associated with an adjusted risk of increased mortality. Increasing age, men, smoking, diabetes and comorbidities are associated with increased mortality risk.

CONCLUSION

For patients with CKD stages 1-4, the divergence of SBP above or below 100-120 mmHg was found to be associated with higher all-cause mortality, especially in those patients on antihypertensive medication. These findings support the recent guideline of an optimal target goal SBP of 100-120 mmHg in patients with CKD stages 1-4.

Blood pressure management and renal protection: Revisiting hypertensive nephropathy

Hypertension has traditionally been the most common cardiovascular disease, and epidemiological studies suggest that the incidence continues to rise. Despite a plethora of antihypertensive agents, the management of blood pressure (BP) remains suboptimal. Addressing this issue is paramount to minimize hypertensive complications, including hypertensive nephropathy, a clinical entity whose definition has been challenged recently. Still, accumulating studies endorse poorly managed BP as an independent risk factor for both the onset of renal dysfunction and aggravation of baseline kidney disease. Nevertheless, current recommendations are not only discordant from one another but also offer inadequate evidence for the optimal BP control targets for renal protection, as since the cutoff values were primarily established on the premise of minimizing cardiovascular sequelae rather than kidney dysfunction. Although intense BP management was traditionally considered to compromise perfusion toward renal parenchyma, literature has gradually established that renal prognosis is more favorable as compared with the standard threshold. This review aims to elucidate the renal impact of poorly controlled hypertension, elaborate on contemporary clinical references for BP control, and propose future directions to improve the holistic care of hypertensive individuals.

Impact of the initial decline in estimated glomerular filtration rate on the risk of new-onset atrial fibrillation and adverse cardiovascular and renal events in patients with type 2 diabetes treated with sodium-glucose co-transporter-2 inhibitors

AIM

To investigate the impact of initial decline in estimated glomerular filtration rate (eGFR) in patients with type 2 diabetes (T2D) following sodium-glucose co-transporter-2 inhibitor (SGLT2i) treatment.

MATERIALS AND METHODS

We used medical data from a multicentre healthcare provider in Taiwan and recruited 11 769 patients with T2D with baseline/follow-up eGFR data available after 1 to 3 months of SGLT2i treatment from 1 June 2016 to 31 December 2018. Patients were followed up from the drug index date until the occurrence of adverse clinical events, SGLT2i discontinuation or the end of the study period, whichever took place first.

RESULTS

Overall, SGLT2i treatment was associated with an initial eGFR decline of 3.5% ± 14.0% after a median treatment period of 10 weeks. A total of 37.1% (n = 4371) of patients experienced no eGFR decline, and 30.5% (n = 3593), 20.2% (n = 2376), 8.5% (n = 999) and 3.7% (n = 430) of patients experienced an eGFR decline of 0%-10%, 10%-20%, 20%-30% and more than 30%, respectively. The mean eGFR over time became stable after 6 months in all eGFR decline categories, even in the group with a pronounced eGFR decline of more than 30%. Compared with no eGFR decline, an initial eGFR decline of 0%-10%, 10%-20% or 20%-30% was not associated with a higher risk of atrial fibrillation (AF), major adverse cardiovascular events (MACE, including ischaemic stroke, systemic embolism and acute myocardial infarction)/heart failure (HF) and composite renal outcome (doubling of the serum creatinine level/end-stage kidney disease), whereas an eGFR decline of more than 30% was associated with a higher risk of new-onset AF (adjusted hazard ratio [aHR] = 2.20, 95% confidence interval [CI] = 1.40-3.47), MACE/HF (aHR = 2.09, 95% CI = 1.04-4.17) and composite renal outcome (aHR = 1.82, 95% CI = 1.18-2.83). The multivariate analysis indicated that the use of a diuretic or insulin, presence of stroke, older age, female sex, a higher HbA1c level, and a lower body mass index of less than 25 kg/m² were independent factors associated with an eGFR decline of more than 30% following SGLT2i initiation.

