Plasma somatostatin in advanced heart failure: association with cardiac filling pressures and outcome

BACKGROUND: Somatostatin inhibits intestinal motility and hormonal secretion and is a potent arterial vasoconstrictor of the splanchnic blood flow. It is unknown if somatostatin concentrations are associated with central hemodynamic measurements in patients with advanced heart failure (HF).

METHODS: A prospective study of HF patients with a left ventricular ejection fraction (LVEF) <45% referred to right heart catheterization (RHC) for evaluation for heart transplantation (HTX) or left ventricular assist device (LVAD).

RESULTS: Fifty-three patients were included with mean LVEF 18 ± 8% and majority in NYHA-class III-IV (79%). Median plasma somatostatin concentration was 18 pmol/L. In univariable regression analysis, log(somatostatin) was associated with increased central venous pressure (CVP; r2 = 0.14, p = 0.003) and a reduced cardiac index (CI; r2 = 0.15, p = 0.004). When adjusted for selected clinical variables (age, gender, LVEF, eGFR and BMI), log(somatostatin) remained a significant predictor of CVP (p = 0.044). Increased somatostatin concentrations predicted mortality in multivariable models (hazard ratio: 5.2 [1.2-22.2], p = 0.026) but not the combined endpoint of death, LVAD implantation or HTX.

CONCLUSIONS: Somatostatin concentrations were associated with CVP and CI in patients with HF. The pathophysiological mechanism may be related to congestion and/or hypoperfusion of the intestine. Somatostatin was an independent predictor of mortality in advanced HF.