Are the favorable cardiovascular outcomes of empagliflozin treatment explained by its effects on multiple cardiometabolic risk factors? A simulation of the results of the EMPA-REG OUTCOME trial

Expected Health Benefits of SGLT-2 Inhibitors and GLP-1 Receptor Agonists in Older Adults

Background. Older and sicker adults with type 2 diabetes (T2D) were underrepresented in randomized trials of glucagon-like peptide 1 receptor-agonist (GLP1RA) and sodium-glucose cotransporter 2 inhibitors (SGLT2I), and thus, health benefits are uncertain in this population. Objective. To assess the impact of age, health status, and life expectancy in older adults with T2D on health benefits of GLP1RA and SGLT2I. Design. We used the United Kingdom Prospective Diabetes Study (UKPDS) model to simulate lifetime health outcomes. We calibrated the UKPDS model to improve mortality prediction in older adults using a common geriatric prognostic index. Participants. National Health and Nutrition Examination Survey 2013-2018 participants 65 y and older with T2D, eligible for GLP1RA or SGLT2I according to American Diabetes Association guidelines. Interventions. GLP1RA or SGLT2I use versus no additional medication. Main Measures. Lifetime complications and weighted life-years (LYs) and quality-adjusted life-years (QALYs) across overall treatment arms and life expectancies. Key Results. The overall older adult population was predicted to experience significant health benefits from GLP1RA (+0.29 LY [95% confidence interval: 0.27, 0.31], +0.15 QALYs [0.14, 0.16]) and SGLT2I (+0.26 LY [0.24, 0.28], +0.13 QALYs [0.12, 0.14]) as compared with no added medication. However, expected benefits declined in subgroups with shorter life expectancies. Participants with <4 y of life expectancy had minimal gains of <0.05 LY and <0.03 QALYs from added medication. Accounting for injection-related disutility, GLP1RA use reduced QALYs (-0.03 QALYs [-0.04, -0.02]). Conclusions. While GLP1RA and SGLT2I have substantial health benefits for many older adults with type 2 diabetes, benefits are not clinically significant in patients with <4 y of life expectancy. Life expectancy and patient preferences are important considerations when prescribing newer diabetes medications.

Highlights

On average, older adults benefit significantly from SGLT2I and GLP1RA use. However, the benefits of these drugs are not clinically significant among older patients with life expectancy less than 4 y.There is potential harm in injectable GLP1RA use in the oldest categories of adults with type 2 diabetes.Heterogeneity in life expectancy and patient preferences for injectable versus oral medications are important to consider when prescribing newer diabetes medications.

Sodium-glucose cotransporter 2 inhibitor effects on heart failure hospitalization and cardiac function: systematic review

AIMS

To systematically review randomized controlled trials assessing effects of sodium-glucose cotransporter 2 inhibitors (SGLT2is) on hospitalization for heart failure (HHF) and cardiac structure/function and explore randomized controlled trial (RCT)-derived evidence for SGLT2i efficacy mechanisms in heart failure (HF).

METHODS AND RESULTS

Systematic searches of Medline and Embase were performed. In seven trials [3730-17 160 patients; low risk of bias (RoB)], SGLT2is significantly reduced the relative risk of HHF by 27-39% vs. placebo, including in two studies in patients with HF with reduced ejection fraction with or without type-2 diabetes mellitus (T2DM). Improvements in conventional cardiovascular risk factors, including glycaemic levels, cannot account for these effects. Five trials (56-105 patients; low RoB) assessed the effects of 6-12 months of SGLT2i treatment on left ventricular structure/function; four reported significant improvements vs. placebo, and one did not. Five trials (low RoB) assessed SGLT2i treatment effects on serum N-terminal pro B-type natriuretic peptide levels; significant reductions vs. placebo were reported after 8-12 months (two studies; 3730-4744 patients) but not ≤12 weeks (three studies; 80-263 patients). Limited available RCT-derived evidence suggests various possible cardioprotective SGLT2i mechanisms, including improved haemodynamics (natriuresis and reduced interstitial fluid without blood volume contraction/neurohormonal activation) and vascular function, enhanced erythropoiesis, reduced tissue sodium and epicardial fat/inflammation, decreased sympathetic tone, and beneficial changes in cellular energetics.

CONCLUSIONS

Sodium-glucose cotransporter 2 inhibitors reduce HHF regardless of T2DM status, and reversal of adverse left ventricular remodelling likely contributes to this efficacy. Hypothesis-driven mechanistic trials remain sparse, although numerous trials are planned or ongoing.

