Impacts of CIHR-funded research: Heart Disease

[ Table of Contents ]

Protecting patients' hearts during surgery
Long-recommended drug may not be advisable

Overview

The world's largest randomized trial looking at whether beta-blocker drugs protect the heart during surgery came up with a surprising finding: these drugs, routinely prescribed for more than a decade for patients undergoing non-cardiac surgery, may help prevent heart attacks, but they also may increase the risk of death and major stroke. The study, led by Drs. P.J. Devereaux of McMaster University and Homer Yang of the University of Ottawa, found that of 1,000 patients receiving a beta-blocker drug, the drug will prevent 15 patients from having a heart attack, three from having angioplasty or coronary artery bypass surgery and seven from developing new atrial fibrillation (a heart rhythm disorder), but would cause eight patients to die, five to have a stroke, 53 to experience low blood pressure requiring treatment and 42 to experience a low heart rate requiring treatment.

Impact

This study provides research evidence about widely-used drugs. Its results will change how patients are cared for after surgery and bring physicians to question whether there are better alternatives.

First Published

CIHR Institute of Circulatory and Respiratory Health, newsletter, summer 2008


Surgery improves survival in patients with heart failure
Study provides much-needed evidence to support treatment choice

Overview

Bypass surgery? Angioplasty? Both are often recommended for patients with heart failure. Anxious patients understandably want to know whether either surgery is necessary. Now, Dr. Ross Tsuyuki of the University of Alberta has gathered the evidence to reassure patients that surgery is well worth it. He looked at Alberta heart failure patients to compare the outcomes of bypass surgery, angioplasty or neither. He found that mortality rates among those who had either procedure were half those who had neither and chose, instead, management with medication and lifestyle changes.

Impact

Physicians have stronger evidence upon which to base treatment recommendations to their patients with heart failure. Patients can make treatment decisions with lessened anxiety about the right route to take.

First Published

Research profile, February 2007


Menopause delivers change in heart health
Is there a role for hormone replacement therapy?

Overview

Hot flashes and mood swings get the attention – but the health effects of menopause go right to the heart. Menopause marks the end of the hormones that keep women's hearts healthy. Hormone replacement therapy (HRT) can make up for the lack of natural hormones, but there is concern about its effects on health more broadly. Dr. Sandra Davidge of the University of Alberta has found that HRT can be effective if given at the onset of menopause. That's because it can help prevent deterioration of blood vessels. However, later on, when blood vessels have already deteriorated, it's not as beneficial.

Impact

Evidence of the harms and/or benefits of HRT are still being debated. Dr. Davidge's work provides evidence of when HRT can be beneficial, providing guidance to menopausal women and their physicians.

First Published

Research profile, February 2008


Calculating the risks
Giving emergency physicians a better way to make decisions

Overview

When a person arrives at the emergency department complaining of chest pain, physicians spring into action, aided by guidelines that tell them what to look for, what tests to perform, what treatments to try and whether to admit or discharge. But when a person shows up with complications from acute heart failure, such as difficulty breathing, the steps to take are less clear and admission to hospital is largely a judgment call. Patients tend to respond quickly to treatment and admitting all of them is not an option, given that 40,000 such patients show up at Ontario emergency departments alone each year. Dr. Douglas Lee of the Institute for Clinical Evaluative Sciences is creating a set of decision guidelines to assist emergency physicians.

Impact

The guidelines have the potential to save hundreds of lives and millions of health-care dollars each year.

First Published

Research profile, February 2009


Following up success
A simple phone call can improve outcomes

Overview

Congestive heart failure patients often need extra attention. Their hearts have difficulty pumping blood, leaving them short of breath or dizzy. Their ankles swell. And, unsure of what to do, they often end up in their doctor's office or at the emergency department. Dr. Alan Katz of the University of Manitoba developed a project to follow up with these patients with a phone call on a regular basis to support them in taking steps to improve their health, such as watching fluids, taking medications and exercising as much as they could. Those receiving phone support experienced significant weight loss, felt better and made fewer visits to their family physicians or emergency departments.

