Fifty years ago, heart-attack patients were put to bed for three or four weeks. Unfortunately, strict bed rest was of little benefit to the heart, and moving as little as possible was a bit like long-haul flying - some succumbed to blood clots which formed in their leg veins and broke off, blocking blood flow to the lungs.
Twenty years ago things had started to look up. Aspirin, an old drug used to relieve pain and reduce fever, had been found to block platelets, part of the blood-clotting process. Clot-dissolving drugs called thrombolytics could open the blocked vessel causing the heart attack, and if thrombolytics were given with aspirin soon enough, mortality was reduced by 40 per cent.
Intravenous lignocaine was widely used because heart-attack patients were more likely to have extra irregular heartbeats; those with extra beats did worse than those without, and lignocaine suppressed the extra beats.
Today, the best treatment is primary angioplasty - bringing the patient as quickly as possible to a cardiac catheterisation laboratory, taking pictures of the blood vessels to the heart, and using balloon catheters and stents to open the blocked vessel.
Outcomes are better than with thrombolysis because most blockages can be opened - thrombolytic drugs worked only half of the time - and the increased bleeding caused by thrombolysis is avoided.
The procedure cost is more than offset by a reduced hospital stay - two or three days, compared with a week or more in the thrombolysis era. Lignocaine isn't given because large, well-designed trials have shown that, although extra irregular heartbeats are reduced, patients are more likely to die.
Other cardiac conditions previously requiring surgery can now be treated less invasively. Aortic stenosis is a narrowing of the heart valve between the left ventricle, the main pumping chamber of the heart, and the aorta. Untreated, most symptomatic patients with severe aortic stenosis die within two years.
While surgical replacement of the valve is an excellent operation, the narrowed valve can be opened by balloon inflation, followed by inserting a new valve mounted on a metal frame, via the groin.
Many patients with aortic stenosis are elderly and at increased surgical risk. In this group the costs and outcomes of surgery and transcutaneous aortic valve implantation (TAVI) are similar out to two years. Patients value the minimal pain and quick recovery time after TAVI.
Another new procedure is renal denervation for hypertension. In those with elevated blood pressure that hasn't responded adequately to medications, a catheter is inserted through the groin into the blood vessels to the kidneys and energy applied to block the nerves to the kidneys. This simple, 20-minute procedure lowers blood pressure much more effectively than adding more drugs, and the benefit seems to be sustained.
How do you introduce technologies in challenging economic times? There are two keys to success. The first is a rigorous assessment process of both clinical and cost-effectiveness. Because the scientific evidence base for new technologies will always be evolving and incomplete, skilled judgment is needed. This assessment is best done by experienced clinicians from other fields, with advice from statisticians and health economists, as needed.
The second is a dedicated budget so that some new technologies - those which rank highest across all disciplines - are funded, as occurs in Victoria, Australia.
The National Health Committee was established over a year ago, following the failure of the previous ministry process, and given the Herculean task of assessing new and existing procedures and technologies. As currently configured, they will also fail. There are only two clinicians on the committee, they have modest resources for technology assessment and, most importantly, they have no budget to fund the introduction of new technology.
If a new technology is endorsed by the committee, a clinical service could introduce it only by cutting something else they provide.
This doesn't fit with the current funding model of payment per patient by discharge diagnosis, and provides a perverse incentive to keep doing something of little or no benefit, to have something to "give up". The rate of change in medicine is not equal across all specialties, so those areas advancing most rapidly are the most disadvantaged.
Renal denervation is a good example of the current impasse. It is currently available only in the public sector in New Zealand as part of a clinical trial. It was one of five new technologies selected for assessment by the committee during their first year - their evaluation is still awaited. Each procedure costs about $10,000 with a gain, measured in cost per quality-adjusted life years, estimated at $3500 making the procedure extremely cost-effective.
The benefit from effectively treating hypertension is reduced stroke, heart failure and kidney failure during subsequent years. The procedure is great for the patient, good for society, but untenable for an unfunded service provider.
In heart-attack treatment over the last 20 years, aspirin has stood the test of time, lignocaine hasn't, and thrombolysis has been superseded by primary angioplasty.
The only thing certain about treatment in another 20 years is that it will be different from today. New Zealand cannot afford every new medical advance. Some won't be that much better than currently available options and others will be just too expensive.
However, there must be a simple, workable mechanism for assessing new technology and funding those which provide a substantial and cost-effective clinical benefit.
Mark Webster is an Auckland cardiologist.By Mark Webster