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)

Anthony A. Bavry, M.D., M.P.H.; Deepak L. Bhatt, M.D., F.A.C.C.

Disclosures

Cardiosource 

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.

Drugs/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.

Conditions

  • Coronary heart disease / Angina pectoris / Stable

  • Arteriosclerosis

Therapies

  • Stent/drug-eluting

  • Stent

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%

Primary Endpoints

Vasoconstriction response to acetylcholine at 6-month follow-up

Patient Population

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

Comments

3090D553-9492-4563-8681-AD288FA52ACE

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