Impact

The program resulted in better health for patients and less pressure for overworked primary care physicians. Manitoba health authorities want to expand the program and extend it to other chronic diseases.

First Published

Research profile, February 2009


Pacemaker choice can save health-care system millions
No difference in effectiveness

Overview

In 1950, Canadian electrical engineer John Hopps designed and built the first external pacemaker. Pacemakers are now widely used to regulate heartbeat, with different models available. Dr. Stuart Connolly of McMaster University looked at some of these models and concluded that dual-chamber pacemakers are no more effective than the single-chamber version of the devices, but cost about $2,500 more. More than 40% of the 10,000 pacemakers implanted in Canada in year are dual-chamber.

Impact

Switching to single-chamber pacemakers could save the health-care system up to $10 million per year. While Dr. Connolly has not attempted to measure the degree to which this has happened, he believes that the research slowed the growth of dual-chamber pacemakers. The recommendation to use single-chamber pacemakers has appeared in guidelines.

First Published

CIHR Health Research Results, 2003-04; updated 2009


Rebuilding damaged hearts
Development of functional nanostructures can promote regeneration of healthy heart tissue

Overview

Angioplasty – inflating blocked veins or arteries – and stents to maintain the wider passageway have greatly reduced deaths due to heart disease. Dr. Maryam Tabrizian of McGill University is working to improve the procedure, working at the sub-microscopic level to develop functional nanostructures that can be used to deliver medications directly to where they are needed. The nanostructures can adhere to the surface of stents or be delivered by catheter directly to the surface of the arterial wall.

Impact

A coated stent proved successful in animal models. The next step is to find a partner (a stent manufacturer) willing to adapt its stent to test in humans. Delivering the medication directly through the catheter has not been as successful, but Dr. Tabrizian and her team continue to develop ways to overcome the difficulties, including developing a probe, using quantum dots, and imaging techniques to follow the medication on its path to the arteries.

First Published

CIHR Health Research Results, 2006-07; Regenerative Medicine and Nanomedicine – Investing Today in the Promise of Tomorrow, second edition, 2009; updated 2009


Simple solutions for a healthier heart
Surgery may not be the answer

Overview

Angioplasty is a popular procedure for unblocking blocked arteries – so popular that, in 2003-04, physicians performed 167 of them per 100,000 Canadians over the age of 20. But in a seven-year study of patients with blocked coronary arteries, Drs. Koon Teo and William Boden of McMaster University have found that angioplasty is no more effective than medication and lifestyle changes such as stopping smoking, exercising and eating better when it comes to preventing heart attacks and strokes. The Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation (COURAGE) studied more than 2,000 patients at 50 hospitals in the United States and Canada.

Impact

The finding has had a significant impact on practice, with reports of decreased volumes in cardiac catheterization (the procedure used in angioplasty) in many hospitals. The findings in many cases have confirmed usual practice, with cardiologists reporting that they appreciate having the data to support their practice.

First Published

CIHR Health Research Results, 2006-07; CIHR Institute of Circulatory and Respiratory Health, newsletter, summer 2007; updated 2009


Do cranberries help keep arteries healthy?
Compound may prevent hardening

Overview

Hardening of the arteries, or atherosclerosis, occurs when the muscle cells lining arteries change the way they grow and behave, leading to the formation of plaques that can restrict blood flow, which can result in hypertension, heart attack or stroke. Dr. Robert Hurta of the University of Prince Edward Island is studying whether eating cranberries can help prevent atherosclerosis. He believes that "bioactive" compounds found in cranberries can prevent or slow the development of atherosclerosis by modulating the underlying molecular processes that contribute to disease onset and progression.

Impact

Findings from the study suggest that including cranberries in your diet can protect against cardiovascular disease and possibly against liver damage as well.

