Macleans

The heart of the matter

Thu Sep 10, 12:00 AM

Think youre at risk for cardiac arrest? Consider a move to Vancouver. Or, if you can swing it, aim to settle in Seattle. Canadas national survival rate for out-of-hospital cardiac arrests is less than comforting: under five per cent, says the Heart and Stroke Foundation of Canada (HSF). But while the risk of cardiac arrest is the same across the country, the likelihood of survival is not.

When someone in Toronto has a cardiac arrest outside the hospital and receives emergency medical services treatment, the chance he will live to tell the tale is 5.5 per cent, according to a report published by the American Medical Association. But if the same person lives in Vancouver, his likelihood of living is nearly twice as high: 9.7 per cent. And hed be better off yet if he lived in the cardiac champion of cities: Seattle, which reigns over North America at 16.3 per cent. These regional variations expose a host of deficiencies in Canadas approach to cardiac arrest, the nations leading cause of death. What is surprising is, many of the failures come in to play not in the ambulance or the ERbut on the street, before paramedics even arrive.

So why arent we all performing at the level of Vancouver or Seattle? If you ask Dr. Laurie Morrison, emergency medicine specialist at Torontos St. Michaels Hospital, where the biggest gap in cardiac arrest response lies, shell be quick to name the culprit: CPR, or rather the lack of it. The truth, says Morrison, is that cardiac arrest is different from other major killers. With cancer, youve got to make sure that we have all these diagnostic devices and that people have access to resources. Whereas, with cardiac arrest, simple things can make a 100-fold difference.

For starters, basic CPRinvolving cycles of chest compressions and breathscan boost survival rates by 400 per cent. But Canadians, for some reason, do not get down on their hands and knees and do CPR. Its the most pathetic thing, Morrison charges. The chance that a bystander in Canada knows and will perform CPR is around 15 per cent, according to an Ottawa Hospital Research Institute (OHRI) study. Thats miserable, says Linda Piazza, an HSF researcher, adding: We have one of the worst responder rates in the Western world. Those figures are even worse when the cardiac arrest happens at homeas 80 per cent doand family members are too paralyzed by fear to act.

Morrison speculates that Canadians quintessential prudence could be at fault. I dont know whether its a Canadian cultural thing, she muses. Like, I dont want to get involved. I dont want to interfere. That may be true, but it does not explain why survival rates vary so much by region, even within Canada. Edmontons bystander CPR rate, for instance, is fairly high: around 46 per cent. Of course, factors outside the scope of cardiac sciencefrom city layout, which impacts ambulance response times, to the way cities collect EMS datacan skew the numbers.

But a crucial determinant is know-howSeattles rst leg up. Many of us wouldnt have the first idea of how to resuscitate someone. When you live in Seattle, its expected that you should know CPR, explains Dr. Christian Vaillancourt, clinical epidemiologist at OHRI. Vaillancourt estimates that Seattle has the worlds highest bystander CPR ratepossibly with the exception of Oslo. But Seattles CPR-friendly culture did not spontaneously take root. It is largely the fruit of an aggressive municipal scheme. Since 1971, Seattle firefighters have trained over 771,000 locals in CPR. The training takes just three hours. Morrison says there are no Canadian programs on that scalethough Vancouver, say, does a better job training citizens.

Canada also falls short when it comes to teaching people how to use automatic external defibrillators (AEDs), Morisson sayspointing out that in Seattle, bystanders are eight times more likely to use the devices than in Toronto. That number is compelling, because a victims chance of pulling through falls seven to 10 per cent for every minute delay in defibrillation. The thing that drives me to distraction she raves, is that we have lots of AEDs, but nobody knows where we have them. In most cities, defibrillators do not have to be registered with local EMS providers. The result is that 911 dispatchers arent always able to direct bystanders to nearby devices at a time of need. Morrison says she plans to pay Toronto Mayor David Miller a visit, to ask him to mandate registration: It doesnt take any brains to figure that it could be helpful there.

