Intracoronary Stenting and Angiographic Results: Drug-Eluting Stents for Unprotected Coronary Left Main Lesions - ISAR-LEFT MAIN
Recent literature suggests that drug-eluting stents are superior to bare-metal stents in patients undergoing unprotected left main (LM) stenting. The current trial sought to compare sirolimus-eluting (SES) and paclitaxel-eluting stents (PES) in patients undergoing unprotected LM stenting.
PES would be noninferior to SES in patients undergoing unprotected LM stenting.
Patients Screened: 694
Patients Enrolled: 607
Mean Follow Up: 1 year
Mean Patient Age: 69 years
Mean Ejection Fraction: 54%
Patients with ischemic symptoms or evidence of myocardial ischemia in the presence of ≥50% stenosis located in unprotected LM lesions
- Age <18 years
- Cardiogenic shock
- ST-elevation acute MI within 48 hours of symptom onset
- In-stent restenosis
- Prior coronary artery bypass surgery
- LM size >4.5 mm by visual estimation
- Malignancies with life expectancy <1 year
- Planned staged percutaneous coronary intervention (PCI) within 30 days from index PCI
- Planned elective surgical procedure necessitating discontinuation of clopidogrel during the first 6 months
Incidence of MACE, defined as death, MI, or need for target lesion revascularization at 1 year
Angiographic restenosis at 6- and 9-month follow-up angiogram
LM stenting with either PES or SES. Use of two stents in “culotte” with final kissing balloon inflation was the preferred technique for distal bifurcation lesions.
All patients received clopidogrel 600 mg at least 2 hours before the procedure, in addition to 500 mg of intravenous aspirin. In addition, all patients received clopidogrel (150 mg/day for the first 3 days, 75 mg/day thereafter) and aspirin 200 mg/day indefinitely. Patients also received heparin and glycoprotein IIb/IIIa inhibitors (10%) or bivalirudin (15%). Other medications included statins (95%) and beta-blockers (98%).
A total of 607 patients were randomized, 302 to PES, and 305 to SES. Baseline characteristics were fairly similar between the two groups. About 29% of the patients were diabetic, 42% presented with an acute coronary syndrome, and about 73% of the patients had evidence of three-vessel disease. Trifurcation morphology was present in about 25% of the patients. The mean LM size was about 3.8 mm. The majority of LM lesions were distal (63%), whereas about 12% were ostial LM lesions. The mean EuroSCORE was 4.6.
About one-half of the patients received a single stent, whereas Culotte stenting was employed in most of the other patients; T-stenting was employed in only about 1.5% of the patients. An intra-aortic balloon pump was necessary in only 1% of the patients. Intravascular ultrasound (IVUS) was not used in this study.
The use of PES was noninferior compared with SES in the incidence of major adverse cardiac events (MACE) at 1 year (13.6% vs. 15.8%, relative risk [RR] 0.85, 95% confidence interval [CI] 0.56-1.29; p for noninferiority < 0.001). The incidence of death (5.0% vs. 6.6%), myocardial infarction (MI) (5.0% vs. 4.6%), and stroke (1.7% vs. 1.0%) at 1 year was similar between the two arms. Angiographic restenosis was similar between the two arms at 6-9 months as well (16.0% vs. 19.4%, p = 0.3).
Two-year target lesion revascularization rates were similar as well (9.2% vs. 10.7%, p = 0.47). The incidence of definite (0.3% vs. 0.7%, p = 0.57) and probable (0% vs. 0.3%, p = 0.32) stent thrombosis at 2 years was also similar between the two arms. Thirty-day outcomes were also similar between the two arms. Results for the main outcome were similar in diabetic patients.
The results of this trial confirm the safety of drug-eluting stent PCI in treating unprotected LM lesions, and indicate that PES are noninferior to SES for this indication. The incidence of 2-year stent thrombosis was about 0.5-1.0% (all events occurred before 30 days), although all patients were on dual antiplatelet therapy indefinitely. Further long-term data are necessary.
Mehilli J, Kastrati A, Byrne RA, et al., on behalf of the ISAR-LEFT MAIN (Intracoronary Stenting and Angiographic Results: Drug-Eluting Stents for
Unprotected Coronary Left Main Lesions) Study Investigators. Paclitaxel- versus sirolimus-eluting stents for unprotected left main coronary artery disease. J Am Coll Cardiol 2009;Feb 25:[Epub ahead of print].
Presented by Dr. Julinda Mehili at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2008), Washington, DC, October 2008.
Keywords: Paclitaxel, Risk, Myocardial Infarction, Stroke, Coronary Restenosis, Thrombosis, Drug-Eluting Stents, Constriction, Pathologic, Confidence Intervals, Sirolimus, Angioplasty, Balloon, Coronary, Diabetes Mellitus
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