Serum heart-type fatty acid-binding protein concentration positively correlates with the length of aortic dissection

Background Patients with aortic dissection (AD) often demonstrate positive heart-type fatty acid-binding protein (H-FABP), but its significance is unclear. Methods and Results In 63 of 64 consecutive AD patients, the serum H-FABP concentration was measured and the H-FABP positive rate calculated (cutoff value: 6.2 ng/ml) for each of following factors: (1) with or without dissection of the ascending aorta; and (2) a thrombosed false lumen; (3) length score; (4) presence of shock; (5) malperfusion of limbs; (6) ST elevation and/or depression on electrocardiogram; and (7) renal dysfunction. In total 36 AD patients had a positive H-FABP test. Statistically significant differences in the H-FABP positive rate were observed between those with and without ascending AD (76.7% vs 39.4%, p=0.003), and in the length score (p < 0.001). Multivariate logistic regression test demonstrated that the most significant factor was the length score (odds ratio: 2.239 (95% confidence interval: 1.119-4.481), p=0.023). Moreover, a significant correlation was observed between length score and absolute H-FABP value (r=0.420, p=0.001). Conclusions In patients with AD, an increased serum H-FABP concentration is caused by the protein being released not only from the cardiac muscle but also from skeletal muscle, or possibly the aortic wall. Physicians using H-FABP for detection of myocardial injury need to be aware that patients with a long or ascending AD will show an elevation of H-FABP.