乌鸦传媒

Percutaneous coronary intervention (PCI) done under intravascular ultrasound (IVUS) guidance instead of angiography has an outcome advantage in the era of drug-eluting stents (DES), as seen with bare metal stents previously, according to a meta-analysis.

Routine 15 months following DES placement (6.5% versus 10.3% for angiography, odds ratio [OR] 0.60, 95% confidence interval [CI] 0.46-0.77), , of the North Florida/South Georgia Veterans Health System in Gainesville, Fla., and colleagues reported online in Circulation: Cardiovascular Interventions.

That advantage was mainly driven by the reduction in ischemia-driven target lesion revascularization (4.1% versus 6.6%, OR 0.60, 95% CI 0.43-0.84). In addition, PCI for IVUS-guided patients was associated with borderline fewer cases of cardiovascular mortality (0.5% versus 1.2%, OR 0.46, 95% CI 0.21-1.00) and stent thrombosis during follow-up (0.6% versus 1.3%, OR 0.49, 95% CI 0.24-0.99).

A reduced risk of myocardial infarction, on the other hand, failed to reach statistical significance (0.8% for IVUS versus 1.5% for angiography, OR 0.52, 95% CI 0.26-1.02).

"In the era of DES for diffuse coronary lesions, IVUS-guided PCI is superior to angiography-guided PCI in reducing the risk of major adverse cardiac events," Bavry's group concluded.

Thus, "the routine use of IVUS for revascularization of diffuse coronary lesions should be considered," the investigators concluded, arguing for an expanded indication for IVUS in guidelines.

Bavry's investigation included seven randomized trials with a total of 3,192 patients who received DES implantation with first- and second-generation devices.

When it came to major adverse cardiovascular events, the benefit of IVUS was apparent at both 1 year (OR 0.56, 95% CI 0.40-0.77) and 2 years (OR 0.67, 95% CI 0.46-0.97). Excluding patients with first-generation DES yielded no change in the advantage for IVUS (OR 0.57, 95% CI 0.41-0.79).

The caveat, they noted, was that their conclusions were based on a population with diffuse coronary artery disease, whose lesions measured a mean of 32 mm. Other limitations included differing definitions of major adverse cardiovascular events among the trials -- with one study in particular, AIR-CTO, not reporting the definition used -- and the lack of patient-level data available for the meta-analysis.

Yet, while citing the ADAPT-DES study, Bavry and colleagues suggested that IVUS-guided PCI may have benefits related to larger postintervention diameters when compared with angiography. That in turn facilitates the "selection of larger size stents/balloons, higher inflation pressures, longer stents, and additional postdilatation," they wrote. A similar pattern of frequent postdilatation and large postintervention lumen diameters was observed in their meta-analysis.

"The latter has been believed to be a major contributing factor for the prevention of restenosis after DES implantation," the authors commented.

Despite the recent slew of positive data for IVUS, Bavry and colleagues argued that its benefits do not seem to have swayed practice much. As of late, IVUS use only accounts for 20% of PCI procedures in the U.S.

"A potential explanation for infrequent use could be perceived lack of benefit from this technology because some operators may think that visual assessment of the coronary lesions is sufficient," they suggested.

By now, however, "it is well known that physician's assessment of the severity of coronary lesions is variable and poorly correlates with myocardial ischemia," they emphasized.

Similarly countered was the suggestion that the cost of IVUS equipment and the lack of reimbursement may be yet other factors in the general underutilization of the technology.

The authors pointed to a prior study showing that IVUS guidance was "not only cost-effective, but may be cost-saving among patients who are at increased risk of restenosis."

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