Prognostic value of SYNTAX score for patients with coronary in-stent restenosis

Background Previous studies suggest that SYNTAX score can predict the incidence of coronary in-stent restenosis in patients after percutaneous coronary intervention (PCI). Nevertheless, few studies focus on the correlation between SYNTAX score and long-term prognosis of patients with in-stent restenosis.

Objective To investigate the effect of SYNTAX^ISR score on the prognosis of patients with in-stent restenosis (ISR) undergoing PCI.

Methods Patients with in-stent restenosis undergoing coronary angiography in the Cardiology Department of Chinese PLA General Hospital from December 2016 to March 2020 were included in our retrospective cohort study, and they were followed up until December 2023. Multivariable Cox regression analysis was used to identify the association between SYNTAX^ISR score and major adverse cardiovascular events (MACEs). Kaplan-Meier curve and log-rank test were used to assess the differences among risk groups. Subgroup analysis was undertaken to investigate the consistency of the association between SYNTAX^ISR score and MACEs among different subgroups. Time-dependent receiver operating characteristic (ROC) curve was used to assess the capacity of SYNTAX^ISR score to predict MACEs.

Results Of the 356 cases, 68 cases were female, and the average age was 63.61 ± 9.82 years, 49 were lost to follow-up, with follow-up rate of 86.3%. The subjects were divided into three groups according to the cutoff of SYNTAX^ISR score (≤22, 23-32, ≥33) recommended by guideline. The patients in the much higher SYNTAX^ISR score group would have higher cTnT and BNP. In the high SYNTAX^ISR score group, the Mehran classification tended to be total occlusion. Most importantly, the incidence of MACEs tended to be higher. In multivariate Cox regression analysis, SYNTAX^ISR score was significantly correlated with MACEs (HR=1.039, P＜0.001). The incidence of MACEs in high risk group (SYNTAX^ISR≥33) was significantly higher than that in intermediate risk group (23≤SYNTAX^ISR≤32) (P＜0.05) or low risk group (SYNTAX^ISR≤22) (P＜0.001). The subgroup analysis confirmed the significant association between SYNTAX^ISR score and MACEs. The AUC of time-dependent ROC curve from 1 to 6 years was 0.636, 0.620, 0.648, 0.601, 0.635 and 0.619, respectively.

Conclusion SYNTAX^ISR score is an independent risk factor for MACEs in patients with in-stent restenosis.