Improvement in renal function following cryoballoon ablation for atrial fibrillation

Purpose

Patients with chronic kidney disease are predisposed to heart rhythm disorders including atrial fibrillation (AF). Several studies have suggested that radiofrequency catheter ablation of AF improves renal function. However, little data exists for pulmonary vein isolation with cryoballoon ablation (CBA). The purpose of this study is to assess change in renal function following CBA for AF.

Method

This is a single-center retrospective study that included patients who underwent CBA for AF between 2011 and 2016. Patients were grouped by baseline-estimated glomerular filtration rate (eGFR): ≥?90 (Stage G1), 60–89.9 (Stage G2), and 30–59.9 mL/min/1.73 m² (Stage G3). Change in eGFR was assessed >?3 months post-ablation.

Results

A total of 306 patients with both pre- and post-ablation serum creatinine measurements available were included. Baseline eGFRs for Stages G1, G2, and G3 patients were 103.5?±?12.9 (n?=?82), 74.7?±?8.2 (n?=?184), and 52.6?±?6.6 mL/min/1.73 m² (n?=?40), respectively. Renal function was assessed 310.8?±?104.2 days post-ablation. Average intra-procedural contrast use was 58.4?±?23.8 mL. There was no significant change in eGFR following CBA in Stage G1 patients (p?=?0.10). For those with Stages G2 and G3 renal function, eGFR improved by 6.1% (4.2 mL/min/1.73 m², p?<?0.01) and 13.8% (7.2 mL/min/1.73 m², p?<?0.01), respectively. This improvement was seen regardless of the presence or absence of recurrent atrial arrhythmias.

Conclusions

CBA for AF may be associated with an improvement in renal function, particularly among those with a reduced baseline eGFR despite recurrence of atrial arrhythmias and intra-procedural contrast use.

     

Could mean platelet volume be a promising biomarker of progression of chronic kidney disease?

The mean platelet volume (MPV), a readily available indicator of platelet activation and function, is a useful predictive and prognostic biomarker of cardiovascular and cerebrovascular disease (CVD). It is associated with a variety of prothrombotic and proinflammatory diseases. Larger platelets are more likely to aggregate and release greater quantities of adhesive molecules. MPV has seldom been investigated in patients with chronic kidney disease (CKD). This study aimed to investigate the relationship between MPV levels and the glomerular filtration rate (GFR) in patients with CKD. We reviewed the medical records of patients with CKD who visited the nephrology outpatient clinics of Soonchunhyang University Bucheon Hospital between January 2010 and May 2013. A total of 553 patients were included in the present retrospective study. According to the estimated GFR (eGFR) calculated by the abbreviated the Modification of Diet in Renal Disease (MDRD) equation, the patients were allocated to Group 1 (GFR, 60–89?ml/minute/1.73?m²; n?=?64), Group 2 (GFR, 30–59?ml/minute/1.73?m²; n?=?268), Group 3 (GFR, 15–29?ml/minute/1.73?m²; n?=?147), or Group 4 (GFR, <15?ml/minute/1.73?m² and non-dialysis; n?=?74). Data were analyzed by Student’s t-test, the chi-squared test, Pearson’s correlation coefficient (r), Tukey’s honestly significant difference (HSD) test, and one-way analysis of covariance. The MPV values had a negative correlation with eGFR in patients with CKD (Pearson’s correlation coefficient?=??0.553, p?<?0.001). The mean MPV values in Groups 1–4 were 9.81?±?0.13?fl, 10.34?±?0.08?fl, 10.86?±?0.09?fl, and 11.19?±?0.11?fl, respectively (p?<?0.001). Multiple comparisons of MPV values in the four groups by Tukey’s HSD test showed statistically significant intergroup differences, with all p values <0.001. Platelet counts and PDW decreased along with eGFR, and there were no significant differences with respect to plateletcrit. Patients with prevalent coronary artery disease (CAD) or CVD had higher MPVs than did those without CAD or CVD. MPV was significantly increased with progression of CKD. MPV may be a useful indicator of increased risks of CAD or CVD in patients with CKD.     

Accessibility and adherence to positive airway pressure treatment in patients with obstructive sleep apnea: a multicenter study in Latin America

Purpose

Information on access and adherence to positive airway pressure (PAP) treatment is lacking at the regional level in Latin America. This study characterized access and adherence to PAP in patients with moderate-severe obstructive sleep apnea (OSA) in Latin America.