CONCLUSIONS

A pronounced eGFR decline of more than 30% following SGLT2i treatment was associated with adverse cardiovascular or renal events among patients with T2D.

The challenge of early glomerular filtration rate decline in response to antihypertensive treatment and chronic kidney disease outcomes

Hypertension and chronic kidney disease (CKD) are closely linked pathological processes. Combating high blood pressure (BP) is an essential part of preventing CKD progression and reducing cardiovascular (CV) risk. Data from recent randomized controlled trials on patients at high CV risk showed the beneficial effects of intensive action to meet BP targets on mortality related to CV disease. The impact of meeting such targets on renal function is still unclear, however, particularly for patients with CKD. This issue has been the object of several post hoc analyses because lowering BP definitely has a nephroprotective role, but the early decline in glomerular filtration rate (GFR) associated with antihypertensive therapies and strict BP targets is still a concern in nephrology clinical practice. The present review discusses the results of studies on this topic, focusing specifically on the clinical significance of early GFR decline in response to treatment with angiotensin-converting enzyme inhibitor/angiotensin receptor blocker, or to different BP targets, in terms of renal and CV outcomes, and how this tips the balance towards continuing or discontinuing antihypertensive therapy.

Intensive BP Control and eGFR Declines: Are These Events Due to Hemodynamic Effects and Are Changes Reversible?

PURPOSE OF REVIEW

Acute declines in estimated glomerular filtration rate (eGFR) are often observed during intensive blood pressure (BP) lowering. This review focuses on identifying the various mechanisms of eGFR decline associated with intensive BP lowering and evaluates the evidence linking BP control with kidney and cardiovascular (CV) outcomes.

RECENT FINDINGS

In 2017, the American College of Cardiology and the American Heart Association (ACC/AHA) began recommending treatment of all individuals to a BP target of < 130/80 mmHg. Since then, multiple post hoc analyses of BP trials have associated intensive BP lowering with acute declines in kidney function and acute kidney injury; whether these represent reversible changes in the kidney is still debated. There is ample evidence that intensive BP lowering is associated with declines in eGFR. The clinical implications of these events remain unclear. Individualizing the risks and benefits of intensive BP therapy continues to be warranted.

Kidney Disease, Intensive Hypertension Treatment, and Risk for Dementia and Mild Cognitive Impairment: The Systolic Blood Pressure Intervention Trial

BACKGROUND

Intensively treating hypertension may benefit cardiovascular disease and cognitive function, but at the short-term expense of reduced kidney function.

METHODS

We investigated markers of kidney function and the effect of intensive hypertension treatment on incidence of dementia and mild cognitive impairment (MCI) in 9361 participants in the randomized Systolic Blood Pressure Intervention Trial, which compared intensive versus standard systolic BP lowering (targeting <120 mm Hg versus <140 mm Hg, respectively). We categorized participants according to baseline and longitudinal changes in eGFR and urinary albumin-to-creatinine ratio. Primary outcomes were occurrence of adjudicated probable dementia and MCI.

RESULTS

Among 8563 participants who completed at least one cognitive assessment during follow-up (median 5.1 years), probable dementia occurred in 325 (3.8%) and MCI in 640 (7.6%) participants. In multivariable adjusted analyses, there was no significant association between baseline eGFR <60 ml/min per 1.73 m² and risk for dementia or MCI. In time-varying analyses, eGFR decline ≥30% was associated with a higher risk for probable dementia. Incident eGFR <60 ml/min per 1.73 m² was associated with a higher risk for MCI and a composite of dementia or MCI. Although these kidney events occurred more frequently in the intensive treatment group, there was no evidence that they modified or attenuated the effect of intensive treatment on dementia and MCI incidence. Baseline and incident urinary ACR ≥30 mg/g were not associated with probable dementia or MCI, nor did the urinary ACR modify the effect of intensive treatment on cognitive outcomes.

