Summary | Current management of heart failure & T2DM
As an introduction to the symposium, chairman prof. Adriaan Voors (UMCG, Groningen, The Netherlands) introduced a patient he saw in his clinic, who illustrated relevance of the topic of this symposium; a 49-year old morbid obese (BMI: 51 kg/m2) woman with heart failure with preserved ejection fraction (HFpEF) and type 2 diabetes (T2DM), who had to be hospitalized for acute decompensated HF. She showed a very poor response on furosemide, and renal function worsened. Recently, she had switched from metformin 2 dd 850 mg to insulin. The 2016 European Society of Cardiology (ESC) guidelines on the treatment of acute and chronic HF1 state that insulin may exacerbate fluid retention, which may lead to worsening of HF. The latter risk is also seen with thiazolidinediones, as with sulphonylureas. This situation led to several questions on how this patient could best be managed, which culminate into ‘should diabetic patients with HF be treated differently from patients with diabetes without HF’?
The question posed by prof. Voors is relevant one, as diabetes is very common in patients with HF. Prof. Cowie showed that over 33% of patients with both HF with reduced EF (HFrEF) and HFpEF have also been diagnosed with diabetes. Moving from patients with pre-diabetes, via newly diagnosed diabetes to long-lasting diabetes, patients show a higher risk of mortality or hospitalization for HF.2 Nevertheless, the most recent ESC Guidelines for the diagnosis and management of HF1 write little about patients with diabetes. The two main points state that metformin should be considered as first-line treatment of glycemic control, and that thiazolidinediones are not recommended in patients with HF, as they may increase the risk of HF worsening due to increased fluid retention.
With regard to metformin, some evidence exists that it has CV benefits, but no specific data in the HF population is available. Metformin improves glycemic control, and patients do not tend to gain weight or retain fluid. Caution should be given to renal function, and metformin is contra-indicated if eGFR <30 ml/min/1.73 m2, in light of the rare but serious metabolic complication of lactic acidosis.
Hence, limited options are recommended to treat patients with both HF and diabetes. In management of diabetes alone however, more options are available, including:
- drugs that enhance insulin action in peripheral tissues: thiazolidinediones and metformin,
- drugs that enhance endogenous insulin secretion: sulphonylureas, glucagon-like peptide-1 receptor agonists (GLP-1RA), dipeptidylpeptidase 4 (DPP-4) inhibitors,
- drugs that suppress endogenous glucose production: metformin and thiazolidinediones,
- drugs that delay the absorption of carbohydrate from the gastrointestinal tract: alpha glucosidase inhibitors.
Cowie likes to think of these agents in terms of oral tablets on the one hand, and injectables on the other hand. Injectables include insulin, and the incretin mimetics GLP-1RAs and GLP analogues. Oral agents include the new class of glucosurics, or sodium-glucose cotransporter-2 (SGLT2) inhibitors, which will be discussed in more detail later in this symposium.
Treatment of patients with diabetes and HF is evolving rapidly. Before publishing an update of the ESC Guidelines on HF, a position statement has been issued by the Heart Failure Association (HFA) of the ESC, on treatment of T2DM and HF.3 The document states that HF patients with diabetes should not be treated any differently from HF patients without diabetes when it comes to disease-modifying drugs and devices. There is no evidence that T2DM modifies the benefit of guideline-based therapies for HF. It is pointed out, however, that limited data are available on treatment with hypoglycemic agents in HF patients; no large randomized controlled trials (RCTs) have been conducted, let alone specifically in patients with HF.
When a patient with both HF and T2DM comes to the clinic, the treating cardiologist may wonder whether the diabetes is his/her responsibility. Cowie showed a list of actions that every patient with diabetes deserves and should expect from their treating physician, composed by a diabetes organization. The list contains 15 aspects, some of which need to be performed annually, such as checking glycemic control, blood pressure, cholesterol profile, and looking at legs and feet, doing a kidney function test, checking for proteinuria, ensuring a flu vaccination in autumn, and checking for retinopathy. Other items on the list include ongoing, individualized dietary advice, but also emotional and psychological support, education, seeing a specialist professional, in case of hospitalization high quality care, exploration of sexual problems, support to stop smoking, and specialist input if a pregnancy is desired and planned. Cowie showed the list of actions again, this time to demonstrate that these are, in fact, almost all relevant in good care of patients with HF. Only screening for retinopathy and cholesterol profile may not be performed so regularly, but he emphasized that all other things also apply to patients with HF. Thus, considering the overlap between what a diabetologist does and what a HF specialist thinks should be done with a patient, it is a missed opportunity if cardiologists do not check these things from a diabetic point of view if they are seeing their HF patients.
In conclusion, Cowie is of the opinion that it is important that HF physicians know what diabetes care looks like, and what the treatment options are. This can lead to better treatment choices and better support for patients. It is also useful for a cardiologist to develop a good relationship with the local diabetologist, as more complicated situations that need specialist input are likely to occur. In general, it is wise to check HF patients occasionally if they are developing diabetes, as many will. As patients may not expect their cardiologist to ask them about their diabetes, Cowie suggests to positively surprise patients by informing about other things they may be concerned about.
This is a summary of the presentation given by prof. Cowie, during the PACE symposium entitled 'Contemporary management of a patient with heart failure and diabetes: Implications from recent trials', held during Heart Failure 2018 in Vienna, Austria, on May 28, 2018