Analysis of short-term and long-term clinical outcomes in patients with acute myocardial infarction after one year of coronary stent implantation

Abstract

Objective: To observe in-hospital and 1-year prognosis of patients with acute myocardial infarction after one year of coronary stent implantation. Methods: From January 2015 to February 2018, 329 patients with acute myocardial infarction (AMI) after 1 year of coronary artery stent implantation were enrolled and received coronary angiography. These patients were divided into two groups (very late stent thrombosis (VLST) group and denovo group) according to whether the occurrence of acute myocardial infarction was due to stent thrombosis (ST), and in-hospital and long-term (1 year) outcomes were compared between the two groups. The primary end points included cardiac death and recurrent acute myocardial infarction. The secondary study end points included target lesion revascularization (TLR), re-stent thrombosis, heart failure, and stroke. Results: In total, 72.9% of patients with AMI after one year of coronary stent implantation were caused by VLST. There were no significant differences of both primary and secondary end-point events between the two groups during in-hospital period (3.3% vs 3.4%, P=0.987; 5.4% vs 4.5%, P=0.956). After a mean follow-up of 1 year, there were no significant differences of the primary end-point events between the two groups. The secondary end-point events and TLR incidence were higher in the VLST group (16.3% vs 6.7%, P=0.026; 9.6% vs 2.2%, P=0.026). Kaplan and Meier survival analysis showed that there were no significant differences of the 1-year cumulative non-primary and non-secondary end-point survival rates between the two groups (P=0.124 and 0.004, respectively). COX regression analysis showed that heart function ≥Ⅲ level (Killip's) and VLST were independent predictive risk factors for end-point events, while postprocedural thrombolysis in myocardial infarction (TIMI) flow grade 3 was an independent protective factor. Conclusion: In-hospital end points show no significant differences between VLST and denovo groups patients. However, the VLST group patients have a poor prognosis and a higher proportion of TLR after 1 year follow-up. The patients with heart function ≥Ⅲ level (Killip's) or VLST have a poor prognosis, while the patients with postprocedural TIMI flow grade 3 have a good prognosis.