Tricuspid regurgitation contributes to renal dysfunction in patients with heart failure.

BACKGROUND: In heart failure (HF), renal dysfunction is associated with an adverse prognosis. Impaired renal perfusion from left ventricular dysfunction is thought to be a principal underlying mechanism. Less is known about the influence of venous congestion, including the potential contribution of tricuspid regurgitation (TR). METHODS AND RESULTS: Echocardiograms and a simultaneous (+/-1 day) blood sample from 196 HF patients were analyzed. Patients with at least moderate TR (n = 78) had larger right-sided cardiac cavities, higher right ventricular systolic pressure, lower estimated glomerular filtration rate (eGFR), higher serum urea nitrogen (SUN), and SUN/creatinine ratio than patients with less than moderate TR (n = 118). In multivariate linear regression analysis, TR severity (P = .003), older age (P < .001), and loop diuretic use (P = .008) were independently associated with lower eGFR, and use of inhibitors of the renin-angiotensin-aldosterone system was associated with higher eGFR (P = .001). TR severity (P < .001) and older age (P < .001) were independently associated with higher SUN. TR severity (P = .004) and smaller left ventricular end-diastolic diameter (P = .048) were independent predictors of a higher SUN/creatinine ratio (P = .004). CONCLUSIONS: Although a causal relationship cannot be proven, we suggest that significant TR contributes to renal dysfunction in HF patients, probably by elevation of central and renal venous pressure.

Augmentation of endothelial function following exercise training is associated with increased L-arginine transport in human heart failure.

We have reported previously a decrease in the clearance of the NO (nitric oxide) precursor L-arginine in the forearm circulation of CHF (congestive heart failure) patients, suggesting a potential rate-limiting mechanism contributing to the common finding of endothelial dysfunction in CHF. Given data that show exercise training augments endothelial function in CHF, the aim of the present study was to investigate whether these improvements were due to an increase in L-arginine transport. Measures of L-arginine transport, endothelial function and exercise capacity were repeated before and after 8 weeks of "usual living" or exercise training in 21 CHF patients [NYHA (New York Heart Association) class II/III]. Exercise capacity (6-min walk test) increased following exercise training (496+/-21 to 561+/-17 m; P=0.005), whereas the control group demonstrated no change [488+/-18 to 484+/-21 m; P=ns (not significant)]. Basal FBF (forearm blood flow) remained stable following exercise training (2.68+/-0.55 to 2.46+/-0.32 ml.min(-1).100 ml(-1) of tissue) and "usual living" (2.16+/-0.37 to 2.91+/-0.55 min(-1).100 ml(-1) of tissue). FBF responses to ACh (acetylcholine) increased following exercise by 49.6+/-17.7% (area under curve; P=0.01) demonstrating augmented endothelial function. FBF responses to SNP (sodium nitroprusside) were also improved following exercise training (30.8+/-8.2%; P=0.02). There was no change in vascular function in the "usual living" group. The clearance of L-arginine was significantly increased following involvement in the exercise programme (69.4+/-7.8 to 101.0+/-9.5 ml/min; P=0.04), whereas there was no change in the "usual living" group (78.4+/-17.5 to 81.0+/-14.9 ml/min; P=ns). In conclusion, the augmentation in endothelial function observed following exercise may be due, in part, to an increase in the transport of L-arginine in CHF patients.

Exercise training increases arterial compliance in patients with congestive heart failure.

Systemic arterial compliance (SAC) makes an important contribution to cardiac afterload, and thus is a significant determinant of left ventricular work. Previous studies have suggested that arterial compliance may be reduced in patients with congestive heart failure (CHF), and that SAC is increased after a 4-week exercise training programme in healthy, sedentary individuals. The present study aimed to investigate the effects of an 8-week exercise training programme on arterial mechanical properties, left ventricular performance and quality of life in CHF patients. A total of 21 patients with NYHA class II or III CHF (mean+/-S.D. age 55+/-13 years) were randomly allocated to either an 8-week exercise training group or a "usual lifestyle" control group. SAC, as determined non-invasively using applanation tonometry and Doppler aortic velocimetry, increased from 0.57+/-0.11 to 0.77+/-0.14 arbitrary compliance units (mean+/-S.E.M.; P=0.01) in the exercise group, while no change occurred in the control group. Left ventricular structure and function was assessed by echocardiography, and these parameters were unchanged over the 8-week study period. Exercise training significantly increased exercise capacity, measured by a 6-min walking test (474+/-27 to 547+/-34 m; P=0.008). Quality of life, as assessed using the Minnesota Living with Heart Failure Evaluation, demonstrated a decrease in heart failure symptoms from 46+/-7 to 24+/-5 units (P=0.01) following the exercise training programme. These data show that exercise training improves SAC in patients with CHF. The accompanying improvement in exercise capacity may be due, in part, to an improvement in arterial function.