Long-Term Change in Flow Rates in Patients with Coronary Slow Flow

Background: Coronary slow flow (CSF) is a condition characterized by impaired blood flow rates in the coronary arteries. It can result in severe cardiovascular outcomes. There is not sufficient evidence regarding the certain etiology and reversibility of slow flow patterns and change in frame counts with long-term management. Methods: We retrospectively enrolled 48 patients with chronic coronary syndrome and CSF who underwent a second angiography. A corrected coronary frame rate (CFR) > 27 was defined as CSF. We created 3 groups according to the change in CSF status as the improved, not changed, and worsened groups. We compared the CFR and CSF status of the patients between the first and second angiographies within a median of 2.6 years. Results: We determined a non-significant change in cCFR in LAD (34.4 [18.9] vs. 31.59 [10.3], p=0.35), Cx (42.84 [12.56] vs. 40.66 [13.2], p=0.35), and RCA arteries (57.80 [30.13] vs. 50.32 [19.5], p=0.11). In the comparison of CSF status of LAD (75% vs. 63%, p=0.27), Cx (96% vs. 83%, p=0.09), RCA (94% vs. 94%, p=1.0) between first and second angiographies there was no significant change. In the comparison of 3 the groups according to the improvement of CSF status, there was not any significant difference in demographic features, change in laboratory parameters, and time between the groups. Conclusion: In conclusion, there was no significant change in the median CFR and CSF status in the overall group between the two angiographies after 3 years.