Diagnostic accuracy of CCTA matches catheter angiography

Researchers from the Charité University Hospital in Berlin have established that, in certain cases, the diagnostic reliability of non-invasive coronary computed tomography (CT) angiography is as good as that of coronary angiography – thereby dispensing with the need for invasive procedures.(Haase R et al. Diagnosis of obstructive coronary artery disease using computed tomography angiography in patients with stable chest pain depending on clinical probability and in clinically important subgroups: meta-analysis of individual patient data. BMJ. 2019 Jun 12; 365: l1945. doi: 10.1136/bmj.l1945).

Symptoms such as dull chest pain or a feeling of tightness in the chest may be indicative of coronary artery disease (CAD). In the worst-case scenario, CAD can lead to a life-threatening heart attack or sudden cardiac death. Prompt diagnosis is therefore essential.

Until now, patients with suspected CAD have often been examined using cardiac catheterization for coronary angiography, the procedure that involves a catheter being inserted into a blood vessel then advanced to the heart. The advantage of this method is that it combines diagnosis with treatment: if a narrowed segment is detected, the intervention to open up the affected artery can be performed immediately. However, the procedure is not without its risks, and out of a total of 880,000 patients who undergo the procedure in Germany every year, approximately 58% do not actually require such an intervention. Led by the Charité hospital, an international research consortium has now been able to show that, in certain patients, an equally accurate diagnosis can be achieved using non-invasive cardiac CT angiography.

Research groups from 22 countries worked together to analyze the data of more than 5,300 patients from a total of 65 completed studies. Their analysis revealed that coronary CT angiography is a suitable diagnostic technique in patients with a low to intermediate probability of CAD. “Physicians can determine a patient’s probability of having CAD using individual factors such as age, sex and type of chest pain,” says study leader Prof. Marc Dewey, of the Department of Radiology on Campus Charité Mitte. “If this probability is between 7 and 67 percent, coronary CT angiography will provide a reliable diagnosis as to whether or not the patient has narrowed arteries. Cardiac catheterization is indicated in patients with higher probabilities, as these patients are likely to need an intervention.

The study’s first author, Robert Haase said “Our work shows that, in both men and women, cardiac CT method is capable of clearly visualizing narrowed segments”.

Our findings will make it easier for physicians to determine which patients may benefit from having a coronary CT angiogram rather than a catheter-based procedure to diagnose coronary artery disease,” says Prof. Dewey. “I hope that the study will contribute to the harmonization of clinical practice guidelines. Country-specific guidelines continue to vary in terms of courses of action recommended when dealing with suspected CAD”.

doi: 10.1136/bmj.l1945