Improved clinical outcome after widespread use of coronary-artery stentingin Canada

Background: The introduction and refinement of coronary-artery stenting dra matically changed the practice of percutaneous coronary revascularization i n the mid-1990s. We analyzed one-year follow-up data for all percutaneous c oronary interventions performed in a large, unselected population in Canada to determine whether the use of coronary stenting has been associated with improved outcomes. Methods: Prospectively collected data on all percutaneous coronary interven tions performed on residents of British Columbia, Canada, between April 199 4 and June 1997 were linked to province-wide health care data bases to prov ide the date of the following end points: subsequent target-vessel revascul arization, myocardial infarction, and death. Base-line characteristics and procedural variables were identified and Kaplan-Meier survival curves were generated for 9594 procedures divided into seven groups, one for each seque ntial half-year period. Results: The overall burden of coexisting illnesses remained stable through out the study period. A large increase in the rate of coronary stenting (fr om 14.2 percent in the period from April to June 1994 to 58.7 percent in th e period from January to June 1997) was associated with a significant reduc tion in the rate of adverse cardiac events at one year (from 28.8 percent t o 22.8 percent; adjusted relative risk, 0.79; 95 percent confidence interva l, 0.69 to 0.90; P<0.001). This reduction in adverse events was exclusively due to a large reduction in subsequent target-vessel revascularization (fr om 24.4 percent to 17.0 percent; adjusted relative risk, 0.72; 95 percent c onfidence interval, 0.62 to 0.83; P<0.001) without significant changes in t he overall rates of myocardial infarction (5.4 percent, P=0.28) or death (3 .9 percent, P=0.65). Conclusions: The need for target-vessel revascularization during one year o f follow-up after percutaneous coronary intervention decreased during the m id-1990s. The reduction was coincident with the introduction and subsequent widespread use of coronary stenting. (N Engl J Med 1999;341:1957-65.) (C)1 999, Massachusetts Medical Society.