The role of IVUS guidance in PCI of the LM remains controversial and regulatory guidelines give only a Class IIB recommendation for the use of IVUS guidance during LM PCI is Class IIb. There is a lack of prospective clinical trial data assessing the benefit of IVUS-guided DES implantation. A 2014 study analysed 4 large registries of patients with LM disease treated with DES in Spain The study included 1670 patients from 21 centres, who underwent DES implantation. Of these, 505 patients who underwent DES implantation with IVUS guidance were propensity score-matched with 505 patients who underwent DES implantation without IVUS guidance. The groups were well matched in terms of patient and procedural characteristics. At 3-year follow up, the survival free of cardiac death, myocardial infarction, and target lesion revascularization was significantly better in the IVUS-guided group compared with the non-IVUS group (88.7% vs 83.6%; p = 0.04) for the overall population. This finding was even more pronounced in subgroups with distal LM lesions (90% and 80.7%, respectively, p=0.03). In addition, the incidence of definite and probable stent thrombosis was significantly lower in the IVUS group (0.6% vs. 2.2%; p=0.04). IVUS-guided revascularization was identified as an independent predictor for major adverse events in the overall population (HR 0.70, 95% CI 0.52 to 0.99; p=0.04) and in the subgroup with distal lesions (HR 0.54, 95% CI 0.34 to 0.90; p=0.02).
Limitations of the study include the fact that this was a retrospective study based on registry data, and therefore may not have accounted for other confounding factors in assessing the clinical benefits associated with IVUS guidance. None of the registries was designed to evaluate the effect of IVUS on outcomes. However, the study was well powered statistically. The investigators concluded that IVUS guidance has a positive impact on PCI of LM lesions with DES, especially when lesions affect the bifurcation.
- de la Torre Hernandez JM, Baz Alonso JA, Gomez Hospital JA, et al., Clinical impact of intravascular ultrasound guidance in drug-eluting stent implantation for unprotected left main coronary disease: pooled analysis at the patient-level of 4 registries, JACC Cardiovasc Interv, 2014;7:244-54.