Predisposing factors leading to subacute stent thrombosis (SAT) in patients who have undergone percutaneous coronary intervention (PCI) in patients presenting with acute coronary syndrome

Background: Stent thrombosis is less common but life-threatening that in most cases leads to death or a big non-fatal ST-elevation myocardial infarction (STEMI). Past research data suggests multiple predisposing factors play role in sub-acute thrombosis (usually with ST elevation). However, very few studies have been conducted regarding the predisposing factors of subacute stent thrombosis (SST) in Pakistan, and hence, there is very limited knowledge regarding the trend of risk factors associated with SST. Objective: This study will determine the predisposing factors that lead to subacute stent thrombosis in patients with the acute coronary syndrome who have undergone PCI. Methodology: Retrospective demographical and angiographical data of the patients who have undergone PCI and also were presented with ACS was gathered from the hospital registry. All the data were analyzed using SPSS and were presented as mean ± SD and percentages for continuous and categorical variables, respectively. Univariate and multivariate analysis was carried out to analyze the subacute stent thrombosis predictors. Results: The occurrence of subacute stent thrombosis was found to be 4..9 %. A significant higher number of patients who have developed subacute stent thrombosis were male (81.4 %, p = 0.037), suffered from diabetes mellitus (48.1 %, p = 0.034), had hypertension (59.2 %. P = 0.016), with pre-procedural decreased left ventricular ejection fraction (LVEF) (36.11?±?6.86, p < 0.001) and Killip Class (p < 0.001). Significantly higher odds were observed among patients with diabetes (2.13 [1.01–4.34]), hypertension (2.33 [1.17–4.86]), and the Killip Class III or IV patients (6.4 [2.35–17.41]). The single independent predictor of the subacute stent thrombosis was found to be Killip Class III-IV with an adjusted ratio of 5.1 [1.81–15.32]. Conclusion: Subacute stent thrombosis in patients who have undergone PCI for acute myocardial infarction is not as infrequent as demonstrated by the previous studies accruing with a frequency of 4.9 % with a death rate of 7 % in the patients with SST. Diabetes and hypertension were observed to be associated and served as risk factors for the development of SST. Killip class III-IV was demonstrated to be the single independent predictor of subacute stent thrombosis.