Value of brain natriuretic peptide in the perioperative follow-up of children with valvular disease

Objective: To characterize N-terminal pro-brain natriuretic peptide (N-proBNP) and troponin I (TnI) profile following mitral and/or aortic valve surgery and to evaluate correlations with echocardiography measures and outcome criteria. Design and setting: Prospective cross-controlled study in auniversity children's hospital. Patients: Twenty children with acquired valvular disease requiring valvular surgery. Interventions: We prospectively studied clinical, biochemical, and echocardiographic characteristics at baseline and 6, 12, 24 h and 3-4 weeks postoperatively. Results: TnI peaked 6 h after surgery and remained elevated during the first 24 h. N-proBNP was significantly lower 3-4 weeks after surgery than during the perioperative period. Overall, N-proBNP was correlated with the Pediatric Heart Failure Index, left ventricle shortening fraction, left atrium to aorta ratio, left ventricle mass index, end-systolic wall stress, and with outcome measures such as inotropic score, duration of inotropic support, and ICU length of stay. Preoperative N-proBNP was significantly more elevated in patients with complicated outcome than in patients with uneventful postoperative course. Conclusions: In pediatric valvular patients, perioperative N-proBNP is apromising risk stratification predicting factor. It is correlated with evolutive echocardiographic measures, need for inotropic support, and ICU length of sta

Preoperative diastolic function predicts the onset of left ventricular dysfunction following aortic valve replacement in high-risk patients with aortic stenosis

INTRODUCTION: Left ventricular (LV) dysfunction frequently occurs after cardiac surgery, requiring inotropic treatment and/or mechanical circulatory support. In this study, we aimed to identify clinical, surgical and echocardiographic factors that are associated with LV dysfunction during weaning from cardiopulmonary bypass (CPB) in high-risk patients undergoing valve replacement for aortic stenosis. METHODS: Perioperative data were prospectively collected in 108 surgical candidates with an expected operative mortality ≥ 9%. All anesthetic and surgical techniques were standardized. Reduced LV systolic function was defined by an ejection fraction <40%. Diastolic function of the LV was assessed using standard Doppler-derived parameters, tissue Doppler Imaging (TDI) and transmitral flow propagation velocity (Vp). RESULTS: Doppler-derived pulmonary flow indices and TDI could not be obtained in 14 patients. In the remaining 94 patients, poor systolic LV was documented in 14% (n = 12) and diastolic dysfunction in 84% of patients (n = 89), all of whom had Vp <50 cm/s. During weaning from CPB, 38 patients (40%) required inotropic and/or mechanical circulatory support. By multivariate regression analysis, we identified three independent predictors of LV systolic dysfunction: age (Odds ratio [OR] = 1.11; 95% confidence interval (CI), 1.01 to 1.22), aortic clamping time (OR = 1.04; 95% CI, 1.00 to 1.08) and Vp (OR = 0.65; 95% CI, 0.52 to 0.81). Among echocardiographic measurements, Vp was found to be superior in terms of prognostic value and reliability. The best cut-off value for Vp to predict LV dysfunction was 40 cm/s (sensitivity of 72% and specificity 94%). Patients who experienced LV dysfunction presented higher in-hospital mortality (18.4% vs. 3.6% in patients without LV dysfunction, P = 0.044) and an increased incidence of serious cardiac events (81.6 vs. 28.6%, P < 0.001). CONCLUSIONS: This study provides the first evidence that, besides advanced age and prolonged myocardial ischemic time, LV diastolic dysfunction characterized by Vp ≤ 40 cm/sec identifies patients who will require cardiovascular support following valve replacement for aortic stenosis