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.

Long-term follow-up of moderately hypercholesterolemic hypertensive patients following randomization to pravastatin vs usual care: the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT-LLT).

The authors conducted a randomized, controlled, multicenter trial, in which they assigned well-controlled hypertensive participants aged 55 years and older with moderate hypercholesterolemia to receive pravastatin (n=5170) or usual care (n=5185) for 4 to 8 years, when trial therapy was discontinued. Passive surveillance using national databases to ascertain deaths and hospitalizations continued for a total follow-up of 8 to 13 years to assess whether mortality and morbidity differences persisted or new differences developed. During the post-trial period, fatal and nonfatal outcomes were available for 98% and 64% of participants, respectively. The primary outcome was all-cause mortality and the secondary outcomes included cardiovascular mortality, coronary heart disease (CHD), stroke, heart failure, cardiovascular disease, and end-stage renal disease. No significant differences appeared in mortality for pravastatin vs usual care (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.89-1.03) or other secondary outcomes. Similar to the previously reported in-trial result, there was a significant treatment effect for CHD in black patients (HR, 0.79; 95% CI, 0.64-0.98). However, the in-trial result showing a significant treatment by race effect did not remain significant during the entire follow-up (P=.08). These findings are consistent with evidence from other large trials that show statins prevent CHD and add evidence that they are effective for CHD prevention in black patients.

Sulodexide fails to demonstrate renoprotection in overt type 2 diabetic nephropathy.

Sulodexide, a mixture of naturally occurring glycosaminoglycan polysaccharide components, has been reported to reduce albuminuria in patients with diabetes, but it is unknown whether it is renoprotective. This study reports the results from the randomized, double-blind, placebo-controlled, sulodexide macroalbuminuria (Sun-MACRO) trial, which evaluated the renoprotective effects of sulodexide in patients with type 2 diabetes, renal impairment, and significant proteinuria (>900 mg/d) already receiving maximal therapy with angiotensin II receptor blockers. The primary end point was a composite of a doubling of baseline serum creatinine, development of ESRD, or serum creatinine ≥6.0 mg/dl. We planned to enroll 2240 patients over approximately 24 months but terminated the study after enrolling 1248 patients. After 1029 person-years of follow-up, we did not detect any significant differences between sulodexide and placebo; the primary composite end point occurred in 26 and 30 patients in the sulodexide and placebo groups, respectively. Side effect profiles were similar for both groups. In conclusion, these data do not suggest a renoprotective benefit of sulodexide in patients with type 2 diabetes, renal impairment, and macroalbuminuria.

Effects of sulodexide in patients with type 2 diabetes and persistent albuminuria.

BACKGROUND: Urinary albumin excretion frequently persists in diabetic patients who are treated with angiotensin-converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB). Sulodexide, a glycosaminoglycan mixture of 80% heparan sulfate and 20% dermatan sulfate, has been hypothesized to reduce persistent albuminuria. We have conducted a multi-center randomized double-blind pilot study in order to determine the effect of 6 months' therapy with sulodexide on urinary albumin excretion and to address logistical issues for a full-scale trial. METHODS: A total of 149 patients with type 2 diabetes and an albumin:creatinine ratio (ACR) between 20 and 300 mg/g were randomized with equal allocation to either placebo, 200 mg of sulodexide or 400 mg of sulodexide. The primary endpoint was the achievement, at 6 months, of either 3(1) return to normoalbuminuria (ACR < 20 mg/g with a decrease of at least 25%) or (2) a decrease in ACR of at least 50% from the baseline value. All patients used a maximum tolerated recommended FDA approved dose of an ACEI or ARB for at least 60 days and had stable blood pressure prior to randomization. RESULTS: The primary efficacy endpoint was achieved in 25.3% of the patients in the two sulodexide groups combined versus 15.4% of the placebo-treated patients (P = 0.26). The primary endpoint was achieved in 33.3% (P = 0.075 for the comparison to placebo) in the sulodexide 200 mg group and 18.4% (P = 0.781) in the sulodexide 400 mg group. (No consistent patterns of side effects were observed. CONCLUSION: Based on the experience gained in this pilot study, one full-scale trial is currently being conducted to evaluate the effects of sulodexide on change in ACR in patients with persistent microalbuminuria, and a longer-term trial is underway to evaluate the effects of sulodexide on long-term renal disease progression in patients with overt proteinuria.

