A positive stress test result means you may have a heart condition. Something that you may not like. 

If you then have a positive stress test, you’ll likely be led to the catheter lab for a coronary angiogram. The procedure usually detects atherosclerotic plaque, does not matter if the plaque is big enough to cause a blockage. 

If plaque is detected, you’ll then be recommended to have a coronary stent or even a bypass surgery. Unfortunately, stents and bypass grafts could create a false sense of security, both for doctors and their patients.

This progression—from stress test to cardiac catheterization to stent—is tragically a common triad of cardiology practices. But this is often unnecessary, which costs the American healthcare system billions of dollars each year. 

Worse, if the stress test result is a false positive, then those cath and stent procedures would be for nothing. The rates of positive stress tests that are false range from 32.5% to much higher (Qamruddin, 2016).


Cardiac Catheterization

Cardiac catheterization (or cardiac cath) involves inserting a catheter (a long thin tube) in a blood vessel in the groin or arm of a patient. With catheterization, doctors can perform diagnostic procedures (like coronary angiography) and treatments (like coronary stenting).

Cardiac cath

Coronary Angiography

Angiography is a procedure that combines catheterization, X-ray, and dye injection to produce images (“angiograms”) of blood vessels. If it’s for the heart, it’s called coronary angiography. It’s also known by many names: arteriography; invasive, percutaneous, interventional, or catheter angiography; and cardiac cath with dye. 

Here are some examples of angiograms:

CT angiogram

CT angiogram

The standard coronary angiography differs from CT angiography. While both use X-ray, CT angiography combines X-rays and computers to produce more detailed images. 

A Brief History of Coronary Angiography

The first angiogram was done in 1927 by Portuguese physician Egas Moniz at the University of Lisbon. It was a picture of the arteries of the brain. 

The first heart catheterization was done in 1929 by Berman physician Werner Forssmann. He inserted a tube in the cubital vein of his arm. He then guided the tube up to the right chamber of his heart. (I’m guessing that was not very comfortable.) 

Forssmann then took an X-ray to prove his success. He then published this on Nov 5, 1929, with the title Die Sondierung des Rechten Herzens (“The Probing of the Right Heart”). 

Dr. Mason Sones, a pediatric cardiologist at the Cleveland Clinic, did the first coronary arteriogram sometime between 1958 and 1960. It was an accident, though, as he was originally looking to image the aorta. 

Dr. Sones’ procedure was not unusual—he guided a catheter to the origin of the aorta, injected the dye, and took an X-ray. However, instead of the aorta, he got a picture of an artery supplying the muscle of the heart. 

Dr. Sones was surprised to see his mistake. Unfortunately, the patient’s heart stopped beating. Good thing he was able to restart the heart, and the patient got no permanent damage. (At least it seemed so.) 

Many of us would have been concerned about that bad luck that day. But Dr. Sones was excited about the newfound possibility of coronary angiography. And after seeing images of coronary angiograms, it’s easy to understand why he was so excited. His discovery had the promise of opening up a whole new area of medicine. And that’s just what it did.

Coronary stents

A stent is a small, mesh-like tube. When placed in a narrowed or clogged artery, it opens the artery and prevents it from closing.

Overutilization of stents

Dr. Pastor-Cervantes has a schedule for cardiac catheterization. The procedure determined that only one of his patient’s blood vessels required stenting. The patient is Alex, who went to Memorial Cardiac and Vascular Institute, where Dr. Pastor-Cervantes uses a robot to precisely place stents.

Dr. Pastor-Cervantes performed the entire procedure through Alex’s wrist, and Alex was up and walking within 2 hours. If Alex chose surgery, Dr. Pastor-Cervantes said it would have taken a large incision in the chest, more invasive procedures, 5 to 7 days of hospital stay, and an extended recovery period. 

“When it’s needed, it’s needed,” said Dr. Pastor-Cervantes about stents. “But in this particular case, Alex needed to have just one, only one stent. And that’s what we did.”

In the US, around 2 million stents are done each year. Despite the high number, many medical standards bodies—from ACC and AHA to internal and family medicine groups—agree that stents are overused. With too many procedures being unnecessarily done, stents have a similar backstory with stress tests.

Although coronary angiography detects plaques, we need to avoid the logic trap that any plaque needs a stent. While doctors and patients assume stents fix the problem, the science suggests they do not.

Don’t get me wrong. In the right situation, stents can save lives.  They work well for treating heart attacks. However, that situation only occurs in 10% of stenting cases (less than 200,000 times per year). For the other 90%, stents are placed for 2 unnecessary reasons. 

One, to prevent heart attacks. Unfortunately, that doesn’t work, as shown by the COURAGE trial (Boden, April 2007). Two, to cure angina or chest pain. That doesn’t work either, as shown by the ORBITA trial (Al-Lamee, 2018). 


The COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial was published in The New England Journal of Medicine way back in 2007. It reported that placing a stent and unclogging arteries failed to reduce the risk of death, heart attacks, or other cardiovascular events (Boden, Jan 2007). 

The ORBITA Trial

The ORBITA (Objective Randomized Blinded Investigation with Optimal Medical Therapy of Angioplasty in Stable Angina) trial was particularly an interesting study. It was done in 5 centers in the UK. 

ORBITA researchers randomized the subjects. Subjects were told they would be given a stent, but in reality, only half of them got a stent. The result: Those who had a stent were no better than the ones that didn’t have a stent for treating angina (Al-Lamee, 2018).

