The prognosis of acute myocardial infarction due to stent thrombosis after 2nd generation drug eluting stents era (comparative study with acute myocardial infarction due to plaque rupture or erosion)
Authors: Kirii Y , Kurita T , Mori H , Ito H , Ishiyama M , Takasaki A , Dohi K 
Published: October 2024

Abstract

Backgrounds
Stent thrombosis (ST) is a rare complication after percutaneous coronary intervention (PCI), and more than 70% of ST cases result in acute myocardial infarction (AMI). Although a new generation of drug-eluting stents (DES) and newer antiplatelet therapies have been shown to reduce the incidence of ST, ST-related AMI continues to be observed in contemporary practice. The prevalence and prognosis of ST results in AMI have not been well evaluated after the 2nd generation DES (G2-DES) era.

Purpose
The purpose of this study was to evaluate the prevalence and prognosis of AMI due to ST after the G2-DES era compared with AMI due to plaque rupture or erosion.

Methods
Among 6601 AMI patients enrolled in the Mie ACS registry from January 2013 to November 2022, 6273 AMI patients with AMI due to ST(ST) and AMI due to plaque rupture and erosion (AMI:P) were included for this analysis after excluding other types of AMI. ST was confirmed by angiography. The primary endpoint was defined as all-cause mortality, and revascularization after PCI for AMI was also evaluated.

Results
Seventy-eight patients, or 1.2% of all AMI in this study, had AMI due to ST, including early ST n=13 (16.7%), late ST n=4 (5.1%), and very late ST n=61 (78.2%). Stent types were G2-DES n=35 (44%), G1-DES n=18 (23.1%), bare metal stent (BMS) n=12 (15.4%), and unknown n=13 (16.7%). According to the KM survival curve, the 30-day mortality rate of ST was 2.6%, while the AMI:P rate was 6.7%, which was not statistically significant, but the ST was half the mortality rate. Furthermore, in the landmark analysis, the 2-year mortality rates were 6.2% for ST and 7.0% for AMI:P (P=0.66, Figure 1). ST was not an independent predictor of poor prognosis by multivariate Cox regression analysis. Even after the propensity score matching analysis as a sensitivity analysis, ST was not an independent predictor of poor prognosis in AMI patients. Among ST patients, 82.2% were treated with balloon angioplasty (without additional stenting) at the time of AMI, whereas 9.7% of AMI:P patients were treated with balloon angioplasty (P&lt;0.001). Compared to patients with AMI:P, patients with ST had a higher incidence of revascularization after PCI for AMI within 2 years (21.8% vs. 11.2%; P=0.02, Figure 2A). Multivariate Cox regression analysis also showed that ST was an independent predictor of revascularization after PCI for AMI with a hazard ratio of 2.00 (P&lt;0.01, Figure 2B).

Conclusion
The prognosis of ST patients tended to be better than that of AMI:P patients. The proportion of ST in AMI has decreased in the G2-DES era, and the higher proportion of VLST in ST suggests that its prognosis may be better than that of AMI:P . However, the rate of revascularization is higher in ST patients because stenting was not performed in the acute phase of PCI for AMI, and the appropriate use of stents depending on the type of ST may lead to a reduction in revascularization.Figure1Figure2