CONCLUSIONS

Among hypertensive adults, declining kidney function measured by eGFR is associated with increased risk for probable dementia and MCI, independent of the intensity of hypertension treatment.

Initial Estimated Glomerular Filtration Rate Decline and Long-Term Renal Function During Intensive Antihypertensive Therapy: A Post Hoc Analysis of the SPRINT and ACCORD-BP Randomized Controlled Trials

Lowering blood pressure (BP) can lead to an initial decline in estimated glomerular filtration rate (eGFR). However, there is debate how much eGFR decline is acceptable. We performed a post hoc analysis of ACCORD-BP (Action to Control Cardiovascular Risk in Diabetes-Blood Pressure) and SPRINT (Systolic Blood Pressure Intervention Trial), which randomized patients to intensive or standard systolic BP-targets. We determined the relation between initial decline in mean arterial pressure and eGFR. Subsequently, we stratified patients to BP-target and initial eGFR decrease and assessed the relation with annual eGFR decline after 1 year. A total of 13 266 patients with 41 126 eGFR measurements were analyzed. Up to 10 mm Hg of BP-lowering, eGFR did not change. Hereafter, there was a linear decrease of 3.4% eGFR (95% CI, 2.9%-3.9%) per 10 mm Hg mean arterial pressure decrease. The observed eGFR decline based on 95% of the subjects varied from 26% after 0 mm Hg to 46% with a 40 mm Hg mean arterial pressure decrease. There was no difference in eGFR slope (P=0.37) according to initial eGFR decline and BP-target, with a decrease of 1.24 (95% CI, 1.09-1.39), 1.20 (95% CI, 0.97-1.43), and 1.14 (95% CI, 0.77-1.50) in the 5%, 5% to 20%, and >20% stratum during intensive and 0.95 (95% CI, 0.81-1.09), 1.23 (95% CI, 0.97-1.49), and 1.17 (95% CI, 0.65-1.69) mL/minute per 1.73 m2 per year during standard treatment. In patients at high cardiovascular risk with and without diabetes mellitus, we found no association between initial eGFR and annual eGFR decline during BP-lowering treatment. Our results support that an eGFR decrease up to 20% after BP lowering can be accepted and suggest that the limit can be extended up to 46% depending on the achieved BP reduction. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT00000620, NCT01206062.

Cerebral White Matter Hyperintensities, Kidney Function Decline, and Recurrent Stroke After Intensive Blood Pressure Lowering: Results From the Secondary Prevention of Small Subcortical Strokes ( SPS 3) Trial

Background

We aimed to determine whether cerebral white matter hyperintensities (WMHs) can distinguish stroke survivors susceptible to rapid kidney function decline from intensive blood pressure (BP) lowering.

Methods and Results

The SPS3 (Secondary Prevention of Small Subcortical Strokes) trial randomized participants with recent lacunar stroke to systolic BP targets of 130 to 149 and <130 mm Hg. We included 2454 participants with WMH measured by clinical magnetic resonance imaging at baseline and serum creatinine measured during follow‐up. We tested interactions between BP target and WMH burden on the incidence of rapid kidney function decline (≥30% decrease from baseline estimated glomerular filtration rate at 1‐year follow‐up) and recurrent stroke. Rapid kidney function decline incidence was 11.0% in the lower‐BP‐target arm and 8.1% in the higher‐target arm (odds ratio=1.40; 95% CI=1.07–1.84). Odds ratio for rapid kidney function decline between lower‐ and higher‐target groups ranged from 1.26 in the lowest WMH tertile (95% CI, 0.80–1.98) to 1.71 in the highest tertile (95% CI, 1.05–2.80; P for interaction=0.65). Overall incidence of recurrent stroke was 7.9% in the lower‐target arm and 9.6% in the higher‐target arm (hazard ratio=0.80; 95% CI, 0.63–1.03). Hazard ratio for recurrent stroke in the lower‐target group was 1.13 (95% CI, 0.73–1.75) within the lowest WMH tertile compared with 0.73 (95% CI, 0.49–1.09) within the highest WMH tertile (P for interaction=0.04).