Methods

Cross-sectional study, conducted at 9 sleep centers across Argentina, Brazil, Chile, Colombia, Mexico, and Peru. Adults diagnosed with moderate-severe OSA (apnea-hypopnea index [AHI] ≥?15/h) in the previous 12–18 months were eligible. Anthropometrics, health coverage, and OSA severity data were collected. Data on access to therapy, barriers to access, adherence, and factors related to non-compliance were obtained via standardized telephone survey.

Results

Eight hundred eighty patients (70% male, 54?±?13 years, AHI 49?±?28/h, body mass index 32?±?7 kg/m²) were included. Four hundred ninety patients (56%) initiated PAP, 70 (14%) discontinued therapy during the first year (mainly due to intolerance), and 420 (48%) were still using PAP when surveyed. Health insurance was private in 36.9% of patients, via the social security system in 31.1%, and via the state in 13.3%, and 18.7% did not have any coverage; 49.5% of patients had to pay all equipment costs. Reasons for not starting PAP were unclear or absent indication (42%), coverage problems (36%), and lack of awareness of OSA burden (14%). Patients with better adherence were older (55.3?±?13 vs 52?±?13; p?=?0.002) and had more severe OSA (AHI 51.8?±?27 vs 45.6?±?27; p?=?0.001).

Conclusions

Less than half moderate-severe OSA patients started and continue to use PAP. Unclear or absent medical indication and financial limitations were the most relevant factors limiting access to therapy.

     

Metabolic outcomes in adults with type 2 diabetes and sleep disorders

Purpose

Insomnia is frequently co-morbid with obstructive sleep apnea (OSA); the effect of insomnia or co-morbid insomnia and OSA (OSA?+?I) on associated metabolic outcomes in adults with type 2 diabetes (T2D) remains unclear. This study in adults with T2D compared metabolic outcomes among persons with OSA, insomnia, or OSA?+?I.

Methods

This study analyzed baseline data from the Diabetes Sleep Treatment Trial of persons recruited for symptoms of OSA or poor sleep quality. Home sleep studies determined OSA presence and severity. Insomnia was evaluated using the Insomnia Severity Index. Height and weight to calculate body mass index (BMI) and blood for laboratory values were obtained. Multivariate general linear models were used to examine the impact of the type of sleep disorder and sociodemographic, lifestyle, and sleep risk factors on metabolic outcomes.

Results

Participants (N?=?253) were middle-aged (56.3?±?10.5 years), white (60.5%), obese (mean BMI of 35.3?±?7.1 kg/m²), and male (51.4%) with poor glucose control (mean HbA1c of 8.0?±?1.8%). Most participants had OSA?+?I (42.7%) or insomnia only (41.0%). HbA1c and BMI differed among the sleep disorder groups. In addition, in the adjusted models, having insomnia only, compared to OSA only, was associated on average with higher HbA1c levels (b?=?1.08?±?0.40, p?<?0.007) and lower BMI (b?=????7.03?±?1.43, p?<?0.001).

Conclusions

Findings suggest that insomnia frequently co-exists with OSA, is independently associated with metabolic outcomes in adults with T2D, and should be considered in investigations of the effects of OSA in persons with T2D.

Trial registration

Diabetes-Obstructive Sleep Apnea Treatment Trial (NCT01901055), https: Clinicaltrials.gov/ct2/show/NCT01901055; Registration date: July 17, 2013.

     

Prevalence and associations for abnormal bleeding times in patients with renal insufficiency

