IVUS Guidance of PCI May Lower In-Hospital Mortality vs Angiography

IVUS-guided PCI is associated with a lower in-hospital mortality risk but slightly higher costs and complication rates than angiography, according to a study published online February 19, 2015, ahead of print in the American Journal of Cardiology. 

 “Our study represents the largest comparative analysis between IVUS- and angiography-guided PCI in the current DES era, which adds to the growing literature on beneficial effects of IVUS on reducing adverse outcomes post-PCI,” Apurva O. Badheka, MD, of Yale School of Medicine (New Haven, CT), and colleagues write.

The researchers examined data from the Nationwide Inpatient Sample on 401,571 PCIs performed from 2008 through 2011; 377,096 were guided by angiography alone and 24,475 employed IVUS. Interventions using FFR were excluded.

In unadjusted analyses, IVUS guidance was associated with a shorter length of stay, higher hospitalization costs, and lower in-hospital mortality. Although the overall complication rate was 5.5% in each group, rates of vascular and cardiac complications were higher following procedures in which IVUS was used (table 1).

After multivariate adjustment, IVUS guidance remained a predictor of lower in-hospital mortality (OR 0.65; 95% CI 0.52-0.83), with similar reductions observed in the high-risk subgroups of patients with acute MI and/or shock and with higher comorbidity burdens (Charlson’s comorbidity index ≥ 2).

Also, the cost of IVUS-guided procedures was higher by $2,302 (P < .001), although length of stay no longer differed based on the type of guidance used.

A propensity-matched analysis confirmed the results of the multivariate analysis.

Debate About Clinical Impact of IVUS in PCI

Compared with angiography, IVUS has been shown to provide complementary information on coronary anatomy and plaque burden and composition, and to be helpful in choosing a treatment strategy, sizing stents, and guiding deployment, according to the authors.

“Thus, superior outcomes with IVUS-guided PCI might conceptually be in part a result of earlier recognition of periprocedural complications like stent fracture, malapposition, or underexpansion,” Dr. Badheka and colleagues write.

But some questions remain about the effects of IVUS guidance on clinical outcomes after PCI in the DES era.

“The utility of IVUS guidance has been debated in the past due to minimal clinical benefit observed in the previous small studies and due to significant reduction in restenosis rates following the introduction of DES into clinical practice,” Dr. Badheka and colleagues write, pointing to the results of the AVIO trial and a more recent cohort study that failed to show a clinical benefit from IVUS guidance.

Both studies, however, were possibly underpowered to detect differences in stent thrombosis and in-hospital mortality, which have become less frequent in the DES era, they add. That hypothesis is supported, they say, by an analysis of the larger ADAPT-DES trial, which demonstrated reductions in stent thrombosis and cardiac mortality with IVUS guidance.

Although the current study also suggests that IVUS guidance can improve PCI outcomes, its design—a post hoc look at administrative data—precludes a definitive conclusion regarding causality, the authors acknowledge, noting the lack of information on coronary anatomy, lesion characteristics, stent sizes, procedural details, and postdischarge mortality in the database.

“While acknowledging these limitations, the present study has important strengths including the largest sample size and the use of standardized definitions of preventable adverse events that are established by the [Agency for Healthcare Research and Quality],” they write. “Our results need to be replicated in larger randomized trials with detailed angiographic analysis to better understand the pathophysiological underpinnings of positive outcomes afforded by IVUS guidance.”  

Source: 
Singh V, Badheka AO, Arora S, et al. Comparison of in-hospital mortality, length of hospitalization, costs, and vascular complications of percutaneous coronary interventions guided by ultrasound versus guided by angiography. Am J Cardiol. 2015;Epub ahead of print.  

Disclosure:

• Dr. Badheka reports no relevant conflicts of interest.

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