Conclusions

Participants with higher WMH burden appeared to experience greater benefit from intensive BP lowering in prevention of recurrent stroke. By contrast, intensive BP lowering increased the odds of kidney function decline, but WMH burden did not significantly distinguish this risk.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00059306.

Management of Presumed Acute Kidney Injury during Hypertensive Therapy: Stay Calm and Carry on?

BACKGROUND

Recent studies have demonstrated that intensive blood pressure control is associated with improved cardiovascular outcomes. Acute kidney injury (AKI), however, was more common in the intensive treatment group prompting concern in the nephrology community.

SUMMARY

Clinical trials on hypertension control have traditionally defined AKI by changes in serum creatinine. However, serum creatinine has several inherent limitations as a marker of kidney injury, with various factors influencing its production, secretion, and elimination. Urinary biomarkers of kidney injury and repair have the potential to provide insight on the presence and phenotype of kidney injury. In both the Systolic Blood Pressure Intervention Trial and the Action to Control Cardiovascular Risk in Diabetes study, urinary biomarkers have suggested that the increased risk of AKI associated with intensive treatment was due to hemodynamic changes rather than structural kidney injury. As such, clinicians who encounter rises in serum creatinine during intensification of hypertension therapy should "stay calm and carry on." Alternative explanations for serum creatinine elevation should be considered and addressed if appropriate. When the rise in serum creatinine is limited, particularly if albuminuria is stable or improving, intensive blood pressure control should be continued for its potential long-term benefits. Key Messages: Increases in serum creatinine during intensification of blood pressure control may not necessarily reflect kidney injury. Clinicians should evaluate for other contributing factors before stopping therapy. Urinary biomarkers may address limitations of serum creatinine as a marker of kidney injury.

Effect of Blood Pressure Control on Long-Term Risk of End-Stage Renal Disease and Death Among Subgroups of Patients With Chronic Kidney Disease

Background

Our objective was to explore the effect of intensive blood pressure (BP) control on kidney and death outcomes among subgroups of patients with chronic kidney disease divided by baseline proteinuria, glomerular filtration rate, age, and body mass index.

Methods and Results

We included 840 MDRD (Modification of Diet in Renal Disease) trial and 1067 AASK (African American Study of Kidney Disease and Hypertension) participants. We used Cox models to examine whether the association between intensive BP control and risk of end‐stage renal disease (ESRD) or death is modified by baseline proteinuria (≥0.44 versus <0.44 g/g), glomerular filtration rate (≥30 versus <30 mL/min per 1.73 m²), age (≥40 versus <40 years), or body mass index (≥30 versus <30 kg/m²). The median follow‐up was 14.9 years. Strict (versus usual) BP control was protective against ESRD (hazard ratio [HR]_ESRD, 0.77; 95% CI, 0.64–0.92) among those with proteinuria ≥0.44 g/g but not proteinuria <0.44 g/g. Strict (versus usual) BP control was protective against death (HR_death, 0.73; 95% CI, 0.59–0.92) among those with glomerular filtration rate <30 mL/min per 1.73 m² but not glomerular filtration rate ≥30 mL/min per 1.73 m² (HR_death, 0.98; 95% CI, 0.84–1.15). Strict (versus usual) BP control was protective against ESRD among those ≥40 years (HR_ESRD, 0.82; 95% CI, 0.71–0.94) but not <40 years. Strict (versus usual) BP control was also protective against ESRD among those with body mass index ≥30 kg/m² (HR_ESRD, 0.75; 95% CI, 0.61–0.92) but not body mass index <30 kg/m².

