Medicine for heart disease has come a long way in 50 years, but now the hard work lies in modifying lifestyle, writes DR MUIRIS HOUSTON
A LITTLE LESS than 50 years ago my grandfather stood for the National Anthem at a Munster football final and promptly fell to the ground; he was pronounced dead where he lay. Grandad’s passing was emblematic of many men of his generation, taken from us by a massive heart attack.
In the 1960s, ischaemic heart disease (IHD), also known as coronary heart disease, was a big killer in Ireland. Age-standardised mortality rates (which take account of changes in the structure of the population) for IHD in Ireland from 1950 to 1999 show a steady rise in IHD mortality from 1950 through 1974, followed by a “plateau” to 1985. (see graphic).
Writing in the 2001 report 50 Years of Heart Disease in Ireland, Dr Mary Codd said “data from the 1950s and 1960s point to an ongoing epidemic of heart disease in Ireland for at least half a century. This is evidenced by the fact that in 1950, 31 per cent of all deaths were due to vascular diseases.”
Of course, the coding of cardiac disease 50 years ago was much less accurate; nonetheless the “epidemic trend” of death from heart disease in the 1960s is clear.
Where once tuberculosis and other infectious diseases posed the main threat of premature death, heart disease now assumed the killer mantle, driven by increasingly sedentary lifestyles and dietary change.
But the exact molecular explanations for the phenomenon had yet to be worked out.
We were still in the era of rheumatic heart disease: when the Irish Heart Foundation (IHF) began its work in 1966, rheumatic heart disease accounted for approximately 25 per cent of cardiac deaths. Cardiac surgery was required for large numbers of adult patients suffering from rheumatic damage to their mitral and aortic valves.
But Prof Risteard Mulcahy and the other founding members of the IHF quickly established a mobile Mediscan service in recognition of the growing problem of coronary heart disease.
A screening programme conducted by nurses which aimed to identify patients’ risk factors included a blood pressure check, cholesterol and weight estimation, and a smoking and exercise history.
It wasn’t until 1974 that the first coronary artery bypass operation was performed at Dublin’s Mater hospital and more than a decade would pass before balloon angioplasty – in which a balloon is threaded from the groin to the coronary artery and inflated so as to push the blockage back into the arterial wall – became an established procedure.
The use of metal stents to achieve the same result followed. In 1985 the late Maurice Neligan and Freddie Wood carried out Ireland’s first heart transplant at the National Cardiac Surgery Centre in the Mater hospital.
From a medication perspective, immense strides have been made in the past 50 years. The powerful diuretic, Lasix, came on the market in 1962 and joined digitalis as treatment for the heart failure that plagued those lucky enough to survive a heart attack in the 1960s.
Almost one-third of patients admitted to hospital after a heart attack died there, most as a result of disturbances to the heart’s natural pacemaker.
Nitroglycerin, used to dilate the coronary arteries, was also available to treat heart disease. Some drugs to treat hypertension also existed, although they were “blunderbuss” therapies by today’s standards.
Writing in 2006, noted cardiac epidemiologist Dr Emer Shelley observed that since the mid-1980s death rates from coronary heart disease have been reducing steadily in Irish men and women.
“The proportion of all deaths in Ireland assigned to cardiovascular disease has decreased from 50 per cent in the 1980s to 36 per cent in 2005.”
The big question that follows this big drop in deaths from coronary heart disease is how was it achieved?
While there may be some argument about specific percentages it is generally accepted that about half the improvement is down to changes people have made to their lifestyles and the other half can be attributed to specific medical treatments and interventions.
As well as reducing death rates from IHD, we are seeing a lot more people surviving with heart disease. It’s part of a phenomenon whereby coronary heart disease is now seen as a chronic illness to accompany the person into old age rather than a likely cause of premature death.
This brings us to the current array of treatments for ischaemic heart disease. Starting with a risk assessment, some modifiable risk factors such as smoking or a lack of exercise may emerge.
Other factors such as a strong family history or the person’s sex are immutable but nonetheless help assess the likelihood of experiencing a serious cardiac event in the future.
Physical examination will reveal data such as body mass index or waist to hip ratio, heart rate and rhythm, blood pressure readings and other relevant findings.
Secondary prevention, that is, the medical treatment of known risk factors for coronary heart disease, has been proven beyond doubt to prevent future heart attacks and other acute coronary events.
Subject to individual assessment, someone with known coronary heart disease will be advised to take a daily aspirin (for its anti-platelet action), a lipid-lowering drug (usually a statin) and either a beta blocker or an angiotensin-converting-enzyme inhibitor, or both.
The latter are used primarily to control blood pressure, but may also be helpful in reducing heart rate or protecting the kidneys. A bottle of glyceryl trinitrate spray to use in the event of sudden chest pain completes the typical package.
Another major treatment advance is the likelihood that someone experiencing an acute heart attack will be given either clot-busting drugs before they reach the hospital or will be brought straight to a coronary catheter lab and an emergency angioplasty carried out. Both of these interventions are designed to reverse the heart attack as it is taking place in order to preserve as much heart muscle function as possible.
We have come a long way in 50 years. From being left resting in a hospital bed for a month after a heart attack, to today’s highly interventional approach to treatment followed by early discharge represents a massive change.
But the real hard work, especially with rising obesity levels, lies in the painstaking and sometimes unglamorous modification of lifestyle factors undertaken by each person with a history or risk of coronary heart disease.
WHAT IS CORONARY HEART DISEASE?
Coronary heart disease affects the heart’s blood vessels, usually as a result of the accumulation of blood in the arteries. Plaque consists of fatty substances that restrict and sometimes block blood flow to the heart, resulting in angina and heart attack. A heart attack may cause permanent damage to the heart muscle and weaken its ability to pump blood. Treatment for coronary heart disease includes lifestyle modifications, medication, the insertion of stents and bypass operations.
