Deaths from severe heart attacks following admission to hospital have nearly halved in six years as a result of advances in medical treatment.
In the largest study of its kind, research led by the University of Edinburgh, analysed hospital treatment and outcomes for 44,372 patients admitted to 113 hospitals in 14 countries with heart attacks or unstable angina (threatened heart attacks).
As well as a significant reduction in death rates, the study published in the Journal of American Medical Association also established a decline in heart failure - a progressive disorder when damage to the heart weakens the cardiovascular system and poor heart muscle function causes fluid in the lungs.
This is the first time such findings relating to heart failure, a chronic condition often requiring specialised nursing care in the community, have been made.
In patients admitted with a severe heart attack, where the arteries were completely blocked, death rates reduced from 8.4 to 4.5 per cent. Their risk of heart failure also nearly halved with a reduction from 20 to 11 per cent. For every 1,000 patients presenting themselves to hospital this means 39 fewer death and 90 less patients with new heart failure.
Patients who suffered from severe heart attacks also saw subsequent rates of critical heart failure - cardiogenic shock - reduce from 7.1 to 4.7 per cent. This is important as 70 per cent of patients with cardiogenic shock die.
Professor Keith Fox, British Heart Foundation professor of cardiology at the University of Edinburgh, said: "We know that advances in medical treatments have improved outcomes due to large scale trials of therapies but there has been a substantial gap in knowing how this relates to how new drugs and procedures are being used and implemented in hospitals.
"Our study enables us to look at differences in practice in a clinical setting over time and it has reflected significant changes in how patients with heart attacks are treated, showing that guidelines are being followed. As a result there is a major reduction in death rates."
Deaths in patients admitted with milder forms of heart attacks, where the artery was not completely blocked, also reduced (from 2.9 to two per cent).
Both patients with severe and milder heart attacks were less likely to suffer from strokes and further heart attacks in the following six months.
For those who suffered from severe heart attacks, their risk of having a stroke reduced from 1.3 to 0.5 per cent and also more than halved for heart attacks (down from 4.8 to 2 per cent).
For those who had suffered a milder heart attack, the risk of stroke reduced from 1.26 to 0.67 per cent and the risk of having another heart attack reduced from 3 to 1.9 per cent.
Professor Fox, said: "There have been many advances in medical treatment for heart attacks over recent years - which includes the use of beta-blockers, statins or angiotensin-converting enzyme inhibitors (ACE) and anti-clotting agents.
"However, these long-term prevention methods do not account for improved outcomes while patients are in hospital, which must be down to the acute treatments given after admission. We have taken into account risk factors and the improved outcomes are not because patients are less unwell when they arrive at hospital.
"Our study supports the fact that hospitals are using new treatments effectively. Patients now have a much reduced risk of dying or having another stroke while being treated in hospital and are also less likely to suffer a stroke or further heart attack once they have been discharged."
The study looked at patients between July 1999 and the end of 2006. Countries involved in the study included Britain, the United States, Canada, France, Germany, Belgium, Spain and Poland.
Professor Peter Weissberg, Medical Director at the British Heart Foundation (BHF), said: "This is a great example of why long-term investment in heart research is vital. The study shows that fewer people are dying, and fewer are developing debilitating heart failure thanks to research evidence prompting these hospitals to improve the way they treat people with heart disease.
"Every day, heart patients are benefiting from research made possible partly by generous public donations to the BHF."