Intermediate and high peri-operative cardiac enzyme release following isolated coronary artery bypass surgery are independently associated with higher one-year mortality

• Main Authors: Stables RH, Hine TJ, Grayson AD, Palmer ND, Oo AY, Newall N, Fabri BM, Ramsdale DR
• Format: Article
• Language: English
• Published: BMC 2006-08-01
• Series: Journal of Cardiothoracic Surgery
• Online Access: http://www.cardiothoracicsurgery.org/content/1/1/20

<p>Abstract</p> <p>Background</p> <p>The relationship between cardiac enzyme (CE) release following coronary artery bypass surgery (CABG) and medium term outcome is unclear. We sought to determine the relationship between post-operative CE release and one-year survival following isolated CABG.</p> <p>Methods</p> <p>Over three years 3,024 consecutive patients underwent isolated CABG. Patient characteristics were prospectively recorded in a cardiac surgical database. CE release, taken as the highest single measurement recorded in the first 24 hours post-op, was abstracted from an electronic archive. All cause mortality was taken from a national registry of deaths.</p> <p>Results</p> <p>Data were complete for 2,860 (94.6%) patients. CK-MB isoenzyme (reference range 5–24 U/l) was recorded in 2,568 (89.8%), total CK in 292 (10.2%).</p> <p>CE release three or more times the upper limit of the reference range (ULR) were recorded in 498 (17.4%) patients, 163 (5.7%) patients had CE more than six times ULR. There were 122 deaths (4.3%). Cox proportional hazards analysis showed that CE release 3–6 times ULR (adjusted HR 2.1 [95% CI: 1.6 to 2.6], p = 0.002) and CE release six or more times the ULR (adjusted HR 5.0 [95% CI: 4.5 to 5.4], p < 0.001) were independently associated with increased one-year mortality.</p> <p>Conclusion</p> <p>Cardiac enzyme release following CABG is associated with increased one-year all-cause mortality. The definition of peri-operative myocardial infarction following CABG should include elevation of CK-MB three or more times the upper limit of normal.</p>