MUNICH, Germany — The controversy over the use of drug-eluting stents (DES) for treating coronary disease could be heard throughout the sessions, seminars, press conferences and even hallway discussions at the annual congress of the European Society of Cardiology (ESC; Sophia Antipolis, France), being held here this week.

Without clear practice guidelines, cardiologists are left to choose among competing views and conflicting study results to find guidance for patients choosing how to have blocked arteries reopened.

Adding to the confusion were further clinical trials and sessions that aimed to address the issues head on but just as often left participants as uncertain coming out as they were going into the debate.

In a session dubbed "Safety of drug-eluting stents two years after Barcelona," Carlo DiMario, MD, from the Royal Brompton Hospital (London), said the positive side of the debate over DES since their usage was challenged at the ESC meeting in 2006 is that existing randomized trials and registries have been intensely scrutinized and plans have been made for more adequately powered trials with results applicable to the majority of patients treated for coronary artery disease and not just the high-risk, off-label uses that set off the concerns.

Another benefit has been the sharp fall in DES prices, which has forced a reappraisal of cost-effectiveness analyses such as was recently seen in England with new guidelines from the influential National Institute for Health and Clinical Excellence (Medical Device Daily, Feb 4, 2008).

But like all presenters, DiMario was forced to inconclusively wrap up, saying that "more data is needed from dedicated trials addressing the long-term safety and efficacy of DES in high-risk subgroups like diabetics, and patients with stent thrombosis (ST) and non-ST segment elevation, myocardial infarctions or complex lesions."

The demand for solid data, and not more randomized trials, was emphatically put to journalists during a press conference on "Coronary stents: Safety and Long-term Results," by Jean Marco, MD, director of the annual Paris Course on Revascularization (EuroPCR) meeting and founder of the interventional cardiology unit at the Clinique Pasteur (Toulouse, France).

"We need 30,000 patients measured for not less than 12 parameters before we will have the evidence we need for practice guidelines," said Marco.

William Wijns, MD, president of the European Association for Percutaneous Cardiovascular Interventions (EAPCI), the sponsor of EuroPCR, said, "The question is when will we be ready such a trial. It will be years before we will have such results, many years."

Wijns took up one side of a debate at the ESC congress titled "Drug-eluting Stents and Diabetes: Pros and Cons," arguing what he called an extreme position that DES should not be used at all for diabetic patients.

Both he and his opponent in the debate, Sigmund Silber, MD, of Mueller Hospital (Munich), started out agreeing, again, that there was insufficient data to even be debating the issue of DES for diabetics.

Wijns went on to say, "It is naive, and even arrogant, to think that with a piece of metal, coated with a drug or not, that we are going to change this complex coronary condition. By the time a diabetic patient hits the cath lab, he already has a 20-year history with this condition."

A special ESC forum on DES, held at the organization's European Heart House in Sophia Antipolis in late-September 2007, reviewed data on long-term efficacy and safety with the goal of identifying specific indications, to specify guidelines for current and possible future trial design, and significantly, to review the DES registration process in Europe.

The conclusions of the forum are to be published in an upcoming edition of the European Heart Journal, although Wijn, who is the lead author, declined to specify when the text would finally be approved for the meeting held almost one year ago.

In his comments, DiMario hinted at some of the findings of the task force set up during the ESC forum.

He said ESC will ask for randomized controlled trials that have fewer inclusion and eclusion criteria, the so-called "all-comers" trials similar to the just-released SYNTAX trial.

DiMario said cardiologists will ask that these studies provide data on hard end-points, such as death, cerebrovascular accident and myocardial infarction (MI), between three and five years, and also similar to SYNTAX, and that randomized trials be followed by large-scale all-comers registries.

He also reported that ESC will promote unified criteria for assessment of DES to be defined by European Commission for the Competent Authorities of the Member States and the Notified Bodies who issue the CE mark allowing products to be sold and distributed in Europe.

DiMario said future initial market approvals of DES in Europe might be based on assessment of restenosis from angiography or intraveneous ultrasound, or neointimal formation and stent coverage using optical coherence tomography or endothelial function studies.

Similar to the guidelines for clinical trials, ESC would recommend to the regulatory authorities that these assessments of products for initial market approvals include one-year clinical follow up and that data should be followed by the assessment of death, MI and stent thrombosis over longer follow-up periods, extending out to five years.