First Published

CIHR Health Research Results, 2006-07; updated 2009


Save time, save lives
Edmonton advance starts treatment when the paramedic arrives

Overview

Heart attacks can cause major damage to the heart in just a few hours. Typically, there is a two-to-three hour delay between the onset of symptoms and a patient's arrival at the hospital – time that can make a huge difference in outcomes. Dr. Paul Armstrong of the University of Alberta looked to Europe for inspiration to ensure that heart attack patients receive speedy care – even before they arrive at the emergency department. Basing his plan on a system that has existed in France for many years, Dr. Armstrong developed a way to train paramedics to carry out a 12-lead electrocardiogram (ECGs) of the heart and transmit the results to a cardiologist on call. With earlier diagnosis, paramedics can administer clot-busting drugs to restore normal heart function in patients who experience the most deadly type of heart attack, acute ST elevation myocardial infarction, or STEMI.

Impact

Armstrong's innovation has shaved about one hour off the normal treatment time, with some patients being treated within an hour of symptom onset, thus being spared any permanent muscle damage to the heart.

First Published

CIHR-CMAJ Top Canadian Achievements in Health Research Award, 2009


The heart – it's more than just a brawny muscle
Solving the heart's mysteries

Overview

The heart is a tireless workhorse, pumping thousands of litres of blood through your body every day of your life. For many years, this was thought to be its only function. But Dr. Adolfo de Bold of the University of Ottawa Heart Institute has discovered that the heart does so much more. He found storage granules located in heart muscle cells looked very similar to the granules that produce insulin in the pancreas. Through his research, he found that these granules release a hormone called Atrial Natriuretic Factor (ANF) that controlled water and salt levels in the body. When the heart muscle is stressed, it releases ANF, which then tells the kidneys to filter out salts and reduce the amount of fluid the overworked heart has to pump. The discovery of ANF revealed a new function for the heart muscle, a function that physicians could use to increase or decrease the load on the heart, reducing hypertension and helping the heart compensate after heart failure. Physicians can also measure ANF levels to assess heart health.

Impact

The discovery of the heart's endocrine function offers physicians a new way to reduce the load on stressed hearts and a test to diagnose heart failure and assess treatment efficacy.

First Published

CIHR-CMAJ Top Canadian Achievements in Health Research Awards, 2009


How do you mend a broken heart?
Do it fast!

Overview

STEMI heart attacks – short for ST-segment elevation myocardial infarction – are the most serious kind of heart attack. Quick action is essential to prevent damage. Now, patients in eastern Ontario are getting that quick action, thanks to a program developed by Dr. Michel Le May of the University of Ottawa Heart Institute. The program trains paramedics to conduct an electrocardiogram and, if the test shows evidence of a STEMI, to reroute the ambulance directly to the Heart Institute, where optimal care is delivered as quickly as possible.

Impact

An evaluation of the program published in the New England Journal of Medicine found that it reduced chances of dying of a heart attack by 50%: fewer than 5% of Heart Institute patients treated through the protocol died, compared to 10% of those who received conventional treatment of clot-busting drugs and monitoring. The protocol also cut emergency room congestion, reducing paramedic traffic volume by about 40% and reducing wait times for all patients. The program, which began as a pilot program in 2001, has treated 2,000 patients so far and been a model for similar programs in other urban areas, including Kingston, Hamilton, Quebec City and Vancouver. The program has now been extended to 16 hospitals in the eastern Ontario (Champlain) Local Health Integration Network, so that patients as far away as Barrie's Bay, 183 kilometres away, benefit from the protocol, with slight adaptations, including a stop for clot-busting drugs before being transported by helicopter to the Heart Institute.

