Clinical Outcomes of Polymer-Free Versus Polymer-Coated Drug-Eluting Stents in Patients With Coronary Artery Disease: A Systematic Review and Meta-Analysis

Abstract

Drug-eluting stents have transformed the treatment of coronary artery disease (CAD), and there are two types: polymer-free and polymer-coated stents. Polymer-free stents have a coating that is quickly absorbed by the body, whereas polymer-coated stents have a coating that remains on the stent surface. This meta-analysis and systematic review aimed to compare the clinical outcomes of these two stent types in patients with coronary artery disease. The literature and abstracts from significant databases were reviewed to compare polymer-free drug-eluting stents (PF-DES) and polymer-coated drug-eluting stents (PC-DES) for the treatment of coronary artery disease (CAD). The primary efficacy endpoints of the study were all-cause mortality and deaths from cardiovascular and non-cardiovascular causes. Among the secondary outcomes were incidences of myocardial infarction (MI), target lesion revascularization (TLR), target vessel revascularization (TVR), stent thrombosis, stroke, and major adverse cardiovascular events (MACEs). In terms of the primary outcomes, the combined analysis revealed a marginally lower risk of all-cause mortality (relative risk, RR (95% CI) = 0.92 (0.85, 1.00), p = 0.05, I² = 0%) with the use of PF-DES versus PC-DES. Nonetheless, there was no significant difference in cardiovascular mortality (RR (95% CI) = 0.97 (0.87, 1.08)) or non-cardiovascular mortality (RR (95% CI) = 0.87 (0.69, 1.10), p = 0.25, I² = 9%) between the groups. Furthermore, univariate meta-regression revealed that male gender and prior myocardial infarction were independently associated with an increased risk of all-cause mortality and cardiovascular disease. According to the current meta-analysis, no statistically significant differences existed in PF-DES and PC-DES outcomes. More extensive research is needed to investigate these findings further and establish their validity.

Keywords: cad; coronary artery disease; drug-eluting stent; meta-analysis; pc-des; pf-des; polymer coated; polymer-free; systematic review.

Figure 1. PRISMA flow chart.

PRISMA: preferred reporting items for systematic review and meta-analysis.

Figure 2. Cochrane risk of bias tool for assessing publication bias in randomized controlled trials.

Figure 3. Funnel plot of (a) death from all causes, (b) cardiovascular death.

SE: standard error, RR: relative risk.

Figure 4. Funnel plot of non-cardiovascular death.

SE: standard error; RR: relative risk.

Figure 5. Forest plot of death from all causes.

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19-28,30-41].

Figure 6. Forest plot of non-cardiovascular death.

RR: relative risk, CI; confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19,20,23-27,31,35,36,38].

Figure 7. Forest plot of cardiovascular death.

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19-38,40].

Figure 8. Forest plot showing the rate of myocardial infarction (MI).

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19-41].

Figure 9. Forest plot showing the rate of stent thrombosis.

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19-41].

Figure 10. Forest plot showing target lesion revascularization (TLR).

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19-31,33,35-41].

Figure 11. Forest plot showing target vessel revascularization (TVR).

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19,20,22,24,26,27,29-36,38-41].

Figure 12. Forest plot showing major adverse cardiovascular events (MACEs).

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [19,20,22,23,26,27,31-36,39-41].

Figure 13. Forest plot showing the rate of stroke.

RR: relative risk, CI: confidence interval, PF-DES: polymer-free drug-eluting stent, PC-DES: polymer-coated drug-eluting stent. Sources: References [27,28,33,35,37,38,41].