But prescient planning isnt enough. Cities need more consistent protocols to help untrained bystanders when they observe a cardiac arrest. Take Ontario. Historically, says Vaillancourt, it boasted Canadas lowest bystander CPR rate, by about 10 per cent. Part of the problem was the province wasnt giving citizens the right emergency instruction. Today, any Canadian outside Ontario who calls 911 to report a cardiac arrest is coached by dispatchers to provide chest compressions without the breathing component, often the main deterrent among bystanders. But Ontarians only started getting dispatch assistance in 2004years after other provinces. And Ontario remains the only province whose dispatchers instruct bystanders in mouth-to-mouth. That instruction, says Vaillancourt, takes an extra 1.5 minutestime that patients dont have.

At the heart of all this, says Morrison, is the simple fact that cardiac arrest research was never a priority for our government. Perhaps nothing demonstrates this more than the dearth of information surrounding cardiac arrests. Most cities, explains Dr. Ian Stiell, chair of emergency medicine research at OHRI, cant tell you what their bystander CPR rate is. They cant tell you how fast they are with the defibrillator. And they cant tell you the survival rate. Canada does not have a national cardiac arrest database that would allow cities to compare notes and borrow methods. Stiell says hes pushed for one, but his efforts have been met with apathy. They wouldnt do it. I guess it costs too much. But an awful lot of people die.

Pre-hospital cardiac care is like an orphan, Stiell says; it slips through the bureaucratic cracks. Municipalities, for instance, control refighter units, but provinces set ambulance guidelines. And while the feds direct funding, independent groups like HSF generate CPR guidelines. Morrison notes that when shes hunting for grant money, shes often forced to team up with specialists in other elds. Vaillancourt swears that the huge scale of cardiac arrest research trialswhich often involve hundreds of patientsmakes grant boards nervous, and more inclined to fund basic science projects. Research on the effect of such and such a protein on muscle contractivity sells better than a social science project trying to improve CPR rates, he argues.

Recently, though, there has been a resurgence of interest in CPR. For a long time, says Stiell, weve [focused on] drugs and gadgets. But CPR is back. This interest is largely fuelled by the Resuscitation Outcomes Consortium (ROC), a coalition of Canadian and U.S. research teams conducting the first large-scale clinical trials in the cardiac arrest field. Part of the issue, says Stiell, is that modern CPR was designed in the 1960s. Since then, weve basically accepted that formula.

One city that hasnt accepted the norm is Vancouver. Several years ago, Vancouver EMS threw standard CPR guidelines to the wind. Now, its paramedics do continuous-compression CPR; in other words, they dont stop compressions for breaths. The same applies to Seattle paramedics. Stiell cautiously agrees that the departure could help explain Vancouvers cardiac success. Indeed, a growing body of evidence suggests that interrupting the flow of blood provided by compressions reduces a patients chances of survival. But continuous-compression CPR has not been scientifically analyzed. That will soon change; a forthcoming ROC study will examine the role of breathing in CPRs efficacy. (For Vancouver, to Stiells dismay, the evidence already available may be compelling enough; B.C. Ambulance has not decided if it will take part in the study.)

Today, the most active Canadian research sites are those involved in ROC: Toronto, Vancouver, and a group of cities under Ottawas leadership. Piazza admits their research is very dependent on our southern neighbour. If it werent for the U.S. National Institute of Health, she says, theres no way we would have the money to do this. The amount dedicated to cardiac arrest research is a drop in bucket compared to something like oncology, adds Morrison. As a result, there is very little resuscitation research ongoing in Canada. In fact, for ROCs next funding cycle, beginning in 2010, the Canadian Institutes of Health Research will actually decrease its contribution from almost $3 million to $2 million. HSF will make up the difference.

A 2008 report in the Journal of the American Medical Association claims that if all North American cities could match Seattles success rate, we would save 15,000 more lives a year. Most cities still trail behind, though. I think with some diseases, says Piazza, everyone knows somebody who has them, whereas its almost hidden when somebody collapses from a cardiac arrest and is resuscitated. Stiell agrees: Cardiac arrest goes sort of under the radar. Its not like a plane crash or a pandemic. But how can the nations number one cause of deatha disease that affects 35,000 to 45,000 Canadians each yearbe a silent killer?