Valentina A. Rossi

Effects of obstructive sleep apnoea on heart rhythm

Symptomatic obstructive sleep apnoea (OSA) has been proven to be a risk factor for hypertension and vascular dysfunction, and has been proposed to be causally related with cardiac arrhythmias and sudden cardiac death. Searches of bibliographical databases revealed that several mechanisms seem to underpin the association between OSA and cardiac arrhythmias: intermittent hypoxia associated with autonomic nervous system activation and increased oxidative stress, which may lead to cardiac cellular damage and alteration in myocardial excitability; recurrent arousals, resulting in sympathetic activation and coronary vasoconstriction; and increased negative intrathoracic pressure which may mechanically stretch the myocardial walls and, thus, promote acute changes in myocardial excitability as well as structural remodelling of the myocardium. Findings from cross-sectional studies suggest a high prevalence of cardiac arrhythmias in patients with OSA and a high prevalence of OSA in those with cardiac arrhythmias. Preliminary evidence from uncontrolled interventional studies suggests that treatment of OSA may prevent cardiac arrhythmias. In conclusion, there is preliminary evidence that OSA is associated with the development of cardiac arrhythmias. Data from randomised controlled studies are needed to definitively clarify the role of OSA in arrhythmogenesis.

The effects of Provent on moderate to severe obstructive sleep apnoea during continuous positive airway pressure therapy withdrawal: a randomised controlled trial

Objectives The aim of this study was to test the effectiveness of Provent, an expiratory nasal resistance valve, to prevent the recurrence of OSA following CPAP withdrawal. Design Randomised, partially blinded, parallel, placebo-controlled trial. Setting Outpatient sleep clinics in the UK (Oxford) and Switzerland (Zurich). Participants 67 patients with OSA receiving CPAP were randomised to one of three groups for 2 weeks: continuing CPAP, Provent or placebo Provent. Main outcome measures Primary outcomes included for Provent versus placebo Provent, OSA severity (oxygen desaturation index (ODI), apnoea–hypopnoea index (AHI)) and Epworth Sleepiness Scale (ESS) score. Secondary outcomes for Provent versus placebo Provent included ODI from ambulatory pulse oximetry and blood pressure (BP). For CPAP versus Provent, or CPAP versus placebo Provent, secondary outcomes included ODI/AHI, ESS and BP. Results 63 patients were included in the per protocol analysis. OSA recurred in the Provent (ODI 35.8, SD 17.4) and placebo Provent (ODI 28.2, SD 18.3) groups, and there was no significant difference in ODI, AHI and ESS between Provent and placebo Provent at 2 weeks (mean difference ODI −1.0, 95% CI −10.0 to +12.0, p=0.85; AHI +3.2, 95% CI −7.7 to +14.1, p=0.52; and ESS −1.4, 95% CI −4.1 to +1.4, p=0.33). ODI from ambulatory pulse-oximetry and BP at 2 weeks were not different in the Provent versus placebo Provent groups. ODI, AHI and BP, but not ESS, were significantly higher in the Provent and placebo Provent groups compared with CPAP. Conclusions Provent cannot be recommended as an alternative short-term therapy for patients with moderate to severe OSA already on CPAP. TrialRegNo NCT01332175.

Predicting Daily Physical Activity in Patients with Chronic Obstructive Pulmonary Disease

Background Objectively measuring daily physical activity (PA) using an accelerometer is a relatively expensive and time-consuming undertaking. In routine clinical practice it would be useful to estimate PA in patients with chronic obstructive pulmonary disease (COPD) with more simple methods. Objectives To evaluate whether PA can be estimated by simple tests commonly used in clinical practice in patients with COPD. Methods The average number of steps per day was measured for 7 days with a SenseWear Pro™ accelerometer and used as gold standard for PA. A physical activity level (PAL) of <1.4 was considered very inactive. Univariate and multivariate analyses were used to examine the relationship between the 6-minute walking distance (6MWD), the number of stands in the Sit-to-Stand Test (STST), hand-grip strength and the total energy expenditure as assessed by the Zutphen Physical Activity Questionnaire (TEEZPAQ). ROC curve analysis was used to identify patients with an extremely inactive lifestyle (PAL<1.4). Results In 70 patients with COPD (21 females) with a mean [SD] FEV1 of 43.0 [22.0] %predicted, PA was found to be significantly and independently associated with the 6MWD (r = 0.69, 95% CI 0.54 to 0.80, p<0.001), STST (r = 0.51, 95% CI 0.31 to 0.66, p = 0.001) and TEEZPAQ (r = 0.50, 95% CI 0.30 to 0.66, p<0.001) but not with hand-grip strength. However, ROC curve analysis demonstrated that these tests cannot be used to reliably identify patients with an extremely inactive lifestyle. Conclusions In patients with COPD simple tests such as the 6-Minute Walk Test, the Sit-to-Stand Test and the Zutphen Physical Activity Questionnaire cannot be used to reliably predict physical inactivity.

