Bypassing bypass surgery by growing new arteries

by Carolyn Thomas  @HeartSisters

The human body is endlessly fascinating, isn’t it? Consider how humans get started in the first place – only after one tiny sperm, one of hundreds of millions, has somehow negotiated its way past the lethal acid coating the vagina and made its long journey up to the waiting egg.  The odds are stupefyingly against that one brave little sperm. How did any of us even get born?

Also, consider the heart.

Before my heart attack, I had never heard of the heart’s little collateral arteries. These are small, normally closed arteries that, in times of dire need (like a blocked coronary artery that can lead to a heart attack) can “wake up” and enlarge enough to form a kind of detour around the blockage, thus providing an alternate route of blood supply to feed the oxygen-starved heart muscle. Do-it-yourself bypass surgery!

Consider also the example of Juliet’s life-saving collateral arteries. At the age of 46, this young mother of two in London, England suffered a heart attack due to Spontaneous Coronary Artery Dissection (SCAD).

Like most SCAD patients, she had no cardiac risk factors, and was very healthy at the time. (Just the day before, she had gone on a 40-minute run). But her early heart attack symptoms were initially misdiagnosed, and she now suspects that the tear in her artery continue to unravel.  Juliet ended up with five stainless steel stents implanted along the length of her torn Left Anterior Descending (LAD) coronary artery.

But then things went from bad to worse for Juliet, as over the next three months, her stents re-stenosed (blocked) due to scar tissue build-up. She explains:

”   During the period of re-stenosis and for about a year after, I suffered angina pain on exertion and most particularly after eating. Unfortunately, the stents subsequently failed, and my LAD is now 100% occluded with scar tissue. But that part of my heart is now functioning on collateral circulation. The chest pain symptoms disappeared slowly as my collateral arteries developed.

“It was a happy surprise to discover how wonderfully a heart can adapt with collaterals, and although I would love to still have the use of my LAD, I am doing fine without it!

“My cardiologists said these collateral arteries would have started to develop as soon as my LAD started to re-stenose, especially as I went straight back to running, post-cardiac rehab. I am surprisingly well and happy to be alive.”


Drawing of the coronary artery circulation with (left panel) and without (right panel) collateral artery growth between the right coronary artery (these are the small red blood vessels in the left illustration) and the blocked artery.  The grey area below the blockage shows the area of the heart muscle at risk of permanent damage in the absence of collaterals. (Illustration by Anne Wadmore, London, UK). From BMCMed.

Some researchers suggest that, because Juliet was already a physically active runner, her own collateral arteries may have already started this important process called arteriogenesis, which is defined as the transformation of pre-existing collateral artery pathways into conducting vessels.

In 2004, Swiss researchers, for example, found that enhanced physical exertion (like running) may indeed help those tiny collaterals to kick into creating that detour around a blockage.(1)  Study authors explained in the journal, Heart:

“For the first time in a human being with entirely normal coronary arteries, we have shown evidence of enhanced coronary collateral flow in response to an endurance exercise program.”

I’ve been told the same theory – that my 19 years of distance running contributed to that enhanced coronary collateral flow, which may have been the factor that helped to save me during my own heart attack, despite having a Left Anterior Descending coronary artery that was also fully occluded. My misdiagnosis also meant that I’d been sent home from Emergency despite my textbook cardiac symptoms (central chest pain, nausea, sweating and pain down my left arm) – ironically signalling the pre-existing collateral vessels to get ready because my heart was in trouble. This collateral growth is called arteriogenesis; it happens through a remodeling process of those pre-existing small collaterals.

Some researchers suggest that your blood type may affect the likelihood that your body will produce collateral circulation.  Having O type blood, for example, was found to be an independent predictor of good coronary collateral circulation among heart attack patients.(1) 

Not every collateral will work when it needs to. And not everybody has functional collateral arteries (a blood flow of 20% to 25% is generally considered sufficient to provide the required blood supply to the heart muscle at rest). Only one in three patients with coronary artery disease has sufficient pre-existing collaterals.(2)  We don’t know the reasons for this, but genetic factors are likely to play a role. Some factors that may influence whether patients with coronary artery disease develop collaterals include the severity of the coronary blockage(3), a longer duration of angina, and the location of the blockage.

Find out more about Spontaneous Coronary Artery Dissection (SCAD).


