ISAR-CABG: DES Superior to BMS in Saphenous Vein Graft Lesions

NEW ORLEANS, LA—In high-risk saphenous vein graft (SVG) lesions, drug-eluting stents (DES) cut target lesion revascularization (TLR) rates almost in half, leading to an overall decrease in late outcomes, according to results from the ISAR-CABG study, the largest randomized trial to compare the 2 stent types in SVG disease. The findings were presented during a late-breaking trial session at the annual American College of Cardiology Scientific Session/i2 Summit on April 4, 2011.

For ISAR-CABG (Is drug-eluting Stenting Associated with improved Results in Coronary Artery Bypass Grafts?), researchers led by Julinda Mehilli, MD, of Deutsches Herzzentrum (Munich, Germany), randomized 610 patients with de novo SVG lesions to treatment with DES (n = 303) or BMS (n = 307) at 4 German centers. DES used in the study included sirolimus-eluting stents (permanent-polymer and bioabsorbable-polymer) and paclitaxel-eluting stents.

After PCI, TIMI 3 flow was at least 90% in both groups, up from roughly 74% at baseline. At 30 days, MACE (composite of all-cause death, cardiac death, and MI) was lower with DES (2.6% vs. 5.9%; P = 0.05), due primarily to a trend for fewer MIs (2.0% vs. 4.6%; P = 0.07). All-cause death and cardiac death were similar.

At 1 year, the primary composite endpoint of death, MI, and TLR showed a 35% relative risk reduction with DES, due solely to a TLR rate that was almost cut in half. The other component endpoints, as well as stent thrombosis, were all similar, while TVR was reduced with DES (table 1).

Table 1. One-Year Outcomes

 

DES
(n = 303)

BMS
(n = 307)

P Value

Death/MI/TLR

15.4%

22.1%

0.03

Death

5.2%

4.7%

0.82

MI

4.2%

6.0%

0.27

TLR

7.2%

13.1%

0.02

TVR

11.5%

17.8%

0.03

Definite/Probable Stent Thrombosis

0.7%

0.7%

0.99


“Out to 12 months, drug-eluting stents are superior to bare-metal stents in this large study powered for clinical endpoints,” Dr. Mehilli said. “And regarding the safety parameters such as stent thrombosis, death, and MI, DES were comparable to bare-metal stents.”

Dr. Mehilli explained that previous trials comparing DES and BMS for SVG disease were smaller and contradictory, thus necessitating a larger, more definitive trial to address the issue.

Commenting on the trial, panel member Steven R. Bailey, MD, of the University of Texas Health Science Center (San Antonio, TX), expressed amazement at the excellent TIMI 3 flow rates achieved in the trial considering the extremely low use of embolic protection.

“We don’t use embolic protection routinely now,” Dr. Mehilli acknowledged. “It was used in less than 5% of patients.” She added that the MACE rates achieved in ISAR-CABG are actually lower than in previous studies that used protection devices.

Study Details

SVG degeneration greater than 75% was present in about 18% of patients, with 20% of patients having 50 to 75% degeneration, 26% having 25 to 50% degeneration, and 35% having degeneration under 25%. Lesions within the SVG were distal in about 15% of patients, medial in 27%, proximal in 24%, coronary in 11%, aortal in 17%, and diffuse in 5%.

Clopidogrel was continued for at least 6 months after PCI in all patients, with aspirin continued indefinitely. Almost all patients had multivessel disease, and just under two-thirds had stable angina. The average age was 71 years.

 


Source:
Mehilli J. ISAR-CABG: Randomized, superiority trial of drug-eluting stent and bare-metal stent in saphenous vein graft lesions. Presented at: American College of Cardiology Scientific Session/i2 Summit; April 4, 2011; New Orleans, LA.

 

Disclosures:

  • Dr. Mehilli reports receiving lecture fees from Abbott Vascular.

 

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