What's worse, US government-sponsored evidence from five years ago warning of the limitations of the procedure have been largely ignored by doctors, who have come to view stents and angioplasty as a lucrative, insurance-paid, bread-and-butter part of their practice.
Propping up the solution
A hospital survey carried out by a cardiology team at St Luke's Mid-America Heart Institute in Kansas City, MO, checked the statistics from more than 1000 American hospitals across the country against guidelines developed by several medical organizations in 2009 on the appropriate use of stents. In the 71 per cent of cases that were true emergencies, with a patient suffering a heart attack, the team found that the hospitals did a good job; 99 per cent of those procedures were deemed appro-priate, although the researchers had to exclude 100,000 cases for lack of information.
Of the non-emergency remainder, the thousands of stents insert-ed as a just-in-case procedure for patients with chronic but stable chest pain, 38 per cent, or 55,000, were of uncertain benefit, and a further 16,838, or 12 per cent, were clearly inappropriate (JAMA, 2011 ;306: 53-61).
In fact, in more than half of the inappropriate cases, the patient had no evidence of heart disease whatsoever.
If these figures are extrapolated across the US, of the 900,000 patients receiving stents every year, 261,000 could be receiving stents inappropriately-many of which will hasten a heart attack. And many doctors believe that these figures could be wildly conservative.
Solution for the solution
Since 1986, when a cardiac surgeon inserted the first stent into the first guinea-pig heart patient, doctors believed they'd finally cracked the problem of atherosclerosis with the best of modern high-tech medicine-state-of-the-art bypass surgery, high-tech procedures to unblock arteries and, with the stent, a bionic section of artery to keep them open permanently.
Stents were created ostensibly to solve the limitations of another medical procedure-balloon angioplasty-which took over from coronary bypass surgery as the less-invasive way to prevent a heart attack in patients with clogged coronary arteries. The procedure involves threading a tiny balloon through blocked arteries and inflating it to clear them, usually by pressing the fatty plaques against the arterial wall.
Nevertheless, doctors were dismayed to notice that 're-stenosis', or re-closing of the arterial wall, occurred within six months after surgery among as many as three-quarters of all patients. In many instances, the diameter of the blood vessels treated was only just 16 per cent larger than before treatment.
In many instances, angioplasty was itself a blunt instrument, often causing damage to the arterial wall and blood clots. Consequently, in an attempt to solve the problems caused by the high-tech medical solution, another high-tech solution was born: the stent is essentially a bit of bionic arterial scaffolding, inserted as a flat-packed piece of mesh tubing and then expanded, ostensibly to keep the drain unblocked, and usually used with a cocktail of antiplatelet drugs called the IIb/IIa inhibitors to prevent blood clots.
Subsequent studies on both angioplasty and stents continue to reveal the limitations of treating the valves of the heart like a clogged drain that needs to be unblocked.
Although the drug/stent combo appeared to solve the blood-clot problem, it did nothing to prevent the problem of restenosis; within six months of their insertion, some 40 per cent of stents are blocked again, requiring a repeat operation (Medicina [Kaunas], 2007; 43: 183-9).
Consequently, medical-supply companies came up with yet another solution to the problem created by the solutions: the idea of providing stents coated with a thick polymer containing sirolimus. This powerful immuno-suppressant agent drip-feeds into the system in low doses-a process called 'elution'-to block the body's own attempts to heal the artery.
These 'drug-eluting stents' (DES) have their own set of problems. Swedish research involving 20,000 patients found that deaths and heart-attack rates were 30 per cent higher among DES patients compared with patients harbouring the old-style 'bare-metal' stents (N Engl J Med, 2007; 356: 1009-19).
In 2007, the US Congress appropriated $1.1 billion to fund studies into which medical treatments can deliver the best solutions at the most competitive cost. This is a rarity in the world of medicine, where health insurers almost never examine effectiveness against cost.
One such study, entitled COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) and published in the New England Journal of Medicine, rocked the world of cardiology when it discovered that its 2287 patients tracked for five years enjoyed no benefits in terms of preventing heart attack, stroke or death when given either angioplasty or stents, compared with a cocktail of generic heart drugs: aspirin, beta-blockers, calcium-channel blockers, blood-vessel dilators and ACE inhibitors, plus statins (N Engl J Med, 2007; 356: 1503-16). Indeed, the day the news broke, shares of the leading stent-maker, Boston Scientific Corporation, fell and, a month later, the incidence of stent implants in the US fell by 13 per cent.
Nevertheless, as soon as the memory of the headlines faded, the use of stents quickly crept up to pre-COURAGE levels, and have now peaked at some one million procedures per year.
The reason why doctors continue to use stents is not difficult to find -if you follow the money. Each stent costs, on average, about $15,000 to implant and, every
year in the US alone, $15 billion are spent on stent procedures. In fact, a cardiologist receives about $900 per procedure-about nine times what he gets for a simple office visit for a heart-drug prescription-and a hospital receives $10,000 per procedure.
During the past decade, when improvements in stents led to an explosion in their use, US cardiol-ogists installing stents made, on average, $500,000 (according to 2008 figures)-an increase of 22 per cent over the past 10 years.
After the publication of the COURAGE study, a Washington state agency called the Health Technology Assessment Program, or HTAP, wished to consider putting the COURAGE findings into practice, and commissioned a review of the evidence supporting the use of stents, whereupon a number of cardiologists joined together to fight the review and discredit the COURAGE findings.
When HTAP convened a conference call with representatives of stent-makers and cardiologists, requesting assistance in comparing appropriate stent and drug use, the industry and doctors declined to help.
As Mitchell Sugarman, senior director of health economics for stent-maker Medtronic Inc. announced on the call: "We don't want to end up being our own willing executioners".
Factfile: High on the hog
The three-way lucrative relationship between medical-supply company, doctor and hospital can best be illustrated by the case of Baltimore cardiologist Dr Mark Midei. After Dr Midei had inserted 30 stents in a single day in August 2008-a personal best, if not a world record-an appreciative Abbott Laboratories, manufacturers of the device, spent more than $2000 on a whole slow-smoked pig and lavish barbeque at the doctor's home. The hog roast was one small token of the millions in salaries and other perks awarded to the doctor by Abbott as the fifth most enthusiastic stent-inserter in the US Northeast, handling, by his own estimate, some 1200 operations a year.
This only came to light when a Senate Finance Committee heard that Dr Midei had inserted stents in patients who didn't need them, and was collecting high reimbursements from Medicare and private insurers. A subsequent investigation discovered that Dr Midei may have implanted 585 stents that were medically unnecessary in one two-year period, with Medicare picking up $3.8 million of the $6.6 million tab.
Furthermore, and possibly even more damning, the report claims that the allegations against Midei did not appear to be a deterrent to Abbott's "interest in assisting him".
Moreover, with no admission of wrongdoing, the St. Joseph Medical Center, where the procedures had been done, had to pay a $22 million fine to settle charges that it had paid illegal kickbacks to Dr Midei's medical practice in exchange for patient referrals.
Before the situation came to light, when Dr Midei was thinking of relocating, St. Joseph was so alarmed about the potential fall in income that it offered him a $1.2 million salary if he would leave the new practice and join the hospital's staff.
These kinds of cases-involving kickbacks for heart procedures-are 'flavour of the month,' says J. Stephen Simms, a Baltimore lawyer handling a lawsuit against such a case.
Abbott's response to the scandal was to hire Dr Midei as a consultant as a reward for past services rendered. "It's the right thing to do," wrote an Abbott executive in an e-mail disclosed in the Senate investigation.
WDDTY VOL. 23 NO. 1, APRIL 2012