Intravascular ultrasound usage booms on increased stent caution

Concerns about the danger of thrombosis resulting from the use of drug-eluting stents, combined with confidence in the safety of bare metal stents, have driven down the use of drug-eluting stents substantially over the past year, according to Volcano Corporation. That's bad news for the makers of drug-eluting stents but good news for the makers of intravascular ultrasound systems. The top executive at Volcano reports a surge in the sale of the systems.

"Stent placement is really the only factor that is fully within the control of the physician," said Scott Huennekens, Volcano president and CEO. "I think the added confidence provided by IVUS imaging is directly related to the increase in Volcano catheter usage over the past 12 months."

Before news of the increased risk of heart attack involving the use of drug-eluting stents spread, these stents had been used in about 89% of percutaneous coronary interventions in the U.S., according to Volcano. Over the past year, use of these stents in these interventions has dropped to about 70%. In the same period, Volcano has seen an increase of 25% in IVUS revenue, demonstrating that reliance on detailed imaging to guide optimal drug-eluting and bare metal stent placement has grown.

"The negative press around acute and late stent thrombosis with drug-eluting stents has led physicians to reexamine the safety of stenting and their control over patient outcomes," said Dr. Martin B. Leon, chair emeritus of the Cardiovascular Research Foundation and a professor of medicine at Columbia University Medical Center. "Interventionalists are now taking two proactive measures to protect their patients: prolonged duration of dual-antiplatelet therapy and increased focus on stent placement technique."

This drive to improve patient outcomes and confirm proper stent expansion and apposition is increasing use of detailed imaging modalities such as IVUS, Leon said.

At the March 7 to 9 Cardiovascular Revascularization Therapies conference in Washington, DC, Dr. Renu Virmani cited improper stent placement as among the major contributing factors to late stent thrombosis. Virmani, medical director of CVPath of the International Registry of Pathology, in Gaithersburg, MD, conducted a postmortem study on victims of sudden cardiac death. She noted that imaging modalities such as IVUS can help reduce the risk of stent thrombosis.

IVUS might improve outcomes in bare metal stenting as well. Evidence supports the belief that IVUS-guided stenting with bare metal devices improves clinical outcomes, according to Dr. Peter Fitzgerald, director of the Center for Cardiovascular Technology at Stanford University.

"Many physicians may have lost sight of this fact with the advent of drug-eluting stents," Fitzgerald said. "This current moment of pause in the industry, however, has led many interventionalists back to established bare metal stent platforms. Regardless of stent type, the value of IVUS guidance is certainly gaining momentum for both drug-eluting and bare metal stent procedures."