Venous Transvascular Autonomic Modulation (TVAM), Initial Assessment and Safety

Authors: Michael A. Arata, M.D.

Background

Patients undergoing central venous angioplasty (CVA) have demonstrated improvement in autonomic parameters. We hypothesize that this results from stimulation of low pressure baroreceptors during balloon inflation. This report describes the assessment of the autonomic effect of CVA using HRV parameters. Further, the veins were treated independent of anatomic abnormality deviating from conventional angioplasty. Herein we detail the safety of this approach.

Methods

131 patients exhibiting symptoms of autonomic dysfunction were treated and assessed by HRV analysis. Dilation of each central vein (internal jugular, azygos and renal veins) occurred regardless of the presence of vascular abnormalities. The treatment’s objective was to dilate 10-25% beyond vessel area, as determined by intravascular ultrasound. The effect upon ANS function was indicated by HRV parameters as the outcomes of interest. Data are presented as mean ± sd. The distribution of each parameter was checked for normality. The before and after measurements of each parameter were compared using pair t-test for normal distribution and Wilcoxon signed rank test for skewed distribution. All statistical testing was performed at a two-sided 5% level of significance and used Statistical Analysis System version 9.3 software (SAS Institute, Cary, NC).

Results

The CVA procedure was successfully completed in all cases (technical success 100%). Post-treatment HRV analysis demonstrated an objective response by increases in MCR, E/I and postural components, MCR reaching statistical significance of 0.75±2.1, P <0.01 (Table 1). Acute adverse events did not occur during any of the procedures (0.0% acute adverse events).

Conclusion

The autonomic effect of CVA was demonstrated by HRV analysis. CVA with dilation of vessel independent of morphology appears safe. Validation and elucidation of the treatment effect is warranted, in light of the lack of definitive treatment options for autonomic dysfunction patients.

Table 1

HRV Parameters

Preprocedure (mean±std)

Postprocedure (mean±std)

HRV change (mean±std) with P value

MCR 2.23 2.99  0.75±2.1, P <0.01†
E/I 1.09 1.10  0.75±2.1, P 0.38*
Valsalva 1.77 1.70  -0.08±0.57, P 0.13†
Standing 1.56 1.64  0.09±3.25, P 0.1*

† Paired T-Test
*Wilcoxon Signed Rank Test

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