Study Outlines Benefit of Intravascular Ultrasound-Guided PCI

August 19, 2020

An analysis of Medicare patient data suggest use of intravascular ultrasound during PCI could reduce long-term mortality risk.

Despite a low frequency of use, results of a new study offer further support of use of intravascular ultrasound (IVUS) during coronary stenting to reduce risk of long-term mortality and adverse events.

An analysis of more than 1 million Medicare patients who underwent percutaneous coronary intervention (PCI), results of the study indicate greater use of IVUS during PCI could reduce long-term mortality as well as lower rates of myocardial infarction and repeat revascularization these patients.

“In this study from Medicare database we demonstrate several findings,” wrote study investigators. “First, overall IVUS use during PCI remains low in the United States during our study period with a wide variation in its use among different facilities. Second, the use of IVUS during PCI in the United States was associated with a lower risk of mortality, MI, and hospitalization for repeat revascularization compared with patients in whom IVUS was not used during PCI.”

Despite previous studies reporting benefit from use of IVUS in PCI, real-world use remains low. With this in mind, a University of Iowa Carver College of Medicine-led team designed the current study to further understand the frequency of use and impact on real-world outcomes.

Using January 2009 through December 2017 as the study period, investigators identified 1,877,177 patients who underwent PCI for inclusion in their study. The primary outcome of the study was long-term all-cause mortality and secondary outcomes were myocardial infarction and repeat revascularization. Investigators noted the aforementioned outcomes were assessed at 1-year post-coronary intervention and at a long-term follow-up.

For the purpose of the analysis, investigators used propensity score matching and inverse probability to adjust for baseline characteristics. Additionally, investigators pointed out patients undergoing IVUS-guided PCI were matched to non-IVUS-guided patients in the same hospital and year to account for hospital effects.

Of the 1.8 million patients identified by investigators, 5.6% underwent IVUS-guided PCI. In comparison, those undergoing IVUS-guided PCI had a greater prevalence of most comorbidities, including heart failure (28.6% vs 25.8%), prior coronary artery disease (22.8% vs 21.8%), prior stroke (5.1% vs 4.2%), chronic kidney disease (21.1% vs 19.3%), chronic lung disease (22.9% vs 20.9%), and pulmonary hypertension (4.8% vs 3.9%) compared to patients undergoing non-IVUS-guided PCI (P for all <.001).

Results of the propensity-matched analysis indicated IVUS-guided PCI was associated with lower rates of 1-year mortality (11.5% vs 12.3%), myocardial infarction (4.9% vs 5.2%), and repeat revascularization (6.1% vs 6.7%) than non-IVUS-guided PCI (P for all <.001). Results of the inverse probability weighting analysis, which had a median follow-up of 3.7 years, suggested IVUS-guided PCI was associated with a lower risk of mortality (aHR, 0.903; 95% CI, 0.885-0.922), MI (aHR, 0.899; 95% CI, 0.893-0.904), and repeat revascularization (aHR, 0.893; 95% CI, 0.887-0.898) (P for all <.001).

Investigators noted multiple limitations to take into account when interpreting the results of their study. Specific limitations pointed out by investigators included lack of information on stent or vessel diameter, inability to determine whether IVUS imaging changed management of patients in the IVUS-guided group, and inability to ascertain if a repeat revascularization procedure was in the same treated vessel or a new vessel, among others.

“Among Medicare patients, the contemporary use of IVUS in the United States remains low and highly variable across hospitals,” wrote investigators “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.”

This study, “Long-Term Outcomes of Coronary Stenting With and Without Use of Intravascular Ultrasound,” was published in JACC: Cardiovascular Interventions.