First Published

CIHR-CMAJ Top Canadian Achievements in Health Research Awards, 2009; updated 2009


The fluid hypothesis
Just walk it off – a simple solution to sleep apnea

Overview

Obstructive sleep apnea (OSA) robs 10-15% of the adult population of North America of their sleep and puts them in danger of heart disease. Dr. Douglas Bradley of the University of Toronto has found that OSA is linked to fluid retention in the legs brought on by a sedentary lifestyle. His discovery has found both a cause of and a treatment for OSA. He found that the severity of OSA was closely linked to the amount of fluid that shifted from the legs to the neck while lying down during sleep. The amount of this fluid shift was, in turn, directly related to the amount of time patients spent sitting during the day. Preventing fluid retention could be a viable treatment of OSA and could be as simple as walking around regularly during the day. Right now, the best available treatment for OSA has been something called CPAP – continuous positive airway pressure. Applied through a nasal mask, CPAP functions like a reverse vacuum cleaner, pumping air into the throat and keeping it from collapsing.

Impact

The prescription for treating sleep apnea may be as simple as taking a walk – and could save patients from having to use CPAP every night.

First Published

Research profile, February 2009


Getting to the root of poor sleep
Sleep apnea has immediate and long-term harms

Overview

People with sleep apnea have short pauses in their breathing while they sleep – often dozens, or even hundreds, of times a night. In the short term, people with sleep apnea feel the effects of poor sleep. In the longer term, it can lead to heart attacks, stroke and high blood pressure. There are treatments, ranging from lifestyle changes to surgery, but first, sleep apnea has to be diagnosed. Dr. John Remmers of the University of Calgary is the co-inventor of the Remmers Sleep Recorder, a tool that can be used at home, without attendants or technicians, to diagnose sleep apnea. Dr. Remmers founders SagaTech Electronics to manufacture and market the device.

Impact

The development of the Sleep Recorder has resulted in the revision of guidelines in the United States and Canada for testing patients suspected of having sleep apnea to include the use of a valid portable monitor as a means of testing. In Calgary, some 50-60 home recorders are used each night, changing patterns of practice, so that primary care physicians can order the low-cost tests, the results of which are then interpreted by a sleep specialist.

First Published

CIHR Health Research Results, 2003-04; updated 2009


Detecting impending heart disease
Test more effective than measuring cholesterol

Overview

Generally, testing blood cholesterol has been a common way of flagging impending heart disease. But another blood test may provide a better way. According to research by Dr. Benoit Lamarche of Laval University, people with high levels of C-reactive protein (CRP) in their blood are at increased risk of heart disease. Further research has since revealed that treating people with normal blood cholesterol but elevated CRP levels significantly reduced the risk of first heart attack. Dr. Lamarche has also determined that high concentrations of CRP associated with abdominal obesity and metabolic syndrome is largely due to increased production of CRP by the liver, rather than a reduced ability of the body to "clear" CRP.

Impact

Partly based on these important findings, the most recent Canadian guidelines for the diagnosis and treatment of cholesterol now suggest using CRP to better evaluate a patient's risk for heart disease.

First Published

CIHR Health Research Results, 2003-04; updated 2009


Ensuring life-saving drugs in the emergency room
Overcrowding big part of the problem

Overview

Heart attack victims can be helped with potentially life-saving drugs – but only if they're administered within 30 minutes of their arrival in the emergency room. However, fewer than half actually receive the drugs, according to research by Dr. Jack Tu and the Canadian Cardiovascular Outcomes Research Team (CCORT). Overcrowding could be part of the reason for the drugs not being administered. Better organization of emergency rooms, routine monitoring of treatment times and a triage system that deals with chest pain patients immediately could help reach the 30-minute treatment goal.

Impact

Many hospitals in Ontario have used this research to re-organize their emergency rooms and improve their treatment times. Among the changes made were initiatives to improve "door-to-needle" times and changing policies to allow emergency room physicians to make the decision to administer the drugs directly, as opposed to transferring the patient to the intensive care unit or cardiac care unit or consulting the cardiology department. The research has also had an impact on provincial planning. "Over the last several years the Ministry has increased the amount of publically available data on performance for every hospital in the province. It ranges from access data to safety data to other things. CCORT has provided both evidence, and given confidence to, policy direction," says Adelsteinn Brown, Assistant Deputy Minister of the Health System Strategy Division at the Ontario Ministry of Health and Long-Term Care .

First Published

CIHR Health Research Results, 2004-05; updated 2010

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