Diagnosis

Which Non-Invasive Test Can Diagnose CAD in Patients With Angina?

A few non-invasive cardiac tests outperform invasive tests for ruling in and out coronary artery disease (CAD) in patients with angina, according to results of a new review.

 

To conduct their review, the researchers identified studies published on electronic databases from inception to August 2017.

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Studies were included if they had evaluated 6 non-invasive cardiac tests in more than 100 patients with stable CAD and utilized either invasive coronary angiography or invasive coronary angiography with fractional flow reserve measurement as a reference. Tests that were evaluated in these studies included:

  • Stress electrocardiogram (ECG),
  • Stress echocardiography,
  • coronary computed tomography angiography (CCTA),
  • Single-photon emission computed tomography (SPECT),
  • Positron emission tomography (PET), and
  • Cardiac magnetic resonance (CMR).

The pre-test probability ranges for each test to rule in or rule out significant CAD were defined as more than 85% and less than 15%, respectively.

 

The analysis included 28,664 patients from 132 studies that used invasive coronary angiography as a reference and 4131 from 23 studies that used fractional flow reserve.

 

Results of the analysis showed that for anatomically significant CAD, stress ECG can successfully rule it in when pre-test probability is 80% or more and rule it out when pre-test probability is 19% or less. CCTA can rule it in at a pre-test probability of 58% or more and rule it out at a pre-test probability of 80% or less.

 

For functionally significant CAD, CCTA can rule it in when pre-test probability is 75% or more and rule it out when pre-test probability is 57% or less. Invasive coronary angiography can rule it in at a pre-test probability of 71% or more and rule it out at a pre-test probability of 25% or less, which demonstrates poorer performance of anatomic imaging against fractional flow reserve.

 

However, functional imaging techniques such as PET or stress CMR are able to rule in functionally significant CAD when pre-test probability is 46% to 59% and rule it out when pre-test probability is less than or equal to 34% to 57%.

 

“The various diagnostic modalities have different optimal performance ranges for the detection of anatomically and functionally significant CAD,” the researchers concluded. “Stress ECG appears to have very limited diagnostic power. The selection of a diagnostic technique for any given patient to rule-in or rule-out CAD should be based on the optimal PTP range for each test and on the assumed reference standard.”

 

—Amanda Balbi

 

Reference:

Knuuti J, Ballo H, Juarez-Orozco LE, et al. The performance of non-invasive tests to rule-in and rule-out significant coronary artery stenosis in patients with stable angina: a meta-analysis focused on post-test disease probability. Eur Heart J. 2018;39(35):3322-3330. https://doi.org/10.1093/eurheartj/ehy267.