Correlation of Fractional Flow Reserve Computed Tomography (FFR CT) Findings With Invasive FFR in Coronary Artery Disease (CAD) in a Multi-ethnic Cohort- a Retrospective Study

This retrospective study will analyse the existing Computed Tomography Coronary Angiogram (CTCA) database for patients treated at Sandwell and West Birmingham (SWBH) National Health Service (NHS) Trust between January 1, 2019, and December 31, 2023, with the clinical team screening the database to identify patients who fit with the eligibility criteria.

The proposed study is a retrospective analysis of the clinical and imaging data over a five-year period in patients with stable chest pain (approximately 500 patients), who underwent CTCA, FFR CT, and invasive FFR at SWBH NHS Trust. The study will assess the correlation between these diagnostic measures. The aim of this investigation is to address the ongoing discrepancies in the diagnostic accuracy of FFR CT compared to the gold standard invasive FFR, which persist despite the increasing adoption of FFR CT in clinical practice. While initial trials indicated promising sensitivity and specificity for FFR CT, recent observational studies including one involving 2,298 patients who underwent FFR CT, reported varying positive and negative predictive values, with a low positive predictive value of 49% (24). This variability raised concerns about the reliability of FFR CT across different patient populations, and the real-world accuracy and cost-effectiveness of FFR CT remain subjects of ongoing debate.

This study aims to examine the correlation between FFR CT and invasive FFR in a real-world setting using existing data, providing practical insights directly applicable to patient care. By confirming or examining the accuracy of FFR CT in a clinical setting, our analysis could support its broader adoption as a routine non-invasive diagnostic tool potentially (a) reducing the need for invasive testing (b) minimising associated risks, and(c) lowering healthcare costs and provide fresh insights into non-invasive coronary diagnostics. Our findings will also help understand the relevance of these tests across different ethnic groups and the population the investigators serve.

The patient data will be identified by accessing the CTCA database, and the study will adhere to the STrengthening the Reporting of OBservational studies in Epidemiology (STROBE) guidelines (25).

The eligibility criteria are as follows: