Next Steps in Heart Attack Care

June 13, 2011

A recent conference in Washington, D.C., on cardiovascular research technologies hailed the success of life-saving strategies for emergency heart attack patients who suffer ST-elevation myocardial infarction (STEMI). The Beat spoke about recent developments in these strategies with Dr. Michel Le May, who developed the Heart Institute’s pioneering STEMI program. This program has been responsible for a remarkable 50 per cent drop in death rates for heart attack patients. The STEMI program functions as a complex medical protocol that is triggered instantly beginning with a 911 call to the paramedic service.

The Beat: In terms of an emergency heart attack, the key message is that swift action to save a STEMI patient is good but not good enough now. Why is this true?

Dr. Le May: We know that door-to-balloon time is a reliable marker for survival—that is, the time it takes to deliver a patient from home by paramedic service and into the catheterization lab for angioplasty and an emergency stent to open the arteries and restore blood flow to the heart. We can and do better than that. You need a hospital that can provide excellent care once you’ve done a percutaneous coronary intervention (PCI; opened an artery with a balloon and inserted a stent).

We’ve had some complicated STEMIs—people who have had cardiac arrests, people who are in need of cardiac hypothermia and people who are complicated by renal failure who need dialysis; some people are in shock and they need bypass surgery. A tertiary care hospital will need to provide all those elements to optimize care.

The Beat: So, we are talking about a comprehensive program of care afterward?

Dr. Le May: At the Heart Institute, our teams go beyond coronary intervention. We have a Coronary Care Unit that involves our nurses, our staff and our consultations with other teams, and our cardiac surgeons. Once the patient is discharged, still other teams come into play. The cardiac rehab team plays a critical role in ensuring that a patient has a good recovery, can return to work and has good psychological and physical function. The smoking cessation program plays a support role. We provide good lipid management and good communication with the family physician for the patients in the STEMI clinic requiring good cholesterol management. We provide guidelines for medications when the patient is discharged and instructions on the importance of continuing medications, why they are important and how they work.

We address complications about returning to work safely, resuming driving and questions about sexual function and how soon intimate relations can resume. Sometimes people suffer depression. We provide psychological and psychiatric care. It’s important to understand that the family dynamic and the spouse are key components.

The Beat: How much of this is possible for other hospitals to replicate? They can’t possibly provide the same services as the Heart Institute.

Dr. Le May: They can import part of our STEMI program and some of the measures we use. They can adopt our smoking cessation guidelines, our lipid management guidelines and some of the other models we provide. They won’t be able to transplant patients or offer emergency cardiac care in terms of surgery and ventricular assist devices. But they certainly can cover 90 to 95 per cent of patients in remote areas. We are now encouraging regions everywhere to develop STEMI systems with the protocols that we have in place.

Other parts of the country are following the pattern we have set. Calgary, Edmonton and Vancouver are all following our lead and organizing programs based on their own environments. They have to develop ways of transporting patients, getting them to the tertiary care centres in a timely way and using an approach that fits their own areas. Vancouver and Montreal have a lot of bridges and complex traffic patterns that need to be addressed in order to speed patients to hospital.

Stakeholders need to collaborate and tailor the model to their own requirements.

The Beat: How do we teach others to collaborate as well with their stakeholders as we do?

Dr. Le May: It’s important to bring together successful program directors—the champions—and organize symposiums and workshops so key leaders in STEMI can share how their systems have been developed. This requires representatives from all parts of the coronary care system. When we developed our system, which has now spread to 22 hospitals in the region, we always included one representative from each department at the Heart Institute. Administrators, the paramedic service, critical care staff, the Coronary Care Unit and nursing coordinators all helped design the best way to service various emergency departments before we launched the program.

Everything has to be organized, structured and monitored. It is critical to collect data and troubleshoot the program, as well as provide feedback on a daily basis. That means exploring cases that went well with positive feedback, but also, for those cases that didn’t go well, it means resolving the issues and improving speed with efficiency.

The Beat: What are the next steps for STEMI?

Dr. Le May: We are developing a cardiac arrest program for patients who collapse at the time of their infarct. These people have profound neurological injury, and we are developing a program called therapeutic hypothermia to minimize that damage. We can bring down the patient’s body temperature to 32 degrees Celsius for 24 hours. Think of when you injure your knee. You apply ice to reduce the swelling. We are following the same principle of preserving the brain by blocking pathways that could lead to cell death. We can decrease the swelling in the brain and shut down complex pathways that are in the process of destroying brain cells. Cooling the heart very early may also preserve the heart.

We have been doing this at the Heart Institute for more than a year now. At this point, we are extending the program to the emergency departments, so physicians and staff are being trained at other hospitals. Our paramedics will be trained to begin cooling a patient during transport. Data now suggests that early cooling is better.

The Beat: Does the Heart Institute have other new clinical trials under way related to heart attack?

Dr. Le May: Over the next few years, we will be investigating whether the best approach for PCI catheterization is access through a femoral artery or a radial artery. We want to understand whether it makes a difference and why. The radial approach results in less bleeding because it is easier to compress the wrist area. Bleeding from the femoral artery brings a lot of blood into the groin. The counter issue is whether we can get the catheter to the heart through the wrist as quickly and efficiently.

We’ve been looking at new medications as well. We have shifted to a new category of medication that shows we can reduce bleeding. We know there is a link between bleeding and survival. If we have to stop important drugs, such as Aspirin or clopidegril, because of bleeding, we risk clogging the stent. If there is a major bleed, it can be associated with shock or require transfusion. So, we’re focused on minimizing bleeding.

For those who have very bad outcomes, we have some coming trials looking at approaches to regenerating cardiac cells using stem cells and other techniques.

You always think you reach a threshold, believing you can’t advance the cause any further. But we can always advance further, and we’re looking at this from many different directions.