- The Excel trial, which was sponsored by U.S. stent manufacturer Abbott, compared the use of drug-eluting stents to coronary-artery bypass grafting (CABG)
- The results suggested the two procedures were equivalent in terms of deaths that occurred among patients after three years
- The results, however, didn’t show the full picture, as at the time of the study’s publication, the researchers had access to data from five years’ prior
- There was evidence that the stents were deadlier than CABG, but the researchers chose to only look at the data up to three years — and not a day after
- When the five-year data were factored in, there was evidence that stents were causing more deaths than bypass surgery
- A number of surgical organizations and others have called for an independent review of the raw data used in the trial, and the researchers have agreed, but there is concern that the reviewers may not be independent
A stent is a wire mesh tube that may be implanted into a coronary artery during a percutaneous coronary intervention (PCI), or angioplasty, procedure. It’s intended to treat a clogged artery, which has reduced blood flow due to a buildup of fatty deposits, or plaque. The blockage can lead to a heart attack, but the stent helps to prevent this by expanding the artery and holding it open, improving blood flow to the heart.
According to the American Heart Association, in over one-third of patients who have an angioplasty without a stent, the artery becomes narrowed again within months, in a process known as restenosis. As such, most angioplasties include stents.1
The procedure is also said to have a much faster recovery period, and be less uncomfortable, than coronary artery bypass surgery, making them “fairly common.” In the U.S., more than 1.8 million stents are implanted annually, with 965,000 of them being coronary stents. Stenting procedures have been under scrutiny in the past, when it was estimated that about 30% of such procedures may be unnecessary.2
Controversy has been renewed once again, amid news reports suggesting the procedure not only may be ineffective but may cause more deaths than alternatives — a finding not made public because key data were held back from publication.3
Researchers Withheld Key Data From Publication
The Excel trial, which was sponsored by U.S. stent manufacturer Abbott, compared the use of drug-eluting stents, which are covered in drugs to help prevent the blood vessel from reclosing, to coronary-artery bypass grafting (CABG) for patients with left main coronary artery disease. The primary end point of the study was the rate of death from any cause, stroke or heart attack at three years.
The results found that, at three years, death had occurred in 15.4% of patients in the stent group and 14.7% of those in the bypass group, a result that showed the two treatments to be equivalent, or noninferior. The researchers concluded “… PCI with everolimus-eluting stents was noninferior to CABG with respect to the rate of the composite end point of death, stroke, or myocardial infarction at three years.”4
The results, however, didn’t show the full picture, according to a BBC Newsnight investigation. At the time of the study’s publication, the researchers had access to data from some of the original enrollees, which had had the procedure performed five years’ prior.
There was evidence that the stents weren’t performing as well as CABG, but the researchers chose to only look at the data up to three years — and not a day after.
A spokesman for Abbott told BBC, “The study’s execution, data collection, analysis and interpretation were entirely performed by independent research organizations. The publication of three-year Excel data reflects the original follow-up period and endpoints the study was powered to assess.”5 Professor Nick Freemantle, a biostatistician at University College London, had a different view entirely, telling BBC:6
“If somebody had died three years and one day into the trial, that death wouldn’t have been counted in the results. I’m absolutely appalled that they’ve done this. I’ve taken a straw poll of my professional colleagues and it draws disbelief that people would do this.”
Stents Deadlier Than Open Heart Surgery
When the five-year data were factored in, there was evidence that stents were causing more deaths than bypass surgery. According to Newsnight, “[T]he unpublished data that used the universal definition to measure MI [myocardial infarction] showed that ‘80% more patients with stents had heart attacks than those who had surgery.’”7 BBC News further reported that there were doubts even after three years:8
“Newsnight has seen information shared between people involved with the safety of the trial that suggested things were starting to look worse for people with stents after three years. More people were dying than those who had had surgery. Emails from the trial’s safety committee warned that all the data about deaths should be viewed by the researchers and published.
‘It might be very concerning if in the future, suspicions were raised that already available information on mortality was withheld from the cardiology and thoracic surgery community,’ Dr Lars Wallentin, the head of the safety committee, wrote to the researchers in 2017.”
European clinical guidelines for treatment of left main coronary artery disease were drawn up based on the Excel trial, but the European Association of Cardio-Thoracic Surgery (EACTS) withdrew its support of the guidelines following the investigation.9 A statement from EACTS secretary-general, Domenico Pagano, says:10
“The reported outcomes of the EXCEL trial were one of the major clinical trial results used to inform the joint 2018 EACTS-ESC Clinical Guidelines for Myocardial Revascularisation. We recognise that if the data and the analysis Newsnight has carried out are correct, as they appear to us to be, patients have been subjected to an increased risk of death.
That is why the EACTS Council voted unanimously to withdraw our support for the guidelines on left main disease with immediate effect. We urge our members to disregard the guidelines relating to left main disease for the time being.”