Inhibition of SGLT2 Rescues Bone Marrow Cell Traffic for Vascular Repair: Role of Glucose Control and Ketogenesis

The mechanisms by which sodium-glucose cotransporter 2 inhibitors (SGLT2i) improve cardiovascular outcomes in people with diabetes are incompletely understood. Recent studies show that SGLT2i may increase the levels of circulating cells with vascular regenerative capacity, at least in part by lowering glycemia. In this study, we used mice with streptozotocin-induced diabetes treated with the SGLT2i dapagliflozin at a dose that reduced glucose levels by 20%. Dapagliflozin improved the diabetes-associated defect of hematopoietic stem cell mobilization after stimulation with granulocyte colony-stimulating factor. Dapagliflozin rescued the traffic of bone marrow (BM)-derived cells to injured carotid arteries and improved endothelial healing in diabetic mice. Defective homing of CD49d⁺ granulocytes was causally linked with impaired endothelial repair and was reversed by dapagliflozin. The effects of dapagliflozin were mimicked by a similar extent of glucose reduction achieved with insulin therapy and by a ketone drink that artificially elevated β-hydroxybutyrate. Inhibition of endothelial repair by resident cells using the CXCR4 antagonist AMD3100 did not abolish the vascular effect of dapagliflozin, indirectly supporting that endothelial healing by dapagliflozin was mediated by recruitment of circulating cells. In summary, we show that dapagliflozin improved the traffic of BM-derived hematopoietic cells to the site of vascular injury, providing a hitherto unappreciated mechanism of vascular protection.

Prediction of transient ischemic attack and minor stroke in people with type 2 diabetes mellitus

AIMS

People with type 2 diabetes (T2DM) have an increased risk of transient ischemic attack and minor stroke (TIA) which are frequently followed by an ischemic stroke. We aimed to develop a predictive model for incident TIA in people with T2DM.

METHODS

We pooled data from two longitudinal cohort studies, Atherosclerosis Risk in Communities (ARIC) and the Cardiovascular Health Study (CHS), using a two-stage approach. First, we used a random effects model to interpolate risk factors of individuals between follow-up exams. Second, we used forward selection to develop a proportional hazards model for time to incident TIA. We internally validated our model using 10-fold cross-validation.

RESULTS

Among 3575 participants with T2DM, mean (SD) age was 60 (10) years and body mass index was 30 (6) kg/m2. Sixty-nine incident TIAs occurred during 38,364 person-years of follow-up. The multivariable model included age at diagnosis of diabetes (hazard ratio 1.13 (95% confidence interval: 1.05,1.21) per year), systolic blood pressure (1.25 (1.04,1.49) per 10 mmHg), a quadratic function of diastolic blood pressure, and history of congestive heart failure (2.08 (1.26, 3.42)). The median cross-validated Harrell's C-index was 0.80.

CONCLUSION

Blood pressure and heart failure are risk factors for the earliest stages of cerebrovascular disease.

Macrovascular Risk Equations Based on the CANVAS Program

BACKGROUND

Widely used risk equations for cardiovascular outcomes for individuals with type 2 diabetes mellitus (T2DM) have been incapable of predicting cardioprotective effects observed in recent cardiovascular outcomes trials (CVOTs) involving individuals with T2DM at high risk for or with established cardiovascular disease (CVD).

OBJECTIVE

We developed cardiovascular and mortality risk equations using patient-level data from the CANVAS (CANagliflozin cardioVascular Assessment Study) Program to address this shortcoming.

METHODS

Data from 10,142 patients with T2DM at high risk for or with established CVD, randomized to canagliflozin + standard of care (SoC) or SoC alone and followed for a mean duration of 3.6 years in the CANVAS Program were used to derive parametric risk equations for myocardial infarction (MI), stroke, hospitalization for heart failure (HHF), and death. Accumulated knowledge from the widely used UKPDS-OM2 (United Kingdom Prospective Diabetes Study Outcomes Model 2) was leveraged, and any departures in parameterization were limited to those necessary to provide adequate goodness of fit. Candidate explanatory covariates were selected using only the placebo arm to minimize confounding effects. Internal validation was performed separately by study treatment arm.

RESULTS

UKPDS-OM2 predicted CANVAS Program outcomes poorly. Recalibrating UKPDS-OM2 intercepts improved calibration in some cases. Refitting the coefficients but otherwise preserving the UKPDS-OM2 structure improved the fit substantially, which was sufficient for stroke and death. For MI, reselecting UKPDS-OM2 covariates and functional form proved sufficient. For HHF, selection from a broad set of candidate covariates and inclusion of a canagliflozin indicator was required.

CONCLUSION

These risk equations address some of the limitations of widely used risk equations, such as the UKPDS-OM2, for modeling cardioprotective treatments for individuals with T2DM and high cardiovascular risk, including derivation from overly healthy patients treated with agents that lack cardioprotection and have been described as reflecting a different therapeutic era. Future work is needed to examine external validity.

Sodium-glucose cotransporter type 2 inhibitors for the treatment of type 2 diabetes mellitus

The management of type 2 diabetes mellitus (T2DM) is becoming increasingly complex. Sodium-glucose cotransporter type 2 inhibitors (SGLT2is) are the newest antidiabetic agents for T2DM. By targeting the kidney, they have a unique mechanism of action, which results in enhanced glucosuria, osmotic diuresis and natriuresis, thereby improving glucose control with a limited risk of hypoglycaemia and exerting additional positive effects such as weight loss and the lowering of blood pressure. Several outcome studies with canagliflozin, dapagliflozin or empagliflozin reported a statistically significant reduction in major cardiovascular events, hospitalization for heart failure and progression to advanced renal disease in patients with T2DM who have established atherosclerotic cardiovascular disease, several cardiovascular risk factors, albuminuric mild to moderate chronic kidney disease or heart failure. Current guidelines proposed a new paradigm in the management of T2DM, with a preferential place for SGLT2is, after metformin, in patients with atherosclerotic cardiovascular disease, heart failure and progressive kidney disease. Ongoing trials might extend the therapeutic potential of SGLT2is in patients with, but also without, T2DM. This Review provides an update of the current knowledge on SGLT2is, moving from their use as glucose-lowering medications to their new positioning as cardiovascular and renal protective agents.

