Clinical Characteristics of Early and Late Drug-Eluting Stent In-Stent Restenosis and Mid-Term Prognosis After Repeated Percutaneous Coronary Intervention
Coronary stenting has become a primary strategy for revascularization in patients with coronary artery disease. Despite the significant reduction in the incidence of in-stent restenosis (ISR) with the advent of drug-eluting stents (DES), DES-ISR still affects approximately 5% to 10% of patients undergoing percutaneous coronary intervention (PCI). The treatment of DES-ISR remains a major challenge due to its association with worse outcomes compared to bare metal stent (BMS) ISR. This study aims to explore the clinical characteristics of early and late DES-ISR and identify predictors of mid-term major adverse cardiac events (MACE) after repeated PCI.
Study Design and Patient Selection
This retrospective single-center study included 250 patients who underwent initial DES implantation and were readmitted for recurrent significant DES-ISR in 2016. Patients were categorized into early ISR (E-ISR; <12 months; n = 32) and late ISR (L-ISR; ≥12 months; n = 218) based on the time of ISR occurrence after initial DES implantation. The primary composite endpoint of MACE included cardiac death, non-fatal myocardial infarction (MI), or target lesion revascularization (TLR).
Baseline Characteristics
Most baseline characteristics were similar between the E-ISR and L-ISR groups, except for the period of ISR, initial pre-procedure thrombolysis in myocardial infarction (TIMI) flow, and some serum biochemical indicators. The median time interval from initial PCI to index interventions was significantly shorter in the E-ISR group (0.8 years) compared to the L-ISR group (5.1 years; P < 0.001). Other baseline clinical characteristics, including age, gender, body mass index (BMI), diabetes mellitus, hypertension, dyslipidemia, and history of smoking, were similar in both groups.
Echocardiographic and Blood Sample Characteristics
Echocardiographic data revealed higher rates of regional wall motion abnormality and left ventricular systolic or diastolic dysfunction in the E-ISR group compared to the L-ISR group, although these differences were not statistically significant. Blood profile analysis showed significantly higher levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and erythrocyte sedimentation rate (ESR) in the E-ISR group. In contrast, low-density lipoprotein cholesterol (LDL-C) levels were higher in the L-ISR group.
PCI Characteristics and Clinical Outcomes
There were no significant differences in baseline performances and angiographic characteristics between the two groups, except for a higher prevalence of pre-procedure TIMI flow grade 0 in the E-ISR group (31.3% vs. 14.7%; P = 0.019). Treatment strategies for DES-ISR and the outcomes of index PCI were similar in both groups. However, during the 12-month follow-up, the incidence of MACE was significantly higher in the E-ISR group (37.5% vs. 5.5%; P < 0.001), primarily driven by a higher rate of TLR (37.5% vs. 5.0%; P < 0.001). The re-hospitalization rate was also higher in the E-ISR group.
Multivariate Analysis and Predictors
Multivariate logistic regression analysis identified early ISR (odds ratio [OR], 13.267; 95% confidence interval [CI] 4.984–35.311; P < 0.001) and left ventricular systolic dysfunction (OR, 6.317; 95% CI 1.145–34.843; P = 0.034) as independent predictors of MACE during the mid-term follow-up in DES-ISR patients after repeated PCI. Traditional cardiovascular risk factors such as hypertension, hyperlipidemia, and diabetes mellitus were not significant predictors of MACE in this study.
Discussion
The findings of this study highlight the differences in clinical outcomes between early and late DES-ISR. Early ISR is associated with a significantly higher incidence of MACE, primarily due to increased TLR rates. The underlying mechanisms for these differences may involve neointimal proliferation and accelerated neoatherosclerosis in early ISR. The use of intravascular imaging, such as optical coherence tomography (OCT), could provide further insights into the morphological characteristics of DES-ISR and guide treatment strategies.
The study also emphasizes the importance of left ventricular systolic dysfunction as a predictor of poor outcomes in DES-ISR patients. Abnormal left ventricular function may reflect underlying myocardial damage and contribute to adverse clinical events. These findings suggest that early ISR patients may require more intensive clinical surveillance and tailored treatment approaches to mitigate the risk of MACE.
Limitations
This study has several limitations. The small sample size and retrospective design may introduce confounding factors and limit the generalizability of the findings. The use of telephonic follow-up may not provide reliable data on adverse events. Additionally, the lack of intravascular imaging data limits the ability to fully characterize the underlying substrates of DES-ISR. Further studies with larger sample sizes and prospective designs are needed to validate these findings and explore the mechanisms of DES-ISR.
Conclusion
In conclusion, early ISR and left ventricular systolic dysfunction are associated with an increased risk of MACE during the mid-term follow-up period in DES-ISR patients after repeated PCI. These findings may aid in risk stratification and secondary prevention strategies for DES-ISR patients in clinical practice. Future research should focus on understanding the pathological mechanisms of DES-ISR and developing targeted therapies to improve outcomes in this high-risk patient population.
doi.org/10.1097/CM9.0000000000001135
Was this helpful?
0 / 0