1. S Celebi et al.  “Blood Group Types O and Non-O Are Associated With Coronary Collateral Circulation Development”;  Clinical and Applied Thrombosis/Hemostasis. January 2020.
2. R Zbinden et al.  “Direct demonstration of coronary collateral growth by physical endurance exercise in a healthy marathon runner”. Heart. 2004 November; 90(11): 1350–1351.
3. T Pohl  et al. “Frequency distribution of collateral flow and factors influencing collateral channel development. Functional collateral channel measurement in 450 patients with coronary artery disease.”  J Am Coll Cardiol. 2001;38:1872–1878.


NOTE FROM CAROLYN:  I wrote more about amazing ways the human body tries to keep you alive during a heart attack in my book  A Woman’s Guide to Living with Heart Disease.(Johns Hopkins University Press).   You can ask for it at bookstores (please support your local independent bookseller!) or order it online (paperback, hardcover or e-book) at Amazon –  or order it directly from my publisher Johns Hopkins University Press (use their code HTWN to save 30% off the list price).


84 thoughts on “Bypassing bypass surgery by growing new arteries

  1. Hi
    I too gained collateral circulation. I had had a total of 4 heart attacks. Had 2 stents put in. Had a heart attack last August. Took 5 months off sick and done absolutely nothing.

    Amazing – 7 months later I have a good heart.

    Liked by 1 person

    1. That’s amazing, John!

      I had a heart attack in 1992, and a GP said it was probably ‘just bad gas’. In April 2022, I experienced something far worse than 1992, and was really hoping it was what the first practitioner said in 1992 vs what a series of tests and imaging proved otherwise by several Cardiologists later.

      This time, it felt like a blowtorch in my throat into my esophagus and a ball of fire across my chest. Months prior, I experienced pain across my collarbones, shoulders, and upper back around my shoulder blades (primarily left). In April, the pain spread down both arms to my fingertips as though the life was being drained from my entire body. . . not to mention the upper GI pain and impending doom. In a series of imaging and switching to another Cardiologist, we discovered my RCA had a 60% blockage in the center, and 100% Total CTOs (*Chronic Total Occlusions, or blockages that have typically been present for more than three months) of my RCA, at what was supposed to be the bottom.

      This was discovered after my new Cardiologist did a heart Cath with plans to put in a stent … only to discover the 100% blockage.

      No stent – no surgery… I’m walking 3-5 miles a days … and it feels great to be alive. My Cardiologist said, “Most of us are born with 3 main vessels, you were born with 4, but that’s besides the point… you have a very healthy Left Anterior Descending artery and the extra vessel that helped the collateral arteries to do their own bypass. If you’re walking 3 miles without any pain, keep walking!”
      Cool! I feel great!

      Liked by 1 person

  2. After a triple CABG In 1997 and 9 stents over the last several years, my last Cath showed total blockages of two bypass grafts and restenting was found to be too risky.

    But, significant collateral vessel growth was also discovered. Cardiac Rehab was prescribed and after 18 sessions with 18 to go, I have to say my angina and shortness of breath have improved significantly.

    This is not to suggest that this result would be the same for everyone but for me it seems to have been a blessing.

    Liked by 1 person

    1. That is absolutely fantastic news, Lou – and what perfect timing for those wonderful little collaterals to go back into business to help you out!! I’m a big believer that cardiac rehabilitation can make a remarkable difference (researchers tell us that completing a full series of rehab classes can reduce mortality risk by 2/3 over a 15 year period of follow-up compared to heart patients who don’t go to cardiac rehab!

      And each stent or bypass graft helps only one small area of the heart at a time, but regular physical exercise helps every cell in our bodies for as long as keep it up! “Exercise is medicine”, as cardiologists like to say.

      Keep up the good work… Take care, stay safe!


      1. Hi Carolyn,
        After having a stent fitted my angina pain did not go away, but changed! Before stenting, as I previously told you, I could wait for the pain to go and then exercise without any further discomfort. Consultant confirmed I was making pathways.

        Now, I get a pain after a while when exercising, wait for it to go or use a spray under my tongue, upon continuing to exercise the pain returns again and again.

        I believe I would have been better off not having the stent procedure. I had the stent fitted in August. By the way the consultant believes my 90% blockage was congenital.

        Many thanks,

        Liked by 1 person

        1. Hello again Michael – this is discouraging. Unfortunately you can’t turn back the clock on that decision to stent. I’m not a physician (as I always hasten to add) but I’m wondering if this pain during exercise might be due to something called “stretch pain” due to the dilation and stretching of a coronary artery during the implanting of the stent. This is usually a short-term and benign problem, but in some cases it can last for months. Your stent was implanted in August, which means you’re still in early days.

