Despite current established therapy, heart failure (HF) remains a leading cause of hospitalization and mortality worldwide. Novel therapeutic targets are therefore needed to improve the prognosis of ...patients with HF. The EMPA-REG OUTCOME trial (Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients) demonstrated significant reductions in mortality and HF hospitalization risk in patients with type 2 diabetes mellitus (T2D) and cardiovascular disease with the antihyperglycemic agent, empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor. The CANVAS trial (Canagliflozin Cardiovascular Assessment Study) subsequently reported a reduction in 3-point major adverse cardiovascular events and HF hospitalization risk. Although SGLT2 inhibition may have potential application beyond T2D, including HF, the mechanisms responsible for the cardioprotective effects of SGLT2 inhibitors remain incompletely understood. SGLT2 inhibition promotes natriuresis and osmotic diuresis, leading to plasma volume contraction and reduced preload, and decreases in blood pressure, arterial stiffness, and afterload as well, thereby improving subendocardial blood flow in patients with HF. SGLT2 inhibition is also associated with preservation of renal function. Based on data from mechanistic studies and clinical trials, large clinical trials with SGLT2 inhibitors are now investigating the potential use of SGLT2 inhibition in patients who have HF with and without T2D. Accordingly, in this review, we summarize the key pharmacodynamic effects of SGLT2 inhibitors and the clinical evidence that support the rationale for the use of SGLT2 inhibitors in patients with HF who have T2D. Because these favorable effects presumably occur independent of blood glucose lowering, we also explore the potential use of SGLT2 inhibition in patients without T2D with HF or at risk of HF, such as in patients with coronary artery disease or hypertension. Finally, we provide a detailed overview and summary of ongoing cardiovascular outcome trials with SGLT2 inhibitors.
Inhibition of the sodium–glucose cotransporter (SGLT) 2 in the proximal tubule of the kidney has a broad range of effects on renal function and plasma volume homeostasis, as well as on adiposity and ...energy metabolism across the entire body. SGLT2 inhibitors are chiefly used in type 2 diabetes for glucose control, achieving reductions in HbA
1c
of 7–10 mmol/mol (0.6–0.9%) when compared with placebo. This glucose-lowering activity is proportional to the ambient glucose concentration and glomerular filtration of this glucose, so may be greater in those with poor glycaemic control and/or hyperfiltration at baseline. Equally, the glucose-lowering effects of SGLT2 inhibitors are attenuated in individuals without diabetes and those with a reduced eGFR. However, unlike the glucose-lowering effects of SGLT2 inhibitors, the spill-over of sodium and glucose beyond the proximal nephron following SGLT2 inhibition triggers dynamic and reversible realignment of energy metabolism, renal filtration and plasma volume without relying on losses into the urine. In addition, these processes are observed in the absence of significant glucosuria or ongoing natriuresis. In the long term, the resetting of energy/salt/water physiology following SGLT2 inhibition has an impact, not only on adiposity, renal function and blood pressure control, but also on the health and survival of patients with type 2 diabetes. A better understanding of the precise biology underlying the acute actions of SGLT2 inhibitors in the kidney and how they are communicated to the rest of the body will likely lead to improved therapeutics that augment similar pathways in individuals with, or even without, diabetes to achieve additional benefits.
The efficacy and safety of sodium-glucose cotransporter 2 inhibitors such as sotagliflozin in preventing cardiovascular events in patients with diabetes with chronic kidney disease with or without ...albuminuria have not been well studied.
We conducted a multicenter, double-blind trial in which patients with type 2 diabetes mellitus (glycated hemoglobin level, ≥7%), chronic kidney disease (estimated glomerular filtration rate, 25 to 60 ml per minute per 1.73 m
of body-surface area), and risks for cardiovascular disease were randomly assigned in a 1:1 ratio to receive sotagliflozin or placebo. The primary end point was changed during the trial to the composite of the total number of deaths from cardiovascular causes, hospitalizations for heart failure, and urgent visits for heart failure. The trial ended early owing to loss of funding.
