Vascular function and mortality in haemodialysis patients: a pilot study.

Background: Haemodialysis patients often have impaired vascular function that can contribute to mortality. Endothelial-dependent and -independent vascular function can be assessed using the brachial artery reactivity (BAR) technique that measures flow-mediated dilatation (FMD) and the response to glyceryl trinitrate (GTN), respectively.

Aims: The aim of this pilot study was to determine whether BAR measurements in haemodialysis patients were associated with mortality.

Methods: Brachial artery responses to FMD and administration of GTN were assessed in consecutive haemodialysis patients. Patients were then followed up to 18 months after BAR measurements.

Results: Seventeen patients were included in the study. After 18 months of follow-up, patients were divided into two groups: survived (n=12) and deceased (n=5). Patients who survived had a significantly greater median percentage vasodilatation to GTN than those who died (19.1% vs 8.8%; P=0.04); and a significantly greater median area under the diameter change-time curve (318 vs 146 mm/s; P=0.03). However, there were no significant differences between survivors and deceased in median percentage vasodilation to FMD (6.0% vs 4.3%; P=0.21), time to peak dilation (45 vs 40s; P=0.66) or area under the diameter change-time curve (35.5 vs 20 mm/s; P=0.29).

Conclusion: In this pilot study in a small group of haemodialysis patients, endothelial-independent vasodilatory response to GTN was associated with mortality and was of better prognostic value than the endothelial-dependent response to FMD. This finding needs to be investigated in a larger cohort.