Are the benefits of SGLT2 inhibitors in heart failure and a reduced ejection fraction influenced by background therapy? Expectations and realities of a new standard of care

Physician perceptions, attitudes, and strategies towards implementing guideline-directed medical therapy in heart failure with reduced ejection fraction. A survey of the Heart Failure Association of the ESC and the ESC Council for Cardiology Practice

AIMS

Recent guidelines recommend four core drug classes (renin-angiotensin system inhibitor/angiotensin receptor-neprilysin inhibitor [RASi/ARNi], beta-blocker, mineralocorticoid receptor antagonist [MRA], and sodium-glucose cotransporter 2 inhibitor [SGLT2i]) for the pharmacological management of heart failure (HF) with reduced ejection fraction (HFrEF). We assessed physicians' perceived (i) comfort with implementing the recent HFrEF guideline recommendations; (ii) status of guideline-directed medical therapy (GDMT) implementation; (iii) use of different GDMT sequencing strategies; and (iv) barriers and strategies for achieving implementation.

METHODS AND RESULTS

A 26-question survey was disseminated via bulletin, e-mail and social channels directed to physicians with an interest in HF. Of 432 respondents representing 91 countries, 36% were female, 52% were aged <50 years, and 90% mainly practiced in cardiology (30% HF). Overall comfort with implementing quadruple therapy was high (87%). Only 12% estimated that >90% of patients with HFrEF without contraindications received quadruple therapy. The time required to initiate quadruple therapy was estimated at 1-2 weeks by 34% of respondents, 1 month by 36%, 3 months by 24%, and ≥6 months by 6%. The average respondent favoured traditional drug sequencing strategies (RASi/ARNi with/followed by beta-blocker, and then MRA with/followed by SGLT2i) over simultaneous initiation or SGLT2i-first sequences. The most frequently perceived clinical barriers to implementation were hypotension (70%), creatinine increase (47%), hyperkalaemia (45%) and patient adherence (42%).

CONCLUSIONS

Although comfort with implementing all four core drug classes in patients with HFrEF was high among physicians, a majority estimated implementation of GDMT in HFrEF to be low. We identified several important perceived clinical and non-clinical barriers that can be targeted to improve implementation.

Guideline-directed medical therapy for HFrEF: sequencing strategies and barriers for life-saving drug therapy

Multiple landmark trials have helped to advance the treatment of heart failure with reduced ejection fraction (HFrEF) significantly over the past decade. These trials have led to the introduction of four main drug classes into the 2021 ESC guideline, namely angiotensin-receptor neprilysin inhibitors/angiotensin-converting-enzyme inhibitors, beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter-2 inhibitors. The life-saving effect of these therapies has been shown to be additive and becomes apparent within weeks, which is why maximally tolerated or target doses of all drug classes should be strived for as quickly as possible. Recent evidence, such as the STRONG-HF trial, demonstrated that rapid drug implementation and up-titration is superior to the traditional and more gradual step-by-step approach where valuable time is lost to up-titration. Accordingly, multiple rapid drug implementation and sequencing strategies have been proposed to significantly reduce the time needed for the titration process. Such strategies are urgently needed since previous large-scale registries have shown that guideline-directed medical therapy (GDMT) implementation is a challenge. This challenge is reflected by generally low adherence rates, which can be attributed to factors considering the patient, health care system, and local hospital/health care provider. This review of the four medication classes used to treat HFrEF seeks to present a thorough overview of the data supporting current GDMT, discuss the obstacles to GDMT implementation and up-titration, and identify multiple sequencing strategies that could improve GDMT adherence. Sequencing strategies for GDMT implementation. GDMT: guideline-directed medical therapy; ACEi: angiotensin-converting enzyme inhibitor; ARB: Angiotensin II receptor blocker; ARNi: angiotensin receptor-neprilysin inhibitor; BB: beta-blocker; MRA: mineralocorticoid receptor antagonist; SGLT2i: sodium-glucose co-transporter 2 inhibitor.

Sodium-Glucose Co-transporter 2 Inhibitors Versus Metformin as the First-Line Treatment for Type 2 Diabetes: Is It Time for a Revolution?

Sodium-glucose co-transporter 2 inhibitors (SGLT2i) have emerged as a promising therapeutic option for hyperglycemia and its complications. However, metformin remains the first-line pharmacological treatment in most algorithms for type 2 diabetes (T2D). Although metformin is generally believed to exert positive effects on cardiovascular (CV) outcomes, relevant data are mainly observational and potentially overinterpreted. Yet, it exerts numerous pleiotropic actions that favorably affect metabolism and diabetes comorbidities. CV outcome trials have demonstrated cardiorenal protection with SGLT2i among people at high CV risk and mostly on concomitant metformin therapy. However, post hoc analyses of these trials suggest that the cardiorenal effects of gliflozins are independent of background treatment and consistent across the full spectrum of CV risk. Considering the importance of addressing hyperglycemia as a means of preventing diabetic complications and significant knowledge gaps, particularly regarding the cost-effectiveness of SGLT2i in drug-naïve populations with T2D, the position of metformin in the management of people with diabetes at low CV risk remains solid for the moment. On the other hand, available evidence-despite its limitations-suggests that specific groups of people with T2D, particularly those with heart failure and kidney disease, could probably benefit more from treatment with SGLT2i. This narrative mini-review aims to discuss whether current evidence justifies the use of SGLT2i as the first-line treatment for T2D.