Of 19,188 patients screened, 10,584 were enrolled, with 5292 assigned to the sotagliflozin group and 5292 assigned to the placebo group, and followed for a median of 16 months. The rate of primary end-point events was 5.6 events per 100 patient-years in the sotagliflozin group and 7.5 events per 100 patient-years in the placebo group (hazard ratio, 0.74; 95% confidence interval CI, 0.63 to 0.88; P<0.001). The rate of deaths from cardiovascular causes per 100 patient-years was 2.2 with sotagliflozin and 2.4 with placebo (hazard ratio, 0.90; 95% CI, 0.73 to 1.12; P = 0.35). For the original coprimary end point of the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke, the hazard ratio was 0.84 (95% CI, 0.72 to 0.99); for the original coprimary end point of the first occurrence of death from cardiovascular causes or hospitalization for heart failure, the hazard ratio was 0.77 (95% CI, 0.66 to 0.91). Diarrhea, genital mycotic infections, volume depletion, and diabetic ketoacidosis were more common with sotagliflozin than with placebo.
In patients with diabetes and chronic kidney disease, with or without albuminuria, sotagliflozin resulted in a lower risk of the composite of deaths from cardiovascular causes, hospitalizations for heart failure, and urgent visits for heart failure than placebo but was associated with adverse events. (Funded by Sanofi and Lexicon Pharmaceuticals; SCORED ClinicalTrials.gov number, NCT03315143.).
The primary objective of this mechanistic open-label, stratified clinical trial was to determine the effect of 8 weeks' sodium glucose cotransporter 2 inhibition with empagliflozin 25 mg QD on renal ...hyperfiltration in subjects with type 1 diabetes mellitus (T1D).
Inulin (glomerular filtration rate; GFR) and paraaminohippurate (effective renal plasma flow) clearances were measured in individuals stratified based on having hyperfiltration (T1D-H, GFR ≥ 135 mL/min/1.73m(2), n=27) or normal GFR (T1D-N, GFR 90-134 mL/min/1.73m(2), n=13) at baseline. Renal function and circulating levels of renin-angiotensin-aldosterone system mediators and NO were measured under clamped euglycemic (4-6 mmol/L) and hyperglycemic (9-11 mmol/L) conditions at baseline and end of treatment. During clamped euglycemia, hyperfiltration was attenuated by -33 mL/min/1.73m(2) with empagliflozin in T1D-H, (GFR 172±23-139±25 mL/min/1.73 m(2), P<0.01). This effect was accompanied by declines in plasma NO and effective renal plasma flow and an increase in renal vascular resistance (all P<0.01). Similar significant effects on GFR and renal function parameters were observed during clamped hyperglycemia. In T1D-N, GFR, other renal function parameters, and plasma NO were not altered by empagliflozin. Empagliflozin reduced hemoglobin A1c significantly in both groups, despite lower insulin doses in each group (P≤0.04).
In conclusion, short-term treatment with the sodium glucose cotransporter 2 inhibitor empagliflozin attenuated renal hyperfiltration in subjects with T1D, likely by affecting tubular-glomerular feedback mechanisms.
http://www.clinicaltrials.gov. Unique identifier: NCT01392560.
Aims/hypothesis
In previous work, we reported the HR for the risk (95% CI) of the secondary kidney composite endpoint (time to first event of doubling of serum creatinine from baseline, renal ...dialysis/transplant or renal death) with ertugliflozin compared with placebo as 0.81 (0.63, 1.04). The effect of ertugliflozin on exploratory kidney-related outcomes was evaluated using data from the eValuation of ERTugliflozin effIcacy and Safety CardioVascular outcomes (VERTIS CV) trial (NCT01986881).
