Correlation Between NT-Pro BNP Levels and Left Ventricular Wall Stress, Sphericity Index and Extent of Myocardial Damage: A Magnetic Resonance Imaging Study

Abstract 

Background

To determine the relationship between N-terminal pro-brain natriuretic peptide (NT-pro BNP) levels and left ventricular wall stress, sphericity index, function, and extent of myocardial damage in patients with coronary artery disease and abnormal left ventricular wall motion.

Methods and Results

All patients underwent cardiac magnetic resonance imaging (CMR). Measurements of sphericity index and wall stress were performed. Percentages of myocardial scarring were calculated from delayed-enhancement images. Correlations between log NT-pro BNP levels and various parameters were evaluated. There were 125 patients with an average age of 62.6 ± 9.6 years. Median levels of NT-proBNP were 1012 pg/mL. Average left ventricular ejection fraction (LVEF) was 37 ± 14.4%. Log NT-proBNP levels had positive correlations with wall stress, sphericity index, left ventricular dimension, volume, mass, wall motion score, extent of myocardial scarring, and age, and had negative correlations with creatinine clearance, LVEF, stroke volume, and body size. Multiple linear regression analysis showed that diastolic and systolic wall stress and systolic sphericity index were independent predictors for log NT-proBNP levels.

Conclusions

NT-proBNP levels strongly correlated with left ventricular wall stress and moderately correlated with sphericity index.

Key Words: BNP, NT-proBNP, magnetic resonance imaging, wall stress, sphericity index, left ventricular ejection fraction