The 2013 European Society of Cardiology (ESC) Guidelines on diabetes, pre-diabetes, and cardiovascular disease, developed in collaboration with the European Association for the Study of Diabetes (EASD), were published last month online in European Heart Journal1 and on the ESC website (www.escardio.org/guidelines).

Previous ESC/EASD Guidelines on diabetes were published in 2007. The EASD and ESC appointed chairs to direct the activities of the task force. Its members were chosen for their particular areas of expertise. Initial editing and review of the manuscripts took place at the task force meetings, with systematic review and comments provided by the ESC Committee for Practice Guidelines and the EASD Panel for Overseeing Guidelines and Statements.

HbA1c

The 2013 version introduces glycated haemoglobin (HbA1c) to diagnose diabetes. If HbA1c is elevated, the patient is diagnosed with diabetes. If HbA1c is not elevated, patients with cardiovascular disease should receive an oral glucose tolerance test (OGTT). This requires fasting patients to ingest glucose and blood levels are measured before and after two hours.

Joint Task Force Chair Professor Lars Rydén (Sweden) of the ESC said: "We have simplified diagnosis because many patients may be disclosed with HbA1c, limiting the numbers who need the lengthier test. But a normal HbA1c does not rule out diabetes in high risk patients, who need to have an oral glucose tolerance test."

Cardiovascular risk assessment

Cardiovascular risk assessment has also been simplified and risk engines are no longer advocated. Patients with diabetes are considered at high cardiovascular risk. Patients with diabetes and cardiovascular disease (myocardial infarction, angina pectoris or peripheral vascular disease) are at very high risk of recurrent cardiovascular disease.

Professor Peter Grant (UK) of the EASD said: "Risk engines which accumulate risk factors and produce a low, medium or high risk score are less useful for patients with diabetes."

Revascularisation

Recommendations on revascularisation have undergone two major changes since 2007. In patients with stable coronary artery disease and no complex coronary lesions, medical therapy is recommended before interventions. Professor Rydén said: "In former days we were quick to do coronary interventions but based on new trial data we now do not advocate bypass surgery and coronary angioplasty until medical therapy has been tried."

Artery stenoses

Also new is the recommendation that patients with several or complex coronary artery stenoses should be offered bypass surgery before percutaneous coronary dilatation. Professor Rydén said: "New trial data clearly shows that morbidity and mortality are inferior with bypass surgery compared to coronary dilatation even with the use of drug eluting stents."

Targets

Targets for blood pressure and glucose are now individualised. The general blood pressure target for diabetics is <140/85mmHg (in 2007 it was 130/80mmHg). In patients who also have kidney disease the target is <130/85mmHg. Control should also be stricter in patients at risk of stroke. Glycaemic control should be carefully implemented with lower targets in young patients recently diagnosed with diabetes and untouched by cardiovascular disease. Control should be modest in older patients with longstanding diabetes and cardiovascular complications to avoid side effects.

Other changes include the prioritisation of weight stabilisation over reduction and a recommendation against drugs to increase HDL cholesterol. Aspirin is not advocated in patients with diabetes unless they also have cardiovascular disease and in this case novel platelet stabilising drugs may be more effective. A completely new chapter on patient centred care has been included in which advocates shared decision making. Professor Grant said: "Diabetes is a complex disease and it is very important that cognitive behavioural strategies are built into the treatment strategy so that the patient is empowered to take care of themselves to a large extent."

Main messages

Diabetes

Diabetes is described in the guidance as a metabolic disorder characterised by chronic hyperglycaemia resulting from defects in insulin secretion or action, or a combination of both-95% comprised by type 2 diabetes. It is an important contributor to vascular damage inducing a high risk of macro-and microvascular complications.

Screening

Screening for type 2 diabetes can be implemented using a non-invasive risk score (eg. FINDRISC) supplemented by the assessment of glycaemia in people at high risk.

