News · Heart & Metabolic
One in three patients with chest pain and clear arteries had a hidden circulation problem
An angiogram showing open arteries is usually treated as reassurance. Measuring the smaller vessels in 1,003 patients found a third had dysfunction, and it tracked worse outcomes.
- About a third of patients investigated for chest pain had small-vessel dysfunction.
- Their rate of serious heart events was roughly double over about two years.
- The association held after accounting for other risk factors.
- The measurement is taken during an angiogram, not by a separate test.
- A registry of 1,003 patients, so this describes risk rather than proving benefit from acting.
There is a familiar and unsatisfying ending to a cardiac investigation. The patient has chest pain, the angiogram shows arteries that are open, and they are sent home told their heart is fine.
For a large number of them the heart is not fine. The vessels causing the trouble are simply too small for the camera to see.
What was measured
Writing in the European Heart Journal, investigators used a registry of patients undergoing angiography for suspected heart disease and added a measurement of the small vessels while the catheter was already in place.
The measure captures how much the small circulation can open up when the heart demands more blood, and it is constructed to be independent of any narrowing in the large arteries. That independence is the point: it isolates the part of the problem an angiogram cannot show.
Previously the prognosis attached to that measurement had not been established at this scale.
How common it was
Coronary microvascular dysfunction was identified in 334 of 1003 patients, which is a third of everyone investigated.
That number reframes the reassurance. A third of the people being told their arteries are clear had a measurable circulation problem that the clear arteries did not rule out.
Whether it mattered
Over a median of just under two years, serious events were roughly twice as common in the group with dysfunction: about 18% against about 9%.
The events counted were death, heart attack, a repeat procedure to restore blood flow, or admission for heart failure. So this is not a symptom score; it is the outcomes cardiology exists to prevent.
The association survived adjustment for the other things that predict those events, which means the small-vessel measurement carries information beyond the usual risk factors rather than simply repeating them.
The limits worth stating plainly
This is a registry, not a trial. Everyone had the measurement and nobody was randomized to anything, so it establishes that the finding marks risk and not that acting on it reduces risk.
That distinction is the whole practical question. A test that identifies a high-risk group is only useful if something can then be done, and this study does not test any treatment.
Just under two years is also short for outcomes that accumulate over decades, and 1,003 patients at specialist centers are not a cross-section of everyone with chest pain.
Why it still changes something
Chest pain does not always mean that you are having a heart attack, and the reflex when it is not is to look for another explanation entirely.
For patients with unobstructed arteries, the honest answer has often been a shrug. What this supplies is a measurement that turns a diagnosis of exclusion into a positive finding with a known prognosis, which is worth having even before anyone knows what to do about it. It also names a group, disproportionately women, whose symptoms have been dismissed on the strength of a picture that was never looking in the right place.
People also ask
What did the study find?
Coronary microvascular dysfunction was identified in 334 of 1,003 patients (33.3%). At a median 1.9 years, the primary endpoint occurred in 47 of 334 (18.2%) with dysfunction against 49 of 669 (8.6%) with preserved function (hazard ratio 1.94; 95% CI 1.30-2.90; P = 0.001), and remained independently associated on multivariable analysis (adjusted hazard ratio 1.78; 1.06-2.99; P = 0.030).
What is coronary microvascular dysfunction?
A problem in the small vessels that feed heart muscle, too small to see on a standard angiogram. They can fail to widen properly when the heart needs more blood, producing the symptoms of restricted supply while the large arteries look open.
Why does an angiogram miss it?
Because an angiogram images the large arteries. If those are clear, the traditional conclusion has been that the chest pain is not cardiac, which leaves a substantial group of patients told nothing is wrong while their symptoms continue.
What is microvascular resistance reserve?
A measure of how much the small vessels can widen when demanded, taken during the same catheter procedure. It is designed to be independent of any narrowing in the large arteries, so it isolates the small-vessel component.
Who does this affect most?
Patients, disproportionately women, who are investigated for chest pain, found to have unobstructed arteries, and discharged without an explanation. This gives that group a measurable finding rather than a diagnosis of exclusion.
Does treating it help?
That is the open question. This study shows the dysfunction identifies people at higher risk; it does not test any treatment, and identifying risk is not the same as being able to reduce it.
What should a patient with unexplained chest pain do?
Whether this measurement is available and appropriate is a cardiology decision, and symptoms that persist deserve to be raised again rather than accepted. This is general information rather than medical advice.