Platelet dysfunction and associated hemorrhagic complications are often encountered in patients with chronic kidney disease. This study aimed to evaluate the prevalence and associations for abnormal bleeding time (BT) in patients with renal dysfunction. Hemoglobin, hematocrit, platelet, blood urea nitrogen, creatinine, and parathyroid hormone levels were determined in 1716 patients (55.18?±?17.19 years, men 50.8%). For these patients, BTs were estimated using a platelet function analyzer-100. Glomerular filtration rates (GFRs) were estimated using the Chronic Kidney Disease Epidemiology Collaboration equation. The study population was divided into six groups according to the estimated GFR (eGRF): group I, eGFR?≥?90?ml/min/1.73?m²; group II, 60?≤?eGFR?<?90?ml/min/1.73?m²; group III, 30?≤?eGFR?<?60?ml/min/1.73?m²; group IV, 15?≤?eGFR?<?30?ml/min/1.73?m²; group V, eGFR?<?15?ml/min/1.73?m²; and group VI, undergoing regular hemodialysis. Renal insufficiency was defined as eGFR?<?60?ml/min/1.73?m². To further investigate the role of inflammatory cytokines, nitric oxide (NO) and tumor necrosis factor alpha (TNF-α) were measured in a 327-patient subset of the total patient population (52.82?±?18.3 years, men 60.9%). Abnormal BT occurred in 11.8% of group I, 15.3% of group II, 29.1% of group III, 37.5% of group IV, 35.0% of group V, and 32.1% of group VI. By Pearson correlation coefficient, eGFR (r?=??0.089), hemoglobin (r?=??0.127), platelet (r?=??0.054) were correlated with BT. Multivariate analysis revealed that age [odds ratio (OR), 1.013; 95% CI, 1.004–1.022], renal insufficiency (eGFR?<?60?ml/min/1.73?m²; OR, 2.271; 95% CI, 1.672–3.083), anemia (hemoglobin?<?120?g/l; OR, 1.486; 95% CI, 1.089–2.027), and thrombocytopenia (platelet?<?150?×?10⁹/l; OR, 1.445; 95% CI, 1.089–1.918) were independently associated with prolonged BT. Plasma levels of NO and TNF-α were increased in patients with renal insufficiency (eGFR?<?60?ml/min/1.73?m²). Plasma levels of NO in renal insufficiency group were higher in prolonged BT than those in normal BT. A significant positive correlation was noted between BTs and NO levels (r?=?0.152, p?=?0.009) but not with TNF-α levels. The prevalence of abnormal BTs was higher as eGFR declined. Old age, renal insufficiency, anemia, and thrombocytopenia were independent associations for abnormal BT.     

Positive airway pressure therapy adherence for obstructive sleep apnea during the COVID-19 pandemic

Purpose

Positive airway pressure (PAP) adherence is a significant issue among patients with obstructive sleep apnea (OSA). However, the data are limited regarding PAP adherence during the current COVID-19 pandemic.

Methods

A cross-sectional study was conducted between February and October 2020 at the Excellence Center for Sleep Disorders, King Chulalongkorn Memorial Hospital, Bangkok, Thailand. Patients with ongoing PAP-treated OSA were recruited. Data on PAP adherence before and during the COVID-19 pandemic were collected. Furthermore, pre-test and post-test questionnaires on knowledge on COVID-19, OSA, and PAP before and after tele-education were also evaluated.

Results

Of a total 156 patients, the majority had severe OSA (72%). By self-report, there was no significant difference in PAP usage in hours per day before compared to during the pandemic (p?=?0.45), though in a subgroup with highest educational attainment (degree higher than bachelor’s), PAP usage did increase during the pandemic (mean difference 0.23?±?0.10; 95% CI 0.02–0.40, p?=?0.03). However, objective PAP usage data demonstrated a trend towards increased usage comparing before and during the pandemic (4.64?±?1.49 vs 5.12?±?1.41; mean difference 0.48?±?1.33; 95% CI 0.13–10.90, p?=?0.12). Basic knowledge was significantly improved after tele-education (p?<?0.001).

Conclusion

By objective data, there was a trend towards increased PAP usage during the COVID-19 pandemic for the entire group. In a subgroup of patients with highest educational attainment, PAP adherence increased by self-report. Tele-education appeared to improve knowledge on COVID-19, OSA, and PAP usage.

     

Effects of 12 weeks of regular aerobic exercises on autonomic nervous system in obstructive sleep apnea syndrome patients

Introduction

Regular exercise is confirmed as a lifestyle treatment option for all obstructive sleep apnea (OSA) patients. It has beneficial effects other than weight loss, although the mechanisms remain unclear. Autonomic function imbalance plays an important role in OSA, so that it is meaningful to observe the effect of exercise on autonomic function.

Methods

Seventy mild to moderate OSA patients were divided into two groups. The exercise group received a 12-week exercise program prescribed according to their first cardiopulmonary exercise tests, while the control group kept previous lifestyle. All patients underwent blood tests, cardiopulmonary exercise tests, and polysomnography studies at enrollment and at the 12-week’s follow-up.

Results

At the end of 12 weeks, three patients of the exercise group did not complete the program due to lack of adherence. The current study showed 12-week aerobic exercises could improve body mass index (27.6?±?4.7 kg/m² vs. 24.5?±?4.2 kg/m², P?<?0.05), exercise capacities, apnea-hypopnea index (total AHI 20.2?±?7.5 vs. 16.4?±?5.2, P?<?0.05; supine AHI 22.1?±?6.3 vs. 18.3?±?4.9, P?<?0.05), average oxyhemoglobin saturation (AverSpO2), time/percentage SpO2 below 90%, and heart rate recovery (HRR) of OSA patients. Moreover, AverSpO2 change was significantly associated with HRR change in the exercise group.