Diagnosis

Diagnosis of diabetes can be made by the measurement of fasting plasma glucose (FPG) (>7.0mmol/L), 2hPG (>11.1mmol/L) or HbA1c (>6.5%). HbA1C <6.5% does not exclude a diagnosis of diabetes which should be further investigated by an oral glucose tolerance test (OGTT) in people at high risk of disturbed glucose metabolism. Abnormal PG or HbA1C test results should be repeated to confirm the diagnosis. Progression of IGT to diabetes can be delayed by lifestyle intervention in about 50% of individuals. The intervention effect is sustained after lifestyle counselling has ceased. Pharmacotherapies (a-glucosidase inhibitors, metformin, glitazones, insulin, ARBs) can delay progression to diabetes in people with IGT whilst the drug is taken.

Risk factors

• For assessment of individual cardiovascular risk, classical risk factors are family history, lifestyle, smoking, hypertension, dyslipidaemia.

• Glycaemic status should be considered.

• Other risk factors are: macrovascular disease (coronary, cerebrovascular and peripheral artery disease, heart failure) and microvascular disease (retinopathy, nephropathy, neuropathy). Also arrhythmias especially atrial fibrillation.

Patient education and empowerment includes:

• Lifestyle advice.

• Smoking cessation.

• Personalised treatment of blood pressure, lipids, glucose and thrombotic risk.

Lifestyle intervention includes:

• Daily consumption of vegetable and fruits.

• Increased dietary fibre intake.

• Moderate intake of simple carbohydrates.

• Reduced total dietary fat intake.

• Replacement of saturated fat by monounsaturated or polyunsaturated fat.

• Physical activity >30 min/day or at least 150 min/week.

• Weight reduction >5% if BMI >25kg/m2.

• Moderate alcohol consumption.

Key targets* for prevention of cardiovascular disease include:

• BP <140/85mmHg.

• LDL cholesterol <1.8mmol/L (<70mg/dL).

• HbA1c <7% (<53mmol/mol).

*These targets should be applied with individual needs taken into account.

Multifactorial medical management should include:

• A combination of blood pressure lowering agents is often required to achieve control and RAAS blockade should be part of the treatment.

• Lipid control is based on statins.

• Antiplatelet therapy is recommended for secondary prevention of CVD.

• A combination of glucose lowering agents is often required to achieve glycaemic control and metformin should be considered as first line treatment especially in overweight/obese patients.

Options for revascularisation include:

• Acute coronary syndromes. Early angiography and culprit lesion revascularisation should be offered.

• Stable coronary artery disease. CABG is preferred if the myocardial area at risk is large (multi-vessel disease, complex coronary lesions).

• PCI with DES may be performed for symptom control in single- and two-vessel disease.

• Peripheral artery disease. Critical limb ischaemia and symptomatic carotid artery disease should be revascularised.

Heart failure

Type 2 diabetes is a major risk factor for the development of heart failure. The combination of diabetes and heart failure has a 12-fold higher mortality than diabetes alone. Pharmacological management include combinations of RAAS inhibitors, beta blockade and diuretic therapy. Non-pharmacological approaches should be considered as in patients without diabetes.

Multidisciplinary strategies

The guidelines state that comprehensive care of diabetes patients often requires collaboration between specialists in cardiology, diabetology and primary care and several other subspecialties such as surgery ophthalmology, nephrology and psychiatry. Nurses, dieticians, podiatrists and physiotherapists and care professionals are also important collaborators.

Conclusion

The emphasis in these guidelines is to provide information on the current state of the art in how to prevent and manage the diverse problems associated with the effects of diabetes on the heart and vasculature in a holistic manner. The authors state that there is a clear need for this guidance because diabetes and coronary heart disease are more common than imagined.

 

References

1. The Task Force on diabetes, pre-diabetes, and cardiovascular diseases of the European Society of Cardiology (ESC) and developed in collaboration with the European Association for the Study of Diabetes (EASD). ESC Guidelines on diabetes, pre-diabetes, and cardiovascular diseases developed in collaboration with the EASD. Eur Heart J (2013) doi: 10.1093/eurheartj/eht108 First published online: August 30, 2013