          Please make an appointment with your consultant if this chest pain during exertion continues or worsens, but I’m hoping that the symptoms will gradually improve over time.

          Good luck to you… take care, stay safe..


          1. Hi Carolyn, I think I said August, it has only been 2 months since the procedure was carried out. I have had contact with the consultant and he did say about other small arterial blockages, however as I had a!ready made pathways, I find the present situation somewhat confusing.

            I am going in for an echo cardiogram shortly to see if my aortic stenosis gradient has worsened. It was 36%. However, chest pain is not a symptom of stenosis.

            I like to believe that stretch pains could be a possibility, but the pain I am getting now is so similar to my previous periods of discomfort. Thank you so much for taking the time to reply,it is so much appreciated.


  3. I have just had an angiogram which has shown one artery to be 90% blocked. Laying on the table having a conversation with the doctor, I mentioned that I developed angina after about 2 to 4 hundred metres of walking. Having slowed down or stopped and waited until the pain went, I could then walk for the rest of the day without pain. The doctor mentioned pathways. The first time I had heard about a possible non surgical solution to my problem.

    After taking it easy for a few months, I have now started exercising properly. Fingers crossed. Also I need a valve replacement, going towards severe gradient, I do not believe that this would cause my angina pain?

    Liked by 1 person

    1. That’s a good example of how those collateral arteries work, Michael. The human body is truly amazing at trying to heal what ails us! You didn’t mention if your doctor prescribed nitroglycerin for occasional episodes of angina during exertion (I think you call it TNG in the UK?) If you don’t have this, ask your doctor. It is your friend if angina strikes!!

      Here’s more info. Might be handy to have on hand, just in case…

      I’m not a physician so cannot comment specifically on your valve replacement in the future, but I can tell you generally that the commonly experienced chest pain of angina is more often related to coronary artery disease/heart attack. Valve issues often present with symptoms like palpitations, shortness of breath, fatigue or fainting. But every patient is different – talk to your doctor about your own specific case. Best of luck to you…


      1. Hi Carolyn, thanks for the reply. I have just had notification that the doctors are intending to put a stent into my 90% blocked artery. I am having an echocardiogram to determine the condition of my aortic valve on the 23rd January. If this is still in the moderate range they will proceed with the stent only. I have read that collateral pathways alone are unable to supply enough oxygenated blood during strenuous exercise. Is this always the case?

        I have recommenced exercise and I am feeling very positive. Again, many thanks,

        Liked by 1 person

        1. Hi again, Michael. Again, I’m not a physician, but my understanding is (as the Swiss study mentioned above suggests) “evidence of enhanced coronary collateral flow in response to an endurance exercise programme.” My question is always about symptoms. Are you symptomatic or ASYMPTOMATIC? In other words, do your symptoms affect your quality of life to the extent that intervention will make your life better/improve longterm outcomes, etc? An interesting study from Germany that I often quote: Dr. Rainer Hambrecht found that patients “with significant coronary artery blockages actually do better in longterm follow-up studies when they participate in regular exercise programs compared to those having invasive cardiac procedures done to help revascularize those blocked arteries.”

          And you may have heard of the very recent $100 million ISCHEMIA study reported at the American Heart Association’s annual Scientific Meetings last month which found that, essentially, the outcomes of patients with stable angina (pain comes on with exertion/goes away with rest) who had had either bypass surgery or stents for blocked arteries were no better than those who were prescribed only Optimal Medical Therapy (lifestyle improvements plus cardiac medications).

          As I wrote about in my own article abut the ISCHEMIA study, it’s not surprising that, if a physician tells you that you have a 90% blockage in your coronary artery, you would most likely want that artery opened up!! NOW!!!

          I had a similarly blocked artery, but debilitating heart attack symptoms (e.g. chest pain so bad that I could not walk more than five steps). The big ISCHEMIA study suggested that although bypass surgery or stenting does address a specific area that’s blocked, it does not “fix” what caused that problem in the first place, likely decades earlier – but lifestyle improvements (like your exercise program) DO affect/improve every cell of your body.

          The most important factor in all medical decision-making is that you and your physician have an open, frank communication about your unique situation and all of the risks/benefits of your potential treatment options. Good luck!!


  4. Following popliteal entrapment syndrome which I wasn’t even aware existed, my leg developed a collateral artery bypass because I went to the gym to workout and slowly I could increase my walking distance over the course of a year just by using a treadmill and hiking
    In the beginning I couldn’t walk further than 50 yards before my foot went numb with pins and needles.
    Now I can go a couple of miles.
    When I went to an orthopedic surgeon and they took a picture of my blood vessels it shows my dead popliteal artery has been bypassed by my collateral artery and I have very little side effects of my body’s bypass.