Induction of RET Dependent and Independent Pro-Inflammatory Programs in Human Peripheral Blood Mononuclear Cells from Hirschsprung Patients

Hirschsprung disease (HSCR) is a rare congenital anomaly characterized by the absence of enteric ganglia in the distal intestinal tract. While classified as a multigenic disorder, the altered function of the RET tyrosine kinase receptor is responsible for the majority of the pathogenesis of HSCR. Recent evidence demonstrate a strong association between RET and the homeostasis of immune system. Here, we utilize a unique cohort of fifty HSCR patients to fully characterize the expression of RET receptor on both innate (monocytes and Natural Killer lymphocytes) and adaptive (B and T lymphocytes) human peripheral blood mononuclear cells (PBMCs) and to explore the role of RET signaling in the immune system. We show that the increased expression of RET receptor on immune cell subsets from HSCR individuals correlates with the presence of loss-of-function RET mutations. Moreover, we demonstrate that the engagement of RET on PBMCs induces the modulation of several inflammatory genes. In particular, RET stimulation with glial-cell line derived neurotrophic factor family (GDNF) and glycosyl-phosphatidylinositol membrane anchored co-receptor α1 (GFRα1) trigger the up-modulation of genes encoding either for chemokines (CCL20, CCL2, CCL3, CCL4, CCL7, CXCL1) and cytokines (IL-1β, IL-6 and IL-8) and the down-regulation of chemokine/cytokine receptors (CCR2 and IL8-Rα). Although at different levels, the modulation of these “RET-dependent genes” occurs in both healthy donors and HSCR patients. We also describe another set of genes that, independently from RET stimulation, are differently regulated in healthy donors versus HSCR patients. Among these “RET-independent genes”, there are CSF-1R, IL1-R1, IL1-R2 and TGFβ-1, whose levels of transcripts were lower in HSCR patients compared to healthy donors, thus suggesting aberrancies of inflammatory responses at mucosal level. Overall our results demonstrate that immune system actively participates in the physiopathology of HSCR disease by modulating inflammatory programs that are either dependent or independent from RET signaling.

The effects of continuous positive airway pressure therapy withdrawal on cardiac repolarization: data from a randomized controlled trial †

AIMS The preliminary evidence supports an association between obstructive sleep apnoea (OSA), disturbed cardiac repolarization, and consequent cardiac dysrhythmias. The aim of the current trial was to assess the effects of continuous positive airway pressure (CPAP) therapy withdrawal on the measures of cardiac repolarization in patients with OSA. METHODS AND RESULTS Forty-one OSA patients established on CPAP treatment were randomized to either CPAP withdrawal (subtherapeutic CPAP) or continue therapeutic CPAP for 2 weeks. Polysomnography was performed, and indices of cardiac repolarization (QT(c), TpTe(c) intervals) and dispersion of repolarization (TpTe/QT ratio) were derived from 12-lead electrocardiography (ECG) at baseline and 2 weeks. Continuous positive airway pressure withdrawal led to a recurrence of OSA. Compared with therapeutic CPAP, subtherapeutic CPAP for 2 weeks was associated with a significant increase in the length of the QT(c) and TpTe(c) intervals (mean difference between groups 21.4 ms, 95% CI 11.3-1.6 ms, P < 0.001 and 14.4 ms, 95% CI 7.2-21.5 ms, P < 0.001, respectively) and in the TpTe/QT ratio (mean difference between groups 0.02, 95% CI 0.00-0.03, P = 0.020). There was a statistically significant correlation between the change in apnoea/hypopnoea index (AHI) from baseline, and both the change in the QT(c) interval and the TpTe(c) interval (r = 0.60, 95% CI 0.36-0.77, P < 0.001 and r = 0.45, 95% CI 0.17-0.67, P = 0.003, n = 41, respectively). CONCLUSION Continuous positive airway pressure withdrawal is associated with the prolongation of the QT(c) and TpTe(c) intervals and TpTe/QT ratio, which may provide a possible mechanistic link between OSA, cardiac dysrhythmias, and thus sudden cardiac death.

