Summary | The essentials for diabetes and heart failure

Diabetes is common in HF patients, regardless of whether one looks at data from clinical trials or real world registries [1]. Between one-quarter and one-third of HF patients have diabetes, and in some parts of the world, for example in the Middle-East and Asia the proportion is even higher, up to 50-60%. Registry data from the UK showed that one-third of patients admitted to the hospital for HF have diabetes. The risk of developing diabetes increases in HF patients with time. As the dose of diuretics increases as a reflection of the severity of HF, the risk of diabetes rises quite remarkably [2]. Moreover, not only is HF a risk factor for diabetes, but the treatment for HF (especially diuretics) also increases the risk for development of diabetes.

Prof. Cowie emphasized that HF physicians need to know about diabetes, how it impacts the prognosis of patients, and how it might affect treatment decisions and recommendations. He backed this up with data showing that all-cause mortality, HF hospitalization, and combined endpoints were all increased in HF patients with diabetes compared to HF patient without diabetes or with prediabetes [3].

Then Cowie changed perspective and asked how common HF is in diabetes patients. Age is a strong risk factor for HF, as well as the duration of having diabetes [4]. Between 10-15% of diabetes patients have HF [1].

Thus, diabetes and HF often interact and Cowie stated that it is time that clinicians think more about these conditions simultaneously. That raises the question whether treatment of patients with HF with reduced ejection fraction (HFrEF) should be modified based on the presence of diabetes. Cowie answered firmly that this is not the case. All evidence-based therapies show benefit for diabetes patients in subgroup analyses, with similar relative risk reduction and even greater absolute risk reduction compared to non-diabetes patients. The only caveat is that control of potassium levels by the kidney of diabetes patients can be reduced with use of renin-angiotensin-aldosterone system inhibitors (RAASi) and aldosterone antagonists, resulting in increased risk of hyperkalemia. Therefore, more frequent monitoring of renal function is required in these patients.

Does HF modify treatment decisions for diabetes patients? This is a moving field with a lot of clinical data in the last few years and more data of RCTs are awaited in the next two years. A consensus document published in 2018 by the EASD and ADA, considers two groups of diabetes patients at high CV risk with separate recommendations for therapy (after metformin and lifestyle changes): for patients with atherosclerotic CVD, glucagon-like peptide-1 receptor agonists (GLP-1Ras) are recommended and for patients with HF or chronic kidney disease (CKD), SGLT2 inhibitors (SGLT2i) are recommended.

Considering the new data and insights, when is it time to change practice? Although it is a rapidly moving field, Cowie said we have to start now. He showed the recommendation from Diabetes UK [5], a patient and professional group working together on the minimal care patients should expect. The recommendation includes measurement of HbA1c, blood pressure (BP), lipids, retinopathy screen, examination of feet and legs, measurement of kidney function and proteinuria, flu vaccination, dietary advice, and others. Most of these measurements should be done annually.

Indeed, Cowie asks his patients whether they have diabetes, if so, who is responsible for care and advice, if things are working (do the patients feel supported, are they well informed), what their control is, advises them to stop smoking, discusses sexual function, goes through their medication list, checks if they had flu vaccination, and what their GP is up to.

References

Educational information

This is a summary of the presentation given by prof. Martin Cowie, during the PACE symposium entitled 'Heart Failure, diabetes and SGLT2i: Time to change practice?', held during ESC HF in Athens, Greece on May 25, 2019.

View the slides of his presentation Watch the video of his presentation