The Correlation between Preoperative Plasma Leptin and hsCRP as Predictors of Postoperative Myocardial Infarction in Patients Undergoing Cardiac Surgery (Lephs-MI study)

Postoperative cardiovascular complications are major problems associated with morbidity and mortality, especially in patients undergoing high-risk cardiac surgery. Many reports have shown a significant correlation between plasma leptin & high-sensitivity C-reactive protein (hsCRP) with the severity of myocardial infarction (MI), but no previous studies regarding the correlation between both biomarkers and postoperative MI have been reported. Objectives: To assess the correlation between plasma leptin and hsCRP as a predictor of postoperative myocardial infarction and other postoperative major adverse cardiac events (MACE) within 30 days after cardiac surgery. Methods: Every consecutive patient who underwent cardiovascular surgery from February 1, 2009 to January 31, 2010 was recruited. Plasma leptin and hsCRP levels were measured in the morning on the day of surgery. Baseline demographic data including perioperative and postoperative complications were reviewed and analyzed. Results: 105 patients were enrolled. The mean age was 59 ± 16 years. The male to female ratio was 3:1 with mean heart rate 75 ± 13 bpm, mean left ventricle ejection fraction (LVEF) 56 ± 16%, mean preoperative creatine kinase MB 5.85 ± 16.32 ng/ml, plasma leptin 9.55 ± 10 ng/ml and hsCRP 9.87 ± 22.65 g/dL. Cardiac complications occurred in 53.33% of patients (acute coronary syndrome 25%, arrhythmia 75%, congestive heart failure 46%, cardiac tamponade2%, and others 9%), while non-cardiac complications occurred in 43% of patients. Deaths were found in 7% of cases (cardiac 4%, non-cardiac 3%), and re-admission in 16% of cases (cardiac 6%, non-cardiac 10%). In multivariate analysis, risk factors for cardiac complications were intensive care unit (ICU) admission time (HR 1.002, 95%CI 1.001-1.003, p = 0.029) and plasma leptin level (p = 0.013), especially a high leptin level >14 ng/ml (HR 2.89, 95%CI 1.3-6.41, p = 0.009). Leptin is an independent factor associated with cardiac complications after adjusting for other factors, and when combined with hsCRP; the high levels of both leptin and hsCRP showed the worst prognosis. Conclusion: In patients who underwent cardiac surgery, high plasma leptin level may be used as a predictor of postoperative