Feature / Heart of the matter

Our ‘Knowing the business’ series continues with a look at the work of cardiologists. Seamus Ward reports

It is a sobering thought that every seven minutes – perhaps the time taken to read this article – a person dies from a heart attack. Heart attacks or myocardial infarctions cause most of the deaths from coronary heart disease, often referred to as coronary artery disease, which is the UK’s single biggest killer. Coronary artery disease accounts for 74,000 deaths a year, according to the British Heart Foundation (BHF). But the charity estimates a further 2.3 million people are living with the disease across the UK.

The BHF estimates there are 900,000 men and more than 400,000 women living in the UK who have had a heart attack. More than 750,000 of these are under the age of 75. Death rates from coronary artery disease are highest in Scotland and northern England and lowest in southern England.

The BHF says coronary artery disease cost the NHS about £1.8bn in 2009. Some 56% of this was the cost of hospital inpatient care, while outpatients accounted for 20%, medication 15%, primary care 6% and A&E 3%. The cost to the economy through premature death, lost productivity, hospital treatment and prescriptions is put at £19bn a year.

Kevin Fox, consultant cardiologist and head of cardiology at Imperial College Healthcare NHS Trust, says cardiologists will see four main categories of patient – those with breathlessness; those with discomfort or chest pain; those who feel their heart is not beating in a regular or normal rhythm; and people who are concerned or who have a risk of developing heart disease.

Coronary artery disease is the most common diagnosis, followed by heart muscle failure, some of which may be the result of coronary artery disease. Coronary artery disease occurs when fatty deposits build up within the artery walls.

A heart attack can occur if these deposits become unstable. A piece of a deposit may break off and lead to the formation of a blood clot. If this clot blocks the coronary artery, the heart will be starved of oxygen and damage the muscle.

Dr Fox says cardiologists in most district generals will deal with three main diagnoses – coronary artery disease, heart failure and abnormal heart rhythm (arrhythmia). Heart failure means the heart is not pumping blood around the body as efficiently as it used to, often because it has been damaged (by a heart attack, for example).


Common diagnosis

The most common causes of heart failure are heart attacks, high blood pressure and cardiomyopathy – diseases of the heart muscle that are sometimes hereditary. Other causes are heart valve problems, alcohol or recreational drugs, arrhythmia, congenital heart conditions and a viral infection of the heart muscle.

Abnormal heart rhythms – where the heart beats too fast, too slow or with an irregular pattern – are caused when there is a problem with the electrical system, which tells the heart when to beat. The problem will centre on the sinus node, the heart’s natural pacemaker or further along the conduction pathway of the electrical signals that control the heartbeat.

Patients may present with angina – often characterised by a pain or discomfort in the chest, though some report pain in the stomach, neck, arm or jaw and breathlessness – which is usually caused by coronary artery disease.


Diagnostic tests

There are a number of non-invasive and invasive tests used to diagnose a coronary problem. Non-invasive procedures range from the relatively low tech, such as treadmill or tilt table tests, to high-tech imaging, including CT scanning and cardiac magnetic resonance. Invasive tests include arteriography, where a dye is injected into the bloodstream and X-ray images are taken of the blood vessels around the heart.

Some diagnostic tests are only available in specialist centres. Liverpool Heart and Chest Hospital NHS Foundation Trust provides tertiary level care. Raphael Perry, consultant cardiologist and deputy medical director at the trust, says the specialised nature of the hospital means it is often sent patients through secondary care providers, where tests have been carried out and a diagnosis made. These patients have often been treated exclusively using drugs, but are sent to the trust for more invasive treatment. Sometimes patients are referred to the trust directly by GPs.

