Total stent length and post-stent fractional flow reserve (FFR) were the most important predictors of target vessel failure (TVF) at 2 years, according to study results released Monday.
Doyeon Hwang, MD, and colleagues of Seoul National University Hospital, reported the results of their analysis of the International Post-Percutaneous Coronary Intervention (PCI) FFR Registry in a paper published in the July 27 issue of JACC: Cardiovascular Interventions.
About 10% of patients still experience adverse cardiovascular events after PCI. Identifying patients at high risk for future events is very important for risk stratification. In this study, the authors developed a risk-prediction model incorporating clinical, angiographic, and physiological parameters and investigated the role of post-stent FFR in predicting future clinical outcomes after second-generation drug-eluting stent (DES) implantation.
The study included 2,200 patients who underwent DES implantation with post-stent FFR data from the International Post-PCI FFR Registry (NCT04012281). A risk model was developed to predict the rate at 2 years of target vessel failure, which is defined as a composite of cardiac mortality, target vessel myocardial infarction, and clinically driven target vessel revascularization. The model was developed in 80% of the patients and validated in the remaining 20%.
The mean age of the overall population was 64±10 years; 77% were men, 67% had hypertension, 34% had diabetes and 30% were smokers. About 52% presented with acute coronary syndrome, and most of the treated lesions were in the left anterior descending artery. Mean reference vessel diameter is 3±0.5 mm. The mean total stent length was 37±23 mm, and the mean post-stent FFR was 0.88±0.07.
At 2 years’ follow-up, about 5.9% of the patients had target vessel failure. Six variables were selected in the risk model: total stent length, post-stent FFR, age, post-stent percentage diameter stenosis, reference vessel diameter and diabetes mellitus. This risk model showed better prediction ability than models with clinical risk factors alone or clinical risk factors and angiographic parameter (Harrell’s concordance index, 0.72; 95% confidence interval [CI], 0.62-0.82). When the patients were divided into two groups according to the median of total stent length (30 mm), post-stent FFR and total stent length were the most important predictors. Post-stent FFR showed the highest importance in patients with total stent length <30 mm.
The authors acknowledged some limitations to their analysis: the study population was from four different observational registries, the inherent limitations of observational studies, the role of intracoronary imaging, and non-availability of detailed procedural information and left ventricular function.
Nils P. Johnson, MD, MS, of the McGovern Medical School at UTHealth and Memorial Hermann Hospital, Houston, and Zsolt Piróth, MD, PHD, of the Hungarian Institute of Cardiology, wrote in an accompanying editorial that “focal disease will likely have high post-PCI FFR with large change in FFR and the findings will be reversed for diffuse disease.”
The editorialists suggested that “pre-PCI FFR pullback, accounting for both depth and distribution dimensions will be an important determinant of suitability for revascularization and response to PCI.”
Hwang and colleagues concluded that clinical, angiographic, and post-stent FFR can be helpful in risk stratification of patients after DES implantation and that total stent length and post-stent FFR were the most important predictors of target vessel failure.
Hwang D, Lee JM, Yang S, et al. Role of Post-Stent Physiological Assessment in a Risk Prediction Model After Coronary Stent Implantation. JACC Cardiovasc Interv 2020;13:1639-50. DOI: 10.1016/j.jcin.2020.04.041
Johnson NP, Piróth Z. 2-Dimensional Fractional Flow Reserve: Depth and Distribution. JACC Cardiovasc Interv 2020;13:1651-4. DOI: 10.1016/j.jcin.2020.05.030