Temporal Changes in Periprocedural Events in the Carotid Revascularization Endarterectomy Versus Stenting Trial

Abstract

Background and purpose: Post-hoc, we hypothesized that over the recruitment period of the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), increasing experience and improved patient selection with carotid stenting, and to a lesser extent, carotid endarterectomy would contribute to lower periprocedural event rates.

Methods: Three study periods with approximately the same number of patients were defined to span recruitment. Composite and individual rates of periprocedural stroke, myocardial infarction, and death rate were calculated separately by treatment assignment (carotid stenting/carotid endarterectomy). Temporal changes in unadjusted event rates, and rates after adjustment for temporal changes in patient characteristics, were assessed.

Results: For patients randomized to carotid stenting, there was no significant temporal change in the unadjusted composite rates that declined from 6.2% in the first period, to 4.9% in the second, and 4.6% in the third (P=0.28). Adjustment for patient characteristics attenuated the rates to 6.0%, 5.9%, and 5.6% (P=0.85). For carotid endarterectomy-randomized patients, both the composite and the combined stroke and death outcome decreased between periods 1 and 2 and then increased in period 3.

Conclusions: The hypothesized temporal reduction of stroke+death events for carotid stenting-treated patients was not observed. Further adjustment for changes in patient characteristics between periods, including the addition of asymptomatic patients and a >50% decrease in proportion of octogenarians enrolled, resulted in practically identical rates.

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

Keywords: carotid endarterectomy; carotid stenting; myocardial infarction; random allocation; stroke; temporal trends.

© 2015 American Heart Association, Inc.

Figures

Figure 1

Recruitment to CREST by study month, shown by symptomatic status (symptomatic patients black line, asymptomatic patients gray line). Periods of recruitment were defined by tertile of recruitment for symptomatic patients: period 1 was from the beginning of recruitment (December 2000) through January 3rd 2006 (with 212 asymptomatic and 620 symptomatic patients), Period 2 from January 4th, 2006 through March 19th, 2007 (with 494 asymptomatic and 345 symptomatic patients), and Period 3 from March 20th 2007 through July 2008 (with 475 asymptomatic and 356 symptomatic).