Author + information
- Islam Y. Elgendy, MD,
- Ahmed N. Mahmoud, MD,
- Akram Y. Elgendy, MD and
- Anthony A. Bavry, MD, MPH∗ ()
- ↵∗North Florida/South Georgia Veterans Health System, Malcom Randall Veterans Administration Medical Center, Medical Service, Cardiology Section (111D), 1601 SW Archer Road, Gainesville, Florida 32608
Intravascular ultrasound (IVUS) has emerged as a useful tool to guide stent implantation. Meta-analyses of randomized trials in the era of bare-metal stents, and later with drug-eluting stents, revealed that IVUS-guided percutaneous coronary intervention (PCI) was associated with a reduction in major adverse coronary events (MACE), primarily resulting from reduction in target lesion revascularization (1,2). The benefit of an IVUS-guided approach might be enhanced in longer coronary lesions. To test this hypothesis within a comprehensive dataset, we assumed that the relative benefit with IVUS-guided PCI would be similar between stent types. If this assumption proved valid, then we aimed to determine whether the baseline coronary lesion has an impact on the benefit observed with IVUS guidance.
Electronic databases were searched for randomized trials reporting the outcome of MACE, and comparing an IVUS-guided PCI approach versus an angiography-guided PCI approach. The keywords used for the search were “coronary angiography” and “intravascular ultrasound.” Trials that evaluated angioplasty only or bailout stenting were excluded. MACE was defined as per the individual trials. Summary risk ratios (RRs) were constructed with a DerSimonian and Laird model. Subgroup analysis was stratified according to the stent type. Analysis for interaction in the stent subgroup was evaluated using random-effects analysis. Random-effects meta-regression analysis was performed for the outcome of MACE in relation to baseline lesion length, if reported by the study.
A total of 14 trials, 7 trials in each subgroup (i.e., drug-eluting and bare-metal stents), were included. The baseline lesion length ranged from 8 to 35 mm (mean 25 ± 10 mm). The baseline lesion length was longer in the drug-eluting stents group versus the bare-metal stents group (32 ± 5 mm vs. 13 ± 5 mm; p < 0.0001). IVUS-guided PCI approach was associated with a reduction in the risk of MACE (RR: 0.70; 95% confidence interval [CI]: 0.58 to 0.85; p < 0.0001; I2 = 36%) at a mean follow-up of 14 months. This benefit was observed for both drug eluting stents (RR: 0.65; 95% CI: 0.52 to 0.82; p < 0.0001; I2 = 0%) and bare-metal stents (RR: 0.74; 95% CI: 0.54 to 1.00; p = 0.05; I2 = 50%). There was no difference in the benefit observed based on the type of stent implanted (p for interaction = 0.38). Random-effects meta-regression analysis revealed that for every 10-mm increase in the lesion length, the RR for MACE decreased by approximately 19% (p = 0.037) (Figure 1).
In this meta-regression analysis of 14 randomized trials with a mean baseline coronary lesion length of 25 mm, we demonstrated that an IVUS-guided PCI approach is superior to an angiography-guided PCI approach in reducing the risk of MACE. There was observed benefit for both drug-eluting and bare-metal stents. Because there was no evidence of effect modification based on the implanted stent type, we performed a meta-regression analysis to explore the effect of baseline coronary lesion length. In the latter, we confirmed benefit when IVUS-guided PCI was performed for longer lesions. Although studies have demonstrated that the absolute risk of restenosis is higher with bare-metal stents (3), we expected that any relative difference for IVUS guidance on MACE reduction would be similar, which was confirmed by testing for interaction.
The American College of Cardiology/American Heart Association 2011 revascularization guideline recommends IVUS guidance for left main coronary artery PCI and for the assessment of non-left main intermediate coronary stenosis (4). The results of this analysis support the recommendation to expand IVUS-guidance for PCI of longer coronary lesions (i.e., >30 mm). In this analysis, we did not comment on the impact of IVUS guidance on other outcomes because previous meta-analyses have confirmed this benefit (1,2).
Please note: Dr. Bavry has received honorarium from the American College of Cardiology. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
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