COURAGE and ORBITA are just 2 studies, but others didn’t contradict the evidence shown by these 2 trials. That’s why the American College of Cardiology teamed up with Choosing Wisely® (an affiliate of the American Board of Internal Medicine Foundation) to discourage the practice of unnecessary stent placement.



There’s also the larger ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) trial in 2019. ISCHEMIA covers not only stents but also bypass surgery. 

In this study, around 5,200 patients with moderate or severe ischemia (restricted blood flow to the tissues) were randomly assigned to either have (1) invasive angiography followed by stents or bypass, and medical therapy, or (2) medical therapy alone (Herman, 2019).

The result: ISCHEMIA showed that stents and bypass surgery are no more effective than drugs for treating stable heart disease. ISCHEMIA puts into question the value of stress tests in identifying patients who need to undergo procedures to detect blockage and improve blood flow with stents or bypass.


The Risks of Cardiac Cath, Coronary Angiography, and Stents

Although there is a national cardiac cath and stent registry, there is no routine summary report of deaths from coronary angiography. Because of this, we could only estimate death rates using existing reports. 

Mortality rates ranged from 0.05% to 0.25%. If we multiply such rates by the millions of cath lab angiograms done in the US, we could conclude that there are approximately 800 to 2,500 deaths annually from coronary angiography. 

Not all these deaths, though, should be credited to the procedures alone. This is because cath lab deaths are much higher among individuals with already known serious heart disease. Still, the catheter-based procedures carry a certain risk. 

Some Cardiologists Think Cardiac Caths are Risk-free

Late one evening, a friend of mine who once managed a cath lab found one cardiologist placing a cath. They took turns “cathing” each other to see what it was like to be “cathed” in a patient’s side. 

It is a good thing if doctors walk into their patients’ shoes, but my friend was concerned about the $20,000 expense (another downside to cardiac cath). Others would also be concerned about the inherent risk of performing such an unnecessary procedure, especially if the procedure is invasive. 

But the most significant risk of cardiac catheterization and coronary angiography is not catheter-related injury—it’s the unnecessary stenting or bypass surgery. Not to mention the further delays in treatment, like the lifestyle changes needed to slow down inflammation

If your cardiologist forgets about the risk of injury during a cath procedure, you may want to read or hear Cricket’s experience: 

They made it sound like it was like the smallest deal ever, so I kind of thought it was going to be like giving blood…and I’d be walking around just a few hours later… I really didn’t recover for a full two weeks, so I feel like, you know, I wish I had known that before I had this procedure…

The Risk of Radiation

In the image below, we can see that there is radiation exposure with coronary angiograms (that’s expected with the involvement of X-ray). In fact, coronary angiography has one of the highest X-ray exposures in medical examinations. There is also radiation involved in other tests like coronary calcium scores, CT angiograms, nuclear stress tests, and stents.

Radiation for medical imaging procedures

Mettler (2008). Effective doses in radiology and diagnostic nuclear medicine: a catalog. Millisievert (mSv) is a measure of the health effect of ionizing radiation over time.

The real concern, however, happens with the all-too-common trio of a nuclear stress test followed by coronary angiography and stents, something that’s commonly done in a percutaneous intervention (PCI) procedure. When this combination (or variations of this combination) is repeated multiple times, the risk of radiation becomes more significant.

Are Stress Tests, Cardiac Cath & Stents Unnecessary?

Both doctors and patients assume (albeit incorrectly) that cholesterol tests, blood pressure tests, stress tests, coronary angiograms, stents, and bypass grafts make up the best way to detect and treat heart disease. 

Such an assumption, however, is killing and disabling more people than anything else in the modern and industrialized world. 

I also mentioned that stress tests, cath labs, angiograms, and stents are overused and often for financial reasons. 

Not every overutilization, though, is related to just financial motives. Some patients have limited access to information about their cardiovascular health, so choosing the optimal tests requires understanding lots of things. 

Here’s the bigger picture. There are nearly 100,000 miles of vessels in the average adult human body, and stent repairs around 2 inches only. This is equivalent to a dentist scraping part of one tooth in your mouth. 

We do not wish to diminish the importance of surgical interventions. They can be lifesaving when done during a heart attack. For those who need surgery, there are no better options. But we do want to emphasize that there’s a more effective approach for those who have time on their sides.  

Unfortunately, the current healthcare system is significantly under-diagnosing people with cardiovascular disease. That’s why we must concern ourselves with evidence-based methods. We have to avoid non-contributory procedures like nuclear stress testing, coronary angiogram, stents, and bypass grafts, unless indicated or when the patient is symptomatic.  

Despite all the resources on cardiovascular disease management, many people forget this truth: You can’t supplement, medicate, stent, or bypass your way out of a lifestyle problem. Or, as my friend Dr. David Wright puts it, “There is not a pill made that is more effective than lifestyle choices.”

My name is Ford Brewer. My team and I work to prevent heart attack, stroke, cancer, and dementia. Our goal is to help you understand how to prevent major killers and disablers. Most of them are driven by the process of cardiovascular inflammation

If you want to know more about the science of preventive medicine or you have questions about certain aspects of your health, check out our webinars, membership programs, and online courses.

If you’d like to learn about the basics of heart attack & stroke prevention for free, complete this form, and get access to our CV inflammation course. If you’re interested in how we can help you, check out our services page


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