Conclusions

The ESRD and all‐cause mortality benefits of intensive BP lowering may not be uniform across all subgroups of patients with chronic kidney disease. But intensive BP lowering was not associated with increased risk of ESRD or death among any subgroups that we examined.

Association of Acute Increases in Plasma Creatinine after Renin-Angiotensin Blockade with Subsequent Outcomes

BACKGROUND AND OBJECTIVES

Data from observational and interventional studies provide discordant results regarding the relationship between creatinine increase after renin-angiotensin system inhibition (RASi) and adverse outcomes. We compared health outcomes among patients with different categories of increase in creatinine upon initiation of RASi in a large population-based cohort.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a retrospective analysis of the Stockholm CREAtinine Measurements database, which contains complete information on diagnoses, medication dispensation claims, and laboratory test results for all Stockholm citizens accessing health care. Included were 31,951 adults initiating RASi during 2007-2011 with available pre- and postinitiation creatinine monitoring. Multivariable Cox regression was used to compare mortality, cardiovascular and ESKD events among individuals with different ranges of creatinine increases within 2 months after starting treatment.

RESULTS

In a median follow-up of 3.5 years, acute increases in creatinine were associated with mortality (3202 events) in a graded manner: compared with creatinine increases <10%, a 10%-19% increase showed an adjusted hazard ratio (HR) of 1.15 (95% confidence interval [95% CI], 1.05 to 1.27); HR 1.22 (95% CI, 1.07 to 1.40) for 20%-29%; HR 1.55 (95% CI, 1.36 to 1.77) for ≥30%. Similar graded associations were present for heart failure (2275 events, P<0.001) and ESKD (52 events; P<0.001), and, less consistently, myocardial infarction (842 events, P=0.25). Results were robust across subgroups, among continuing users, when patients with decreases in creatinine were excluded from the reference group, and after accounting for death as a competing risk.

CONCLUSIONS

Among real-world monitored adults, increases in creatinine (>10%) after initiation of RASi are associated with worse health outcomes. These results do not address the issue of discontinuation of RASi when plasma creatinine increases but do suggest that patients with increases in creatinine have higher subsequent risk of cardiovascular and kidney outcomes.

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.

Hypertension in Chronic Kidney Disease: Novel Insights

Management of arterial hypertension in patients with chronic kidney disease (CKD) remains a major challenge due to its high prevalence and associations with cardiovascular disease (CVD) and CKD progression. Several clinical trials and meta-analyses have demonstrated that aggressive treatment of hypertension in patients with and without CKD lowers the risk of CVD and all-cause mortality, nevertheless the effects of blood pressure (BP) lowering in terms of renal protection or harm remain controversial. Both home and ambulatory BP estimation have shown that patients with CKD display abnormal BP patterns outside of the office and further investigation is required, so as to compare the association of ambulatory versus office BP measurements with hard outcomes and adjust treatment strategies accordingly. Although renin-angiotensin system blockade appears to be beneficial in patients with advanced CKD, especially in the setting of proteinuria, discontinuation of renin-angiotensin system inhibition should be considered in the setting of frequent episodes of acute kidney injury or hypotension while awaiting the results of ongoing trials. In light of the new evidence in favor of renal denervation in arterial hypertension, the indications and benefits of its application in individuals with CKD need to be clarified by future studies. Moreover, the clinical utility of the novel players in the pathophysiology of arterial hypertension and CKD, such as microRNAs and the gut microbiota, either as markers of disease or as therapeutic targets, remains a subject of intensive research.

Depressive Symptoms Associate With Race and All-Cause Mortality in Patients With CKD

INTRODUCTION

Depression is common but underrecognized in patients with chronic kidney disease (CKD), especially among racial/ethnic minorities. We examined the association between depressive symptoms and all-cause mortality (including deaths before and after end-stage renal disease [ESRD]) and whether antidepressant use impacts this association, overall, and by race/ethnicity.

