IVUS: Becoming a Cath Lab Staple

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IVUS technology can be integrated into most cath labs. Source: Boston Scientific

Healthcare reform has focused much attention on measuring quality in clinical settings, and as a result, providers must improve procedural outcomes and justify the cost and necessity of procedures. For PCI procedures, intravascular ultrasound (IVUS) provides interventional cardiologists with a tool to assess the lesions and extent of coronary artery disease (CAD) for improved clinical decisions.

When to use IVUS

IVUS improves a physician’s accuracy to identify lesions that need stenting and provides good correlative hemodynamic significance, according to Jeffrey W. Moses, MD, director of cardiac cath labs at New York-Presbyterian/Columbia University Medical Center in New York City. “For instance, many suspected left main stenoses are found to be non-obstructive with IVUS interrogation. You can diagnose unsuspected disease, and rule out disease where angiography provides less certainty,” he says.

“IVUS is helpful in reducing the incidence of stent thrombosis and stent restenosis,” says Lowell F. Satler, MD, director of coronary interventions at Washington Hospital Center in Washington, D.C. “With IVUS, we look for evidence of under-expansion, malapposition and age problems, such as dissection or plaque burden.”

Satler, who uses IVUS in approximately 95 percent of his PCI procedures, says the proliferation of the technology results from more patients presenting with complex lesions, such as left main disease, multi-vessel disease and bifurcation lesions, in whom “angioplasty alone is inadequate to prevent potential complications.”

In complex disease, such as diffused disease or left main disease, there is evidence that the technology improves outcomes. For example, researchers from the University of Louisville found that IVUS minimum lumen diameter (2.8 mm) and minimum lumen area (5.9 mm2) strongly predict the physiological significance of left main coronary artery stenosis (Circulation 2004;110:2831-2836).
 

Adoption barriers & cost considerations

Satler says one barrier to more widespread IVUS adoption is that the technology requires some preparation time for complete integration in the cath lab. “Like any other cath lab tool, if cardiologists do not use it frequently, they will be less confident regarding image interpretation when it is necessary,” he says.

Moses, who employs IVUS in about 35 to 40 percent of PCI procedures, agrees that it hasn’t been thoroughly integrated into the cath lab, even though tableside controls and integration capabilities are present. He adds it would be helpful if readings were a little more automated.

Even though IVUS is reimbursed, Satler says cost also could be a hindrance for some providers, and depending on the contract that a facility has with the IVUS vendor, catheters range in price from $400 to $1,000. He also notes that cost savings would be difficult to identify with IVUS as deferred procedures are difficult to economically assess.

Mueller et al found that in 269 consecutive patients with 356 lesions, the routine use of IVUS-guided PCI procedures is only cost-saving half the time during the two-year follow-up period (Am J Cardiol 2003:91(2):143-147).

Improved patient outcomes will continue to guide clinical decisions, as the current guidelines now incorporate the use of IVUS or fractional flow reserve (FFR) with intermediate lesions to serve as a “tie-breaker on whether to treat or not,” Moses says. “From the hospital standpoint, it’s an important quality measure and payors are increasingly scrutinizing these measures.”

Moses hopes that payors—both private and public—will encourage the appropriate utilization of procedures, as opposed to “ratcheting down expenses arbitrarily.” He points out that the cost of taking care of CAD patients has been below the inflation rate over the past decade.

“Tools such as IVUS and FFR help define the extent of the disease. So, we develop a better strategy in the cath lab for deciding whether PCI, medical therapy or CABG would be a superior modality for optimal patient care,” Satler concludes.