How should CT coronary angiography be integrated into the management of patients with chest pain and how does this affect outcomes?

Mhairi K Doris,David E Newby

doi:10.1093/ehjqcco/qcv027

Abstract

When examining the role of a diagnostic test in clinical practice, consideration must be placed not only on the accuracy of the result, but also its impact on patient care and outcomes. Proving a direct effect on outcomes may be difficult because the impact of the diagnostic test largely depends on the clinician's interpretation and consequent actions as well as the patient's response to changes in their diagnosis, investigations, and treatment. Recent major clinical trials of symptomatic patients with suspected coronary heart disease (CHD) have shown that computed tomography coronary angiography (CTCA) can markedly clarify the diagnosis and lead to major changes in patient investigation and management including the use of invasive angiography, preventative therapies, and coronary revascularization. Thus, when added to our existing clinical tools, such as exercise electrocardiography, CTCA represents a powerful method of identifying and excluding CHD. Furthermore, it can identify patients with prognostically relevant non-obstructive CHD and, with recent technological advances, will be able to assess the functional impact of anatomically detected coronary artery stenoses. Overall, the routine integration of CTCA into the investigation of patients with chest pain improves clinical diagnostic certainty that has led to better targeting of investigations and evidence-based treatments that have ultimately translated into improved clinical outcomes.

Highlights

When introducing a diagnostic test, the first step is to establish its accuracy in comparison with the gold-standard referent investigation
The rapid technological advances of computed tomography coronary angiography (CTCA) have raised promise that this imaging modality may fulfil the role of a gold-standard non-invasive investigation of chest pain
The results have demonstrated that, in the detection of coronary heart disease (CHD), CTCA has a sensitivity and specificity which is similar to invasive coronary angiography

Summary

Introduction

When introducing a diagnostic test, the first step is to establish its accuracy in comparison with the gold-standard referent investigation. 10% of patients not offered investigation were subsequently diagnosed as having significant CHD.[2] This highlights the fact that misclassification can lead to adverse outcomes and reflects the need for a clearer diagnosis in low-risk populations This represents the majority of patients attending cardiology clinics with recent onset chest pain and a test that could reliably exclude CHD in this group of patients may provide reassurance and reduce adverse outcomes.[1,2]. The American College of Cardiology/American Heart Association guidelines primarily recommend exercise electrocardiography, whilst the majority of North American clinicians will undertake nuclear perfusion scans as the non-invasive stress test of choice.[12] the European Society of Cardiology guidelines suggest a ‘preference’ for stress imaging tests above exercise electrocardiography where expertise and resources are available These recommendations have been made based on empirical clinical practice and studies assessing comparative diagnostic accuracy and patient risk stratification but not on clinical outcomes. OMT, optimal medical therapy; MPI, myocardial perfusion imaging; CMR, cardiac magnetic resonance

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