METHODS

We ascertained whether the presence of depressive symptoms, defined by a Beck Depression Inventory II (BDI) score of >14 at cohort enrollment, was associated with all-cause mortality (before or after ESRD) among study participants of the Chronic Renal Insufficient Cohort (CRIC) overall and by race/ethnicity. Models were adjusted for socioeconomic factors, baseline CKD severity, time-updated comorbid conditions, and time-updated antidepressant use. Confirmatory analyses were performed among African American Study of Kidney Disease and Hypertension (AASK) participants.

RESULTS

Among 3739 CRIC participants, 16.3% had a baseline BDI of >14; 18.2% reported antidepressant use. Crude mortality rate was 3.16 per 100 person-years during 6.8 years of median follow-up. Baseline BDI >14 was independently associated with higher risk of all-cause mortality (adjusted hazard ratio [aHR]: 1.27; 95% confidence interval: 1.07-1.52) without attenuation by antidepressant use. Differences among white and black individuals were noted (Pinteraction= 0.02) but not among white versus Hispanic individuals (Pinteraction = 0.43) or black versus Hispanic individuals (Pinteraction = 0.22). Depressive symptoms were associated with higher mortality among white individuals (aHR: 1.66; 1.21-2.28), but not Hispanic individuals (aHR: 1.47; 0.95-2.28) or black individuals (aHR: 1.06; 0.82-1.37). Similar results were noted among 611 AASK participants (aHR: 0.99; 0.69-1.42).

CONCLUSIONS

The presence of depressive symptoms is a risk factor for all-cause mortality among patients with mild-moderate CKD, particularly among white individuals. Further studies are needed to understand the heterogeneity in the response to the presence of depressive symptoms by race.

Effect of Intensive Blood Pressure Lowering on Kidney Tubule Injury: Findings From the ACCORD Trial Study Participants

RATIONALE & OBJECTIVE

Random assignment to intensive blood pressure (BP) lowering (systolic BP<120mmHg) compared to a less intensive BP target (systolic BP<140mmHg) in the Action to Control Cardiovascular Risk in Diabetes BP (ACCORD-BP) trial resulted in a more rapid decline in estimated glomerular filtration rate (eGFR). Whether this reflects hemodynamic effects or intrinsic kidney damage is unknown.

STUDY DESIGN

Longitudinal analysis of a subgroup of clinical trial participants.

SETTINGS & PARTICIPANTS

A subgroup of 529 participants in ACCORD-BP.

EXPOSURES

Urine biomarkers of tubular injury (kidney injury molecule 1, interleukin 18 [IL-18]), repair (human cartilage glycoprotein 39 [YKL-40]), and inflammation (monocyte chemoattractant protein 1) at baseline and year 2.

OUTCOMES

Changes in eGFR from baseline to 2 years.

ANALYTICAL APPROACH

We compared changes in biomarker levels and eGFRs across participants treated to an intensive versus less intensive BP goal using analysis of covariance.

RESULTS

Of 529 participants, 260 had been randomly assigned to the intensive and 269 to the standard BP arm. Mean age was 62±6.5 years and eGFR was 90mL/min/1.73m2. Baseline clinical characteristics, eGFRs, urinary albumin-creatinine ratios (ACRs), and urinary biomarker levels were similar across BP treatment groups. Compared to less intensive BP treatment, eGFR was 9.2mL/min/1.73m2 lower in the intensive BP treatment group at year 2. Despite the eGFR reduction, within this treatment group, ACR was 30% lower and 4 urinary biomarker levels were unchanged or lower at year 2. Also within this group, participants with the largest declines in eGFRs had greater reductions in urinary IL-18 and YKL-40 levels. In a subgroup analysis of participants developing incident chronic kidney disease (sustained 30% decline and eGFR<60mL/min/1.73m2; n=77), neither ACR nor 4 biomarker levels increased in the intensive treatment group, whereas the level of 1 biomarker, IL-18, increased in the less intensive treatment group.

