Coronary CT angiography is a safe gatekeeper in non-ST-elevation acute coronary syndrome - The VECTOR study

In patients with non-ST-segment elevation acute coronary syndrome (NSTEACS), coronary pathology ranges from normal vessels to severe obstructive disease. In NSTEACS patients where invasive coronary angiography (ICA) is recommended, it is unknown whether a non-invasive coronary computed tomography angiography (CCTA) may be used for patient triage. The Very Early Computerized Tomography to Organize Revascularization in patients with NSTEACS (VECTOR) study was a pilot study that assessed whether CCTA can be used to safely discharge NSTEACS patients without obstructive coronary artery disease.

An initial CCTA categorized all patients into CCTA groups: CT_{non-obstructive}, (without stenosis ≥ 50%) who avoided ICA, and CT_obstructive or CT_{non-diagnostic}, who had ICA performed immediately after CCTA. All patients were followed for 12 months. The subsequent safety endpoints were recorded: death, nonfatal myocardial infarction, ischemia-driven revascularization, and development of renal failure.

We prospectively included 250 patients, among which 193 (77%) had elevated troponins, and 81 (32%) had dynamic ECG-changes. All 51 (20%) CT_{non-obstructive} patients could be discharged without ICA with an outcome free 12-month follow-up. In 175 (70%) CT_obstructive patients in whom significant coronary disease was confirmed by ICA in 141 (81%), and 126 (89%) of these were revascularized. In 25% of CT_obstructive patients CCTA could help guide PCI by reducing the ICA radiation dose, invasive equipment and ICA contrast volume. No patients developed renal failure.

In patients with NSTEACS, CCTA allows to avoid ICA in 1 of 5 patient and may guide efficient patient triage and planning of revascularization.