Sequencing of medical therapy in heart failure with a reduced ejection fraction

The management of heart failure with a reduced ejection fraction is a true success story of modern medicine. Evidence from randomised clinical trials provides the basis for an extensive catalogue of disease-modifying drug treatments that improve both symptoms and survival. These treatments have undergone rigorous scrutiny by licensing and guideline development bodies to make them eligible for clinical use. With an increasing number of drug therapies however, it has become a complex management challenge to ensure patients receive these treatments in a timely fashion and at recommended doses. The tragedy is that, for a condition with many life-prolonging drug therapies, there remains a potentially avoidable mortality risk associated with delayed treatment. Heart failure therapeutic agents have conventionally been administered to patients in the chronological order they were tested in clinical trials, in line with the aggregate benefit observed when added to existing background treatment. We review the evidence for simultaneous expedited initiation of these disease-modifying drug therapies and how these strategies may focus the heart failure clinician on a time-defined smart goal of drug titration, while catering for patient individuality. We highlight the need for adequate staffing levels, especially heart failure nurse specialists and pharmacists, in a structure to provide the capacity to deliver this care. Finally, we propose a heart failure clinic titration schedule and novel practical treatment score which, if applied at each heart failure patient contact, could tackle treatment inertia by a constant assessment of attainment of optimal medical therapy.

Cardiovascular benefits of SGLT2 inhibitors in type 2 diabetes, interaction with metformin and role of erythrocytosis: a self-controlled case series study

Background

Sodium-glucose cotransporter-2 inhibitors (SGLT2i) have proven cardiovascular benefits in patients with type 2 diabetes (T2D). This self-controlled case series study aims to evaluate whether metformin use and SGLT2i-associated erythrocytosis influence its cardiovascular benefits.

Methods

T2D patients with metformin and/or SGLT2i prescriptions between 2015 and 2020 were identified from the Hong Kong population. Study outcomes were composite cardiovascular diseases (CVD), coronary heart disease (CHD), hospitalisation for heart failure (HHF), stroke, and erythrocytosis. Risk periods were patient-time divided into four mutually exclusive windows: (i) ‘baseline period’ of metformin use without SGLT2i; (ii) pre-SGLT2i period; (iii) exposure to SGLT2i without metformin; and (iv) exposure to the drug combination. Another SCCS model was applied to evaluate the association between erythrocytosis and cardiovascular outcomes regarding SGLT2i exposure. Four mutually exclusive risk periods included (i) SGLT2i exposure with erythrocytosis; (ii) SGLT2i exposure without erythrocytosis; (iii) absence of SGLT2i exposure with erythrocytosis; and (iv) absence of SGLT2i exposure without erythrocytosis. Incidence rate ratios (IRR) of events at different risk periods were estimated using conditional Poisson regression model.

Results

Among 20,861 patients with metformin and/or SGLT2i prescriptions, 2575 and 1700 patients with events of composite CVD and erythrocytosis were identified, respectively. Compared to metformin use without SGLT2i, SGLT2i initiation was associated with lower risks of composite CVD, CHD, and HHF—regardless of the presence (CVD: IRR = 0.43, 95% CI 0.37–0.51; CHD: IRR = 0.44, 95% CI 0.37–0.53; HHF: IRR = 0.29, 95% CI 0.22–0.40; all p < 0.001) and absence of concomitant metformin (CVD: IRR = 0.31, 95% CI 0.20–0.48; CHD: IRR = 0.38, 95% CI 0.25–0.59; HHF: IRR = 0.17, 95% CI 0.09–0.31; all p < 0.001); while SGLT2i was neutral on stroke risk. Compared to metformin-SGLT2i combination, exposure to SGLT2i alone was associated with comparable risks of all cardiovascular outcomes (all p > 0.05). Incidence rates of erythrocytosis at baseline, SGLT2i without and with metformin use periods were 0.75, 3.06 and 3.27 per 100 person-years, respectively. SGLT2i users who developed erythrocytosis had lower risk of HHF (IRR = 0.38, 95% CI 0.14–0.99, p = 0.049) than those who did not.