Methods
Individuals with type 2 diabetes mellitus and established atherosclerotic CVD were randomised to receive ertugliflozin 5 mg or 15 mg (observations from both doses were pooled), or matching placebo, added on to existing treatment. The kidney composite outcome in VERTIS CV (reported previously) was time to first event of doubling of serum creatinine from baseline, renal dialysis/transplant or renal death. The pre-specified exploratory composite outcome replaced doubling of serum creatinine with sustained 40% decrease from baseline in eGFR. In addition, the impact of ertugliflozin on urinary albumin/creatinine ratio (UACR) and eGFR over time was assessed.
Results
A total of 8246 individuals were randomised and followed for a mean of 3.5 years. The exploratory kidney composite outcome of sustained 40% reduction from baseline in eGFR, chronic kidney dialysis/transplant or renal death occurred at a lower event rate (events per 1000 person-years) in the ertugliflozin group than with the placebo group (6.0 vs 9.0); the HR (95% CI) was 0.66 (0.50, 0.88). At 60 months, in the ertugliflozin group, placebo-corrected changes from baseline (95% CIs) in UACR and eGFR were −16.2% (−23.9, −7.6) and 2.6 ml min
−1
1.73 m
−2
(1.5, 3.6), respectively. Ertugliflozin was associated with a consistent decrease in UACR and attenuation of eGFR decline across subgroups, with a suggested larger effect observed in the macroalbuminuria and Kidney Disease: Improving Global Outcomes in Chronic Kidney Disease (KDIGO CKD) high/very high-risk subgroups.
Conclusions/interpretation
Among individuals with type 2 diabetes and atherosclerotic CVD, ertugliflozin reduced the risk for the pre-specified exploratory composite renal endpoint and was associated with preservation of eGFR and reduced UACR.
Trial registration
ClinicalTrials.gov
NCT01986881
Graphical abstract
Sodium glucose cotransporter 2 inhibitors may reduce kidney hyperfiltration, thereby preventing diabetic kidney disease progression, which may in turn reduce cardiovascular risk, including heart ...failure. However, the mechanisms that regulate renal function responses to sodium glucose cotransporter 2 inhibition are not yet fully understood. We explored the renal protective effects of sodium glucose cotransporter 2 inhibition with empagliflozin, with a focus on glomerular hemodynamic effects and tubuloglomerular feedback using in vivo multiphoton microscopy imaging techniques.
C57BL/6 mice and spontaneously diabetic Ins2
mice were studied. The mice were treated with empagliflozin (20 mg·kg
·d
) and insulin for 4 weeks, and the single-nephron glomerular filtration rate was measured using multiphoton microscope. A neuronal nitric oxide synthase inhibitor (7-nitroindazole, 20 mg·kg
·d
) or a cyclooxygenase-2 inhibitor (SC58236, 6 mg/L), or an A1 adenosine receptor antagonist (8-cyclopentyl-1,3-dipropylxanthine, 1 mg·kg
·d
) was administered to elucidate the mechanisms of tubuloglomerular feedback signaling and single-nephron glomerular filtration rate regulation.
The urinary excretion of adenosine, nitric oxide metabolites, and the prostanoid prostaglandin E2 was also quantified. The single-nephron glomerular filtration rate in the Ins2
group was higher than in controls (C57BL/6; 4.9±1.3 nL/min versus Ins2
; 15.8±6.8 nL/min) and lower in Ins2
/empagliflozin to 8.0±3.3 nL/min (P<0.01). In vivo imaging also revealed concomitant afferent arteriolar dilation (P<0.01) and increased glomerular permeability of albumin in the Ins2
group. Empagliflozin ameliorated these changes (P<0.01). Urinary adenosine excretion in the Ins2
/empagliflozin group was higher than in Ins2
(Ins2
; 3.4±1.4 nmol/d, Ins2
/empagliflozin; 11.2±3.0 nmol/d, P<0.05), whereas nitric oxide metabolites and prostaglandin E2 did not differ. A1 adenosine receptor antagonism, but not neuronal nitric oxide synthase or cyclooxygenase-2 inhibition, blocked the effect of empagliflozin on renal function. Empagliflozin increased urinary adenosine excretion and reduced hyperfiltration via afferent arteriolar constriction, effects that were abolished by A1 adenosine receptor blockade.
