Remember last month when I covered the topic of “stretch pain” in heart patients who have had a coronary stent implanted?
To recap, temporary post-stent stretch pain in the chest is due to the dilation of an artery when a metal stent is being implanted inside that artery, and it typically occurs in about 40 per cent of stent patients.1 A number of you wrote in with some variation of this question: “Is it still stretch pain if it’s happening months afterwards?”
And now a new study published in the Journal of the American College of Cardiology suggests that something entirely different might be going on.2 . . ,
One of my favourite resources for helping me understand Doctor-Speak in cardiology journals is Dr. John Mandrola, a Kentucky electrophysiologist (that means a cardiologist who is an expert in heart rhythm issues). In his regular Medscape podcast called ‘This Week In Cardiology’ , he calls this study “a very important and sobering paper.”
(This podcast, by the way, is for healthcare professionals, but Dr. Mandrola’s clear and engaging style makes him a uniquely helpful resource even if, like me, you have never been to med school).
And if you do need any help translating, visit my patient-friendly, jargon-free glossary while you listen to his podcast.
Like all good educators, Dr. Mandrola starts by telling us a story.
“A few years ago, a man from Kentucky had a treadmill stress test, even though he had no cardiac symptoms. But the stress test was positive. A trip to the cath lab showed a significant blockage in a major coronary artery, and he had a stent implanted. Everybody was happy – until three years later when he had to have back surgery. A pre-op stress test showed everything was clear – thank goodness! But the day after back surgery, he had acute onset chest pain. Further tests showed a clot at the stent site. He developed what’s called cardiogenic shock. He survived – but just barely.”
When Dr. Mandrola later saw this patient in his clinic, the man asked him:
“Did I need that stent in the first place?”
That’s a very good question for all heart patients to discuss with their cardiologists – preferably before making the “to stent or not to stent” decision.
Almost all cardiac studies now suggest that invasive cardiac interventions like stents or bypass surgery can and do save lives – but that is apparently true only for those having or at very high risk for having a heart attack, not generally in those with stable angina, or no cardiac symptoms, or who are considered at low risk for a heart attack.3
In the 2019 ISCHEMIA trial, for example, researchers found that stents and bypass surgery are no more effective than lifestyle modifications and cardiac medications in people with moderate-to-severe stable angina – defined as chest pain that comes on with exertion, and goes away with rest. (Although, as I observed at the time, one significant limitation was that, of the 5,000+ participants enrolled in this $100 million study, over 3/4 were men). See also: “ISCHEMIA Study: That Blockage Isn’t a Time Bomb in Your Chest“
Meanwhile, the JACC study looked at 25,000 heart patients over five years; each was living with either a bare metal stent or a drug-eluting stent (DES, a metal stent coated with time-released medicine to help prevent a new clot from forming inside the stent).
Researchers looked at how many of these patients experienced very late Major Adverse Cardiovascular Events long after their stents were placed (MACE: cardiac death, heart attack or the need to redo the stent).
As Dr. Mandrola explained, in the first year, DES outperformed the bare metal stents. But very late stent-related ischemic events continued to occur, and that rate was rising, increasing at the rate of 2% per year for five years in both DES and bare metal stents, with no signs of a plateau. In fact, the overall MACE rate between 1-5 years was equal to or greater than those within the first year.
Which reminds me of a conversation I had with a local cardiologist while I was in the CCU (the intensive care unit for heart patients) after my own heart attack. I knew nothing about stents at that time, so I asked him, “What’s the difference between the bare metal stent that I have now, and a drug-eluting stent?” His answer:
But back to our study: the authors, who are interventional cardiologists (the ones who implant stents), concluded this:
“Although DES have markedly improved one-year outcomes, the ongoing risk of very late adverse events from both bare metal and DES is similar.”
In a JACC editorial that accompanied the study’s publication, cardiologists if they were to analyze more in depth the type of adverse events, then “only 40% of all adverse events occurring between 1-5 years could be considered stent-related.”
