Intestinal fatty acid binding protein is associated with infarct size and cardiac function in acute heart failure following myocardial infarction.

BACKGROUND: In acute heart failure (HF), reduced cardiac output, vasoconstriction and congestion may damage the intestinal mucosa and disrupt its barrier function. This could facilitate the leakage of bacterial products into circulation and contribute to inflammation and adverse cardiac remodelling. We aimed to investigate gut leakage markers and their associations with inflammation, infarct size and cardiac function. METHODS: We examined 61 ST-elevation myocardial infarction (STEMI) patients who developed acute HF within 48 hours of successful percutaneous coronary intervention (PCI). Serial blood samples were taken to measure lipopolysaccharide (LPS), LPS-binding protein (LBP), soluble cluster of differentiation 14 (sCD14) and intestinal fatty acid binding protein (I-FABP). Cumulative areas under the curve (AUCs) from baseline to day 5 were calculated. Serial echocardiography was performed to assess left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and wall motion score index (WMSI). Single-photon emission CT (SPECT) was performed at 6 weeks to determine infarct size and LVEF. RESULTS: I-FABP(AUC) correlated positively with infarct size (r(s)=0.45, p=0.002), GLS (r(s)=0.32, p=0.035) and WMSI (r(s)=0.45, p=0.002) and negatively with LVEF measured by SPECT (r(s)=-0.40, p=0.007) and echocardiography (r(s)=-0.33, p=0.021) at 6 weeks. LPS(AUC), LBP(AUC) and sCD14(AUC) did not correlate to any cardiac function marker or infarct size. Patients, who at 6 weeks had above median GLS and WMSI, and below-median LVEF measured by SPECT, were more likely to have above median I-FABP(AUC) during admission (adjusted OR (aOR) 5.22, 95% CI 1.21 to 22.44; aOR 5.05, 95% CI 1.25 to 20.43; aOR 5.67, 95% CI 1.42 to 22.59, respectively). The same was observed for patients in the lowest quartile of LVEF measured by echocardiography (aOR 9.99, 95% CI 1.79 to 55.83) and three upper quartiles of infarct size (aOR 20.34, 95% CI 1.56 to 264.65). CONCLUSIONS: In primary PCI-treated STEMI patients with acute HF, I-FABP, a marker of intestinal epithelial damage, was associated with larger infarct size and worse cardiac function after 6 weeks.