An international study, led by the University of Edinburgh, raises concerns that some patients may not be receiving the optimum medical treatment and follow-up care because doctors are misjudging the risk of a further heart attack.
Researchers looked at data taken from the Global Registry of Coronary Events that included more than 46,000 heart attack patients from 115 hospitals in 14 countries.
The likelihood of patients having a further heart attack, or dying, was then compared with whether they had originally been admitted with a "full" heart attack – where the artery was completely blocked – or an "incomplete" heart attack - where there was only partial blockage of the artery.
The findings, published in the September edition of the journal Nature Clinical Practice, contradict the assumption that patients whose arteries had been completely, instead of partially, blocked are the most at risk after they are discharged from hospital.
While patients with full heart attacks were more likely to have another heart attack or die within the first 15 days, the risk for those whose heart attack was originally considered not as severe (incomplete blockage of the artery) overtook the full heart attack group after 26 days.
Professor Keith Fox, British Heart Foundation Professor of Cardiology at the University of Edinburgh, who will present his findings at the European Society of Cardiology in Munich next week, said: "Two-thirds of adverse events after a heart attack – which may be a further heart attack, stroke or major bleed – happen after a patient has been discharged from hospital.
"Our findings are of concern because we believe that the risk for patients whose heart attack was originally considered not as severe may be being misjudged. As a result there may be some patients who should be, but are not, receiving treatments such as the placing of stents to open up the artery, drug treatments and lifestyle changes which could prevent a further heart attack from occurring.
"This does not mean to say that all patients who have had a heart attack will need surgical intervention, but that doctors should carry out a simple recommended risk assessment that unfortunately is not being routinely used, but which takes in a variety of factors to help work out the best treatment."
Source: University of Edinburgh
Explore further: Harried doctors can make diagnostic errors