It's a brave new cardiac world out there, writes DR MUIRIS HOUSTON having attended the cardiology congress in Germany
CARDIOVASCULAR DISEASE is the main cause of death in all European countries, killing more than 4.3 million people in Europe annually. And with a human and economic cost estimated at €192 billion each year, perhaps it is not surprising that the European Society for Cardiology (ESC) is the largest medical congress held on the continent.
It's the place to be for medical and nursing specialists wishing to network with their peers, and hear the latest research in the area of cardiology. Congress hotlines showcase the results of major clinical trials, with the latest news lapped up by more than 500 journalists covering the annual event.
So what caught the eye this year? Undoubtedly, the highlight, and a discovery that is likely to revolutionise cardiac care in a fundamental way in the years to come, was the result of the "Beautiful" trial.
The ESC in Munich was told last week that a person's heart rate was a powerful predictor of their risk of having a heart attack. Patients with existing coronary artery disease and with a heart that is not pumping blood to its full capacity, and who have a heart rate greater than 70 beats per minute, are significantly more likely to die from heart disease or suffer a heart attack.
The study of 11,000 people in 33 countries - including patients from Galway and Dublin - with known coronary artery disease found that those with a resting heart rate of more than 70 beats per minute had a 56 per cent increased risk of developing heart failure. The increased risk of having a heart attack was 46 per cent, while the risk of needing a further stent or a bypass was increased by one-third.
Prof Gabriel Steg, of the Hopital Bichat - Claude Bernard, Paris, said the study was the first one to show that a high resting heart rate (measured while sitting or lying) was an independent risk factor in coronary artery disease patients.
The researchers also reported that reducing a person's heart rate with the drug Ivabradine significantly reduced the risk of hospitalisation with a heart attack by one-third.
Interestingly, the patients studied were already receiving recommended drug treatment for cardiovascular disease: about 90 per cent of participants were taking aspirin, beta-blockers and another cardio-protective drug, angiotensin-converting enzyme (Ace) inhibitors.
"The results of Beautiful constitute a step further in the management of coronary patients with a hear+t rate above 70 beats per minute, because, for the first time it has been shown that pure heart rate reduction with Ivabradine further reduces coronary events even in patients receiving the current optimal cardiovascular therapy," the authors said.
Ivabradine, which is already licensed to treat angina (heart pain), acts on a specific part of the heart's pacemaker called the sino-atrial node. This small area is located in the atrium, the upper chamber of the heart. The drug does not affect blood pressure or change the ability of heart muscle to function.
This major breakthrough means that the simple measurement of heart rate has become a key indicator of how a person with existing heart vessel blockages will progress. While doctors have always measured a person's heart rate as part of a basic medical examination, a rate between 60 and 100 beats per minute was considered normal. But, as long as the heartbeat was regular and full, the measurement did not attract as much attention as other clinical readings. Even for those patients with established coronary artery disease, heart rate did not merit as much scrutiny as blood pressure, cholesterol and sugar levels as long as the beat was regular, and neither too slow or too fast.
However, with the result of the Beautiful trial to hand, heart specialists were openly predicting that a heart rate of 70 beats per minute or less would be targeted in all patients considered at risk of heart disease. A follow-up trial is already under way, which is expected to show that a lower heart rate is important in all patients with a history of angina, bypass surgery, heart attack or who have had a stent inserted to unblock a coronary artery. As with most simple ideas, there is an intuitive logic to protecting the heart by lowering its workload.
Other trial results of note were the "Transcend" trial, which identified an alternative drug - telmisartan - for those patients unable to tolerate the commonly prescribed Ace inhibitor class of drugs. The angiotensin - receptor blocker (ARB) was shown to reduce heart attack and stroke in people with established cardiac disease.
A major heart failure trial produced mixed results. The GISSI research found that statins (cholesterol-lowering drugs) did not improve outcomes in people with heart failure (a condition in which the pumping action of the heart is impaired). However, a separate arm of the study was more encouraging, showing that treatment with polyunsaturated fatty acid ( fish oils) reduced death rates in patients with chronic heart failure.
A session on the cardiac safety of drugs prescribed for other conditions was a reminder that the use of anti-inflammatory drugs in older people remains a potential minefield even after the withdrawal of Vioxx from the market. Experts are concerned about potential cardiac side effects of older non-steroidal anti-inflammatory drugs (NSAIDS). With a typical 70-year-old suffering from arthritis having some four to five co-existing diseases, the potential for interactions leading to cardiac side effects remain a problem.
Two relatively new cardiac problems were also highlighted: for people with diabetes, the glitazone class of drugs increases the risk of congestive heart failure; and people with Parkinson's disease treated with the drug pergolide are at risk of developing heart valve problems.
The congress saw the introduction of new guidelines for the treatment of heart failure. Meanwhile, a stand in the exhibition hall caught my eye: although a commercial rather than a scientific presentation the Lifebridge B2T (Bridge to Therapy), a portable heart-lung machine could offer hope to severely ill heart failure patients. The new device will allow these patients be safely transferred from peripheral hospitals to cardiac centres using cardiopulmonary bypass, something not hitherto possible without putting the person's life at risk.
Other futuristic products included a hand-held cardiac ultrasound, raising the prospect of doctors doing echocardiograms during ward rounds; robotic navigation of the heart, meaning that ablation probes can be placed with extreme accuracy during the treatment of an irregular heartbeat; and the development of technology that would do away with the need for open heart surgery when the heart's valves need replacing.
It's a brave new cardiology world out there.
But there is something elegant about the Beautiful study that made it the high point of the event for this writer: proving that something simple like heart rate carries new prognostic value has an artistic merit all its own.
The Munich conference
The European Society for Cardiology (ESC) is the umbrella organisation for doctors, nurses and other health professionals working in the area of heart disease throughout Europe.
It holds an annual congress in August / September. This year's meeting in Munich, Germany attracted some 30,000 people from all over the world, 23,000 of whom were doctors. They chose from 600 hours of scientific sessions over a five-day period.
A sense of the scale of the "Messe Munchen" exhibition centre in the Bavarian capital was that the ESC took up just part of the centre's space, despite requiring eight separate zones and two exhibition areas to accommodate the congress.
Of the 10,000 scientific research papers submitted in advance, some 3,500 were accepted by the organising committee for discussion.
Everything from the basic science of heart disease and cardiac function to the latest drugs and devices for bedside use were covered during the event. State-of- the-art lectures, hotline research sessions and "how-to" seminars enabled participants to learn about the latest innovations across the entire spectrum of cardiology.
And the pharmaceutical and medical device industries occupied two exhibition halls, from where they targeted delegates with the latest information on their products.