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Routine IVUS Guidance Fails to Reduce Target-Vessel Failure in Complex High-Risk PCI
In a randomized trial of 2,020 patients undergoing complex high-risk percutaneous coronary intervention, routine IVUS-guided PCI did not reduce the rate of target-vessel failure compared with angiography-guided PCI alone — with events occurring in 13.9% versus 11.1% of patients, respectively, representing a numerically higher but statistically non-significant risk in the IVUS group (HR 1.25, 95% CI 0.97–1.60; P = 0.08). The result contradicts the anticipated benefit of systematic IVUS guidance with prespecified stent-optimization criteria in this population.
What Was Studied
The trial examined whether performing PCI under real-time intravascular ultrasound (IVUS) guidance — with adherence to structured stent-optimization criteria — would reduce the composite rate of cardiac death, target-vessel myocardial infarction, or clinically indicated target-vessel revascularization compared with standard angiography-guided PCI. The focus was specifically on anatomically complex coronary lesions, a setting where intracoronary imaging is considered most likely to confer benefit and is already recommended by practice guidelines.
How It Was Studied
This was an investigator-initiated, international, open-label, randomized controlled trial enrolling 2,020 patients with complex coronary-artery lesions requiring PCI. Patients had a mean age of 69 years; 79.4% were men and 27.4% presented with an acute coronary syndrome. Participants were randomized 1:1 to either IVUS-guided PCI using prespecified optimization criteria (n = 1,010) or conventional angiography-guided PCI (n = 1,009). The trial was conducted predominantly within European practice settings, and patients were followed for a median of 19.0 months (IQR 15.2–23.4 months).
What Was Observed
- No significant reduction in target-vessel failure with IVUS guidance: The primary composite endpoint occurred in 13.9% of IVUS-guided patients versus 11.1% of angiography-guided patients — a numerically higher rate in the IVUS arm that did not reach statistical significance (HR 1.25, 95% CI 0.97–1.60; P = 0.08). The confidence interval, which nearly crosses 1.0, leaves open the possibility of a modest difference in either direction, but no benefit was demonstrated.
- Longer procedure duration with IVUS: IVUS-guided procedures took notably longer on average — 88.8 minutes compared with 66.2 minutes for angiography-guided PCI — a difference of approximately 22 minutes that reflects the additional imaging and optimization steps involved.
- Higher post-stent balloon dilation rates in the IVUS group: Post-implantation balloon angioplasty was performed in 91.3% of IVUS-guided cases versus 84.5% of angiography-guided cases, indicating that IVUS guidance did result in more frequent active stent optimization as intended by the protocol.
- Procedural complication rates were similar: Procedural complications occurred in 11.3% of IVUS-guided procedures and 10.2% of angiography-guided procedures, with no meaningful difference in the overall frequency of adverse events between groups.
Why This Matters
Practice guidelines already recommend intracoronary imaging for anatomically complex coronary lesions, yet IVUS adoption in Western countries has remained low. This trial was designed to generate evidence directly relevant to European practice and to test whether a protocol-driven IVUS strategy could close the outcome gap. The finding that IVUS guidance — even when applied systematically with optimization criteria — did not lower target-vessel failure rates challenges the assumption that routine adoption of this imaging approach will translate into improved clinical outcomes in Western PCI practice.
How to Read This Result
Although this was a large, well-designed randomized trial, the open-label nature introduces potential for performance bias, the median follow-up of 19 months may be insufficient to detect longer-term differences, and the historically low IVUS expertise in Western centers where the trial was conducted could have attenuated any procedural benefit that might otherwise be expected.
Limitations
The open-label design precluded blinding of operators or outcome assessors. The trial was conducted exclusively in Western European centers where IVUS use has historically been limited, raising questions about whether results apply to higher-volume IVUS programs elsewhere. The median follow-up of 19 months is relatively short for a disease with long-term recurrence risk. Additionally, operator familiarity with IVUS interpretation and optimization criteria likely varied across sites, which may have reduced the real-world efficacy of the imaging-guided approach.