Conclusions

Our findings suggested regular aerobic exercise had beneficial effects on body mass index, functional capacity, intermittent hypoxia, and parasympathetic tone of OSA patients, and whether parasympathetic tone modification plays a role in improving intermittent hypoxia or not deserves further exploration.

     

Agreement between cystatin-C and creatinine based eGFR estimates after a 12-month exercise intervention in patients with chronic kidney disease

Background

Estimation of GFR (eGFR) using formulae based on serum creatinine concentrations are commonly used to assess kidney function. Physical exercise can increase creatinine turnover and lean mass; therefore, this method may not be suitable for use in exercising individuals. Cystatin-C based eGFR formulae may be a more accurate measure of kidney function when examining the impact of exercise on kidney function. The aim of this study was to assess the agreement of four creatinine and cystatin-C based estimates of GFR before and after a 12-month exercise intervention.

Methods

One hundred forty-two participants with stage 3–4 chronic kidney disease (CKD) (eGFR 25–60?mL/min/1.73?m²) were included. Subjects were randomised to either a Control group (standard nephrological care [n?=?68]) or a Lifestyle Intervention group (12?months of primarily aerobic based exercise training [n?=?74]). Four eGFR formulae were compared at baseline and after 12?months: 1) MDRDcr, 2) CKD-EPIcr, 3) CKD-EPIcys and 4) CKD-EPIcr-cys.

Results

Control participants were aged 63.5[9.4] years, 60.3% were male, 42.2% had diabetes, and had an eGFR of 40.5?±?8.9?ml/min/1.73m². Lifestyle Intervention participants were aged 60.5[14.2] years, 59.5% were male, 43.8% had diabetes, and had an eGFR of 38.9?±?8.5?ml/min/1.73m². There were no significant baseline differences between the two groups. Lean mass (r?=?0.319, p?<?0.01) and grip strength (r?=?0.391, p?<?0.001) were associated with serum creatinine at baseline. However, there were no significant correlations between cystatin-C and the same measures. The Lifestyle Intervention resulted in significant improvements in exercise capacity (+?1.9?±?1.8 METs, p?<?0.001). There were no changes in lean mass in both Control and Lifestyle Intervention groups during the 12?months. CKD-EPIcys was considerably lower in both groups at both baseline and 12?months than CKD-EPIcr (Control?=???10.5?±?9.1 and???13.1?±?11.8, and Lifestyle Intervention?=???7.9?±?8.6 and???8.4?±?12.3?ml/min/1.73?m²), CKD-EPIcr-cys (Control?=???3.6?±?3.7 and???4.5?±?4.5, and Lifestyle Intervention?=???3.6?±?3.7 and???2.5?±?5.5?ml/min/1.73?m²) and MDRDcr (Control?=???9.3?±?8.4 and???12.0?±?10.7, Lifestyle Intervention?=???6.4?±?8.4 and???6.9?±?11.2?ml/min/1.73?m²).

Conclusions

In CKD patients participating in a primarily aerobic based exercise training, without improvements in lean mass, cystatin-C and creatinine based eGFR provided similar estimates of kidney function at both baseline and after 12?months of exercise training.

Trial registration

The trial was registered at www.anzctr.org.au (Registration Number ANZCTR12608000337370) on the 17/07/2008 (retrospectively registered).

     

Impact of obstructive sleep apnea on clinical outcomes in patients hospitalized with COVID-19

Purpose

Data from large patient registry studies suggested an increased incidence and increased mortality in coronavirus disease-2019 (COVID-19) in patients with a history of obstructive sleep apnea (OSA). This study aimed to compare the prevalence of OSA in patients with and without COVID-19 among patients admitted to the same hospital in the same time period. In addition, the impact of OSA on clinical outcomes of COVID-19 infection was investigated.

Methods

Observational cohort study. Clinical data were collected retrospectively from the complete medical records for each patient individually from March 1st 2020 to May 16th 2020.

Results

A total of 723 patients were diagnosed with COVID-19 and 1161 with non-COVID-19 disease. The prevalence of OSA did not differ between these groups (n?=?49; 6.8% versus n?=?66; 5.7%; p?=?0.230). In patients with COVID-19, mortality was increased in the group of 49 patients with OSA (n?=?17; 34.7%) compared to 674 COVID-19 patients without OSA (n?=?143; 21.2%; p?=?0.028). This increased risk of mortality in COVID-19 patients with OSA (OR?=?2.590; 95%CI 1.218–5.507) was independent from Body Mass Index (BMI), male gender, age, diabetes, cardiovascular disease, and obstructive lung disease. Presence of OSA in COVID-19 disease was further associated with an increased length of hospital stay (12.6?±?15.7 days versus 9.6?±?9.9 days; p?=?0.049).

