Abstract 3048: A Prospective Randomized Trial of Blood B-type Natriuretic Peptide Levels Informing Management after Elective Coronary Artery Bypass Grafting
Background: Measuring B-type natriuretic peptide (BNP) levels is valuable in diagnosis, risk stratification, and management of patients with congestive heart failure.
Hypothesis: Knowledge of peri-operative levels of BNP by physicians in patients undergoing elective coronary artery bypass grafting (CABG) influences care processes and clinical outcomes.
Methods: Patients undergoing CABG between the ages of 18 –79, with left ventricular ejection fraction (LVEF) ≥ 40%, serum creatinine ≤ 2.0 mg/dl, and without a history of myocardial infarction within six months or a history of atrial fibrillation (AF) at any time were eligible for this prospective randomized trial. Of 150 patients recruited, 75 were randomized to BNP-informed group with levels obtained immediately before surgery, 12, and 72 hours post-operatively. The remaining 75 patients were in a control group and had no routine BNP measurements. Cardiovascular surgeons and cardiologists were presented the BNP results and encouraged to integrate them into clinical decision making. Clinical outcomes were pre-specified as initial hours of post-operative ventilation, re-intubation, weight change from baseline, creatinine change from baseline, occurrence of post-operative AF, post-operative hospital length-of-stay, in-hospital mortality, and re-admission during the first 30 days after discharge.
Results: Both groups were similar in age, BMI, LVEF, pump time, use of intra-aortic balloon pump or inotropes, and prophylactic beta-clocker or amiodarone. The mean BNP values were 63.7±91.4, 131.3±103.4, 315.6±238.4 pg/ml at baseline, 12 and 72 hours after CABG. The rates of post-operative AF were 5/75 (6.7%) and 15/75 (20.0%), in the BNP-informed and control groups, respectively, p=0.02. The median surgery-to-discharge length-of-stays were 5.8±1.8 days and 6.6± 2.5 days respectively, in the BNP-informed and control groups, p = 0.04. There was no difference between the groups in regards to other pre-specified outcomes.
Conclusion: Provision of peri-operative BNP values to cardiothoracic surgeons and cardiologists caring for patients after CABG reduces the occurrence of post-operative AF, and shortens the post-operative length-of-stay.