Adenosine/A1 adenosine receptor pathways play a pivotal role in the regulation of the single-nephron glomerular filtration rate via tubuloglomerular feedback mechanisms in response to sodium glucose cotransporter 2 inhibition, which may contribute to renal and cardiovascular protective effects reported in clinical trials.
Over the past two years, our understanding of anti-hyperglycemic medications used to treat patients with type 2 diabetes (T2D) has fundamentally changed. Before the EMPA-REG OUTCOME trial, agents ...used to lower blood glucose were felt to prevent or delay the development of microvascular complications, but were not known to definitively reduce cardiovascular risk or mortality. Previous studies with then novel sodium-glucose cotransport-2 (SGLT2) inhibitors demonstrated improvements in several cardiovascular and renal risk factors, including HbA1c, blood pressure, weight, renal hyperfiltration, and albuminuria. However, as with other antihyperglycemic drugs, it could not be known if these salutary effects would translate into improved cardiorenal outcomes. In the EMPA-REG OUTCOME trial, SGLT2 inhibition with empagliflozin reduced the primary outcome of major adverse cardiovascular events (MACE), while also reducing mortality, hospitalization for heart failure, and progression of diabetic kidney disease. In the CANVAS Program trials using canagliflozin, the rates of the 3-point MACE endpoint, the risk of heart failure and the renal composite endpoint were also reduced, albeit with an increased risk of lower extremity amputation and fracture. As a result, clinical practice guidelines recommend the consideration of SGLT2 inhibition in high-risk patient subgroups for cardiovascular risk reduction. Ongoing primary renal endpoint trials will inform the cardio-metabolic-renal community about how to optimally treat patients with chronic kidney disease – including those with and without diabetes. Our aim is to review the rationale for renal protection with SGLT2 inhibitors, and their current place in the clinical management of patients with kidney disease.
Sodium-glucose cotransporter 2 (SGLT2) inhibitors favorably affect cardiovascular (CV) and kidney outcomes; however, the consistency of outcomes across the class remains uncertain.
To perform ...meta-analyses that assess the CV and kidney outcomes of all 4 available SGLT2 inhibitors in patients with type 2 diabetes.
A systematic literature search was conducted in PubMed from January 1, 2015, to January 31, 2020.
One hundred forty-five records were initially identified; 137 were excluded because of study design or topic of interest. As a result, a total of 6 randomized, placebo-controlled CV and kidney outcomes trials of SGLT2 inhibitors in patients with type 2 diabetes were identified, with contributory data from 9 publications. All analyses were conducted on the total patient population of these trials.
Standardized data search and abstraction were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Statement. Data were analyzed using a fixed-effect model.
Outcomes included time to the first event of (1) the composite of major adverse CV events of myocardial infarction, stroke, or CV death, and each component, (2) the composite of hospitalization for heart failure (HHF) or CV death (HHF/CV death) and each component, and (3) kidney composite outcomes. For outcomes in the overall trial populations and in selected subgroups, hazard ratios (HRs) and 95% CIs were pooled and meta-analyzed across trials.
