Study looks at real-world, long-term results

Compared with patients undergoing percutaneous coronary intervention (PCI) with angiography only, those whose treatment included intravascular ultrasound (IVUS) showed benefit in 1-year and long-term outcomes in mortality, myocardial infarction (MI), and revascularization whether PCI was complex or not, a retrospective study of Medicare beneficiaries showed.

“Among Medicare patients, the contemporary use of IVUS in the United States remains low and highly variable across hospitals,” noted Amgad Mentias, MD, MSc, of the University of Iowa in Iowa City, and coauthors, in the Journal of the American College of Cardiology: Cardiovascular Interventions.

“Our study and other observational and randomized trials demonstrate that the use of IVUS during PCI is associated with lower long-term mortality, MI, and repeat revascularization compared with conventional angiography-guided PCI,” they wrote. “Such observations remained evident regardless of various clinical and procedural variabilities.”

Complexity of PCI in this analysis was based on criteria of three or more stents placed, two or more vessels treated, and chronic total occlusion or bifurcation lesions. Compared with patients having PCI treated with angiography only, the group with IVUS showed long-term (median 3.7-year follow-up) mortality benefit whether PCI was complex (HR 0.928, 95% CI 0.922 to 0.933) or non–complex (HR 0.889, 95% CI 0.885-0.893; P for interaction <0.001).

Long-term risks for MI and repeat revascularization were lower in the IVUS group overall and were lower for both complex and non-complex PCI subgroups.

One-year outcomes also favored the IVUS group, with lower 1-year mortality (11.5% versus 12.3%), MI (4.9% versus 5.2%), and repeat revascularization (6.1% versus 6.7%; P < 0.001 for all).

“Collectively, the body of evidence investigating the role of IVUS in PCI guidance has matured and data consistently suggest that imaging-guided PCI should become a mainstay of complex PCI procedures,” wrote Lorenz Raber, MD, PHD, and Yasushi Ueki, MD, both of the University of Bern in Switzerland, in an accompanying editorial. “To close the gap between evidence and clinical practice, reimbursement for imaging catheters, easy-to-use semi-automated software applications, and standardized and widespread education are crucial,” they continued.

“The current study is unique in terms of an unselected, very large patient cohort (>1,000,000 U.S. patients undergoing PCI) derived from national administrative database,” they added. “For these reasons, the findings further strengthen and enrich the evidence-based fundament of IVUS-guided PCI.”

Substantial evidence suggests that IVUS improves procedural results and outcomes, with meta-analyses of controlled trial data comparing IVUS guided versus angiography-guided PCI showing lower risk of major adverse cardiovascular events including death, revascularization, and stent thrombosis.

“The benefits of IVUS-guided PCI were observed primarily in complex settings (i.e., long lesion, unprotected left main, and chronic total occlusion), with a mean stent length of 36 mm and acute coronary syndrome presentation in 41% among 10 randomized controlled trials,” the editorialists noted.

Guidelines, including those of the American College of Cardiology/American Heart Association, consider IVUS a class II recommendation. It may not be Class I in part due to a “currently limited (geographical) external validity, with a majority of randomized controlled trials conducted in Asia and an adoption rate that remains notably low except for in Korea and Japan,” the editorialists explained.

In their study, Mentias and colleagues analyzed data for 1,877,177 patients in the 100% Medicare Provider and Analysis Review Part A files, which included nationwide hospital admissions for Medicare beneficiaries by year. They compared outcomes for PCI with IVUS (n = 105,787) to PCI with angiography only (n = 1,771,390) between January 2009 and December 2017 (with mortality data until September 2018). Average age was about 73 and 60% of both groups were male.

Outcomes included all-cause death, MI, and repeat revascularization. The main outcome of the study was long-term (median follow-up 3.7 years) all-cause mortality.

IVUS was used in 5.6% of patients overall (versus 3.0% in 2009 and 6.9% in 2017), with use among 1,934 hospitals varying from <1% of procedures (56% of hospitals) to >10% (12% of hospitals).

Those in the IVUS group had more comorbidities (heart failure 28.6% versus 25.8%; prior CAD 22.8% vs 21.8%; stroke 5.1% versus 4.2%; and pulmonary hypertension 4.8% versus 3.9%; P < 0.001 for all) and had a higher PCI complexity compared to the angiography-only group.

After propensity score matching, IVUS-guided PCI was associated with a lower risk of mortality (11.5% versus 12.3%; P < 0.001), MI (4.9% versus 5.2%; P < 0.001), and repeat revascularization (6.1% versus 6.7%; P < 0.001) at 1 year.

“The benefit of IVUS-guided PCI was consistently observed across several subgroups including stent type (drug eluting stent versus bare-metal stent), presentation (stable angina pectoris versus acute coronary syndrome), PCI complexity, and center-specific IVUS volume,” the authors noted.

Limitations include unmeasured confounding factors (e.g., stent length, stent diameter, and ejection fraction). Outpatient PCI data were not included. As a retrospective observational study, selection bias also may be present.

“The reported main reasons for the reluctance [to] use IVUS are concerns regarding cost, safety, additional procedural time, and operator expertise,” Raber and Ueki noted, but cited prior work showing positive economic effect in higher risk patients and no increased risk of periprocedural MI.

“Straightforward and automated analyses are of key relevance to avoid additional procedural time,” they wrote. “This technology will reduce the additional procedural time required and thus represents a valid option to increase the adoption of imaging-guided PCI.”

  1. Compared with patients undergoing percutaneous coronary intervention (PCI) with angiography only, those whose treatment intravascular ultrasound (IVUS) had benefit in 1-year and long-term mortality, MI, and revascularization whether PCI was complex or not, a retrospective study of Medicare beneficiaries found.

  2. Among Medicare patients, use of IVUS remains low and highly variable across hospitals.

Paul Smyth, MD, Contributing Writer, BreakingMED™

Mentias has received support from National Institute of Health NRSA institutional grant to the Abboud Cardiovascular Research Center.

Raber has received institutional research grant support from Abbott Vascular, Biotronik, Boston Scientific, Heart- Flow, Sanofi, and Regeneron, and has received speaker or consultation fees from Abbott Vascular, Amgen, AstraZeneca, Canon, CSL Behring, Occlutech, Sanofi, and Vifor. Ueki has received travel grants from Infraredx.

Cat ID: 306

Topic ID: 74,306,282,399,464,730,306,192,255,925