Wednesday, November 22, 2006

News from the AHA: Heart attack triage for primary angioplasty

The American Heart Association met in Chicago. This is probably one of the largest medical meetings in the world, attracting about 30,000 attendees. I used to attend this meeting, but felt it was like a circus, where thousands of people moved around from sideshow to sideshow, pointing excitedly at various spectacles. The late breaking trial results (miraculously there is always a few happening just before any meeting) would attract large crowds. Like any good sideshow, you would have to come early to get a seat or have to stand in the corridor.

The big news for this year was the new AHA/ACC/NHLBI sponsored trial to follow the triage of patients with acute myocardial infarction, to reduce the door-to-balloon time, and to see the outcomes. How appropriate that the meeting was set in Chicago. For those of you who watch ER, the excitement is set in County General, which is located in Chicago, and it's always a whirlwind of chaotic activity.

The recommendation is that anyone suffering from an acute myocardial infarction (heart attack) be admitted to a tertiary medical center and have balloon angioplasty performed within 90 mins of arrival. We want to reduce the ischemic time, and improve myocardial salvage thereby improving mortality/morbidity outcomes. Even in the USA, the recommended time of 90 minutes is rarely achieved.

In the leading tertiary medical center where I work the best time to have a heart attack (if there is such a thing) is around 8AM. The Cath Lab is open and the staff are coming in. You might just get a time of 90 minutes assuming you beat the morning rush hour. If you should have an attack at 2-3AM then it will probably be around 2-3 hours before we get to you since the whole team is at home sleeping.

There is no doubt that a reduction in door-to-balloon time reduces myocardial ischemia, and so myocardial necrosis, thereby improving myocardial salvage, and survival from AMI. Otherwise, IV thrombolytic therapy may be a very good alternative.

This current impetus by AHA/ACC/NHLBI is to indentify the areas which may hold up the triage time and recommend shortcuts, so that the door-to-balloon time is reduced. This will necessarily mean that more junior staff will have to take on the role of decision making to activate the triage. Ambulance drivers will do the ECG, which is transmitted to the nearest tertiary care center (there must be a few per community), where the catheter room staff is waiting and ready even as the patient arrives in ER. The relatives must come along to give consent, the patient must have medical insurance that can quickly approve the admission and allow the patient to go on for angioplasty without delay. Having it all come together like that would be like watching a wonderful symphony where every player hits the right note at the right time.

Even as you read, you can see where in our context the delay could be. Well at least we should make a start to get there. Of course, this new emphasis and urgency will also have the attendant risk of false alarms. Can you imagine all the differential diagnosis of chest pains being rush to the cardiac cath room and rejected. Pneumothorax, or dissecting aneurysm, or cholelithiasis being taken to angio room for emergency angioplasty? Well I suppose we have to improve our delivery of healthcare to heart attack patients, but it is sometimes difficult to draw the line, especially in our Malaysian cultural context. We still have some way to go.

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