The Study of Factors Associated with Severity of In-Stent Restenosis in Patients Treated with PCI for Acute Coronary Syndromes

Introduction: The management of in stent restenosis represents a topic of great actuality and interest, especially since the interventional treatment with stent implantation became largely accepted as the metod of choice in patients with acute coronary syndromes. Identification of certain risk factors that could predict the development of an in stent restenosis and its severity could be extremely useful for the clinical management of these patients.
Methods: We retrospectively analyzed a total of 60 stent restenoses encountered in 57 patients admitted and treated in the Cardiology Clinic of Tirgu Mures. The interval of occurrence of restenosis ranged between 2 months and 37 months postintervention. We monitored the demographic characteristics (age, gender, colesterol, presence of renal insufficiency) and we realized a descriptive qualitative analysis of the angiographic procedural aspects. The in stent restenosis occurred most frequently on left anterior descending artery (63%), followed by the circumflex artery (22.15%) and right coronary artery (14.8%), regardless of the degree of stenosis prior to revascularization.
Results: Statistical analysis using Chi square test revealed no statistically significant differences in terms of the correlation between the incidence of restenosis and gender (p=0.14), treatment with ACE inhibitors (p=0.16), implanted stent diameter (p=0.22) or the type of procedure (ram crossing over a secondary branch being considered as a procedure involved in the genesis of severe restenosis) (p=0.02). We used the t-student test for comparative analysis of the correlation between the continuous variables related to initial native lesion diameter and the degree of restenosis, without finding any a statistically significant correlation between them (p=0.226). However, a statistically significant correlation was found between cholesterol levels and the degree of stenosis (p=0.039). Descriptive analysis of restenosis lesions did not find any statistically significant correlation with the type or degree of stenosis in the native vessel, but showed statistically significant differences when evaluating the geometric assumption of restenosis by intraluminal diameter or intraluminal area (p=0.0018), suggesting that assessment of the degree of restenosis should be performed only by planimetric area.
Conclusions: We can conclude that in stent restenosis represents a plurifactorial phenomenon, that is not conditioned by the severity of the native lesion or by the administration of ACE inhibitors or Spironolactone, however it depends directly on the control of cholesterol values afther the coronary revascularization.