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Wednesday, 8 November 2006

Mark Porter discusses heart attacks

From this discussion:
  • i will carry aspirin with me to take in the event of a (suspected) heart attack
  • consider the evidence for taking half an aspirin a day
  • consider the evidence (again) for taking statins - which reduce risk of heart attack or stroke by a THIRD EVEN IF cholesterol levels are average

pdf file transcript (page same as link in title). CASE NOTES 5. - Heart Attacks

RADIO 4 TUESDAY 04/05/2004 2100-2130 PRESENTER: MARK PORTER, CONTRIBUTORS:
TOM QUINN, RORY COLLINS,
British Heart Foundation Professor of Medicine and Epidemilogy at Oxford. TOM MARSHALL visiting fellow at Harvard Medical School


Extracts:

Aspirin

PORTER
I want to go back to aspirin. Tom, there has been some coverage in the press suggesting that we should all be carrying an aspirin around with us, just in case we get chest pain, what do you think of that?

QUINN
I think it's important, I carry aspirin for that reason, just in case someone falls over when I'm on the train or something. Aspirin alone is as effective as one of the clot buster drugs, alone at saving lives, solving heart attacks, it's very important. Given in combination with one of these clot buster drugs it's even more powerful. And as an emergency first aid measure for suspected heart attack it's a pretty good thing.

PORTER
What about low dose aspirin - a daily half or quarter of an aspirin?

QUINN
Yes I think the current guidance on this is that if you've got a cardiac diagnosis you should have been prescribed low dose aspiring almost ad infinitum but if you haven't had a diagnosis then it's probably best to discuss with your GP or practice nurse before starting to take that treatment because even low dose aspirin isn't totally without risk.

Statins & Cholesterol levels

PORTER
Statins - a family of cholesterol lowering drugs that can protect against heart disease. At the moment they are only prescribed on the NHS to people at the highest risk, but there is now good evidence that far more us could benefit them - and there are moves to make them available over-the-counter in the near future. The global prescription market for statins is already worth billions of pounds a year - could the over-the-counter market soon follow suit? Dr I started by asking Tom how the statins work?

PORTER
Because it's possible isn't it to have a higher than ideal cholesterol level, even if you don't eat a particularly poor diet.

MARSHALL
There's a lot of variation between individuals, so that what we find is that different individuals have different cholesterol levels. We know that whatever your cholesterol level is if you eat a diet that's more high in saturated fat your cholesterol will be higher and if you eat a diet that's less high in saturated fats - bit more polyunsaturates - you'd have a lower cholesterol. So there's variation between individuals but there's also variation caused by what people eat. Approximately what they do is whatever your chances are of getting heart disease they knock about a third off that. So if you take a statin it will reduce your risk of heart disease by about a third and probably similar for stroke.

PORTER
Pretty significant given that heart disease and stroke of course are the biggest killers of Americans and British people. But it actually doesn't make an awful lot of difference what your cholesterol level is to start with does it.

MARSHALL
Well that's the curious thing about it because originally we thought that what we were treating was high cholesterol levels and if you brought them down to a more normal sort of level that was really what the advantage was coming from. But what we're finding more and more, for example from the heart protection study, it was a very large study in the UK a couple of years back, is that it doesn't really make a lot of difference what your cholesterol level is, it still reduces your risk. So if you're at high risk, even if your cholesterol level's pretty well average you're better off having a lower cholesterol level. And so the general rule about cholesterol is lower the better.

PORTER
So potentially nearly everyone could benefit from taking a statin?

MARSHALL
Well that's an interesting question. In principle, it would be very hard to prove that you were really benefiting people who very rarely get heart disease anyway but in principle that's probably correct, that virtually everybody can reduce their risk of heart disease, their chances of getting heart disease by about a third by taking a statin. But the key question is a third of what? Because if I've got a very high chance of getting heart disease then reducing my chances by a third seems like a pretty good idea but if I'm the sort of person who is very unlikely to get heart disease it means an awful lot of people like me are going to take the tablet and very few of us are actually going to really prevent anything.

PORTER
Well at the moment statin use is effectively rationed by the NHS to those who need it most - put simply, at around, I suppose, a £1 per day a person, the NHS couldn't afford to supply these drugs to everyone who, the latest evidence shows, may benefit from them. Rory, it's going to a difficult problem to solve.

COLLINS
Well you call it a problem, I call it a solution. The fact is that the statins and cholesterol lowering therapy are much more effective than we had realised - they're more effective for a much wider range of individuals at high risk, they're effective for people at high risk not just of heart attacks or strokes, they're protective for people throughout the cholesterol levels that we see in Western populations. So we can produce benefits for a very much wider range of people who are otherwise going to have a heart attack, stroke and die - or be disabled by those conditions. So I see it as solution. And you say it's an expensive treatment but you know so too is being hospitalised with a heart attack, so too is being disabled with a stroke. And in fact when we do analyses of the benefits in terms of cost terms - leaving aside the human benefits - actually these treatments turn out to be cost effective for a much wider range of individuals than have previously been thought to be the case. And of course now that sinvastatin is no longer protected by patent and is available as a generic drug, as the cost of the drug falls the cost effectiveness of the treatment increases and it will become cost effective, cost saving, for a very much wider range of patients.

PORTER
So what are the downsides Tom?

MARSHALL
Statins do have side effects. There are some that are considered relatively minor and seem to be reversible when you stop them like sometimes people have suffered a little bit of hair loss and things like that. But the most important kind of side effect is a type of muscle damage which can be sort of mild, in the sense that people get some muscle pain and some blood tests show that there's some evidence of muscle damage and they can stop the treatment or in its more severe form can actually be quite a serious problem where there's breakdown of the muscles and this is referred to as rhabdomyolysis.

PORTER
Are there doubts about the current statins that we're using, because this is quite an unusual side effect isn't it?

MARSHALL
It's a very - yeah it's a very unusual thing and when it happens in its full blown form it's pretty serious - people can die from it. In its very serious form it's quite infrequent - it's in the region of 1 in 10,000 or even less frequent than that, so it's really quite infrequent.

PORTER
Rory, what impact do you think deregulation of statins is going to have?

COLLINS
I think number one, the fact it's going over-the-counter emphasises our very good evidence about the safety of this treatment. I think the other thing is that it will bring to the attention, not just of the people that the over-the-counter is targeted at, but also the higher risk patients, the possibility that there are ways of lowering their risk and it may, I hope, encourage them to go and talk to their family doctors to get on to prescribed statin for people with vasc disease or diabetes or hypertension.

PORTER Tom, Katherine - do either of you take a statin?

HENDERSON
I don't but I measure my cholesterol and I know that I don't need to.

PORTER
What about you Tom?

QUINN
I did, my cholesterol was a little bit high, as was my blood pressure, but the statins didn't agree with me so I've now bought a bicycle and try and cycle more and eat less but I don't take a statin.

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