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Friday March 29, 2024

The perils of unapproved stents

By Dr Arshad Rehan
January 25, 2017

‘First, do no harm’ is one of the cardinal principles of medicine and bioethics. In essence it means that, given a particular scenario, a medical intervention or treatment may cause more harm than good and should therefore be avoided. Modern medicine is largely evidence-based and it is a reasonable expectation that good doctors practice it this way.

The recent FIA raid at the Mayo Hospital Lahore, the teaching hospital for King Edwards Medical University – one of the finest medical teaching institution of Pakistan – was an eye-opener. The FIA found vendor stalls selling ‘coronary stents’ to patients. Besides the ethical question of commercial vendors selling their products directly to patients in a government hospital, it was shocking that the majority of the devices being sold were reportedly ‘unregistered’ or ‘unapproved’ by health authorities in Pakistan. This is scandalous to say the least. The Supreme Court has taken suo motu notice of this and has asked for a report.

A coronary stent is a precision device. It is used to open blockages in arteries leading to the heart muscle under strict guidelines. It is a tubular mesh, mounted on a balloon catheter that is placed across the lesion; the balloon is then expanded under high pressure. The stent expands, approximating against the vessel wall and stays in place while the balloon is deflated and withdrawn. The deployed stent acts as a scaffold, preventing the vessel from collapsing or recoiling, thus keeping it open. Once deployed, a coronary stent is part of the patient’s body with no good way of retrieving it.

Coronary stent engineering has come a long way since its introduction in the late 1980s. It has now evolved to a stage where stent struts are as thin as about 74 microns (?m). For comparison, a human hair is about 70 ?m thick. The majority of stents are made of metal alloys; they can be ‘bare’ or coated with a polymer releasing drugs to reduce the chances of blockages reoccurring within the stent. A drug eluting stents (DES) typically cost more than a ‘bare metal’ stent (BMS).

For a medical device to get approved, it must first be studied extensively in clinical trials – starting with animal studies. If the results are satisfactory, human trials are conducted. The best clinical trials are blinded and randomised to eliminate chances of bias. In the US, the Food and Drug Administration (FDA) regulates medical devices and medicines. The data is carefully and extensively vetted, and approval is only granted for devices that satisfy stringent criteria for efficacy and safety. Even after the approval post marketing registry data is maintained and if at any time it is suspected that a device or medicine may be causing more harm than good, warnings are issued or the product is recalled.

It is common knowledge in the cardiology community in Pakistan that some implanting doctors often use devices not fully backed by data. These copycat products are mostly manufactured in countries like China and Korea. They have little, if any, quality data backing their use. In most instances, they have never been studied in large randomised trials evaluating safety and efficacy.

One can never overemphasise the safety issue here. As noted above, stents are precision devices and could cause great harm – even death – with the most minute problems with their engineering and manufacture. This is extremely sensitive work and there is very little room for errors.

The coronary arteries are only a few millimetres in diameter. A typical artery ranges in size from 2.5-3.5mm. A fraction of mm difference in sizing a stent to the vessel could result in catastrophic complications. A broken or protruding strut, a minimal irregularity of the polymer or the metal, a ‘sticky’ balloon’ could all result in abrupt and sudden blockages with resultant heart attacks and deaths. Quality control during the manufacturing process is a must. Even one human life lost out of thousands is one too many.

For a developing country like Pakistan where indigenous resources and good trial data are scant, it should be mandatory to follow the FDA or the European Medicines Agency for regulating medical devices. These agencies have strict approval criteria and also review post marketing safety concerns.

An FDA approved DES costs around $1200 in Pakistan and a BMS around $300. An unapproved Chinese copycat DES on the other hand costs around $500-700. The price differential is the reason most often mentioned as a defence for using unapproved stents.

This is where the principle of ‘primum non nocere’ or ‘first do no harm’ should come into play. The data that is cited for non-approved devices is mostly anecdotal and not from large randomised trials. Long-term follow-up data on patients in Pakistan is limited and poses questions regarding the safety of these devices.

It is unethical to use devices that are copycat products with no large quality studies supporting their safety. These unapproved devices could be great products but we just do not know until large randomised studies confirming their bioethical standards are conducted. Even in a far from ideal scenario, one could only make a case for using these devices if patients are properly informed about the lack of data backing their use and they consent to taking the risk.

People who are privy to the matter say that the prevalent use of unapproved devices in most but not all cases has much to do with the ‘share’ of the implanting doctors rather than a true concern for the patient’s financial situation. It is not uncommon for marketeers of unapproved devices to give a percentage of the price to the implanting physician as their share. This practice is reported even for some marketing FDA approved stents. The ‘commission’ system is also responsible for the criminal practice of implanting devices where none are required.

It might surprise the public to know that the FDA approved stents costing around $1200 in Pakistan are supplied to major hospitals in the rich Gulf Co-operation Council (GCC) countries for almost half this price. The reason is that the health authorities in these countries contract for buying these products as a consortium and bargain hard with the manufacturers. The total population of Pakistan is around four times that of the GCC countries put together. We have a bigger patient population than the GCC so our health administrators would have more leverage than the GCC should they choose to exercise it.

There are many excellent people among the cardiology fraternity in Pakistan. There is no reason why major government hospitals cannot come together as a group to negotiate better prices for medical devices. There are only minor differences in the efficacy and safety data amongst FDA-approved coronary stents. Cardiology leaders from across major hospitals should sit together, decide on data-driven inventory preferences and play hardball with the manufacturers. Standardising inventory across hospitals will certainly result in major cost savings and decrease avenues for corruption.

The writer is the former president of the Association of Pakistani Cardiologists of North America (APCNA). Twitter: @spaelanay