LIMITATIONS

Few participants with advanced baseline chronic kidney disease. Comparisons across treatment groups do not represent comparisons of treatment arms created solely through randomization.

CONCLUSIONS

Among a subset of ACCORD-BP trial participants, intensive BP control was associated with reductions in eGFRs, but not with an increase in injury marker levels. These findings support that eGFR decline observed with intensive BP goals in ACCORD participants may predominantly reflect hemodynamic alterations.

Use of Renin-Angiotensin System Blockade in Advanced CKD: An NKF-KDOQI Controversies Report

Multiple clinical trials have demonstrated that renin-angiotensin system (RAS) blockade with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers effectively reduces chronic kidney disease (CKD) progression. However, most clinical trials excluded participants with advanced CKD (ie, estimated glomerular filtration rate [eGFR]<30mL/min/1.73m²). It is acknowledged that initiation of RAS blockade is often associated with an acute reduction in eGFR, which is thought to be functional, but may result in long-term preservation of kidney function through the reductions in glomerular intracapillary pressure conferred by these agents. In this National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (NKF-KDOQI) report, we discuss the controversies regarding use of RAS blockade in patients with advanced kidney disease. We review available published data on this topic and provide perspective on the impact of RAS blockade on changes in eGFRs and potassium levels. We conclude that more research is needed to evaluate the therapeutic index of RAS blockade in patients with advanced CKD.

Acute Declines in Renal Function during Intensive BP Lowering and Long-Term Risk of Death

BACKGROUND

During intensive BP lowering, acute declines in renal function are common, thought to be hemodynamic, and potentially reversible. We previously showed that acute declines in renal function ≥20% during intensive BP lowering were associated with higher risk of ESRD. Here, we determined whether acute declines in renal function during intensive BP lowering were associated with mortality risk among 1660 participants of the African American Study of Kidney Disease and Hypertension and the Modification of Diet in Renal Disease Trial.

METHODS

We used Cox models to examine the association between percentage decline in eGFR (<5%, 5% to <20%, or ≥20%) between randomization and months 3-4 of the trials (period of therapy intensification) and death.

RESULTS

In adjusted analyses, compared with a <5% eGFR decline in the usual BP arm (reference), a 5% to <20% eGFR decline in the intensive BP arm was associated with a survival benefit (hazard ratio [HR], 0.77; 95% confidence interval [95% CI], 0.62 to 0.96), but a 5% to <20% eGFR decline in the usual BP arm was not (HR, 1.01; 95% CI, 0.81 to 1.26; P<0.05 for the interaction between intensive and usual BP arms for mortality risk). A ≥20% eGFR decline was not associated with risk of death in the intensive BP arm (HR, 1.18; 95% CI, 0.86 to 1.62), but it was associated with a higher risk of death in the usual BP arm (HR, 1.40; 95% CI, 1.04 to 1.89) compared with the reference group.

CONCLUSIONS

Intensive BP lowering was associated with a mortality benefit only if declines in eGFR were <20%.

Deleting Death and Dialysis: Conservative Care of Cardio-Vascular Risk and Kidney Function Loss in Chronic Kidney Disease (CKD)

The uremic syndrome, which is the clinical expression of chronic kidney disease (CKD), is a complex amalgam of accelerated aging and organ dysfunctions, whereby cardio-vascular disease plays a capital role. In this narrative review, we offer a summary of the current conservative (medical) treatment options for cardio-vascular and overall morbidity and mortality risk in CKD. Since the progression of CKD is also associated with a higher cardio-vascular risk, we summarize the interventions that may prevent the progression of CKD as well. We pay attention to established therapies, as well as to novel promising options. Approaches that have been considered are not limited to pharmacological approaches but take into account lifestyle measures and diet as well. We took as many randomized controlled hard endpoint outcome trials as possible into account, although observational studies and post hoc analyses were included where appropriate. We also considered health economic aspects. Based on this information, we constructed comprehensive tables summarizing the available therapeutic options and the number and kind of studies (controlled or not, contradictory outcomes or not) with regard to each approach. Our review underscores the scarcity of well-designed large controlled trials in CKD. Nevertheless, based on the controlled and observational data, a therapeutic algorithm can be developed for this complex and multifactorial condition. It is likely that interventions should be aimed at targeting several modifiable factors simultaneously.

