Comparison of the Coronary Vasomotor Response Associated With a Zotarolimus- vs. Sirolimus-Eluting Stent - Comparison of the Coronary Vasomotor Response Associated With a Zotarolimus- vs. Sirolimus-Eluting Stent

Description:

The goal of the trial was to evaluate coronary vasomotor response with the zotarolimus-eluting stent (ZES) compared with the sirolimus-eluting stent (SES) or a bare-metal stent (BMS).

Hypothesis:

A ZES would be associated with less endothelial dysfunction.

Study Design

  • Randomized
  • Blinded
  • Parallel

Patients Screened: 55
Patients Enrolled: 50
Mean Follow Up: 6 months
Mean Patient Age: 60 years
Female: 48%
Mean Ejection Fraction: 51%

Patient Populations:

  • Patients with stable coronary artery disease undergoing stent implantation to the left anterior descending artery

Exclusions:

  • Presence of a coronary stenosis ≥50% in a nonculprit vessel
  • Coronary vasoconstriction ≥50% in response to acetylcholine in the preintervention test
  • History of acute coronary syndrome or coronary vasospasm
  • Left ventricular ejection fraction ≤30%
  • In-stent restenosis
  • Reference vessel diameter <2.5 mm

Primary Endpoints:

  • Vasoconstriction response to acetylcholine at 6-month follow-up

Drug/Procedures Used:

Patients with stable coronary artery disease undergoing stent implantation to the left anterior descending artery were randomized to a ZES (n = 20), SES (n = 20), or BMS (n = 10).

Concomitant Medications:

Any medications that could affect vasomotor function (long-acting nitrates, beta-blockers, or calcium-channel blockers) were withheld for 72 hours prior to catheterization.

Endothelial function was determined by measuring vasoreactivity of the left anterior descending artery at preintervention and at 6-month follow-up, after infusing increasing concentrations of acetylcholine through the guiding catheter.

At 6-month follow-up, the use of statin medication was 89%, and angiotensin-converting enzyme inhibitor/angiotensin-receptor blocker was 30%.

Principal Findings:

Overall, 50 patients were randomized. There was no difference in baseline characteristics between the groups. In the ZES group, the mean age was 60 years, 48% were women, mean left ventricular ejection fraction was 51%, and diabetes was 21%.

The mean stent length was 24.7 mm with ZES, 27.0 mm with SES, and 21.4 mm with BMS. The reference vessel diameter was 3.2 mm, 3.2 mm, and 3.1 mm, respectively.

In the segment proximal to the stent, the percent diameter change, to the highest concentration of acetylcholine, was -12.7 with ZES (p < 0.05 vs. BMS), -22.8 with SES (p < 0.001 vs. BMS), and -8.99 with BMS.

In the segment distal to the stent, the percent diameter change was -37.7 with ZES (p < 0.05 vs. BMS), -69.9 with SES (p < 0.001 vs. BMS), and -13.2 with BMS.

Interpretation:

Among patients who underwent elective stent implantation to the left anterior descending artery, SES displayed the most vasoconstriction at 6 months, followed by ZES, whereas the least was seen with BMS. This effect was more pronounced in the segments distal to the stents than the proximal segments.

Although differences are emerging regarding late loss and revascularization procedures between ZES and SES, at present, the safety profile of these drug-eluting stents appears to be similar to each other.

Limitations of the study include the small sample size and that it was conducted entirely in Asians, who may have more vasoconstriction than other ethnic groups.

References:

Kim JW, Seo HS, Park JH, et al. A prospective, randomized, 6-month comparison of the coronary vasomotor response associated with a zotarolimus- versus a sirolimus-eluting stent: differential recovery of coronary endothelial dysfunction. J Am Coll Cardiol 2009;53:1653-9.

Clinical Topics: Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Stable Ischemic Heart Disease, Atherosclerotic Disease (CAD/PAD), Interventions and Coronary Artery Disease, Chronic Angina

Keywords: Ethnic Groups, Coronary Artery Disease, Angina, Stable, Metals, Drug-Eluting Stents, Stroke Volume, Sirolimus, Vasoconstriction, Diabetes Mellitus, Stents


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