Comparison of Efficacy and Safety between First- and Second-Generation Drug-Eluting Stents in Patients with Acute Coronary Syndrome.

BACKGROUND

It remains undetermined whether second-generation drug-eluting stents (G2-DESs) outperform first-generation DESs (G1-DESs) in patients with acute coronary syndrome (ACS). We aimed to compare the efficacy and safety of G1-DES and G2-DES in ACS patients in a high-volume cardiovascular center.

METHODS

In 2013, 10,724 consecutive patients underwent percutaneous coronary intervention in our institution. We included 4037 patients with ACS who underwent exclusively G1-DES or G2-DES implantation (n = 364 and n = 3673, respectively). We used propensity score matching to minimize the imbalance between the G1-DES and G2-DES groups and followed patients for 2 years. The efficacy endpoints were major adverse cardiac events (MACEs) and its components including target vessel-related myocardial infarction (TV-MI), target vessel revascularization/target lesion revascularization (TVR/TLR), and cardiac death. The safety endpoint was stent thrombosis. Continuous variables were compared by Mann-Whitney U-test, and categorical variables were compared using Pearson's Chi-square or Fisher's exact test. Kaplan-Meier curves were constructed to compare the event-free survival rates, and multivariate Cox proportional hazards regression analysis was used to assess whether stent type was an independent risk factor for the efficacy and safety endpoints.

RESULTS

At the 2-year follow-up, the results for MACE and it components, as well as stent thrombosis, were similar for G1-DES and G2-DES (MACE, 5.2% vs. 4.3%, χ = 0.514, P = 0.474; TV-MI, 0.8% vs. 0.4%, P = 0.407; TVR, 4.9% vs. 3.7%, χ = 0.939, P = 0.333; TLR, 3.8% vs. 2.5%, χ = 1.610, P = 0.205; cardiac death, 0.3% vs. 0.5%, P = 0.670; and stent thrombosis, 0.5% vs. 0.4%, P > 0.999). Kaplan-Meier analysis indicated similar event-free survival rates between G1-DES and G2-DES after propensity score matching (all: log-rank P > 0.05). Multivariate analysis demonstrated that stent type was not an independent risk factor for the efficacy and safety endpoints (MACE, hazard ratio [HR] = 0.805, 95% confidence interval [CI]: 0.455-1.424, P = 0.456; TV-MI, HR = 0.500, 95% CI: 0.101-2.475, P = 0.395; TVR, HR = 0.732, 95% CI: 0.403-1.330, P = 0.306; TLR, HR = 0.629, 95% CI: 0.313-1.264, P = 0.193; cardiac death, HR = 1.991, 95% CI: 0.223-17.814, P = 0.538; and stent thrombosis, HR = 0.746, 95% CI: 0.125-4.467, P = 0.749).

CONCLUSION

G1-DES and G2-DES have similar efficacy and safety profiles in ACS patients at the 2-year follow-up.