Chronically increased intrarenal angiotensin II causes nephropathy in an animal model of type 2 diabetes.

Diabetic nephropathy characterized by proteinuria and sclerosis is the leading cause of renal failure, but its mechanisms are not well understood. Zucker Obese (ZO) rat model of obesity, insulin resistance, and hypertension has been used to study nephropathy. We hypothesize that chronically elevated intrarenal angiotensin II (ANG II) down-regulates nephrin, a key slit-pore protein and up-regulates fibrogenic molecule transforming growth factor (TGFbeta1) and thus result in progression of nephropathy in type 2 diabetes. Untreated or angiotensin converting enzyme (ACE) inhibitor, captopril, treated ZO and control Lean (ZL) rats were used to measure intrarenal levels of ANG II, glomerular nephrin, TGFbeta1, collagen and fibronectin with age using radioimmunoassay, RT-PCR and immunoblot techniques. Progression of nephropathy was established by measuring proteinuria and sclerosis. ZO rats developed obesity, hyperglycemia, hyperinsulinimia, increase in intrarenal ANG II and proteinuria. Expression of glomerular nephrin decreased while expression of TGFbeta1 and matrix components increased in ZO rats. Captopril treatment prevented increase in intrarenal ANG II, and reversed expression of nephrin, TGFbeta1, collagen and fibronectin. We conclude that in this model of type 2 diabetic nephropathy, chronically elevated intrarenal ANG II causes proteinuria via decrease in nephrin and glomerulosclerosis via TGFbeta1 mediated increase in matrix component.

Impact of achieved blood pressure on cardiovascular outcomes in the Irbesartan Diabetic Nephropathy Trial.

Elevated arterial pressure enhances the risk for cardiovascular (CV) events in patients with diabetic nephropathy. The optimal BP and the component of the elevated BP that affect the risk have not been defined. A post hoc analysis was performed to assess the impact of achieved systolic, diastolic, and pulse pressures on CV outcomes in 1590 adults who had overt diabetic nephropathy and were enrolled in the Irbesartan Diabetic Nephropathy Trial (IDNT) and had a baseline serum creatinine above the normal range, up to 266 micromol/L (3.0 mg/dL), 24-h urine protein >900 mg/d, and at least 6 mo of follow-up. Patients were randomized to irbesartan, amlodipine, or placebo, with other antihypertensive agents to a BP goal of < or =135/85 mmHg. Progressively lower achieved systolic BP (SBP) to 120 mmHg predicted a decrease in CV mortality and congestive heart failure (CHF) but not myocardial infarctions (MI). A SBP below this threshold was associated with increased risk for CV deaths and CHF events. Achieved diastolic BP <85 mmHg was associated with a trend to increase in all-cause mortality, significant increase in MI, but decreased risk for strokes. Increased pulse pressure predicted increased all-cause mortality, CV mortality, MI, and CHF. It is concluded that achieved SBP approaching 120 mmHg and diastolic BP of 85 mmHg are associated with the best protection against CV events in these patients. BP < or =120/85 may be associated with an increase in CV events.

Proteinuria reduction and progression to renal failure in patients with type 2 diabetes mellitus and overt nephropathy.

BACKGROUND: Little is known of the effects of blood pressure reduction by specific classes of antihypertensive drugs on the association between proteinuria reduction and progression of kidney insufficiency and development of end-stage kidney disease in patients with overt diabetic nephropathy in type 2 diabetes mellitus. METHODS: Associations between baseline proteinuria and proteinuria reduction by either irbesartan, amlodipine, or control for similar decrements in blood pressure and the cumulative incidence of renal end points were examined using the Kaplan-Meier method in patients enrolled in the Irbesartan Diabetic Nephropathy Trial. RESULTS: Risk for kidney failure doubled for each doubling of baseline proteinuria level (hazard ratio, 2.04; 95% confidence interval, 1.87 to 2.22; P < 0.001). For each halving of proteinuria level between baseline and 12 months with treatment, risk for kidney failure was reduced by more than half (hazard ratio, 0.44; 95% confidence interval, 0.40 to 0.49; P < 0.001). For the same proportional change in proteinuria, the reduction in risk for kidney failure was significantly greater for irbesartan compared with amlodipine ( P = 0.048), but not control ( P = 0.245). Proteinuria reduction in the first 12 months of therapy with irbesartan is associated with 36% of the total renoprotective effect observed. CONCLUSION: Baseline proteinuria is an important risk factor for kidney failure and provides a means to identify patients at greatest risk. Halving proteinuria halves the kidney risk. Proteinuria reduction using an angiotensin receptor-blocking agent, such as irbesartan, should be regarded as an important therapeutic goal in renoprotective strategies.