Conclusions

Our real-world data suggested that SGLT2i-associated cardiovascular benefits were not attenuated by metformin use. Further studies will delineate the role of erythrocytosis as a surrogate marker of SGLT2i-associated cardiovascular benefit in reducing HHF.

Optimizing Foundational Therapies in Patients With HFrEF

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Clinical practice guidelines emphasize the need for guideline-directed medical therapy in patients with heart failure with reduced ejection fraction.

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Recently, international guidelines and the American College of Cardiology Expert Consensus Decision Pathway recommended quadruple therapy for these patients, including angiotensin receptor blockers/neprilysin inhibitors, beta-blockers, mineralocorticoid receptor antagonists, and sodium–glucose co-transporter 2 inhibitors.

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Strategies to optimize use of novel therapies, achieving target doses and management of side effects and tolerability, are needed to achieve this goal.

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Future prospective studies aimed at guiding optimal implementation of quadruple therapy are needed.

Given the high risk of adverse outcomes in patients with heart failure and reduced ejection fraction (HFrEF), there is an urgent need for the initiation and titration of guideline-directed medical therapy (GDMT) that can reduce the risk of morbidity and mortality. Clinical practice guidelines are now emphasizing the need for early and rapid initiation of therapies that have cardiovascular benefit. Recognizing that there are many barriers to GDMT initiation and optimization, health care providers should aim to introduce the 4 pillars of quadruple therapy now recommended by most clinical practice guidelines: angiotensin receptor–neprilysin inhibitors, beta-blockers, mineralocorticoid receptor antagonists, and sodium–glucose co-transporter 2 inhibitors. A large proportion of patients with HFrEF do not have clinical contraindications to GDMT but are not treated with these therapies. Early initiation of low-dose combination therapy should be tolerated by most patients. However, patient-related factors such as hemodynamics, frailty, and laboratory values will need consideration for maximum tolerated GDMT. GDMT initiation in acute heart failure hospitalization represents another important avenue to improve use of GDMT. Finally, removal of therapies that do not have clear cardiovascular benefit should be considered to lower polypharmacy and reduce the risk of adverse side effects. Future prospective studies aimed at guiding optimal implementation of quadruple therapy are warranted to reduce morbidity and mortality in patients with HFrEF.

Sodium-Glucose Cotransporter-2 Inhibitors Improve Heart Failure with Reduced Ejection Fraction Outcomes by Reducing Edema and Congestion

Pathological sodium-water retention or edema/congestion is a primary cause of heart failure (HF) decompensation, clinical symptoms, hospitalization, reduced quality of life, and premature mortality. Sodium-glucose cotransporter-2 inhibitors (SGLT-2i) based therapies reduce hospitalization due to HF, improve functional status, quality, and duration of life in patients with HF with reduced ejection fraction (HFrEF) independently of their glycemic status. The pathophysiologic mechanisms and molecular pathways responsible for the benefits of SGLT-2i in HFrEF remain inconclusive, but SGLT-2i may help HFrEF by normalizing salt-water homeostasis to prevent clinical edema/congestion. In HFrEF, edema and congestion are related to compromised cardiac function. Edema and congestion are further aggravated by renal and pulmonary abnormalities. Treatment of HFrEF patients with SGLT-2i enhances natriuresis/diuresis, improves cardiac function, and reduces natriuretic peptide plasma levels. In this review, we summarize current clinical research studies related to outcomes of SGLT-2i treatment in HFrEF with a specific focus on their contribution to relieving or preventing edema and congestion, slowing HF progression, and decreasing the rate of rehospitalization and cardiovascular mortality.

Glucose-lowering Drugs and Hospitalization for Heart Failure: A Systematic Review and Additive-effects Network Meta-analysis With More Than 500 000 Patient-years

BACKGROUND

Sodium glucose co-transporter 2 inhibitors (SGLT2is) prevent hospitalization resulting from heart failure (HHF). However, patients with type 2 diabetes mellitus use multiple antihyperglycemic drugs to achieve glycosylated hemoglobin (HbA1c) targets. In these drug combinations, the risk of HHF is unpredictable and so is the parallel effect of glucose-lowering.

PURPOSE

To examine the impact of antihyperglycemic drugs and their association on HHF.

DATA SOURCES

Forty randomized controlled trials (RCTs) reporting HHF.

STUDY SELECTION

Published RCTs were the data source.

DATA EXTRACTION

Incidence rates of HHF.

DATA SYNTHESIS

Random additive-effects network meta-analysis showed that metformin (P = 0.55), sulfonylureas (P = 0.51), glucagon-like peptide-1 receptor-agonist (P = 0.16), and dipeptidyl peptidase 4 inhibitors (DPP4is; P = 0.54) were neutral on the risk of HHF. SGLT2is and SGLT2is + DPP4is reduced the risk of HHF with a hazard ratio (HR) of 0.68 (95% CI, 0.60-0.76; P < 0.0001) and 0.70 (95% CI, 0.60-0.81; P < 0.0001), respectively. Increased risk of HHF was associated with thiazolidinediones (TZDs) as monotherapy or in combination with DPP4is (HR: 1.45; 95% CI, 1.18-1.78; P = 0.0004) and 1.49 (95% CI, 1.18-1.88; P = 0.0008), respectively. Regardless of the therapy, a 1% reduction in HbA1c reduced the risk of HHF by 31.3% (95% CI, 9-48; P = 0.009).

