Heart rate variability as a predictor of disease exacerbation in pediatric inflammatory bowel disease

Transcutaneous auricular vagus nerve stimulation attenuates inflammatory bowel disease in children: a proof-of-concept clinical trial

BACKGROUND

Vagus nerve stimulation is an investigational anti-inflammatory therapy targeting the nervous system to modulate immune activity. This study evaluated the efficacy and safety of transcutaneous auricular VNS (ta-VNS) in patients with pediatric-onset Crohn's disease (CD) or ulcerative colitis (UC).

METHODS

Participants were 10-21 years of age with mild/moderate CD or UC and fecal calprotectin (FC) > 200 ug/g within 4 weeks of study entry. Subjects were randomized to receive either ta-VNS targeting the cymba conchae of the external left ear, or sham stimulation, of 5 min duration once daily for a 2-week period, followed by a cross over to the alternative stimulation for an additional 2 weeks. At week 4, all subjects received ta-VNS of 5 min duration twice daily until week 16. Primary study endpoints were clinical remission, and a ≥ 50% reduction in FC level from baseline to week 16. Heart rate variability measurements and patient-reported outcome questionnaires were completed during interval and week 16 assessments.

RESULTS

Twenty-two subjects were enrolled and analyzed (10 CD, 12 UC). Six of 10 with CD had a wPCDAI > 12.5 and 6/12 with UC had a PUCAI > 10 at baseline, correlating to mild to moderate symptom activity. Among the 12 subjects with active symptomatic disease indices at baseline, clinical remission was achieved in 3/6 (50%) with CD and 2/6 (33%) with UC at week 16. Despite all subjects having FC levels ≥ 200 within 4 weeks of enrollment, five subjects (4 UC, 1 CD) had FC levels < 200 at the baseline visit and were excluded from the FC analysis. Of the remaining 17, median baseline FC was 907 µg/g (IQR 411-2,120). At week 16, 11/17 (64.7%) of those with baseline FC ≥ 200 had a ≥ 50% reduction in FC (95% CI 38.3-85.8). In the UC subjects, there was an 81% median reduction in FC vs baseline (833 µg/g; p = 0.03) while in the CD subjects, median reduction in FC at 16 weeks was 51% (357 µg/g; p = 0.09). There were no safety concerns.

CONCLUSION

Noninvasive ta-VNS attenuated signs and symptoms in a pediatric cohort with mild to moderate inflammatory bowel disease.

TRIAL REGISTRATION

NCT03863704-Date of registration 3/4/2019.

Vagal Nerve Activity and Short-Term Clinical Outcomes after Stroke: What Is Left May Not Be Right

Stroke is a leading cause of death worldwide. Multiple factors influence the severity of stroke. Normal functional and biological differences seen between the hemispheres may also be related to stroke severity. In the present study, we examined the differences in the severity of stroke as a function of stroke side, and whether patients' vagal nerve activity moderated such differences. We included 87 patients with an ischemic stroke, whose medical records were retrospectively examined for background information (age, gender), stroke side and severity by NIHSS, length of stay in hospital, inflammation such as C-reactive protein, and vagal nerve activity. The vagal activity was indexed by patients' heart-rate variability (HRV), fluctuations in the intervals between normal heartbeats, derived from patients' ECG. Results revealed that patients with left-side stroke had significantly worse NIHSS scores (10.6) than those with right-sided stroke (7.6, p < 0.05). However, when dividing the sample into those with low versus high HRV (at the median), only when HRV was low, did patients with left-side stroke have a worse NIHSS score (10.9) compared to those with right-sided stroke (6.5, p < 0.05). In contrast, no differences in stroke severity were seen between left stroke (10.2) and right stoke (8.7, p > 0.05), when HRV was high. These results tended to remain the same when statistically controlling for age effects, which was related to NIHSS, but not to the stroke side. These findings suggest that patients with left-sided stroke may have more severe strokes than those with right-sided ones, but that adequate vagal nerve activity may protect against such differences. Possible mechanisms and suggestions for future directions are provided.

Children with inflammatory bowel disease already have an altered arterial pulse wave

Adults with inflammatory bowel disease (IBD) have an increased risk for vascular events. This study aims to evaluate arterial parameters in paediatric IBD. Carotid intima-media thickness (CIMT) was measured by ultrasound, and Arteriograph was used to assess aortic pulse wave velocity (PWVao), brachial and aortic augmentation indexes (AixBrach, AixAo), central systolic blood pressure (SBPao), and heart rate (HR). A total of 161 children were included; 55 (34%) children with newly diagnosed IBD (median age 14.35 (11.88-16.31) years, 53% males), 53(33%) in remission (median age 15.62 (13.46-16.70) years, 66% males), and 53 (33%) controls (median age 14.09 (11.18-14.09) years, 55% males) were recruited into a case-control study. Compared to controls, patients with active disease and those in clinical remission had significantly lower AixBrach and AixAo (P < 0.001, P = 0.009; P < 0.001, P = 0.003). PWVao and CIMT were still normal. HR was higher in both IBD groups than in controls (P < 0.001; P = 0.006). HR positively correlated with disease duration (P = 0.001). In the ordinary least squares regression models, anti-tumour necrosis factor (TNF) α treatment predicted lower peripheral and central systolic blood pressures, in contrast to aminosalicylates and methotrexate. Aminosalicylate treatment predicted increased HR.  Conclusion: Children with IBD have an increased heart rate, a lower augmentation index and, therefore, an altered pulse waveform. In paediatric IBD, arterial stiffness and CIMT are still normal, indicating the potential for adequate IBD treatment to preserve arterial health. What is Known: • Adult patients with inflammatory bowel disease (IBD) have increased carotid intima-media thickness and arterial stiffness, which positively correlates with cardiovascular risk and predicts mortality. Adequate treatment, especially anti-tumour necrosis factor (TNF) α medications, lower these risks. • Children with IBD have impaired endothelial function and reduced heart rate (HR) variability. What is New: • Children with IBD have impaired endothelial function and reduced heart rate (HR) variability. • Anti-TNFα treatment in children and adolescents with IBD lowers systolic pressure, whereas methotrexate and aminosalicylates have the opposite effect. Amiynosalyiciylate treatment also increases HR.