Renal Considerations in the Treatment of Hypertension

There are renal implications when employing intensive blood pressure control strategies. While this approach provides cardiovascular benefit in patients with and without chronic kidney disease, the impact on renal disease progression differs according to the pattern of underlying renal injury. In the setting of proteinuria, stringent blood pressure control has generally conferred a protective effect on renal disease progression, but in the absence of proteinuria, this benefit tends to be much less impressive. Thiazide diuretics are frequently part of the regimen to achieve intensive blood pressure control. These drugs can cause hyponatremia and present with biochemical evidence mimicking the syndrome of inappropriate antidiuretic hormone secretion. Altered prostaglandin transport may explain the unique susceptibility to this complication observed in some patients. Hyperkalemia is also a complication of intensive blood pressure lowering particularly in the setting of renin-angiotensin-aldosterone blockade. There are strategies and new drugs now available that can allow use of these blockers and at the same time ensure a normal plasma potassium concentration.

Association Between More Intensive vs Less Intensive Blood Pressure Lowering and Risk of Mortality in Chronic Kidney Disease Stages 3 to 5: A Systematic Review and Meta-analysis

Importance

Trials in patients with hypertension have demonstrated that intensive blood pressure (BP) lowering reduces the risk of cardiovascular disease and all-cause mortality but may increase the risk of chronic kidney disease (CKD) incidence and progression. Whether intensive BP lowering is associated with a mortality benefit in patients with prevalent CKD remains unknown.

Objectives

To conduct a systematic review and meta-analysis of randomized clinical trials (RCTs) to investigate if more intensive compared with less intensive BP control is associated with reduced mortality risk in persons with CKD stages 3 to 5.

Data Sources

Ovid MEDLINE, Cochrane Library, EMBASE, PubMed, Science Citation Index, Google Scholar, and clinicaltrials.gov electronic databases.

Study Selection

All RCTs were included that compared 2 defined BP targets (either active BP treatment vs placebo or no treatment, or intensive vs less intensive BP control) and enrolled adults (≥18 years) with CKD stages 3 to 5 (estimated glomerular filtration rate <60 mL/min/1.73 m2) exclusively or that included a CKD subgroup between January 1, 1950, and June 1, 2016.

Data Extraction and Synthesis

Two of us independently evaluated study quality and extracted characteristics and mortality events among persons with CKD within the intervention phase for each trial. When outcomes within the CKD group had not previously been published, trial investigators were contacted to request data within the CKD subset of their original trials.

Main Outcome and Measure

All-cause mortality during the active treatment phase of each trial.

Results

This study identified 30 RCTs that potentially met the inclusion criteria. The CKD subset mortality data were extracted in 18 trials, among which there were 1293 deaths in 15 924 participants with CKD. The mean (SD) baseline systolic BP (SBP) was 148 (16) mm Hg in both the more intensive and less intensive arms. The mean SBP dropped by 16 mm Hg to 132 mm Hg in the more intensive arm and by 8 mm Hg to 140 mm Hg in the less intensive arm. More intensive vs less intensive BP control resulted in 14.0% lower risk of all-cause mortality (odds ratio, 0.86; 95% CI, 0.76-0.97; P = .01), a finding that was without significant heterogeneity and appeared consistent across multiple subgroups.

Conclusions and Relevance

Randomization to more intensive BP control is associated with lower mortality risk among trial participants with hypertension and CKD. Further studies are required to define absolute BP targets for maximal benefit and minimal harm.