LIMITATIONS

There are no data to verify drug combinations available for clinical use and to discriminate the effect of drugs within each of the therapeutic classes.

CONCLUSIONS

The risk of HHF is reduced by SGLT2is as monotherapy or in combination with DPP4is and increased by TZDs as monotherapy or in combination. Glucose-lowering provides an additive effect of reducing HHF.

Effects of SGLT2 Inhibitors on Ion Homeostasis and Oxidative Stress associated Mechanisms in Heart Failure

Sodium-glucose cotransporter 2 (SGLT2) inhibitors present a class of antidiabetic drugs, which inhibit renal glucose reabsorption resulting in the elevation of urinary glucose levels. Within the past years, SGLT2 inhibitors have become increasingly relevant due to their effects beyond glycemic control in patients with type 2 diabetes (T2DM). Although dedicated large trials demonstrated cardioprotective effects of SGLT2 inhibitors, the exact mechanisms responsible for those benefits have not been fully identified. Alterations in Ca²⁺ signaling and oxidative stress accompanied by excessive reactive oxygen species (ROS) production, fibrosis and inflammatory processes form cornerstones of potential molecular targets for SGLT2 inhibitors. This review focused on three hypotheses for SGLT2 inhibitor-mediated cardioprotection: ion homeostasis, oxidative stress and endothelial dysfunction.

Rapid evidence-based sequencing of foundational drugs for heart failure and a reduced ejection fraction

Foundational therapy for heart failure and a reduced ejection fraction consists of a combination of an angiotensin receptor-neprilysin inhibitor, a beta-blocker, a mineralocorticoid receptor antagonist and a sodium-glucose co-transporter 2 (SGLT2) inhibitor. However, the conventional approach to the implementation is based on a historically-driven sequence that is not strongly evidence-based, typically requires ≥6 months, and frequently leads to major gaps in treatment. We propose a rapid sequencing strategy that is based on four principles. First, since drugs act rapidly to reduce morbidity and mortality, patients should be started on all four foundational treatments within 2-4 weeks. Second, since the efficacy of each foundational therapy is independent of treatment with the other drugs, priority can be determined by considerations of relative efficacy, safety and ease-of-use. Third, low starting doses of foundational drugs have substantial therapeutic benefits, and achievement of low doses of all four classes of drugs should take precedence over up-titration to target doses. Fourth, since drugs can influence the tolerability of other foundational agents, sequencing can be based on whether agents started earlier can enhance the safety of agents started simultaneously or later in the sequence. We propose an accelerated three-step approach, which consists of the simultaneous initiation of a beta-blocker and an SGLT2 inhibitor, followed 1-2 weeks later by the initiation of sacubitril/valsartan, and 1-2 weeks later by a mineralocorticoid receptor antagonist. The latter two steps can be re-ordered or compressed depending on patient circumstances. Rapid sequencing is a novel evidence-based strategy that has the potential to dramatically improve the implementation of treatments that reduce the morbidity and mortality of patients with heart failure and a reduced ejection fraction.

Metformin: still the sweet spot for CV protection in diabetes?

Metformin remains the first-line drug treatment for type 2 diabetes (T2D) in most guidelines not only because it achieves significant reduction in HbA1c but also because of a wealth of clinical experience regarding its safety and observational data that has shown that metformin use is associated with lower mortality rates when compared to sulphonylureas or insulin. Recently other diabetes drugs, particularly SGLT2 inhibitors (SGLT2i) and GLP1 receptor agonists (GLP1RA), have attracted considerable attention for their cardioprotective benefits reported in cardiovascular outcome trials (CVOTs). Randomised control trials on these newer drugs are on a larger scale but have shorter follow-up than UKPDS, the main study supporting metformin use. In a recent change to the European Society of Cardiology guidelines, metformin was replaced by SGLT2i and GLP1RA as first-line for T2D with atherosclerotic cardiovascular disease, whereas American Diabetes Association and UK-wide guidelines maintain metformin as first choice drug pharmacotherapy for all T2D. A definitive evidence-base for prioritisation of these drugs is currently missing because there are no head-to-head clinical trial data. Without such trials being forthcoming, innovative, pragmatic and low-cost 'real-world' trial approaches based on electronic health records may need to be harnessed to determine the correct priority, combinations of drugs and/or identify-specific patient populations most likely to benefit from each one.