番茄社区

WASHINGTON -- A year after implant, a everolimus-eluting bioreabsorbable scaffold (Absorb) was as good as a everolimus-eluting metal stent (Xience), but may have been more effective at reducing angina, researchers reported here.

The findings emerged from the first randomized trial comparing the two technologies -- results that come 4 years after the Absorb bioresorbable scaffold received approval in Europe -- and were reassuring for a technology that has already had "widespread dissemination without randomized comparison data," said , of Imperial College in London, and colleagues.

Serruys reported the ABSORB II results at a late-breaking clinical trials plenary session at the Transcatheter Cardiovascular Therapeutics (TCT) meeting.

The primary endpoints of the were angiographic 3-year measurements, but recognizing the scaffold's widespread use -- Serruys estimated 100,000 implants in use, while , TCT director, put the figure at 70,000 -- the ABSORB II investigators decided to "report the secondary clinical endpoints at 1 year in order to provide the medical community with the first randomized data on the device," they said.

The trial enrolled 501 patients in the intent-to-treat cohort; 335 were randomized to Absorb and 166 to Xience. Six patients in the Absorb arm and one patient in the Xience arm withdrew consent. And one Xience patient died so that at 1 year, 329 Absorb patients and 164 Xience patients were evaluable.

Among those 1-year findings:

• No major difference in device success with B1/B2 lesions: 99% for Absorb versus 100% with Xience
• Significant differences in acute gain by angiography (QCA): 1.15 ± 0.4 mm for Absorb versus Xience 1.46 ± 0.4 mm for Xience (P<0.001)
• Significant differences in intravascular ultrasound (IVUS): 2.9 ± 1.3 mm² for Absorb and 3.6 ± 1.3 mm² for Xience (P<0.001)

Although exercise performance and angina status as assessed by the Seattle Angina Questionnaire (SAQ) were comparable, there was a cumulative difference in nitrate use that was significant at 6 months (17.8% versus 26.7%, P=0.02).

Serruys said he was skeptical about the angina difference and at 12 months the angina rate still favored Absorb numerically, but it was no longer significant,(19.5% versus 26.2%, P=0.09).

But several discussants expressed their belief that the resorbable technology was associated with less angina.

director of the Heart & Vascular Division at Scottsdale Healthcare in Arizona, told 番茄社区 that the decrease in angina has been observed in registry trials.

, executive director of interventional cardiovascular programs at Brigham and Women's Hospital in Boston told 番茄社区, that although the ABSORB II is a "small study," he found it very reassuring that there was "no safety issue with the bioresorbable scaffold."

Bhatt, who was not involved in the study, noted that there were only two documented definite scaffold thromboses, one within 24 hours and one within 48 hours.

The average age of ABSORB II patients was 61, and 75% were men. About one in five had diabetes and roughly the same percentage of patients had unstable angina at baseline. The majority of patients, roughly 84%, had single vessel disease.

Differences in both the maximum diameter of the last balloon used (3.08 mm for Absorb versus 3.16 mm for Xience, P=0.02) and atmospheres (14.23 versus 15.03 P=0.01) suggested that operators had some level of caution when deploying the Absorb scaffold, Serruys said.

Comment