1.Definite stent thrombosis among Malaysian population: predictors and insights of mechanisms from intracoronary imaging
Lim Kien Chien ; Yap Lok Bin ; Amin Ariff Nuruddin
The Medical Journal of Malaysia 2020;75(5):472-478
Introduction: Stent thrombosis (ST) is an uncommon, but
significant complication following angioplasty. We aimed to
examine the predictors, clinical outcomes and mechanism
of definite ST cases among patients who underwent
percutaneous coronary intervention (PCI).
Methods: This was a retrospective observational registry of
14,935 patients from the year 2011 till 2015. Clinical
characteristics, clinical outcome and intracoronary imaging
data were recorded in all the patients. The SPSS Statistic
version 24 was used for statistical analysis. The Cox
regression hazard model was used to report calculate the
hazard ratio (HR) with a 95% confidence interval (95%CI).
Independent predictors of ST were identified by univariate
logistic regression analysis. Variables that showed a
statistically significant effect in univariate analyses were
entered in a multivariate Cox proportional hazards model. A
p-value<0.05 was regarded as significant.
Results: The incidence of definite ST was 0.25% (37 out of
14935 patients). 75% of ST group patients presented with ST
elevation myocardial infarction (75% vs. 19.8%, p<0.01).
There was higher mortality among patients with ST when
compared to the group without ST (Hazard Ratio, HR=10.69,
95%CI: 1.13, 100). Two independent predictors of ST were 1)
previous history of acute myocardial infarction (HR=2.36,
95%CI: 1.19, 4.70) and 2) PCI in the context of acute coronary
syndrome when compared to elective PCI (HR=37, 95%CI:
15.7, 91.5). Examination of 19 ST cases with intracoronary
imaging identified nine cases (47%) of underexpanded
stents and five cases (26%) of malopposition of stents.
Conclusions: ST is associated with high mortality. PCI in
acute coronary syndrome setting and a previous history of
acute myocardial infarction were significant predictors for
ST. Intracoronary imaging identified stent underexpansion
and malopposition as common reasons for ST. In cases
where the risk of ST is high, the use of intracoronary
imaging guided PCI is recommended.