High prevalence of altered cardiac repolarization in patients with COPD

BackgroundAltered cardiac repolarization and increased dispersion of repolarization have been identified as risk factors for sudden cardiac death (SCD). The prevalence of and the mechanisms contributing to altered cardiac repolarization are currently unknown in COPD.MethodsIn 91 COPD patients, 32 controls matched for age, cardiovascular risk and medication, and 41 healthy subjects, measures of cardiac repolarization and dispersion of repolarization (QTc interval, QT dispersion) were derived from 12-lead electrocardiography (ECG). Prevalence rates of heart rate corrected QT (QTc) >450ms and QT dispersion >60ms were determined to assess the number of subjects at risk for SCD. Univariate and multivariate analyses were used to identify possible factors contributing to altered cardiac repolarization.ResultsQTc was found to be prolonged in 31.9% and QT dispersion in 24.2% of the COPD patients compared to 12.5% in matched controls and 0% in healthy subjects. The QTc interval was longer in COPD patients compared to matched and healthy controls respectively (437.9 ± 29.5 vs. 420.1 ± 25.3 ms, p = 0.001 and vs. 413.4 ± 18.2 ms, p < 0.001). QT dispersion was significantly increased in COPD patients compared to healthy subjects (45.4 (34.8 , 59.5) vs. 39.7 (29.3 , 54.8) ms, p = 0.049). Only oxygen saturation was independently associated with QTc duration in multivariate analysis (β = -0.29, p = 0.015).ConclusionOne third of a typical COPD population has altered cardiac repolarization and increased dispersion of repolarization, which may be related to hypoxia. Altered cardiac repolarization may expose these patients to an increased risk for malignant ventricular arrhythmias and SCD.

Effects of CPAP and Mandibular Advancement Devices on Health-Related Quality of Life in OSA: A Systematic Review and Meta-analysis

Background Untreated OSA is associated with impaired health‐related quality of life (QoL) and excessive daytime sleepiness, which have been shown to improve with treatment. The aim was to compare the effects of CPAP and a mandibular advancement device (MAD) on health‐related QoL in OSA. Methods MEDLINE and the Cochrane Library were searched up to November 2015 for randomized controlled trials (RCTs) comparing the effect of CPAP, MADs, or an inactive control treatment on health‐related QoL assessed by the 36‐Item Short Form Health Survey (SF‐36) in OSA. Extraction of study characteristics, quality, and bias assessment were independently performed by three authors. A network meta‐analysis using multivariate random‐effects meta‐regression was performed to assess treatment effects on the mental component score (MCS) and the physical component score (PCS) of the SF‐36. Results Of 1,491 identified studies, 23 RCTs were included in the meta‐analysis (2,342 patients). Compared with an inactive control, CPAP was associated with a 1.7 point (95% CI, 0.1‐3.2; P = .036) improvement in the MCS and a 1.7 point (95% CI, 0.5‐2.9; P = .005) improvement in the PCS. MADs were associated with a 2.4 point (95% CI, 0.0‐4.9; P = .053) and a 1.5 point (95% CI, –0.2 to 3.2; P = .076) improvement in the MCS and PCS, respectively, compared with inactive control treatments. There were no statistically significant differences between treatment effects of CPAP and MAD on the SF‐36 scores. Conclusions CPAP is effective in improving health‐related QoL in OSA, and MADs may be just as effective, but further RCTs comparing the two treatments are required.

Is continuous positive airway pressure necessarily an everyday therapy in patients with obstructive sleep apnoea

There are limited data on the evolution of obstructive sleep apnoea (OSA) during continuous positive airway pressure (CPAP) therapy and whether this treatment is required every night. 125 OSA patients with an original oxygen desaturation index (ODI) >10 events per hour, established on CPAP, were asked to withdraw CPAP for four nights and performed ambulatory nocturnal pulse oximetry on the fourth night of CPAP withdrawal. An ODI >10 events per hour during pulse oximetry was considered to indicate persistent OSA. Patients not experiencing recurrence of OSA underwent repeat ambulatory pulse oximetry after a further 2-week period off CPAP. In 71% of the patients, OSA recurred after four nights of CPAP withdrawal (group 1); thus, OSA did not recur in 29% (group 2). 55% of group 2 had an ODI >10 events per hour after 2 weeks off CPAP; thus, 45% remained without a recurrence. In multivariate analysis, higher original ODI, longer duration of CPAP therapy, current smoking status and larger neck circumference were independently associated with a higher ODI after four nights of CPAP withdrawal (all p<0.05). Following CPAP withdrawal, a third of CPAP-treated patients do not experience significant recurrence of oxygen desaturations after 4 days and ∼10% do not after 2 weeks. Thus, a significant proportion of patients may be able to stop CPAP for short periods. OSA does not recur in one-third of patients after 4 nights of CPAP withdrawal and in ∼10% after 2 weeks http://ow.ly/sxqIl