Evaluating the Ability of Economic Models of Diabetes to Simulate New Cardiovascular Outcomes Trials: A Report on the Ninth Mount Hood Diabetes Challenge

OBJECTIVES

The cardiovascular outcomes challenge examined the predictive accuracy of 10 diabetes models in estimating hard outcomes in 2 recent cardiovascular outcomes trials (CVOTs) and whether recalibration can be used to improve replication.

METHODS

Participating groups were asked to reproduce the results of the Empagliflozin Cardiovascular Outcome Event Trial in Type 2 Diabetes Mellitus Patients (EMPA-REG OUTCOME) and the Canagliflozin Cardiovascular Assessment Study (CANVAS) Program. Calibration was performed and additional analyses assessed model ability to replicate absolute event rates, hazard ratios (HRs), and the generalizability of calibration across CVOTs within a drug class.

RESULTS

Ten groups submitted results. Models underestimated treatment effects (ie, HRs) using uncalibrated models for both trials. Calibration to the placebo arm of EMPA-REG OUTCOME greatly improved the prediction of event rates in the placebo, but less so in the active comparator arm. Calibrating to both arms of EMPA-REG OUTCOME individually enabled replication of the observed outcomes. Using EMPA-REG OUTCOME-calibrated models to predict CANVAS Program outcomes was an improvement over uncalibrated models but failed to capture treatment effects adequately. Applying canagliflozin HRs directly provided the best fit.

CONCLUSIONS

The Ninth Mount Hood Diabetes Challenge demonstrated that commonly used risk equations were generally unable to capture recent CVOT treatment effects but that calibration of the risk equations can improve predictive accuracy. Although calibration serves as a practical approach to improve predictive accuracy for CVOT outcomes, it does not extrapolate generally to other settings, time horizons, and comparators. New methods and/or new risk equations for capturing these CV benefits are needed.

For debate; pharmacological priorities in advanced type 2 diabetes

A multitude of therapeutic agents have been available to treat patients with Type 2 diabetes. Unfortunately, many patients with advanced Type 2 diabetes continue to suffer from complications and premature death. To date, all available guidelines emphasize a variety of therapeutic aspects, goals, and pharmacological combinations, without directing the clinician as to which is a higher priority. The following review attempts to clarify which therapeutic option is more important for prognosis in patients with advanced type 2 diabetes. The body of evidence presented, reveal that the most important marker for prognosis is HbA1c. Each 1% incrementally higher HbA1c than ~7% is associated with 15%-45% reduced survival rates. Therefore, any agents that can achieve the time-sensitive objective of lowering HbA1c levels should be used.

Challenges and Opportunities Associated with Incorporating New Evidence of Drug-Mediated Cardioprotection in the Economic Modeling of Type 2 Diabetes: A Literature Review

INTRODUCTION

Cardiovascular disease is a leading cause of mortality in people with type 2 diabetes mellitus (T2DM). Beginning in 2015, long-term cardiovascular outcomes trials (CVOTs) have reported cardioprotective benefits for two classes of diabetes drugs. In addition to improving the lives of patients, these health benefits affect relative value (i.e., cost-effectiveness) of these agents compared with each other and especially compared with other agents. While long-term CVOT data on hard outcomes are a great asset, economic modeling of the value of this cardioprotection faces many new empirical challenges. The aim of this study was to identify different approaches used to incorporate drug-mediated cardioprotection into T2DM economic models, to identify pros and cons of these approaches, and to highlight additional considerations.

METHODS

A review of T2DM modeling applications (manuscript or conference abstracts) that included direct cardioprotective effects was conducted from January 2015 to September 2018. Model applications were classified on the basis of the mechanism used to model cardioprotection [i.e., directly via hazard ratios (HRs) for cardiovascular outcomes or indirectly via biomarker mediation]. Details were extracted and the studies were evaluated.

RESULTS

Five full-length articles and 16 conference abstracts (of which 11 posters were found) qualified for study inclusion. While the approaches used were diverse, the five full-length publications and all but two of the abstracts modeled cardioprotection used direct HRs from the relevant CVOT. The remaining two posters modeled cardioprotection using CVOT HRs in combination with treatment effects mediated through known risk factors.

CONCLUSION

The classification of empirical methods in cardioprotection was intended to facilitate a better understanding of the pros and cons of different methodologies. A substantial diversity was observed, though most used trial HRs directly. Given the differences observed, we believe that diabetes modelers and other stakeholders can benefit from a formal discussion and evolving consensus.

FUNDING

Janssen Global Services, LLC (Raritan, NJ, USA).