Analysis of Data May Be Biased
The study’s authors have stated that Newsnight was supplied with “fake” data and stand behind their methodology. And a follow-up study, which includes five-year outcomes, also states that PCI is equivalent to CABG with regard to the rate of death, stroke or heart attack, although it states in the results, “Death from any cause occurred more frequently in the PCI group than in the CABG group (in 13.0% vs. 9.9% … ).”11 According to Cardiovascular News:12
“A week later [after the follow-up study was published], cardiothoracic surgeon David Taggart (University of Oxford, John Radcliffe Hospital, Oxford, UK) told delegates at the European Association for Cardio-Thoracic Surgery meeting (EACTS 2019; 3–5 October, Lisbon, Portugal) that the definition of MI in EXCEL was incorrect, leading to the wrong conclusion that PCI is non-inferior to CABG at five years for the management of selected patients with left main disease.
He was an EXCEL trial investigator but said that he withdrew his name as an author because of his view on the conclusion.”
A number of surgical organizations and others have called for an independent review of the raw data used in the trial, and the researchers have agreed, but there is concern that the reviewers may not be truly independent.
“Various names have been put forward by the researchers and the European Society of Cardiology about who is doing the analysis. All have ties to the researchers, guidelines process or medical device industry,” BBC News reported.13
Stents No Better Than Drugs, Lifestyle Changes
Results from ISCHEMIA, a $100-million study funded by the National Heart, Lung, and Blood Institute that looked into the use of stents versus medical therapy and lifestyle changes in preventing heart attack in patients with heart disease, has added further questions surrounding the use of stents.14
The study, which involved 5,179 participants, revealed that people with stable heart disease who are treated with medications and lifestyle changes are no more at risk of heart attack or death than those who undergo invasive surgical procedures like stent placement or cardiac bypass surgery.15
This wasn’t true for those who also had angina, or chest pain caused by restricted blood flow to the heart. In that case, stents or bypass surgery helped to improve symptoms. However, the study suggests that for many people with heart disease, surgery may be unnecessary.
The results, which were presented at the 2019 American Heart Association Scientific Sessions in Philadelphia, Pennsylvania, are likely to change practice guidelines, according to commentators.16
Stent Placement May Be No Better Than Placebo
In still other research published in The Lancet, researchers from Imperial College London investigated the difference between patients who had received a stent for stable angina and those who underwent a placebo intervention.17
The researchers recruited 200 participants with severe single vessel blockage from five sites across the U.K.18 During the initial six weeks, all patients underwent an exercise test followed by intensive medical treatment.
At that point they were randomly assigned to two groups. The first underwent a PCI during which coronary angioplasty was performed and a stent was placed. The second group also underwent a PCI procedure with an angiogram but without a balloon angioplasty or stent placement.
For the following six weeks, neither the patient nor the physician knew if the patient received the stent. At the conclusion of the six weeks, patients again underwent an exercise test and were questioned about their symptoms. The researchers found both groups experienced nearly identical improvements in exercise tolerance and no difference in reported improvements of their symptoms.
Even though the PCI procedure may improve blood flow through the blocked artery, it did not improve symptoms or exercise tolerance in study participants. Meanwhile, angioplasty is not without risk. At least one serious side effect has occurred in 7.6% of those undergoing angioplasty, according to one study.19
Enhanced External Counterpulsation (EECP) as an Alternative
If you find out you have a blockage in an artery, the knee-jerk response may be that you need to unblock it using invasive procedures, but there are alternatives. A noninvasive alternative treatment covered by Medicare and used in university and specialty clinical settings like Cleveland Clinic20 is enhanced external counterpulsation (EECP).
This is a painless treatment used to help develop collateral circulation in your heart muscle. If you have blockage in your left anterior descending artery the procedure is not recommended. During the treatment, long inflatable cuffs are wrapped around your legs and buttocks. An electrocardiogram is used to time the inflation of the cuffs with the rhythm of your heart.
While your heart is at rest between beats, the cuffs inflate and squeeze blood from your legs toward your core. Physicians use this procedure to treat stable and unstable angina, chronic heart failure, coronary artery disease and ischemic cardiomyopathy. The additional pressure from the treatment triggers your body to form new blood vessels and thereby improve collateral circulation in your heart.
In the video above, Dr. Thomas Cowan, family physician and a founding member of the Weston A. Price Foundation, also discusses the function of your heart and circulatory system in a way that may change the way you understand heart disease. Meanwhile, foundational principles to improve your heart health include positive nutritional choices, quality sleep, pure, fresh water and exercise.
These principles — diet, exercise, stress reduction and heart-based connections — actually alter gene expression involved in the development of heart disease, and to greatly reduce your risk, including the need for stent placement or other related surgery, read about my top lifestyle changes to build a better heart.
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