Update 2000: Changes in patients undergoing coronary artery bypass grafting: 1987–1990

Abstract

As Originally Published in 1994: Changes in Patients Undergoing Coronary Artery Bypass Grafting: 1987–1990 by Dennis L. Disch, MD, Gerald T. O’Connor, PhD, DSc, John D. Birkmeyer, MD, Elaine M. Olmstead, BA, Drew G. Levy, MPH, and Stephen K. Plume, MD, for the Northern New England Cardiovascular Disease Study Group. Departments of Medicine, Surgery, and Community and Family Medicine, the Program in Medical Information Science, and the Center for Evaluative Clinical Sciences, Dartmouth–Hitchcock Medical Center, Lebanon, New Hampshire, and the US Department of Veterans Affairs Medical Center, White River Junction, Vermont A prospective study of 7,590 consecutive patients undergoing isolated coronary artery bypass grafting at five medical centers in Maine, New Hampshire, and Vermont between July 1987 and December 1990 assessed changes in patient characteristics over time. Variables included age, sex, surgical priority, ejection fraction, left ventricular end-diastolic pressure, and left main coronary artery stenosis of 90% or greater. Trends were assessed for each variable and for predicted mortality using linear regression. The mean age increased significantly, whereas ejection fraction decreased. The percentage of urgent cases increased, whereas the elective cases became less frequent. No changes were observed in the percentages of emergent cases, female patients, or patients with severe left main coronary artery disease. The predicted in-hospital mortality rose significantly from 4.2% to 5.2% ( p 0.001). The increase in urgent surgical intervention was the most substantial contributor. Subgroup analyses did not support a systematic misclassification of elective patients into the urgent group. This study demonstrates that the characteristics of the cohort of patients undergoing coronary artery bypass grafting changed substantially from 1987 to 1990. These changes should be considered when interpreting surgical outcomes.