Effectiveness and safety of paclitaxel-eluting stents in patients with ST-segment elevation acute myocardial infarction

Percutaneous treatment in acute coronary syndromes

Both ST-segment elevation myocardial infarction and non-ST-segment elevation acute coronary syndromes (ACS) are the result of an acute thrombotic lesion obstructing blood flow in the coronary vasculature. Percutaneous treatment has shown to improve clinical outcome in this clinical setting by resolving coronary obstruction with different devices directed to restore coronary blood flow. In comparison with balloon alone angioplasty, implantation of bare metal stents reduced the rate of restenosis and cardiac events, but high rates of restenosis remained, leading to further investigations to develop drug-eluting stents with different pharmacological coatings that reduced restenosis rates and clinical events. In this review, we discuss the current treatment of ACS, reviewing recent randomized clinical trials and advances in medical treatment, including new antiplatelet agents and recent guideline recommendations.

A meta-analysis of randomized trials on clinical outcomes of paclitaxel-eluting stents versus bare-metal stents in ST-segment elevation myocardial infarction patients

A meta-analysis was performed to address the efficacy and safety of paclitaxel-eluting stent (PES) in ST-segment elevation myocardial infarction (STEMI) patients. A systematic literature search was conducted to identify all randomized clinical trials in mortality, recurrent myocardial infarction (rMI), repeat revascularization (RR), and stent thrombosis (ST). A total of 4190 STEMI patients were enrolled in six randomized trials comparing PES with bare-metal stent (BMS). The pooled repeat revascularization rate was 5.7% in PES group, significantly lower than 10.0% in BMS group with an odds ratio (OR) of 0.56, 95% confidence interval (CI) [0.44, 0.72] (P<0.00001). No significant difference was found between PES and BMS groups in mortality at one year after the indexing procedure (3.9% vs. 5.1%, OR 0.88, 95% CI [0.63, 1.21], P=0.42). Similarly, rMI rate did not differ significantly between the two groups (3.4% vs. 4.1%, OR 0.80, 95% CI [0.56, 1.13], P=0.21). PES was also associated with the comparable pooled rate of definite stent thrombosis with BMS (2.3% vs. 2.4%, OR 0.81, 95% CI [0.52, 1.26], P=0.35). The results show that PES improved clinical outcomes in STEMI patients with a decreased need for repeat revascularization and no concerns for safety.

Determining clinical benefits of drug-eluting coronary stents according to the population risk profile: a meta-regression from 31 randomized trials

BACKGROUND

The use of drug-eluting stents (DES) in unfavourable patients has been associated with higher rates of clinical complications and stent thrombosis, and because of that concerns about the use of DES in high-risk settings have been raised.

OBJECTIVE

This study sought to demonstrate that the clinical benefit of DES increases as the risk profile of the patients increases.

METHODS

A meta-regression analysis from 31 randomized trials that compared DES and bare-metal stents, including overall 12,035 patients, was performed. The relationship between the clinical benefit of using DES (number of patients to treat [NNT] to prevent one episode of target lesion revascularization [TLR]), and the risk profile of the population (rate of TLR in patients allocated to bare-metal stents) in each trial was evaluated.

RESULTS

The clinical benefit of DES increased as the risk profile of each study population increased: NNT for TLR=31.1-1.2 (TLR for bare-metal stents); p<0.001. The use of DES was safe regardless of the risk profile of each study population, since the effect of DES in mortality, myocardial infarction, and stent thrombosis, was not adversely affected by the risk profile of each study population (95% confidence interval for β value 0.09 to 0.11, -0.12 to 0.19, and -0.03 to-0.15 for mortality, myocardial infarction, and stent thrombosis, respectively).

CONCLUSIONS

The clinical benefit of DES increases as the risk profile of the patients increases, without affecting safety.

Two-year follow-up after percutaneous coronary intervention with titanium-nitride-oxide-coated stents versus paclitaxel-eluting stents in acute myocardial infarction

BACKGROUND AND AIMS

The aim of this study was to evaluate the long-term effects of the titanium-nitride-oxide-coated (TITANOX) stent and the paclitaxel-eluting stent (PES) in patients who had undergone a percutaneous coronary intervention for acute myocardial infarction (MI).

METHODS AND RESULTS

The TITAX-AMI trial randomly assigned 425 patients with MI to receive either a TITANOX stent or a PES. The primary end-point was a composite of MI, target lesion revascularization, or death from cardiac causes. At 12 months, there was no significant difference between patients receiving TITANOX stent or PES in the rate of primary end-point (10.3% versus 12.8%, P=0.5). After 2 years of follow-up, a significantly lower rate of primary end-point was observed in the TITANOX stent group compared with the PES group (11.2% versus 21.8%, HR 2.2, 95% confidence interval (CI) 1.3-3.8, P=0.004). This difference was driven by a reduced rate of MI (5.1% versus 15.6%, P<0.001) and cardiac death (0.9% versus 4.7%, P=0.02) in favour of the TITANOX stent. Definite stent thrombosis occurred in 0.5% and 6.2% of the patients (P=0.001), respectively.

CONCLUSIONS

The implantation of a TITANOX stent resulted in better clinical outcome compared with a PES during 2 years of follow-up among patients treated for acute MI.

Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

Background— Primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction with bare metal stents (BMS) is well established, while randomized trials suggest equivalent safety and reduced repeat revascularization with drug-eluting stents (DES) in this setting. However, long-term data on DES in PPCI is lacking, especially in those ineligible for inclusion in randomized trials. Our aim was to investigate the long-term outcomes of unselected patients undergoing PPCI with BMS and DES.

Methods and Results— We analyzed all patients (n=1738) undergoing PPCI for a de novo lesion in our institution from 2000 to 2005. Patients from 3 sequential consecutive cohorts of BMS (n=531), sirolimus-eluting (SES, n=185) or paclitaxel-eluting stents (PES, n=1022) were included. The median duration of follow-up was 1185 days (interquartile range, 746 to 1675). There were no differences in all-cause mortality or repeat revascularization between DES and BMS, although there was a nonsignificant trend toward improved survival with SES compared with both BMS (propensity score-adjusted hazard ratio, 0.63; [95%CI, 0.33 to 1.18]) and PES (hazard ratio, 0.71; [95% CI, 0.40 to 1.26]). SES were associated with lower rates of the composite end point of all-cause death, nonfatal myocardial infarction, or target vessel revascularization (hazard ratio, 0.62; 95%CI, 0.40 to 0.96) when compared with PES. Very late stent thrombosis only occurred in the DES groups.

Conclusions— Although DES are not associated with an increase in adverse events compared with BMS when used for PPCI, neither DES reduced repeat revascularizations. Appropriately powered randomized trials with hard clinical end points and an “all-comer” design are required to further assess the benefit of DES in PPCI.