"The nonobstructive plaque may be more important than the obstructive plaque, in terms of mortality and morbidity," Kuntz argued, noting that DESs today are used to treat angina, not prevent sudden death.

Noting that Dr Bernhard Meier (Swiss Cardiovascular Center, Bern, Switzerland) had earlier proposed prophylactic treatment with PTCA alone, Kuntz observed that DESs have the added benefit of reducing adverse tissue reactions to the procedure but inducing sufficient injury to the vessel wall that the vestigial scar is not capable of "growing atherosclerosis."

Obviously we wouldn't be taking patients off the street.

Kuntz also showed data supporting the concept that MIs more commonly originate in the LAD, left circumflex, and right coronary arteries and that over half of these MIs originate in the proximal portion of these vessels. The "hot spots" for prophylactic stenting would thus be within the first 20 mm of both the left anterior descending and left circumflex arteries and between 15 mm and 40 mm in the right coronary artery.

"If we assume that drug-eluting stents cause negligible acute and late complications, that stented segments have a low risk of future atherosclerosis, and that we can identify patients with more than a 3% to 6% risk of MI per year, we may be able to use 'hot-spot' stenting in patients at high risk of MI," Kuntz said.

This strategy would be appropriate in people already undergoing stenting of obstructive coronary disease, he added. "Obviously we wouldn't be taking patients off the street."

It may be time for randomized controlled trials of prophylactic stenting plus obstructive lesion stenting vs obstructive lesion stenting alone, Kuntz concluded.

Dr Andrew Zalewski (Thomas Jefferson University, Philadelphia, PA), who is also an employee and shareholder at GlaxoSmithKline, took the podium to strenuously oppose Kuntz's proposed strategy. "I disagree with Dr Kuntz entirely. Hopefully we will still be on speaking terms after the next 15 minutes," Zalewski joked.

Zalewski stated that plaque vulnerability is too widespread and multifocal to be targeted by stents; moreover, none of the current imaging modalities are capable of fully identifying areas of vulnerable plaque. "While I have great enthusiasm for the novel imaging technology that is emerging, there is no clinical evidence of improved risk prediction today in 2005," Zalewski said.

He also described some of the nonvascular phenomena associated with plaque development and rupture, many of which are blood borne, arise as a product of chronic inflammation, or are related to systemic factors such as adiposity and insulin resistance. Such factors are better targeted by systemic drug therapies than by focal stenting, Zalewski stated.

Attempting to demonstrate a role for prophylactic stenting would be a mammoth undertaking, he added. "To show a 30% reduction in CV events, we would need a trial of 3000 patients followed for one year or 2000 patients followed for two years, and two independent trials would be required for changes in guidelines," he said. "Current trials are underpowered to test this hypothesis."

As such, he concluded, "In the era of scarce healthcare resources, it would potentially divert those resources away from vulnerable patients, if you will, as opposed to vulnerable plaques."

Dr Ron Waksman (Washington Hospital Center, Washington, DC), one of the session moderators, suggested that the audience consider a dental analogy. "If you consider our children's teeth, they no longer get cavities," Waksman pointed out. "I do believe that we should look at some new technologies that would be less traumatic [than stenting] and that do not leave us with the option of always taking patients to the cath lab. Can you imagine if we had to prevent plaques in our teeth by putting prophylactic metal covering all of our teeth? No one would accept it."

Instead, says Waksman, we should consider other options beyond drugs and stenting. "Balloon angioplasty is still not the best option, but other technologies such as photodynamic therapy or cryoplasty or other modalities that would be regional would be a better fit for preventive medicine, because with everything we have accomplished with drug therapy, we still know that there is an issue of compliance, and no one wants to take drugs for his or her entire life. We still have to look at some kind of sealing concept, but in my opinion, it is not going to be stenting."