Diagnostic accuracy of quantitative flow ratio in patients with arrhythmias

Quantitative flow ratio (QFR) has been validated as a wire-free, angiography-based method for the haemodynamic assessment of coronary stenoses1. Among the most important technical requirements for QFR calculation is the absence of arrhythmias, which imply variations in beat-to-beat coronary diastolic filling patterns. In previous studies, 8% of patients were excluded from QFR calculation due to arrhythmias2. No study has so far attempted to validate QFR in patients with arrhythmias. Therefore, we sought to compare the diagnostic performance of QFR in patients with arrhythmias against wire-based physiology indices such as fractional flow reserve (FFR) or non-hyperaemic pressure ratios (NHPR), which are regarded as gold standards in determining the haemodynamic relevance of coronary stenoses.

A total of 214 vessels (81 assessed with FFR, 133 with NHPR) in 161 consecutive patients with chronic coronary syndrome and arrhythmias (defined as atrial fibrillation [AFib] or extrasystole >20% of beats) during coronary angiography who had undergone assessment of at least 1 stenosis with FFR or NHPR across 3 European sites were retrospectively included. These measures were not included in prior studies. The presence of arrhythmia...