Impact of irbesartan, blood pressure control, and proteinuria on renal outcomes in the Irbesartan Diabetic Nephropathy Trial.

BACKGROUND: It is important to know the reliability of early changes in proteinuria in predicting late renal outcomes. The IDNT was a trial in which treatment assignment, baseline and follow-up blood pressure determinations, and albumin/creatinine ratios (ACR), and renal outcomes were recorded. METHODS: Risk of renal outcomes in the IDNT was assessed by proportional hazards modeling as a function of treatment assignment, and achieved systolic blood pressure (SBP) both without, and then with, inclusion of values for baseline proteinuria and early changes in proteinuria. RESULTS: In models without ACR variables, both treatment with irbesartan and achieved SBP during follow-up were significantly predictive of the risk of renal outcomes. Addition of ACR variables to the models reduced the apparent impact of assignment to irbesartan by 52% to 81%, and irbesartan was no longer a significant predictor of renal outcomes. Conversely, addition of ACR variables to the models attenuated the effect of achieved follow-up SBP by only 32% to 46%, and follow-up BP remained a highly significant predictor of renal outcomes. CONCLUSION: The ability of early changes in proteinuria to predict the impact of treatment on renal outcomes is a function of the specific treatment. One must use caution in using early changes in proteinuria as a surrogate for longer-term renal outcomes.

Cardiovascular outcomes in the Irbesartan Diabetic Nephropathy Trial of patients with type 2 diabetes and overt nephropathy.

BACKGROUND: Patients with diabetes have increased risk for adverse cardiovascular events. Angiotensin-converting enzyme inhibitors are protective in type 1 diabetes. However, no definitive studies have examined the use of angiotensin-receptor blockers in patients with type 2 diabetes and overt nephropathy. The primary outcomes of the Irbesartan Diabetic Nephropathy Trial were doubling of serum creatinine levels, end-stage renal disease, and death from any cause. OBJECTIVE: To compare rates of cardiovascular events among patients with type 2 diabetic nephropathy who received conventional antihypertensive therapy with an angiotensin-receptor blocker (irbesartan) or a calcium-channel blocker (amlodipine), or placebo. DESIGN: Randomized double-blind, placebo-controlled trial with a median follow-up of 2.6 years. A time event analysis was used. SETTING: 209 centers in the Americas, Europe, Israel, and Australasia. PARTICIPANTS: 1715 adults with type 2 diabetic nephropathy and hypertension; serum creatinine levels of 89 micromol/L (1.0 mg/dL) to 266 micromol/L (3.0 mg/dL) in women and 106 micromol/L (1.2 mg/dL) to 266 micromol/L (3.0 mg/dL) in men; and urinary protein excretion rates of at least 900 mg/d. INTERVENTION: Treatment with irbesartan, amlodipine, or placebo. MEASUREMENTS: Time to cardiovascular death, myocardial infarction, congestive heart failure, strokes, and coronary revascularization. RESULTS: The three groups were not statistically different in the composite of cardiovascular events. Among the components of the composite, there was a trend toward a decrease in strokes in patients receiving amlodipine versus those receiving placebo (hazard ratio, 0.65 [95% CI, 0.35 to 1.22]; P = 0.18). Likewise, patients receiving amlodipine had a significantly lower rate of myocardial infarction when compared with placebo recipients (hazard ratio, 0.58 [CI, 0.37 to 0.92]; P = 0.02). In contrast, patients receiving irbesartan had a significantly lower incidence of congestive heart failure when compared with placebo recipients (hazard ratio, 0.72 [CI, 0.52 to 1.00]; P = 0.048) or amlodipine recipients (hazard ratio, 0.65 [CI, 0.48 to 0.87]; P = 0.004). CONCLUSION: The composite cardiovascular event rate did not differ in patients with type 2 diabetes and overt nephropathy treated with irbesartan, amlodipine, or placebo in addition to conventional antihypertensive therapy.