Preoperative B-type natriuretic peptide levels are associated with outcome after total cavopulmonary connection (Fontan)

Abstract

Objective: The study objective was to determine the association between preoperative B-type natriuretic peptide levels and outcome after total cavopulmonary connection. Surgical palliation of univentricular cardiac defects requires a series of staged operations, ending in a total cavopulmonary connection. Although outcomes have improved, there remains an unpredictable risk of early total cavopulmonary connection takedown. The prediction of adverse postoperative outcomes is imprecise, despite an extensive preoperative evaluation.

Methods: We prospectively enrolled 50 patients undergoing total cavopulmonary connection. We collected preoperative clinical data, preoperative plasma B-type natriuretic peptide levels, and postoperative outcomes, including the incidence of an adverse outcome within 1 year of surgery (defined as death, total cavopulmonary connection takedown, or the need for cardiac transplantation).

Results: The mean age of patients was 4.7 years (standard deviation, 2.1 years). The median (interquartile range) preoperative B-type natriuretic peptide levels were higher in patients who required total cavopulmonary connection takedown and early postoperative mechanical cardiac support (n = 3; median, 55; interquartile range, 42-121) compared with those with a good outcome (n = 47; median, 11; interquartile range, 5-17) (P < .05). A preoperative B-type natriuretic peptide level of 40 pg/mL or greater was highly associated with the need for total cavopulmonary connection takedown (sensitivity, 100%; specificity, 93%; P < .05), yielding a positive predictive value of 50% and a negative predictive value of 100%. Higher preoperative B-type natriuretic peptide levels also were associated with longer intensive care unit length of stay, longer hospital length of stay, and increased incidence of low cardiac output syndrome (P < .05).

Conclusions: Preoperative B-type natriuretic peptide blood levels are uniquely associated with the need for mechanical support early after total cavopulmonary connection and total cavopulmonary connection takedown, and thus may provide important information in addition to the standard preoperative assessment.

FIGURE 1. Preoperative BNP levels are higher in patients with adverse outcome in the early postoperative period following TCPC

Comparisons of preoperative BNP levels between patients with a good outcome (n = 47) and an adverse outcome (n = 3) after TCPC. Horizontal lines represent median values and interquartile ranges are represented with shaded boxes. An adverse outcome is defined as a failed TCPC requiring an intervention within 12 months of the original procedure.

FIGURE 2. A preoperative BNP level ≥ 40 pg/ml is highly associated with adverse outcome following TCPC (Sensitivity = 100%; Specificity = 93%)

A preoperative BNP cutoff value of 40 pg/mL had a sensitivity of 100% and a specificity of 93% for predicting an adverse outcome (area under the curve: 0.96, 95% CI 0.91–1.0).