    Liked by 1 person

  5. I am a 69 year old male who has been power walking/jogging for 28 years. Last year my cardiologist advised me to have a heart angiogram. I had it done, but they found two blocked arteries. They immediately put me on the list for heart bypass surgery.

    Thank God that hospitals take their time in scheduling their heart surgeries. Three months after the angiogram (during which I stopped all power walking), I asked the same cardiologist to put me on a full stress test. I did this, and passed with 96%. Then with the consent of my cardiologist, I went back to power walking, without the jogging.

    Now, one year and five months after the angiogram, I feel great. I power walk for one hour 4-5 days a week, watch my diet and weight. I cover 6.5 kilometers in one hour during my walk, winter/summer. I’m pretty certain (almost 100%) that heart blood vessel collaterals have saved me from a heart attack.

    I truly believe that a human being must exercise regularly or his/her muscles will start to ‘die’. I hate to be blunt, but I believe this to be a fact.

    Liked by 1 person

    1. Thanks for sharing that amazing story! Some researchers have found similar results (e.g. heart patients divided into two groups: one group has standard invasive treatment, the other rides bicycles, at the end of one year, the cycling group reports better heart health recovery than the treated group!)

      Your 28 years of exercise helped to strengthen your heart muscle, no doubt.

      As cardiologist Dr. John Mandrola says: “You only have to exercise on the days you plan to eat!”


  6. I had a blockage on left side artery, I could walk only 1 block, stopping 5 times. My heart developed artery on its own – no surgery or stents or medication in 5 days.
    I can run, climb, etc, No sign of trouble.
    Keep exercising and yoga.

    Liked by 1 person

    1. I had a heart attack at the end of July. I had a stent placed into my RCA. My LAD is 90% blocked and my LCX is 50% blocked. Yet, I’ve felt better than before the heart attack and I can exercise easier. I’ve a meeting with my cardiologist on Thursday. I’ll see what he says. At the moment I feel like staying on the meds he’s given me and my changed diet of much more fruit and veg, and reduced fast food. I always walked a lot.

      Liked by 1 person

  7. What kind of test could reveal if you are developing collaterals? Would a stress test do? Or perhaps your own observation in terms of improved aerobic capacity?

    Liked by 1 person

    1. Good question, Tudval. I’m not a physician but I can tell you that generally a stress test would not tell you about collaterals. They may be visible during an angiogram. My understanding is that you wouldn’t be able to tell if your own collaterals were functioning or not.


  8. Reblogged this on melonpopzdropz … and commented:
    ANGIOGENESIS – has already occurred…. I am scared, I am grateful and I am also thoroughly amazed. Funny fact is, I recently read about the bodies capabilities to do this taking over when another part is damaged and unable to do the job in the Biology of Belief by Bruce Lipton.. Another funny fact is that part of the text fascinated me most.. Its like I already knew I would need to know this .. or something like that. Just another one of that whack explainable type situations.


  9. Had I known about these collaterals, I wouldn’t have done the PCI and 5 stents 6 mos ago. Was normal and full of energy before the PCI and stenting. Now, I feel very weak and chest discomfort 24 hrs/day. I literally feel like I’m already a dead man, just only still breathing. PCI and stenting is the worst decision I’ve made in my life. And, its irreversible.

    Liked by 1 person

    1. Hello Alex – unfortunately, not everybody has strong collateral vessels that spring into action to appropriately reroute blood flow around a coronary artery blockage. If all of us did, no heart attacks would ever happen.

      I’m more concerned about your debilitating symptoms. Most heart patients start to feel more like their old selves by six months, but a smaller number continue to feel awful despite having newly revascularized arteries. There may be non-cardiac reasons (we know that depression and thyroid issues, for example, can cause symptoms of crushing fatigue and weakness). Something is causing these symptoms, and you need to solve the mystery. Please see your physician, and if you’re unable to get help, seek a second opinion. Best of luck to you…


    2. Hang in there. I felt the same for about 1 and a half years after the 3 vessel/7 stents I had implanted. But once I phased out the blood thinner, I started to have just a bit more energy which allowed me to increase physical activity more and more. Now it’s 2 years after my angioplasty and feel quite a bit better. If I can get again the progress I’ve made over the last 6 months, I’d be quite happy (i.e. about 80% normal).

      I keep in mind that without the stents I might have gotten to 0% pretty soon.


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