https://doi.org/10.1007/s00392-025-02625-4
1Segeberger Kliniken GmbH Herz- und Gefäßzentrum Bad Segeberg, Deutschland; 2Universitätsklinikum Schleswig-Holstein Medizinische Klinik II / Kardiologie, Angiologie, Intensivmedizin Lübeck, Deutschland; 3King Fahad Armed Forces Hospital Jeddah, Saudi Arabien; 4Asklepios Klinik Bad Oldesloe Zentrum für Herz-, Gefäß- und Diabetesmedizin Bad Oldesloe, Deutschland; 5Asklepios Klinik Bad Oldesloe Kardiologie Bad Oldesloe, Deutschland
Background: Physiological assessment is useful in detecting suboptimal results after percutaneous coronary intervention (PCI). However, after successful PCI of a chronic total occlusion (CTO) coronary physiology changes over time, which may impact physiological measurements such as quantitative flow ratio (QFR).
Purpose: To evaluate the functional results of CTO PCI measured by quantitative flow ratio (QFR) immediately and 6 months following the PCI.
Methods: We retrospectively included patients with a successful CTO-PCI from a single center between 2017 and 2020. A total of 182 patients who fulfilled the QFR eligibility criteria, out of 470 CTO-PCIs, were enrolled. The QFR was measured off-line in the target vessel immediately post index procedure and after a short-term follow-up (a median of 6 months).
Results: The mean age was 67.3 ±10.5 years, and 79.1% were males. Three vessel disease was documented in 51.1% of patients. The mean J-CTO score was 2.2 ± 0.9, retrograde approach was used in 14.8%, and right coronary artery was the target vessel in 52.7% of the population. The mean QFR immediately after successful CTO-PCI (0.94 ± 0.06) was numerically increased to (0.96 ± 0.04) after follow-up (p= 0.061). Immediately post CTO-PCI, 18.1% of patients had QFR < 0.91, and 81.9% had QFR ≥ 0.91. After 6 months, QFR increased significantly in patients with initial suboptimal QFR (0.86 ± 0.06 vs 0.95 ± 0.08, p<0.001), while QFR did not change significantly in patients with initial high QFR (0.94 ± 0.1 vs 0.96 ± 0.02, p=0.159). Patients with persistent high QFR or those with improving QFR ≥ 0.91 after a short-term follow up had lower rates of two-year target vessel failure (14.9% vs 26.5%, HR 0.16, 95% CI: 0.07-0.39, p<0.001).
Conclusion: QFR increased significantly in patients with low initial values, while high initial QFR levels were stable at 6-month follow-up. Low QFR measured immediately following a successfully recanalized CTO does not reflect the actual functional status. Persistent high or improving QFR (≥0.91) is associated with better outcome than patients with a persistent low value.