Muscle microcirculation alterations increase with disease severity in chronic heart failure patients

Objective

To evaluate skeletal muscle microcirculation by near-infrared spectroscopy (NIRS) in patients with chronic heart failure (CHF).

Background

Skeletal muscle microcirculation is impaired in patients with CHF, and this impairment seems to correlate with disease severity.

Methods

We evaluated 49 patients with CHF (mean age: 58 ± 12 years) and 12 healthy volunteers. Of the CHF patients, 14 had end-stage heart failure (ESCHF) and were undergoing treatment with intermittent inotropic agent infusion during the period of the study protocol. The thenar muscle tissue oxygen saturation (StO₂%) was measured noninvasively by NIRS before, during and after 3-minute occlusion of the brachial artery (occlusion technique).

Results

Patients with ESCHF (n = 14) and CHF (n = 35) presented a significantly lower tissue oxygen saturation (StO₂) than healthy subjects (75 ± 6%, 77 ± 8% and 85 ± 5%, P = 0.001 respectively). The oxygen consumption rate during the occlusion of the brachial artery differed significantly between patients with ESCHF, CHF and healthy subjects (22.4 ± 9%/min, 29 ± 10%/min and 38.1 ± 11.1%/min, P = 0.001 respectively). The reperfusion rate differed significantly between patients with ESCHF, CHF and healthy subjects (302 ± 136%/min, 393 ± 134%/min and 480 ± 133%/min, P = 0.002 respectively).

Conclusion

Peripheral muscle microcirculation assessed by NIRS is impaired in CHF patients. The degree of dysfunction is associated with disease severity and is acutely partially reversed with inotropic agent infusion.