Prognostic value of CT angiography for major adverse cardiac events in patients with acute chest pain from the emergency department: 2-year outcomes of the ROMICAT trial

Abstract

Objectives: The aim of this study was to determine the 2-year prognostic value of cardiac computed tomography (CT) for predicting major adverse cardiac events (MACE) in patients presenting to the emergency department (ED) with acute chest pain.

Background: CT has high potential for early triage of acute chest pain patients. However, there is a paucity of data regarding the prognostic value of CT in this ED cohort.

Methods: We followed 368 patients from the ROMICAT (Rule Out Myocardial Infarction Using Computer Assisted Tomography) trial (age 53 ± 12 years; 61% male) who presented to the ED with acute chest pain, negative initial troponin, and a nonischemic electrocardiogram for 2 years. Contrast-enhanced 64-slice CT was obtained during index hospitalization, and caregivers and patients remained blinded to the results. CT was assessed for the presence of plaque, stenosis (>50% luminal narrowing), and left ventricular regional wall motion abnormalities (RWMA). The primary endpoint was MACE, defined as composite cardiac death, nonfatal myocardial infarction, or coronary revascularization.

Results: Follow-up was completed in 333 patients (90.5%) with a median follow-up period of 23 months. At the end of the follow-up period, 25 patients (6.8%) experienced 35 MACE (no cardiac deaths, 12 myocardial infarctions, and 23 revascularizations). Cumulative probability of 2-year MACE increased across CT strata for coronary artery disease (CAD) (no CAD 0%; nonobstructive CAD 4.6%; obstructive CAD 30.3%; log-rank p < 0.0001) and across combined CT strata for CAD and RWMA (no stenosis or RWMA 0.9%; 1 feature-either RWMA [15.0%] or stenosis [10.1%], both stenosis and RWMA 62.4%; log-rank p < 0.0001). The c statistic for predicting MACE was 0.61 for clinical Thrombolysis In Myocardial Infarction risk score and improved to 0.84 by adding CT CAD data and improved further to 0.91 by adding RWMA (both p < 0.0001).

Conclusions: CT coronary and functional features predict MACE and have incremental prognostic value beyond clinical risk score in ED patients with acute chest pain. The absence of CAD on CT provides a 2-year MACE-free warranty period, whereas coronary stenosis with RWMA is associated with the highest risk of MACE.

Figure 1. Flow Chart of the ROMICAT Trial Follow-Up

*All patients underwent cardiac computed tomography during index hospitalization and the caregiver and patients remained blinded to the results throughout the study. **Patients were followed by standardized telephone call, a third party, and/or the Social Security Death Index (SSDI). The SSDI search was performed in all patients 3 years after enrollment. ROMICAT = Rule Out Myocardial Infarction Using Computer Assisted Tomography.

Figure 2. Kaplan-Meier Curves of MACE as Stratified by Cardiac Computed Tomography Features

(A) Coronary artery disease (CAD) categories stratified into no CAD, nonobstruc-tive CAD, and obstructive CAD. (B) Coronary stenosis was stratified into no stenosis and stenosis. (C) Coronary and functional computed tomography categories stratified into no stenosis or regional wall motion abnormalities, no stenosis with regional wall motion abnormalities (RWMA), stenosis without RWMA, and stenosis with RWMA. MACE = major adverse cardiac event.

Figure 3. Kaplan-Meier Curves of Late (>30 Days) MACE as Stratified by Cardiac CT Features

(A) Coronary artery disease (CAD) categories stratified into no CAD, nonobstructive CAD, and obstructive CAD. (B) Coronary and functional computed tomography (CT) categories stratified into no stenosis or regional wall motion abnormalities (RWMA), no stenosis with RWMA, stenosis without RWMA, and stenosis with RWMA.