Intravascular ultrasound may provide better long-term outcomes in complex PCI

Intravascular ultrasound (IVUS)-guided PCI was associated with lower long-term risk of cardiac death than an angiography-guided approach in patients with complex lesions, according to a single-center study published in JACC: Cardiovascular Interventions.

Lead author Ki Hong Choi, MD, with Samsung Medical Center in Seoul, South Korea, and co-authors said the findings suggest “IVUS should be actively considered for complex PCI.”

IVUS can provide important information pre-PCI, the authors noted, including on vulnerable plaques and lesion severity, length and morphology. It can also guide optimal stent expansion, extension and apposition and give insight into possible complications post-intervention.

However, the uptake of IVUS remains limited due to cost concerns and a body of evidence built on studies with small sample sizes and short follow-up periods, Choi et al. wrote.

To address these gaps, the researchers enrolled 6,005 patients undergoing PCI with drug-eluting stents (DES) for complex lesions from March 2003 through December 2015. Complex PCI encompassed bifurcation lesions, chronic total occlusions, left main disease, long lesions (implanted stent lengths of at least 38 mm), multivessel PCI, interventions with three or more stents, in-stent restenosis and heavily calcified lesions. Operators used IVUS-guided PCI in 27.9 percent of the patients and angiography in the rest.

Over a median follow-up of 64 months, the IVUS group experienced a 43 percent relative reduction in the primary endpoint of cardiac death compared to the angiography-guided patients (10.2 percent vs. 16.9 percent).

“The risks of all-cause death, myocardial infarction, stent thrombosis, ischemia-driven target lesion revascularization, and major adverse cardiac events were also significantly lower in the IVUS-guided PCI group,” Choi et al. wrote. “These results suggest that IVUS should be used to assess the lesion characteristics and to optimize stent implantation when performing PCI with DES for complex coronary lesion.”

The authors said the “optimization of stent deployment” is one potential explanation for the benefits seen with IVUS. In addition, larger stent sizes, higher inflation pressures and more frequent use of post-dilatation (49 percent vs. 17.9 percent) with IVUS “might result in adequate stent expansion and apposition, and full lesion coverage.”

The single-center, retrospective and observational design of the study was a key limitation, and there were some notable differences between groups. While the IVUS cohort tended to have more complex lesions, those individuals were also younger, had fewer cardiovascular risk factors and were less likely to present with acute coronary syndrome.

“Even though the investigators performed multiple sensitivity analyses, it is not possible to adjust for all the potential biases,” Jose M. de la Torre Hernandez, MD, PhD, wrote in a related editorial. “Having said this, the study is pertinent and provides valuable information.”

De la Torre Hernandez said intravascular imaging should be considered not only for complex lesions, but for complex and vulnerable patients—as patient characteristics also play an important role in determining what is truly “complex PCI.” Although the imaging strategy was left to the operators’ discretion in this study, de la Torre Hernandez believes one thing is clear: IVUS should be used more often than it has been.

“A ‘definitive’ mega-trial, truly powered for death, is hardly foreseeable and in my view not even warranted,” he wrote. “The consistent demonstration of clinical benefits provided by IVUS guidance during PCI with DES, particularly in the complex settings, makes the inertia of its very low penetration in the United States and the European countries unjustifiable.

“Although its systematic use would be unsustainable in terms of cost-effectiveness, intravascular imaging should be used considerably more than it currently is. There is evidence to support it, and there are criteria to apply it.”