Intravascular imaging-guided PCI reduces adverse events compared to angiography-guided PCI in patients with complex coronary artery lesions

This study was a prospective multicenter randomized trial conducted in South Korea. The research population consisted of 1639 patients diagnosed with complex coronary artery lesions. The setting involved multiple centers across the country, utilizing a prospective multicenter open-label design. The primary objective was to evaluate the efficacy of intravascular imaging-guided PCI compared to standard angiography-guided PCI in this specific patient cohort.

The intervention group received intravascular imaging-guided PCI. The comparator group received angiography-guided PCI. The study utilized a median follow-up period of 5.3 years, with the interquartile range spanning from 4.4 to 6.2 years. This extended observation period allows for the assessment of long-term clinical outcomes relevant to coronary artery disease management.

The primary outcome was the composite of cardiac death, target vessel-related myocardial infarction, or clinically driven target vessel revascularization. The primary endpoint occurred in 10.5% of patients in the imaging-guided group versus 14.9% in the angiography-guided group. This represents a hazard ratio of 0.68 with a 95% confidence interval of 0.51 to 0.91 and a P value of 0.009. In absolute numbers, the event rate was 109 of 1,092 patients in the imaging group versus 78 of 547 patients in the angiography group.

Key secondary outcomes included cardiac death or target vessel-related myocardial infarction, clinically driven target vessel revascularization, and definite stent thrombosis. Cardiac death or target vessel-related myocardial infarction occurred in 7.6% of the imaging group versus 10.7% in the angiography group, with absolute numbers of 78 versus 56. Clinically driven target vessel revascularization occurred in 4.4% of the imaging group versus 6.2% in the angiography group, with absolute numbers of 45 versus 32. Definite stent thrombosis was observed in 0.1% of the imaging group versus 0.7% in the angiography group, with absolute numbers of 1 versus 4.

Regarding safety and tolerability, there were no apparent differences in procedure-related safety events between the two groups. The study did not report specific rates for serious adverse events, discontinuations, or detailed tolerability metrics beyond the comparison of procedure-related safety events. The open-label nature of the trial is a key methodological limitation that may influence outcome assessment and introduce potential biases.

This trial provides evidence that intravascular imaging guidance may reduce the risk of major adverse cardiac events in patients with complex coronary artery lesions compared to angiography alone. The results align with the general trend in interventional cardiology toward utilizing intravascular imaging to optimize stent placement and lesion preparation. However, the open-label design and the specific context of complex lesions require careful consideration when applying these findings to routine practice. Further research with blinded endpoints may be necessary to confirm these benefits definitively.

Several questions remain unanswered regarding the long-term cost-effectiveness of routine imaging guidance in all complex cases. The study did not detail the specific imaging modalities used or the protocols for image acquisition and interpretation. Additionally, the lack of data on serious adverse events beyond procedure-related safety events limits the full safety profile assessment. Clinicians should weigh the potential reduction in ischemic events against the procedural time and resource implications of adding imaging steps to standard PCI procedures.

The study findings support the consideration of intravascular imaging guidance for complex coronary artery lesions based on the observed reduction in the primary composite endpoint. However, the open-label design necessitates a cautious interpretation of the results. The absolute reduction in the primary endpoint was 4.4 percentage points, translating to a relative risk reduction of approximately 32%. The hazard ratio of 0.68 indicates a sustained benefit over the median 5.3-year follow-up period. These data contribute to the evolving evidence base for intravascular imaging in percutaneous coronary intervention.

In conclusion, this randomized trial demonstrates that intravascular imaging-guided PCI is associated with lower rates of cardiac death, myocardial infarction, and target vessel revascularization compared to angiography-guided PCI in patients with complex coronary artery lesions. The safety profile appears comparable between the groups. While the results are promising, the open-label methodology and the specific focus on complex lesions mean that these findings should be integrated into clinical decision-making with appropriate caution. Future studies may aim to address the limitations of the current evidence and explore the broader applicability of imaging guidance in less complex scenarios.