Mitral valve velocity time integral and passive leg raise as a measure of volume responsiveness.

Background: Fluid responsiveness is an important topic for clinicians. Aggressive hydration has been shown to lead to worse outcomes. The aim of this study was to investigate the sensitivity and specificity of mitral valve (MV) velocity time integral (VTI) as a non-invasive marker of volume responsiveness.
Methods: This was a prospective observational study conducted in a tertiary emergency department. End-stage renal disease patients presenting to the emergency department requiring emergent hemodialysis were enrolled. A focused echocardiogram was done on enrolled patients. Two sets of measurements were obtained before and after hemodialysis. During each scanning session, the left ventricular outflow tract and the mitral valve VTI were obtained before and after a passive leg raise maneuver.
Results: 54 patients were enrolled, of which, 30 (55%) were male. The mean age was 47.4 years. The mean volume of fluid removed was 3.89 ± 0.91 L. All patients had a diagnosis of hypertension, 22 (41%) patients were diabetic, 14 (26%) patients had coronary artery disease, and 19 (35%) patients had congestive heart failure. The mean change in LVOT VTI was 1.83% (95% CI 0.12-3.55) in the pre-dialysis group and 15.05% (95% CI 12.76-17.34) in the post-hemodialysis cohort. The mean change in MV VTI was 3.74% (95% CI 2.84-4.65) in the pre-dialysis cohort and 12.95% (95% CI 11.50-14.39) in the post-dialysis cohort. For patients who had < 4 L removed, the mean delta LVOT VTI post-hemodialysis was 12.64% (95% CI 9.79-15.49) and the mean delta MV VTI was 10.48% (95% CI 8.28-12.69). For patients who had > 4 L removed, the mean delta LVOT VTI was 16.84% (95% CI 13.47-20.22) and the mean MV VTI was 14.77% (95% CI 13.03-16.51). Mitral valve VTI with PLR was found to have a sensitivity of 89.18% and a specificity of 94.11% in detecting volume responsiveness.
Conclusion: Mitral valve velocity time integral in conjunction with passive leg raise seem to correlate with volume responsiveness in hemodialysis patients.