SAPPHIRE Worlwide registry highlights a higher risk of adverse events in symptomatic, older patients after carotid artery stenting

Christopher Metzger
Christopher Metzger

Data from the large SAPPHIRE WW Worldwide registry suggest that age, symptomatic status, and physiological entry criteria represent high risk features for carotid artery stenting. Christopher Metzger, Wellmont CVA Heart Institute, Kingsport, USA, national co-principal investigator of the registry, presented periprocedural results of 15,000 carotid artery stenting patients at the TCT conference in Miami.

Metzger told delegates that carotid artery stenting remains a viable alternative to carotid endarterectomy, especially in patients considered high risk for surgery. However, he said, “Further studies are needed to determine which patients derive the greatest benefit from carotid artery stenting”. Metzger added that carotid artery stenting results continue to improve over time, in part because of operator experience and “the lessons learned”. He noted that SAPPHIRE Worldwide (SAPPHIRE WW) is the largest carotid artery stenting study to date with over 15,000 patients undergoing stenting with cerebral protection.

SAPPHIRE WW is a multicentre, prospective study to evaluate carotid artery stenting with the Precise nitinol stent (Cordis) and the Angioguard XP/RX emboli capture guidewire system. The inclusion criteria is symptomatic patients with stenosis ≥50% or asymptomatic with ≥80% stenosis and high-risk for adverse events for carotid endarterectomy. The primary endpoint is major adverse events including death of any cause, myocardial infarction or stroke to 30 days after the procedure.

Metzger said that, for the first 15,000 patients enrolled in the study, the mean age was 72.3±9.53 years, 61% were male and 30.5% were symptomatic (n=4,569). Also, 55.2% of the patients had coronary artery disease and 4.8% had renal insufficiency.

The results showed that, at 30 days, the major adverse events rate was 4.5%. The rate of death was 1.2%, myocardial infarction was 0.6% and the rate of any stroke was 3.3%.
In a comparison of symptomatic and asymptomatic patients, major adverse events, death, stroke and stroke or death rates were statistically significantly higher in the symptomatic group (p<0.0001). Patients with only physiological risk (ie, heart failure, age ≥75 years, pulmonary disease) also experienced more adverse events than those with anatomic risks only (ie, previous endarterectomy recurrent stenosis, contralateral occlusion), and patients aged over 75 also had higher rates of death and stroke. There was no difference between results for men and women.

“What about myocardial infarction, does it matter?” asked Metzger. In SAPPHIRE WW, he said, 0.6% patients experienced a myocardial infarction after stenting. “This is significantly less than predicted for similar patients receiving carotid endarterectomy. If patients experienced a myocardial infarction, the 30-day mortality was 19%, and one year mortality was 25.4%, similar to what was seen in the CREST trial.”

To conclude his talk, Metzger stated that
the SAPPHIRE WW, approved for 21,000 carotid artery stenting patients at more than 350 centres, is the largest carotid artery stenting trial to date. Enrolment started in 2006 and is ongoing. “SAPPHIRE WW will continue to provide important information which should help to identify patients who can be treated safely with carotid artery stenting,” he said.