VERMONT non-optimised: can baseline diagnostic catheter images be used to measure angiography based CAAS-vFFR?

Background We have previously reported strong diagnostic accuracy and validity of angiography-based vessel Fractional-Flow-Reserve (CAAS-vFFR) using optimised angiographic cine images compared to conventional wire-based Fractional-Flow-Reserve (FFR). At present, there is a paucity of data regarding the validity of using baseline non-optimised diagnostic cine images in the assessment of CAAS-vFFR. Methods We conducted an investigator-initiated, single-centre, blinded, prospective observational study assessing the diagnostic accuracy and validity of using baseline non-optimised diagnostic cine images in measuring CAAS-vFFR compared to patients undergoing routine wire-based FFR for intermediate coronary stenoses. Results 195 consecutive patients with 205 lesions were recruited over 19 months; 56 (27.3%) lesions were excluded due to unsuitable baseline image quality. 102 (68.5%) had stable symptoms and 107 (71.8%) were male. The median age was 65.0 years (interquartile range 59.0-73.0) and mean body-mass-index was 29.2 kg/m2 (±5.8). The mean wire-based FFR and non-optimised vFFR were 0.82 (±0.1) and 0.79 (±0.1) respectively. Receiver-operating-characteristic (ROC) curve analysis revealed excellent diagnostic accuracy of non-optimised vFFR in predicting a wire based FFR of ≤ 80 (AUC 0.91; 95% CI; 0.87-0.96). Baseline non-optimised diagnostic vFFR images produced a sensitivity of 94.2%, specificity of 75.3%, positive-predictive-value (PPV) of 67.1% and negative-predictive-value (NPV) of 96.1% compared with wire-based FFR. Conclusions CAAS-vFFR derived values from baseline non-optimised diagnostic cine images displayed a high sensitivity, NPV and diagnostic accuracy compared to wire-based FFR. This reflects the potential for CAAS-vFFR to have broader clinical applications and be utilised as a retrospective screening tool for intermediate lesions.