Aims: The risk factors influencing the components of composite endpoint of target lesion failure (TLF) - cardiac death, target-vessel myocardial infarction, or clinically driven target-lesion revascularisation after stent implantation might change over time post-implantation of stent. Therefore, our aim was to assess the main risk factors for early (up to1 month) and late (1 to 24 months) events in the patients treated with one type of drug-eluting stent (DES) in a real life setting.
Methods and results: In a frame of a large multinational registry that enrolled 3.067 consecutive patients undergoing percutaneous coronary intervention with the Nobori® DES, we looked for the independent peri-procedural and clinical risk factors. The following parameters were entered in the two separate initial Cox proportional-hazards regression models: age, gender, diabetes, acut myocardial infarction (MI) at presentation, acute coronary syndrome (ACS), reference vessel diameter (RVD) pre procedure, type C lesion, stented length, stenosis post stenting, number of stents per patient, number of lesions, bifurcation, procedural dissection and Dual Antiplatelet Therapy (DAT) at 1 and 12 months respectively for early and late events. All the variables were retained in the model at a p-value<0.1 and were tested for the Proportional Hazard assumption. TLF was observed in 1.24% (38/ 3.067) of the patients at 1- month and 3.81% (117/3,067) at 24-month post-stenting. The Hazard Ratio (HR), its confidence interval and p value were calculated for all variables in the final model. The TLF risk factors at 1 months were: RVD (HR: 2.1, p=0.04), pre-procedural MI (HR: 2.4, p=0.08, borderline), number of stents per patient (HR: 1.9, p=0.02), bifurcation (HR: 2.2, p=0.07 borderline), dissection (HR: 3.1, p=0.04), DAT ongoing (HR: 0.13, p=0.007, protective role). Between 1 and 24 months, the TLF risk factors were: age (per 10 years HR: 1.3, p=0.01), diabetes (HR: 1.6, p=0.03), number of stents per patient (HR: 1.3, p=0.06, borderline), number of lesions (HR: 1.3, p=0,02), ACS (HR: 1.6, p=0.04).
Conclusions: A very low rate of TLF was observed at both, 1 month and 24 months. The risk factors influencing the early occurrence of the event were predominantly determined by the angiographic and peri-procedural clinical factors (RVD, pre-procedural MI (non-STEMI), number of implanted stents, bifurcation, dissection) as well as the post-procedural DAT. While the risk factors influencing the late events are determined by the extent of disease (number of lesions and implanted stents), clinical factors (age, diabetes) and ACS. As expected, the number of implanted stents is a consistent risk factors for both, early and late TLF.