Objective To investigate the predictive value of CT-derived fractional flow reserve (CT-FFR) combined with serum microRNA-335-5p (miR-335-5p) and microRNA-423-5p (miR-423-5p) for in-stent restenosis (ISR) after percutaneous coronary intervention (PCI) in patients with coronary heart disease (CHD).

Methods A prospective study was conducted in 150 CHD patients (study group), and 108 healthy individuals who underwent health check-ups during the same period and were of the same age range were selected as control group. Based on the ISR assessment results, the patients with sucess of follow-up in the study group were divided into ISR group (42 cases) and non-in-stent restenosis (NISR) group (58 cases). The levels of miR-335-5p and miR-423-5p were compared among different groups. The correlations of miR-335-5p and miR-423-5p with CT-derived fractional flow reserve (CT-FFR) were analyzed. Influencing factors for ISR occurrence after percutaneous coronary intervention (PCI) in CHD patients were screened. The predictive value of CT-FFR combined with serum miR-335-5p and miR-423-5p for ISR occurrence after PCI in CHD patients was evaluated.

Results The serum miR-335-5p levels in the study group were significantly lower than those in the control group, while the miR-423-5p levels were significantly higher (P < 0.05). In the ISR group, the serum miR-335-5p levels were significantly lower than those in the NISR group, and the miR-423-5p levels were significantly higher (P < 0.05). The CT-FFR values in the ISR group were significantly lower than those in the NISR group (P < 0.05). Elevated serum miR-335-5p levels and increased CT-FFR were protective factors against ISR after PCI in CHD patients, while elevated serum miR-423-5p levels were an independent risk factor for ISR after PCI in CHD patients (P < 0.05). Serum miR-335-5p was positively correlated with CT-FFR (r=0.522, P < 0.05), whereas miR-423-5p was negatively correlated with CT-FFR (r=-0.537, P < 0.05). The area under the curve (AUC) of the receiver operating characteristic (ROC) curve for the combined prediction of ISR after PCI in CHD patients using CT-FFR and serum miR-335-5p and miR-423-5p levels was 0.939, which was superior to the prediction using each of these indicators alone (Z=2.992, 2.671, 3.346, P < 0.05).

Conclusion The serum miR-335-5p levels are decreased and the miR-423-5p levels are increased in CHD patients, and these changes are associated with the occurrence of ISR after PCI. CT-FFR combined with serum miR-335-5p and miR-423-5p has certain predictive value for ISR after PCI in CHD patients.