Close X
Thursday, October 31, 2024
ADVT 
National

Heart study subjects not representative of cardiac patients as a whole

Helen Branswell, Canadian Press, 26 Aug, 2014 01:42 PM
    A new study points out a serious problem that plagues research into treatments for heart disease.
     
    It shows that only a tiny fraction of people who have had a heart attack take part in clinical trials looking at cardiac therapies.
     
    And those who do are generally the patients who are the youngest, the healthiest and those who are at lowest risk of dying from heart disease.
     
    The scientists say that as a consequence, the findings of trials can be skewed.
     
    Results in this elite pool of patients can create the expectation that therapies will have more benefit than is actually seen when they are used in the broader community of heart disease patients.
     
    The research was done by a number of Canadian and American scientists and is published in the Journal of the American Medical Association.
     
    The first author of the paper is Dr. Jacob Udell, a cardiologist at Toronto's Women's College Hospital.
     
    Udell explains that he and his colleagues used the U.S. National Cardiovascular Data Registry to explore the question.
     
    They looked at data on patients in the registry to see which people would have been eligible for three clinical trials of clot-busting drugs that were conducted between July 1, 2008, and March 31, 2011. More than 140,000 people had a heart attack during that period and could have been considered for one of the three studies.
     
    He and his colleagues found that about two-thirds of the patients in the registry — 68 per cent — met the eligibility criteria for the studies. But only 2.8 per cent of the people were in one of the trials.
     
    And while the idea behind clinical trials is to test a drug in people who are like those who will eventually use the medication, the 2.8 per cent was not entirely representative of the heart attack patients.
     
    "Trial participants were younger, with less previous cardiovascular disease, lower predicted risk of mortality, shorter hospital stays and more frequent treatment with evidence-based therapy than non-participants," Udell and his co-authors wrote.
     
    The last point, about evidence-based medicine, suggests these patients got a higher level of care than others in the registry.
     
    Dr. Douglas Lee says the paper is an elegant way to illustrate a real problem.
     
    "A drug may have worked in the ideal setting of a clinical trial, but does it also work in the real world?" asks Lee, who is a senior scientist at the Institute of Clinical Evaluative Sciences and a cardiologist at the Peter Munk Cardiac Centre at Toronto's University Health Network.
     
    "There's a threat that they" — the findings from these trials — "may be less relevant for everyone else who's not enrolled in the trial."
     
    Udell says there are a variety of reasons more people don't take part in clinical trials.
     
    They may not be asked; the trial leaders may attempt to cherry pick patients to get the best results. Patients may worry taking part in a study might harm their health. And for others, cost — going back and forth to a clinic, taking time off work — might be an issue if trial subjects are not reimbursed for costs.
     
    Udell suggests big patient registries could be harnessed to more quickly and economically find potential clinical trial subjects who are more representative of the general heart attack population than has been the case up till now.

    MORE National ARTICLES

    ICBC Seeks 5.2% Raise in Basic Insurance Rates

    ICBC Seeks 5.2% Raise in Basic Insurance Rates
    The Insurance Corporation of British Columbia is aiming to hike basic insurance rates by 5.2 per cent.

    ICBC Seeks 5.2% Raise in Basic Insurance Rates

    Confrontations between humans and cougars means more big cats destroyed in 2013

    Confrontations between humans and cougars means more big cats destroyed in 2013
    The number of cougars destroyed by conservation officers in B.C. in the 2013-2014 fiscal year jumped dramatically compared with a year earlier.

    Confrontations between humans and cougars means more big cats destroyed in 2013

    Fortress Paper sells maker of security threads in bank notes for $17.5 million

    Fortress Paper sells maker of security threads in bank notes for $17.5 million
    Pulp and bank note producer Fortress Paper Ltd. is selling its operations that make security film used in bank notes to Nanotech Security Corp. for up to $17.5 million in cash and shares.

    Fortress Paper sells maker of security threads in bank notes for $17.5 million

    Striking B.C. teachers step up pressure tactics as school year looms

    Striking B.C. teachers step up pressure tactics as school year looms
    Secondary schools in Vancouver are expected to be behind picket lines this week as part of a province-wide attempt to pressure the British Columbia government.

    Striking B.C. teachers step up pressure tactics as school year looms

    Kids removed from Manitoba home: parents charged with confinement, sex abuse

    Kids removed from Manitoba home: parents charged with confinement, sex abuse
    Police in western Manitoba have charged a couple with confining, starving and sexually abusing their children.

    Kids removed from Manitoba home: parents charged with confinement, sex abuse

    Quebec calls inquiry into fire that killed 32 people at seniors' residence

    Quebec calls inquiry into fire that killed 32 people at seniors' residence
    The Quebec government has called a public inquiry into the fire that killed 32 people at a seniors' residence last January.

    Quebec calls inquiry into fire that killed 32 people at seniors' residence