Zotarolimus-Eluting Stent vs. Sirolimus-Eluting Stent vs. Paclitaxel-Eluting Stent for Acute Myocardial Infarction Patients - ZEST-AMI — Presented at TCT 2008

Description:

A number of studies have demonstrated the superiority of sirolimus-eluting (SES) or paclitaxel-eluting stents (PES) over bare-metal stents (BMS) in patients presenting with ST-elevation myocardial infarction (STEMI). This trial sought to compare the safety and efficacy of zotarolimus-eluting stents (ZES) with SES and PES in patients presenting with STEMI.

Hypothesis:

ZES would be similar in efficacy to SES and PES in patients with STEMI.

Study Design

Study Design:

Patients Enrolled: 328
Mean Follow Up: 1 year
Mean Patient Age: 60 years
Female: 18
Mean Ejection Fraction: 51%

Patient Populations:

  • Patients with first STEMI requiring primary angioplasty with symptom onset ≤12 hours

Exclusions:

  • Previous administration of fibrinolytic agents
  • Previously documented left ventricular ejection fraction <30%
  • Previous MI
  • Concomitant left main disease
  • Cardiogenic shock
  • Estimated life expectancy of <12 months

Primary Endpoints:

  • Incidence of MACE, defined as death, MI, or ischemia-driven TVR at 1 year

Secondary Endpoints:

  • Mortality at 1 year
  • Recurrent MI at 1 year
  • Stent thrombosis at 1 year
  • Ischemia-driven TVR at 1 year
  • Binary restenosis at 8 months
  • In-segment late loss at 8 months

Drug/Procedures Used:

Randomization to ZES, PES, or SES in a 1:1:1 fashion

Concomitant Medications:

Abciximab (20%), beta-blockers (74.4%), statins (86%), angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers (ACEI/ARB) (75.6%)

Principal Findings:

A total of 328 patients were randomized, 108 to ZES, 110 to SES, and 110 to PES. Baseline characteristics were fairly similar between the three groups, except age, which was lower in the PES arm, and ACEI/ARB use, which was also less frequent in the PES arm. About 26% of the patients had diabetes, and about 46% of the patients presented with an anterior MI.

The median duration of symptoms prior to percutaneous coronary intervention (PCI) was about 4.8 hours. Multivessel disease was noted in about 45% of the patients, with a mean number of 1.2 stents per patient. Multivessel PCI was done in about 18% of the patients. Mechanical thrombectomy was performed in only about 5% of the patients. About 69% of the patients had TIMI 0 or 1 flow on presentation, whereas 86% had TIMI 3 flow post-PCI. The mean reference vessel diameter was 2.9 mm.

There was no difference in the incidence of major adverse cardiac events (MACE) between the ZES, SES, and PES arms (11.1% vs. 9.1% vs. 9.1%, p = 0.83). Similarly, ischemia-driven target vessel revascularization (TVR) was similar (8.3% vs. 5.5% vs. 7.3%, p = 0.74). Stent thrombosis (0% vs. 3.6% vs. 2.7%, p = 0.17), death (2.8% vs. 3.6% vs. 0%, p = 0.14), and MI (0% vs. 1.8% vs. 0%, p = 0.11) at 12 months were similar as well.

Angiographic follow-up data were available for about 225 patients. In-stent late loss was significantly lower with SES (0.3 mm) compared with ZES (0.73 mm) and PES (0.52 mm) (p < 0.001). This translated into a significantly lower incidence of in-stent restenosis with SES compared with ZES and PES (1.4% vs. 15.9% vs. 9.6%, p = 0.009).

Interpretation:

The results of the ZEST-AMI trial indicate that there is no difference in clinical outcomes at 12 months between ZES, PES, and SES in patients with STEMI, but SES are associated with a significantly lower incidence of in-stent restenosis at 8 months compared with ZES and PES.

Although the investigators infer that ZES are thus similar to SES and PES, this was, strictly speaking, not a non-inferiority trial. One significant limitation is that although this trial aimed for, and was powered for, 1,482 patients, only 328 patients could be enrolled.

References:

Presented by Dr. Cheol-Hwan Lee at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2008), Washington, DC, October 2008.

Clinical Topics: Cardiac Surgery, Invasive Cardiovascular Angiography and Intervention, Aortic Surgery, Interventions and Coronary Artery Disease

Keywords: Coronary Artery Disease, Myocardial Infarction, Follow-Up Studies, Drug-Eluting Stents, Sirolimus, Angioplasty, Percutaneous Coronary Intervention, Stents, Paclitaxel, Metals, Thrombectomy, Thrombosis, Research Personnel, Diabetes Mellitus


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