Assessment of the safety and effectiveness of the first sirolimus stent manufactured in Viet Nam

Abstract

Objectives: To evaluate the effectiveness and safety of the first sirolimus-eluting stent made in Vietnam (Xplosion stent) on Vietnamese patients via the following outcomes: restenosis rate in the stent and at the two heads of stent, stent occlusion rate, and mortality rate due to myocardial infarction at 6 months and 12 months following stent placement.

Methods and Results: The prospective, open-label, non-randomized, longitudinal study enrolled 43 patients diagnosed with stable angina and de novo lesions with a 2.5 – 3.5 mm reference diameter and 24 mm in length. The patients received one stent per branch, and some received stents in multiple branches. All patients were scheduled for angiographic follow-up at 6 months, and if subjects consented, at 12 months. The subjects' mean age was 60.05 +/- 11.07 years, and many had cardiovascular risk factors, such as hypertension (83.72%), dyslipidemia (53.49%), and diabetes mellitus (25.58%). Stenting was performed on 50 lesions with a sirolimus drug-eluting stent (1.16 stent/patient on average). Of the patients, 92% had single-vessel coronary artery disease, and type B lesions (AHA) accounted for the majority (56%), with distribution on the LAD (42%), LCx (24%), and RCA (34%). The technical and procedural success rate of stent placement was 97.67%, with a very low complication rate (0%). The restenosis rate at 6 months was 0%. All patients were followed up to 12 months. Only two patients had recurrent chest pain and underwent coronary angiography; however, there was no in-stent restenosis and no need for revascularization. Therefore, the rate of chest pain recurrence after 12 months was 4.65% (2/43), and the rate of target vessel revascularization at 12 months was 0%. At 6- and 12-month follow-up, we observed no death due to unknown causes, no target-vessel myocardial infarction, and two clinically-driven re-angiographies with no need for revascularization. No additional events were reported beyond the 6-month follow-up. During the entire 12-month follow-up period, none of the patients experienced a definite or probable stent thrombosis.

Conclusion: The new sirolimus-eluting stents manufactured in Vietnam use a new technology transferred from the United States. They were placed successfully and showed a sustained favorable safety profile for up to 12 months. These findings suggest that these new stents could be used in many catheterization laboratories in Viet Nam.