Despite being physicians, cardiologists perform some procedures that the layman might assume is carried out by surgeons. Interventional cardiologists such as Dr Perry perform angioplasties – the widening of arteries that have become blocked or narrowed due to fatty deposits (atherosclerosis). A small medical ‘balloon’ is inserted into a blocked or narrowed artery. It inflates and compresses the atherosclerotic material against the arterial wall to open the artery. Usually a metal mesh (a stent) is placed across the artery wall to keep it open. Some patients with extensive coronary artery disease will need a coronary artery bypass graft (CABG), which is performed by cardiac surgeons.

Patients in Cheshire and Merseyside who have an acute heart attack will be taken to Liverpool Heart and Chest Hospital by ambulance. ‘We take them to one of our cath labs, where we image the arteries around the heart. If we see an artery is blocked, we will unblock it using primary percutaneous coronary intervention [emergency angioplasty].’ This is the preferred procedure, he says. Generally, clinicians have stopped giving thrombolytic or clot-busting drugs for acute heart attacks.

Rhythm disturbances can be treated with medication, in many cases in district general hospitals (DGHs). Electrical imbalances that cause arrhythmia can be corrected by radio-frequency ablation – the procedure, performed by an interventional cardiologist using imaging guidance such as X-ray, ultrasound or CT scan, destroys the tissue in the heart causing the arrhythmia.

If a heart goes into cardiac arrest – usually because of arrhythmia, but also other conditions including a heart attack – the heart stops pumping and a defibrillator can be used to shock it back into action. Heart failure is common and managed primarily with drug treatment. Severe symptoms can be addressed using a specialised pacemaker, which can also act as a defibrillator.

Congenital heart problems often require surgery in childhood – for example, to close a hole in the heart. Dr Perry says many DGHs have diagnostic equipment, but cardiologists in such hospitals are trained slightly differently, with a greater emphasis on general rather than sub-specialist cardiology.

Each patient diagnosed with a heart problem should be given a care package that will include a discussion on lifestyle changes and risk factors the patient can control, Dr Fox says. These include smoking, diet, exercise, obesity and blood pressure.

‘The prognosis for most heart disease conditions has improved dramatically over the last decade or two. This is due to the population smoking less and eating better and to improvements in treatment. We offer a well-audited practice with a scientific evidence base, so I know how many of my patients survive after a heart attack and how long they stay in hospital. There’s a national database, so you can find out outcomes for an individual consultant.’

Dr Fox says the safety of the procedures carried out by cardiologists has improved greatly, but the challenge has increased because of the increasing complexity of the patients. ‘We’re offering complex procedures for people in their 80s – the complication risk is real, but so are the benefits of the procedures we offer.’

He adds that the safety of all interventions is audited rigorously, both within the hospital and nationally by the National Institute for Cardiac Outcomes Research (NICOR).

‘Mortality in the procedures is extremely low,’ Dr Perry adds. ‘The technology has moved on a great deal. It’s very safe and we measure that in some detail. At the end of every case, a dataset is entered into the computer and analysed in terms of outcomes, published and scrutinised. Once they’ve been treated, most patients are discharged back to their GPs. Most care is now done in the community under the guidance of a specialist.’


Multiple roles

Dr Fox says cardiologists have a number of responsibilities. Most will have outpatient clinics, some responsibility for inpatients, treatment and research. Typically, they will do two clinics (one day) a week in outpatients, including one for patients needing more specialist care. But more of their time will be spent performing complex diagnostic and therapeutic procedures (often two days a week), with one day on inpatients and a further day on teaching and research.

While the cardiologist may be the central pillar of a patient’s care, they are part of a multidisciplinary team that includes specialist nurses, radiographers and psychologists. ‘At Imperial we offer a comprehensive range of  treatments, from the basics available in most hospitals to those only offered in national and international centres of excellence or “highly specialised centres”,’ Dr Fox adds.

The good news is many heart conditions are preventable and the NHS is geared to diagnose and treat them. Treatment is evidence-based and, more than some other specialties, clinical audit is robust and outcomes published. But heart conditions, particularly coronary artery disease, remain a major cause of death in the UK, especially in less affluent areas.