Long-Term Outcomes of Stenting the Proximal LAD
What are the outcomes of patients undergoing drug-eluting stent (DES) implantation according to lesion location within or outside the proximal left anterior descending (LAD) artery?
Among the 8,709 patients enrolled in PROTECT (Patient Related Outcomes With Endeavor Versus Cypher Stenting Trial), a multicenter percutaneous coronary intervention (PCI) trial, the investigators compared the outcomes of 2,534 patients (29.1%; 3,871 lesions [31.5%]) with stents implanted in the proximal LAD with 6,172 patients (70.9%; 8,419 lesions [68.5%]) with stents implanted outside the proximal LAD. For each event, a multivariate model was constructed that examined the effect of several individual baseline clinical and angiographic characteristics, including proximal LAD target lesion, on outcomes (i.e., MACE [major adverse cardiac events], target vessel failure [TVF], and myocardial infarction [MI]).
At 4-year follow-up, death rates were the same (5.8% vs. 5.8%; p > 0.999), but more MIs occurred in the proximal LAD group (6.2% vs. 4.9%; p = 0.015). The rates of clinically driven TVF (14.8% vs. 13.5%; p = 0.109), MACE (15.0% vs. 13.7%; hazard ratio, 1.1; 95% CI, 0.97-1.31; p = 0.139), and stent thrombosis (2.1% vs. 2.0%; p = 0.800) were similar. DES type had no interaction with MACE or TVF. In multivariate analysis, the proximal LAD was a predictor for MI (p = 0.038), but not for TVF (p = 0.149) or MACE (p = 0.069).
The authors concluded that proximal LAD location was associated with higher rates of MI during the long-term follow-up, but there were no differences in stent thrombosis, death, TVF, or overall MACE.
This post hoc analysis of a prospective, multicenter study reports no difference in the rates of death, MACE, or TVF at 4 years according to intervention at a proximal LAD or nonproximal LAD lesion. The occurrence of the predefined primary endpoint of stent thrombosis was also not dependent on whether a proximal LAD or nonproximal LAD site was treated. However, of note, stenting of proximal LAD lesions was associated with significantly higher rates of MI compared with stenting of nonproximal LAD lesions. Overall, these findings appear to suggest that proximal LAD lesions may not have additional risk in the contemporary DES era, but the higher risk of MI needs to be studied further. Future studies should compare longer-term clinical outcomes between proximal LAD PCI with DES and minimally invasive left internal mammary artery to LAD.
Keywords: Acute Coronary Syndrome, Coronary Vessels, Drug-Eluting Stents, Myocardial Infarction, Myocardial Ischemia, Percutaneous Coronary Intervention, Stents, Thrombosis, Treatment Outcome
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