Low risk for heart disease but chest pain? Which test is warranted: CT angiogram or catheter angiogram?
Find out what someone with low risk for heart disease should do if they have suspicious symptoms and want more than a stress test: cath angiogram or CAT scan?
Suppose you’re at low risk for heart disease (clogged arteries) in that you exercise, don’t smoke, aren’t overweight, have normal blood pressure, are not diabetic and eat mindfully, but…you’ve been having chest pains, especially upon exertion (or new-onset shortness of breath that’s out of proportion to level of activity).
Should you go straight to the cath lab? Or first undergo the non-invasive CT angiogram?
“You need to understand CT angio vs. cardiac cath angio before you throw up your hands in despair,” says Monica Reynolds, MD, a cardiologist with ColumbiaDoctors Medical Group in White Plains, NY.
“In summary – CT angio is really not much safer than a traditional cardiac cath.”
The CT angiogram involves significant radiation exposure, but the cath angiogram requires threading a catheter through the coronary arteries.
“And if significant disease is found, only the traditional cardiac cath allows the operator to proceed directly to stenting,” says Dr. Reynolds.
Placing a stent can be done while the catheter is already in place, if it’s determined that’s all the patient needs (i.e., bypass surgery not needed).
“CT angio for coronary arteries was the hot topic a few years ago, but has since fallen out of favor for several reasons,” continues Dr. Reynolds.
First of all, if one’s coronary calcium score is high enough, the calcified deposits will make it difficult to interpret the image from a CT angiogram.
“Patients with CAD almost always have significant calcium deposits. So CTA is really only useful in patients WITHOUT coronary disease, i.e., in healthy patients to rule out CAD.
“Here’s the downside of the CTA – CTA still requires injection of contrast dye and involves radiation,” says Dr. Reynolds.
“Therefore, the risk of an allergic reaction to the dye or risk to the kidneys from the dye in renal patients is the same whether you get a CTA or cath.
“The only advantage over a regular cardiac cath is that the test is performed using a peripheral IV rather than a central stick (usually into the femoral artery).”
Renal pertains to kidneys. The femoral artery is the main thigh artery.
“As I noted above, the other downside to CTA is that if disease is found, you can’t do anything about it. If a stent is needed, the patient then needs to have a cardiac cath to place the stent.”
When my mother was admitted to the hospital (from the ER) with chest pain, the cardiologist ordered a catheter angiogram; he bypassed the CT angiogram. Why?
Because my mother was at very high risk for severe heart disease or cardiac problems based on several factors: 1) Slightly elevated troponin level during ER visit, 2) Elderly age, 3) Abnormal echocardiogram, 4) High triglycerides.
Why waste time on a CTA with this type of patient?
It would only delay what the cardiologist probably was already anticipating: a need for a stent or even bypass surgery, plus expose her to unnecessary radiation and possible insult to kidneys from the contrast dye.
The catheter angiogram revealed “significant blockage” and about two hours later, she was undergoing quintuple bypass surgery!
“So here we go again – PRETEST PROBABLILITY OF DISEASE – if the doctor thinks a patient has normal coronaries but the patient has ongoing symptoms or is worried about coronary disease (CAD), a CTA can be done to rule out CAD,” explains Dr. Reynolds.
“This is being done more and more in the ER setting to expedite the evaluation process.” See link above in yellow highlight.
“However, if a patient is likely to have coronary disease (or the patient had a high CT calcium score), a cardiac cath is a better, more useful, more direct, and really safer approach to diagnosing and treating the disease.
“Current complication rates for cardiac cath, stent, etc., in a generally healthy patient are extremely low!
“Most complications occur in patients with unstable coronary disease and multiple medical comorbidities.”
Since 1992 Dr. Reynolds has practiced clinical cardiology at ColumbiaDoctors Medical Group, one of the largest multi-specialty practices in New York State.
Lorra Garrick has been covering medical, fitness and cybersecurity topics for many years, having written thousands of articles for print magazines and websites, including as a ghostwriter. She’s also a former ACE-certified personal trainer.