A prospective observational study of associated anomalies in Hirschsprung’s disease

BackgroundAssociated anomalies have been reported in around 20% of Hirschsprung patients but many Authors suggested a measure of underestimation. We therefore implemented a prospective observational study on 106 consecutive HSCR patients aimed at defining the percentage of associated anomalies and implementing a personalized and up-to-date diagnostic algorithm.MethodsAfter Institutional Ethical Committee approval, 106 consecutive Hirschsprung patients admitted to our Institution between January 2010 and December 2012 were included. All families were asked to sign a specific Informed Consent form and in case of acceptance each patient underwent an advanced diagnostic algorithm, including renal ultrasound scan (US), cardiologic assessment with cardiac US, cerebral US, audiometry, ENT and ophthalmologic assessments plus further specialist evaluations based on specific clinical features.ResultsMale to female ratio of our series of patients was 3,4:1. Aganglionosis was confined to the rectosigmoid colon (classic forms) in 74,5% of cases. We detected 112 associated anomalies in 61 (57,5%) patients. The percentage did not significantly differ according to gender or length of aganglionosis. Overall, 43,4% of patients complained ophthalmologic issues (mostly refraction anomalies), 9,4% visual impairment, 20,7% congenital anomalies of the kidney and urinary tract, 4,7% congenital heart disease, 4,7% hearing impairment or deafness, 2,3% central nervous system anomalies, 8,5% chromosomal abnormalities or syndromes and 12,3% other associated anomalies.ConclusionsOur study confirmed the underestimation of certain associated anomalies in Hirschsprung patients, such as hearing impairment and congenital anomalies of the kidney and urinary tract. Subsequently, based on our results we strongly suggest performing renal US and audiometry in all patients. Conversely, ophthalmologic assessment and cerebral and heart US can be performed according to guidelines applied to the general population or in case of patients with suspected clinical features or chromosomal abnormalities. This updated diagnostic algorithm aims at improving overall outcome thanks to better prognostic expectations, prevention strategies and early rehabilitation modalities. The investigation of genetic background of patients with associated anomalies might be the next step to explore this intriguing multifactorial congenital disease.

Laparoscopic Proximal Roux-en-Y Gastrojejunal Diversion in Children: Preliminary Experience from a Single Center

BACKGROUND Neurologically impaired children (NIC) have a high risk of recurrence of gastroesophageal reflux (GER) following fundoplication. A postpyloric feeding tube may be useful when gastric emptying disorders occur; however, dislocation and difficulty in feeding management often require more aggressive procedures. Total esophagogastric dissociation (Bianchis TEGD) is an alternative to the classic fundoplication procedure, whereas laparoscopic gastric bypass is a frequently performed procedure in morbid obesity, improving gastric outlet. AIM The aim of this paper is to present a preliminary experience on the laparoscopic Roux-en-Y gastrojejunal bypass, associated with Nissen fundoplication and gastrostomy, to treat and prevent GER in NIC with gastric emptying disorders. MATERIALS AND METHODS Eight neurologically impaired children underwent surgical treatment because of feeding problems and pulmonary complications. The procedure included: 1) hiatoplasty, 2) Nissen fundoplication, 3) 20-cm Roux-en-Y gastrojejunal anastomosis and jejuno-jejunal anastomosis, and 4) gastrostomy. RESULTS All cases were fed on postoperative day 3 without any intraoperative complications. One case developed an obstruction of the distal anastomosis due to adhesion and needed reoperation. Outcome was clinically evaluated with serial upper gastrointestinal contrast studies and endoscopies. CONCLUSIONS Laparoscopic proximal Roux-en-Y gastrojejunal diversion, without gastric resection, is a safe, feasible procedure that improves gastric emptying and reduces the risk of GER recurrence. Yet, long-term results still have to be evaluated.