“Our results indicate that the accuracy of coronary CTA is highest for clinical decision making if probability of coronary disease is between 7% and 67%,” lead authors Dr. Robert Haase and Dr Marc Dewey from Charite – University Medicine Berlin in Germany, told Reuters Health by email.
“Until now, guidelines recommend to consider CTA in stable chest pain either in all patients with angina pectoris (National Institute for Health and Care Excellence) or only those with 15-50% probability of coronary disease (European Society of Cardiology),” they explained.
Coronary CTA is an accurate non-invasive alternative to invasive coronary angiography and can rule out CAD with high certainty. But it remains unclear which patients might benefit the most from the procedure, the authors note in a report online June 12 in the BMJ.
They designed their study to see whether coronary CTA should be performed in patients with any clinical probability of CAD and whether the diagnostic performance differs by patient subgroup. The study was a meta-analysis of individual patient data (n=5332) from 65 prospective diagnostic accuracy studies that compared coronary CTA with coronary angiography as the reference standard.
According the results, at a pretest probability of 7%, the positive predictive value of coronary CTA was 50.9% and the negative predictive value was 97.8%. The corresponding values at a pretest probability of 67% were 82.7% and 85.0%. The overall sensitivity and specificity of coronary CTA were 95.2% and 79.2%, respectively.
“In this low-to-intermediate clinical probability range, coronary CTA was able to accurately stratify patients into those with a disease post-test probability of below 15%, in whom other reasons for the chest pain should be considered, and those with a probability above 50%, in whom further testing is recommended,” write the researchers.
Coronary CTA using more than 64 detector rows was empirically more sensitive and specific than CCTA using up to 64 detector rows, “indicating that recent CTA technology with more than 64 rows should be used,” they note.
The diagnostic performance of CCTA was not significantly influenced by type of angina pectoris, but it was slightly higher in men and lower in older patients.
This meta-analysis using individual patient data can “help physicians in better identifying the patients for whom coronary CTA is the most appropriate diagnostic test,” they conclude in their article.
The study was funded by the joint program of the German Research Foundation (DFG) and the German Federal Ministry of Education and Research. Several authors disclosed relationships with various pharmaceutical companies.