Changing Volumes, Risk Profiles, and Outcomes of Coronary Artery Bypass Grafting and Percutaneous Coronary Interventions

Abstract

This study analyzed and quantified perceptions that evolving percutaneous coronary intervention technologies changed referral patterns of patients with coronary artery disease and adversely impacted volumes, risk profiles, and outcomes of patients undergoing coronary artery bypass grafting surgery (CABG). Washington State's prospective clinical registry was used to analyze volumes, risk profiles, and outcomes of all patients undergoing isolated CABG and percutaneous coronary intervention. A total of 154,602 revascularization procedures were performed between 1999 and 2007. Total revascularizations procedures (percutaneous coronary intervention plus CABG) increased by 32% (from 14,084 in 1999 to 18,620 in 2007). Compared with 1999, by 2007 CABG volume decreased by 37%, while percutaneous coronary intervention volume increased by 71%. The ratio of percutaneous coronary intervention to CABG increased by 2.7-fold from 1.7:1 to 4.6:1 (p < 0.0001). Three time intervals were compared (1999-2000, 2001-2003, 2004-2007). For patients undergoing CABG, the prevalence of diabetes (28% to 36%), hypertension (66% to 76%), and three-vessel or left main disease (57% to 68%) increased significantly (p < 0.0001 for all). Female sex (28% to 24%), congestive failure (24% to 13%), and smoking (64% to 59%) decreased significantly (p < 0.0001 for all), whereas patients' age, low ejection fraction, and use of intraaortic balloon pump were unchanged. Although mortality (2.4% to 2.2%; p = 0.79), return to the operating room (3.4% to 3.6%; p = 0.41), and need for postoperative hemodialysis (1.2% to 1.0%; p = 0.44) were unchanged, the incidences of stroke (1.9% to 1.3%; p = 0.01), myocardial infarction (1.7% to 0.8%; p < 0.0001), transfusion (40% to 34%; p < 0.0001), and extubation within 6 hours (43% to 60%; p < 0.0001) improved significantly in the past 9 years. Despite significant reduction in both the volume and ratio of patients referred for surgical revascularization, risk profiles of patients undergoing isolated CABG in Washington State changed only modestly. Coronary artery bypass grafting mortality was not adversely affected, and morbidity was reduced.