Cath lab procedures appear to level off, but equipment purchases may be unaffected

The number of cath lab cases performed in 2002 remained level in the U.S. after increasing sharply over the previous four-year period, according to a market research survey. But the flat numbers might not mean a leveling off or drop in the purchase of cardiac imaging equipment.

Instead, as the population ages, more sophisticated imaging systems will continue to replace existing technology. Flat-panel cardiac cath equipment is beginning to take hold at the same time opportunities for the sale of CT and MR systems for cardiac applications are beginning to emerge. Imaging pundits expect equipment sales to get an additional boost as baby boomers become senior citizens, causing a renewed growth in the number of cardiovascular procedures.

Research conducted by IMV Medical Information Division found that the number of cath lab cases remained stable at 3.85 million in 2002 after increasing 17% between 1998 and 2002. Of the cardiac cases performed in 2002, nearly three million were coronary, including diagnostic-only, therapeutic-only, and combined diagnostic and therapeutic. Overall, the number of cath lab cases rose during the five-year period from 1998 to 2002.

"We've seen tremendous growth in the percentage of combined studies," said Lorna Young, IMV senior director of market research.

These cases, she explained, involve two procedures: one diagnostic, the other therapeutic. Typically, these patients enter the cardiac cath suite strongly suspected of having coronary artery disease. Confirmed suspicions are followed immediately by minimally invasive procedures to open clogged vessels.

IMV surveys in the past had considered diagnostic and therapeutic procedures as two cases, if different physicians performed them. In the most recent IMV study, the two were combined into one, raising the possibility that the leveling in the number of procedures may be due partly to a change in survey methodology.

Young suggested that demand for cardiac cath procedures could rise as baby boomers age, noting that the boomers are just entering the period in their lives when cath lab procedures become a reality.

"There are two fundamental engines that drive procedure growth: having therapeutic procedures that work, and the size of the patient population," she said. "Therapeutic procedures for (coronary artery disease) are relatively well developed, so centers are really addressing the patient population."

Attributing the drop in growth to survey methodology meshes with IMV's finding that the number of cath lab rooms increased 5% in 2002. IMV surveyors also found that budgets for catheter-based imaging devices increased dramatically. Both findings suggest that administrators expect an uptick in cath lab procedures in the coming years.

"Can we say the growth is now occurring in terms of more and more patients? Maybe not," she said. "But if we ask 'Is this a strong industry?', the answer is yes."

IMV's 2003 Cardiac Catheterization Lab Census gathered data from 1510 sites, which make up 75% of the identified cath labs in the U.S. The resulting database can be licensed by subscribers and includes contact and site-specific information regarding device utilization by manufacturer and contrast media utilization by brand, cath lab imaging systems, electrophysiology, intravascular ultrasound, digital imagers, filmless technology, hemodynamic systems, and power injectors for cath contrast, plus cardiovascular information management systems and networking.

In explaining the 2002 numbers, Gail Prochaska, vice president of IMV, suggested that other screening procedures may be limiting whether patients are referred to a cath lab. Particularly interesting is the possibility that MR for functional evaluation of the heart and coronary CT angiography are beginning to cut into the diagnostic need for cardiac cath. IMV surveyors did not specifically address this question, but they did find that cardiac procedures involving nuclear medicine, CT, and MR equipment rose from 2001 to 2002.

At the University of California Medical Center in Irvine, the number of cath lab procedures - including diagnostic angiography - has declined significantly in recent years, said Dr. Fong Tsai, director of radiological sciences.

"We used to do catheter angiograms to diagnose vascular disease," he said. "Now, everything is MRI and CTA - especially CTA. These are replacing diagnostic angiography."

The appeal of MR and CT is easy to gauge. Traditional catheter angiography is invasive and risky. CT and MRI are neither. Additionally, CT enables clinicians to examine the vessels and evaluate aneurysms concurrently. The development of MR and CT as cardiac procedures eventually will redefine catheter angiography as a therapeutic rather than a diagnostic procedure, he said.

"We're seeing fewer and fewer diagnostic procedures (in the cath lab)," he said.

CT and MRI are the wave of the future, according to Tsai. In fact, in other countries, physicians use PET/CT to evaluate the coronary arteries and examine myocardial perfusion at the same time.

"I think diagnostic x-ray angiography for the heart, for the peripheral vessels, and for the head and neck will be replaced by CT angiography," he said. "In the next three to five years, you will see the trend."

And this may be only the start. Nuclear cardiology is on the verge of a major step forward with the addition of PET/CT.

"Certainly, PET/CT will increase in demand - no question about it. Sixty-four slices is so fast that you can catch the heart's motion," Tsai said. "But only time will tell whether (traditional) angiography will continue to decline in favor of CT."

At Pomona Valley Hospital, cath lab procedures are declining, although Bob Jacoby, administrative director of radiology, could not explain why. He said several new CT systems have recently been purchased.

Jacoby suggested that more aggressive management by physicians bent on ensuring that cath lab procedures are performed only when appropriate might be one reason for the flat numbers.

"It's probably due to better overall better patient management and being selective about who goes to cath," he said. "The industry as a whole will start to see (patients go to CT rather than cath labs). The 32- and higher slice CT scanners are just starting to come out, and that will begin to have an impact. I don't think it's a contributing factor currently."

Jacoby added that each institution will have to evaluate whether to react to the apparent leveling off in demand for cardiac cath by curtailing big-ticket purchases.

"I don't think it will stop the community from buying technology," he said. "Technology continues to improve dramatically every year, but what we're going to see is a technology shift from doing routine catheter angiography to seeing CT and MR systems begin to take over what was traditionally catheter-based angiography."

At Pomona Valley, there's been no letup in purchasing. Over the past year, the hospital has purchased two 16-slice scanners and one 32-slice CT system.

"We've made a strategic decision that CT will have a very prominent role in imaging here," he said.