Vascular endothelial growth factor (VEGF), also known as vascular permeability factor leading to plasma leakage and tissue edema is overexpressed in patients with congestive heart failure (CHF). The aim of our study was to investigate the short term effects of positive inotropic therapy on hemodynamics and VEGF plasma levels in patients with low output syndrome.
19 Patients were treated with levosimendan (n=13), milrinone (n=5) or dobutamine (n=3) for 24h. Hemodynamics were obtained with a balloon-tipped pulmonary artery catheter before and 30min, 1h, 6h, 12h, 24h after starting therapy. Blood was collected at baseline and after 24h, VEGF plasma levels were measured using an enzyme linked immunosorbent assay.
Effects of inotropic therapy on hemodynamics and VEGF are shown in the tableTable
Patients (N=19) characteristics at baseline and after 24hbaseline24hP-valueAge64±8Sex (f/m)3/16LVEF %22±3HR (bpm)88±1991±18NSBPm (mmHg)77.3±12.671.3±13.0<0.01mPAP mmHg34.0±6.728.8±6.4<0.01PCWP mmHg24.1±5.918.5±5.4<0.001CO l/min3.3±0.84.6±1.2<0.001SvO2 %57.7±8.865.7±7.8<0.001VEGF pg/ml340.3±87.5264.1±68.8<0.01
Abbreviations: LVEF: left ventricular ejection fraction; HR (bpm): heart rate (beats per minute); mBP: mean blood pressure; mmPAP:mean pulmonary arterial pressure; PCWP: pulmonary capillary wedge pressure; CO: cardiac output; SvO2: mixed venous oxygen saturation; VEGF: plasma vascular endothelial growth factor. The decrease in VEGF was most pronounced in patients with high baseline levels (> median value of 220pg/ml; p<0.01) while no change was seen in patients with initialy low levels. Whereas baseline VEGF levels were not different between ischemic and non-ischemic CHF, a significant decrease was seen in ischemic CHF (from 330.5±78.5 to 242.4±62.6 pg/ml; p<0.05). The same phenomenon was true in patients with de novo CHF (from 378.5±148.6 to 246.1±103.3 pg/ml; p<0.05) compared to those who deteriorated from chronic CHF (p=NS). As to hemodynamics, the decrease in VEGF was only significant (from 373.4±113.3 to 298.7±88.4 pg/ml; p<0.05) in patients responding to therapy (CO increase > 20%) which was paralelled by an increase in SvO2 (from 58.9±1.4 to 67.4±1.4 %; p<0.001).
VEGF plasma levels are reduced by positive inotropic therapy in patients with low output syndrome. The decrease was most pronounced in patients with high VEGF levels, ischemic cardiomyopathy, acute heart failure and in hemodynamic responders.
Conceivably, improved tissue oxygenation may explain the effect of inotropic therapy on VEGF and thereby lead to reduced edema formation.
R.H. Zwick, None.