But as Dr. Mandrola wryly observed: “It’s not like nearly half of all late adverse events involving stents is reassuring!”
He admires the study authors, adding that they deserved “kudos for publishing such sobering data.”
Carolyn’s Translation: The reason that they do deserve kudos is that these cardiologists bravely rejected the research practice called “selective outcome reporting” (in which study authors can often cherry-pick certain research results by submitting for publication only the positive results that are favourable to the product/drug/procedure being studied, while ignoring negative results).
Dr. Mandrola continued:
“This highlights a basic premise in medicine: stuff isn’t free.
“Interventions come with a cost. A stent trades a flow-limiting lesion for a metal cage in the artery—you know, the place where platelets flow by.
“At the stent site, the blood vessel tries to heal – that’s inflammation, and then late focal disease can occur – that we give the funny name neo-atherosclerosis.
“So, when you are having a myocardial infarction (heart attack), stents are great, because you are going to lose heart muscle and maybe die, but …” (like that Kentucky patient Dr. Mandrola mentions) “…when you are stable, every shred of evidence we have shows that stents do NOT reduce hard outcomes compared to lifestyle improvements and cardiac medications.”
Dr. Mandrola concludes his podcast with a wish:
“My hope is that someday, we can find a way to convince society that the clogged pipe frame of treating chronic vascular disease is flawed.”
But that list of adverse events that Dr. Mandrola cites may even go beyond the outcomes investigated in this particular study (namely cardiac death, heart attack, or redoing the stent).
Cardiologist Dr. Juan-Carlos Kaski is an internationally recognized expert in coronary microvascular disease (MVD, sometimes called “small vessel disease”). DISCLAIMER: I was also diagnosed with MVD after my 2008 heart attack, and bare metal stent.
Dr. Kaski was a keynote speaker at the 2019 INOCA International “Meeting of the Minds” cardiology conference in London, England, where he told his audience that one in three patients who have a stent successfully implanted can develop MVD as a result of that stent.
He cited, for example, a study published in the European Heart Journal in 2019 that found 20-40 per cent of stented patients develop recurrent or longterm angina after a stent.4
Potential reasons for this post-stent chest pain may include:
- recurrent ischemic lesion
- in-stent restenosis (blockage)
- residual diffuse disease
- myocardial bridging
- coronary microvascular dysfunction due to microvascular spasm and impaired microvascular dilation
Dr. Kaski added an important but often under-acknowledged side effect of this reality:
“People coping with chronic angina are more likely to report limited physical function and depression, and are more likely to be re-hospitalized within one year of their heart attack.”
So what can we learn from this “very important and sobering paper”, as described by Dr. John Mandrola?
As he says in his podcast, there are two reminders in these studies to help patients and their physicians who are deciding together whether“to stent or not to stent”:
- Atherosclerosis (coronary artery disease) is a systemic, all-over disease, so medical therapy and lifestyle improvements are the right approach.
- Stents can come with significant downsides – like those late adverse events.
- et al. “Stent-Related Adverse Events >1 Year After Percutaneous Coronary Intervention”,
- Chao-Chien Chang et al. “Chest pain after percutaneous coronary intervention in patients with stable angina”. Clin Interv Aging. 2016; 11: 1123–1128.
- Hannan, E. “Appropriateness of Coronary Revascularization for Patients Without Acute Coronary Syndromes.” Journal of the American College of Cardiology, 2012; 59:1870-1876.
- Crea F, Bairey Merz CN, Beltrame JF, et al. “Mechanisms and Diagnostic Evaluation of Persistent or Recurrent Angina Following Percutaneous Coronary Revascularization.” Eur Heart J August 2019; 2455-2462.
Q: Are you surprised to learn that “interventions like stents come with a cost?”
Dr. John Mandrola’s blog, especially if you live with any type of heart arrhythmia.
You can watch videos of the 2019 INOCA International “Meeting of the Minds” cardiology conference in London, including Dr. Kaski’s presentation on microvascular disease.