Abstract Body (Do not enter title and authors here): Background:
First generation drug eluting stents (DES) with thick polymers may contribute to local vascular inflammation and late stent thrombosis. Thinner-strut DES (ultrathin), particularly those with biodegradable polymers, aim to reduce this risk by minimizing flow disturbance and vascular injury. However, the long-term safety and efficacy of ultrathin biodegradable polymer sirolimus eluting stents (BP-SES) compared to durable polymer everolimus eluting stents (DP-EES) are still uncertain. Thus, we performed a meta analysis to compare outcomes of these two stents.

Methods:
Inclusion criteria comprised randomized controlled trials comparing ultrathin BP SES and thin DP EES in patients undergoing percutaneous coronary interventions with long term follow-up of at least 3 years. We excluded cohort studies, case reports, editorials, conference abstracts, and animal studies. Primary outcomes were target lesion failure (TLF), cardiac death (CD), target-vessel myocardial infarction (TV-MI), and clinically indicated target lesion revascularization (CI-TLR). We systematically searched PubMed, Cochrane CENTRAL, and Scopus. Cochrane’s ROB 2.0 tool assessed trial quality, and RevMan software (5.4) performed the meta-analysis.

Results:
Our analysis included ten RCTs, totaling 16,216 patients, with 9,108 in the BP SES group and 7,108 in the DP EES group. TLF occurred in 905 patients (9.94%) in the BP-SES group and 821 patients (11.55%) in the DP-EES group, with no statistically significant differences between the groups (RR = 0.92, 95% CI = 0.85 to 1.01, p = 0.08). Additionally, there were no significant differences in cardiac death (RR = 1.00, 95% CI = 0.84 to 1.19, p = 1.00), TV-MI (RR = 0.91, 95% CI = 0.78 to 1.05, p = 0.19), and CI-TLR (RR = 0.88, 95% CI = 0.78 to 1.01, p = 0.06) between the two groups.

Conclusion:
The use of BP-SES did not result in higher rates of TLF, CD, TV-MI, or CI-TLR compared to DP-DES. These findings suggest that both BP-SES and DP-DES are viable options for PCI procedures, with comparable long-term safety profiles. However, some trials used strut thicknesses exceeding 70µm in cases requiring wider diameters, similar to the strut thickness in the DP-EES group. This makes it challenging to assess whether, in addition to biodegradable polymers, lower strut thickness contributes to reducing target lesion-related events. Further research may be needed to explore other relevant outcomes and to confirm these findings in diverse patient populations.