Clinical risk prediction, coronary computed tomography angiography, and cardiovascular events in new-onset chest pain: the PROMISE and SCOT-HEART trials

Abstract

Background and aims: Whether index testing using coronary computed tomography angiography (CTA) improves outcomes in stable chest pain is debated. The risk factor weighted clinical likelihood (RF-CL) model provides likelihood estimation of obstructive coronary artery disease. This study investigated the prognostic effect of coronary CTA vs. usual care by RF-CL estimates.

Methods: Large-scale studies randomized patients (N = 13 748) with stable chest pain to coronary CTA as part of the initial work-up in addition to or instead of usual care including functional testing. Patients were stratified according to RF-CL estimates [RF-CL: very-low (≤5%), low (>5%-15%), and moderate/high (>15%)]. The primary endpoint was myocardial infarction or death at 3 years.

Results: The primary endpoint occurred in 313 (2.3%) patients. Event rates were similar in patients allocated to coronary CTA vs. usual care [risk difference (RD) 0.3%, hazard ratio (HR) 0.84 (95% CI 0.67-1.05)]. Overall, 33%, 44%, and 23% patients had very-low, low, and moderate/high RF-CL. Risk was similar in patients with very low and moderate/high RF-CL allocated to coronary CTA vs. usual care [very low: RD 0.3%, HR 1.27 (0.74-2.16); moderate/high: RD 0.5%, HR 0.88 (0.63-1.23)]. Conversely, patients with low RF-CL undergoing coronary CTA had lower event rates [RD 0.7%, HR 0.67 (95% CI 0.47-0.97)]. The number needed to test using coronary CTA to prevent one event within 3 years was 143.

Conclusions: Despite an overall good prognosis, low RF-CL patients have reduced risk of myocardial infarction or death when allocated to coronary CTA vs. usual care. Risk is similar in patients with very-low and moderate/high likelihood.

Keywords: Chronic coronary syndrome; Clinical likelihood; Coronary computed tomography angiography; Pre-test probability.

Structured Graphical Abstract

The risk factor-weighted clinical likelihood denotes patient-specific procentual estimates on probability of having obstructive coronary artery disease (CAD) at invasive cornary angiography. In the table, blue, green and yellow colours denote patients with ≤5%, 5%–≤15%, and >15% clinical likelihood of obstructive CAD at invasive coronary angiography, respectively. CTA, computed tomography angiography.

Figure 1

Cumulative incidence of myocardial infarction and death stratified by (A) randomisation, (B) RF-CL groups, and (C) randomisation and RF-CL groups. In total, 4483 (32.7%), 6093 (44.4%), and 3135 (22.9%) patients were grouped as RF-CL ≤5%, RF-CL >5%–≤15%, and RF-CL >15%, respectively. Abbreviations: RF-CL, risk factor-weighted clinical likelihood; CTA, computed tomography angiography.

Figure 2

Change in lipid-lowering therapy from baseline to 8 weeks. Data presented for the 11,465/13,711 (83.6%) patients in whom an RF-CL estimate was calculated, and information on test abnormality and lipid-lowering therapy during follow-up was available. Patients without an index test were considered to have a normal test results. Abbreviations: RF-CL, risk factor-weighted clinical likelihood; CTA, computed tomography angiography.

Figure 3

Change in antiplatelet therapy from baseline to 8 weeks. Data presented for the 10 996/13 711 (80.2%) patients in whom an RF-CL estimate was calculated, and information on test abnormality and antiplatelet therapy during follow-up was available. Patients without an index test were considered to have a normal test results. Abbreviations: RF-CL, risk factor-weighted clinical likelihood; CTA, computed tomography angiography.

Figure 4

Revascularisation within 90 days. Data presented for the 12 979/13 711 (94.7%) patients in whom an RF-CL estimate was calculated, and information on test abnormality and revascularisation was available. Patients without an index test were considered to have a normal test results. Abbreviations: RF-CL, risk factor-weighted clinical likelihood; CTA, computed tomography angiography.