Data from 6 trials comprised 46 969 unique patients with type 2 diabetes, including 31 116 (66.2%) with atherosclerotic CV disease. The mean (SD) age of all trial participants was 63.7 (7.9) years; 30 939 (65.9%) were men, and 36 849 (78.5%) were White. The median number of participants per trial was 8246 (range, 4401-17 160). Overall, SGLT2 inhibitors were associated with a reduced risk of major adverse CV events (HR, 0.90; 95% CI, 0.85-0.95; Q statistic, P = .27), HHF/CV death (HR, 0.78; 95% CI, 0.73-0.84; Q statistic, P = .09), and kidney outcomes (HR, 0.62; 95% CI, 0.56-0.70; Q statistic, P = .09), with no significant heterogeneity of associations with outcome. Associated risk reduction for HHF was consistent across the trials (HR, 0.68; 95% CI, 0.61-0.76; I2 = 0.0%), whereas significant heterogeneity of associations with outcome was observed for CV death (HR, 0.85; 95% CI, 0.78-0.93; Q statistic, P = .02; I2 = 64.3%). The presence or absence of atherosclerotic CV disease did not modify the association with outcomes for major adverse CV events (HR, 0.89; 95% CI, 0.84-0.95 and HR, 0.94; 95% CI, 0.83-1.07, respectively; P = .63 for interaction), with similar absence of associations with outcome modification by prevalent atherosclerotic CV disease for HHF/CV death (P = .62 for interaction), HHF (P = .26 for interaction), or kidney outcomes (P = .73 for interaction).
In this meta-analysis, SGLT2 inhibitors were associated with a reduced risk of major adverse CV events; in addition, results suggest significant heterogeneity in associations with CV death. The largest benefit across the class was for an associated reduction in risk for HHF and kidney outcomes, with benefits for HHF risk being the most consistent observation across the trials.
Sodium-glucose cotransporter-2 (SGLT2) inhibitors, including empagliflozin, dapagliflozin, and canagliflozin, are now widely approved antihyperglycemic therapies. Because of their unique glycosuric ...mechanism, SGLT2 inhibitors also reduce weight. Perhaps more important are the osmotic diuretic and natriuretic effects contributing to plasma volume contraction, and decreases in systolic and diastolic blood pressures by 4 to 6 and 1 to 2 mm Hg, respectively, which may underlie cardiovascular and kidney benefits. SGLT2 inhibition also is associated with an acute, dose-dependent reduction in estimated glomerular filtration rate by ≈5 mL·min(-1)·1.73 m(-2) and ≈30% to 40% reduction in albuminuria. These effects mirror preclinical observations suggesting that proximal tubular natriuresis activates renal tubuloglomerular feedback through increased macula densa sodium and chloride delivery, leading to afferent vasoconstriction. On the basis of reduced glomerular filtration, glycosuric and weight loss effects are attenuated in patients with chronic kidney disease (estimated glomerular filtration rate <60 mL·min(-1)·1.73 m(-2)). In contrast, blood pressure lowering, estimated glomerular filtration rate, and albuminuric effects are preserved, and perhaps exaggerated in chronic kidney disease. With regard to long-term clinical outcomes, the EMPA-REG OUTCOME trial (Empagliflozin, Cardiovascular Outcomes, and Mortality in Type 2 Diabetes) in patients with type 2 diabetes mellitus and established cardiovascular disease randomly assigned to empagliflozin versus placebo reported a 14% reduction in the primary composite outcome of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, and >30% reductions in cardiovascular mortality, overall mortality, and heart failure hospitalizations associated with empagliflozin, even though, by design, the hemoglobin A1c difference between the randomized groups was marginal. Aside from an increased risk of mycotic genital infections, empagliflozin-treated patients had fewer serious adverse events, including a lower risk of acute kidney injury. In light of the EMPA-REG OUTCOME results, some diabetes clinical practice guidelines now recommend that SGLT2 inhibitors with proven cardiovascular benefit be prioritized in patients with type 2 diabetes mellitus who have not achieved glycemic targets and who have prevalent atherosclerotic cardiovascular disease. With additional cardiorenal protection trials underway, sodium-related physiological effects of SGLT2 inhibitors and clinical correlates of natriuresis, such as the impact on blood pressure, heart failure, kidney protection, and mortality, will be a major management focus.
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