Conclusion

The prevalence of OSA did not differ between patients with or without COVID-19, but mortality and hospital length of stay were increased in patients with OSA and comorbid COVID-19. Hence, OSA should be included in COVID-19 risk factor analyses, Clinicians should be aware of the association and the mechanism should be further explored.

     

Outcome of TORS to tongue base and epiglottis in patients with OSA intolerant of conventional treatment

Purpose

Transoral robotic surgery (TORS) of the tongue base with or without epiglottoplasty represents a novel treatment for obstructive sleep apnea (OSA). The objective was to evaluate the clinical efficacy of TORS of the tongue base with or without epiglottoplasty in patients who had not tolerated or complied with conventional treatment (continuous positive airway pressure or oral appliance).

Methods

Four-year prospective case series. The primary outcome measure was the apnea-hypopnea index (AHI) in combination with the Epworth Sleepiness Score (ESS). Mean oxygen saturation levels (SaO₂) before and after TORS on respective sleep studies were also recorded. Secondary outcome measures included operative time and complications. Patient reported outcome measures (PROMs) assessed included voice, swallow and quality of life.

Results

Fourteen patients underwent TORS for tongue base reduction with ten having additional wedge epiglottoplasty. A 64 % success rate was achieved with a normal post-operative sleep study in 36 % of cases at 6 months. There was a 51 % reduction in the mean AHI (36.3?±?21.4 to 21.2?±?24.6, p?=?0.02) and a sustained reduction in the mean Epworth Sleepiness Score (p?=?0.002). Mean SaO₂ significantly increased after surgery compared to pre-operative values (92.9?±?1.8 to 94.3?±?2.5, p?=?0.005). Quality of life showed a sustained improvement 3 months following surgery (p?=?0.01). No major complications occurred.

Conclusions

TORS of the tongue base with or without epiglottoplasty represents a promising treatment option with minimal morbidity for selected patients with OSA. Long-term prospective comparative evaluation is necessary to validate the findings of this study.

     

Operator learning curve and clinical outcomes of zero fluoroscopy catheter ablation of atrial fibrillation,supraventricular tachycardia,and ventricular arrhythmias

Purpose

To investigate the learning curve for atrial fibrillation (AF), supraventricular tachycardia (SVT), and premature ventricular contraction (PVC) radiofrequency ablation (RFA) using zero fluoroscopy.

Methods

This is a retrospective, single-center study of 167 patients undergoing ablation between 2016 and 2019. Minimal fluoroscopy approach was initiated after the first 20 cases of PVI and SVT RFA. Procedures were divided consecutively into increments of 10 cases to determine operator learning curve.

Results

A total of 64 (38%) had SVT ablations, 26 (16%) had PVC ablations, and 77 (46%) had AF and underwent PVI. For SVT RFA, fluoroscopy time improved from 4.1?±?3.5 min during the first 10 cases to 0.8?±?1.2 min after 50 cases (p?=?0.0001). Sixty-two out of 64 (97%) of cases were successful. In PVC RFA, fluoroscopy time was 7.7?±?5.5 min for the first 5, 2.3?±?3.4 min after 15, and 0 min after 20 cases (p?=?0.0008). Twenty-four out of 26 (92%) of cases were acutely successful with recurrence in 2/26 (8%) of patients over 9?±?9 months. In PVI, fluoroscopy time was 9.9?±?3.3 min over the first 20 cases, 2.6?±?2.3 min after 40 cases, and 0.1 min after 50 cases (p?<?0.0001). PVI procedure time was 170?±?34 min after 60 cases from 235?±?41 min initially (p 0.001). Six out of 77 (8%) had AF recurrence at 12 months.

Conclusions

Zero fluoroscopy ablation for AF, SVT, and PVC can be safely achieved without increasing procedure time. The steepest learning curve occurs over the first 20, 15, and 40 cases for SVT, PVC, and PVI ablation respectively.

     

Light-chain amyloidosis with renal involvement: renal outcomes and validation of two renal staging systems in the Chinese population

Abstract

Background: Renal involvement is one of the most common complications of light-chain (AL) amyloidosis. For evaluating renal prognosis, two staging systems for renal involvement have been proposed, one in 2014 and one in 2017. However, the two staging systems have not yet been compared and widely used in clinic.

Methods: A total of 76 patients with newly diagnosed AL amyloidosis and renal involvement proven by renal biopsy were included and followed up with an endpoint developing to dialysis. The renal outcome and two criteria were explored.

Results: We confirmed the prognostic value of the 2014 renal staging system based on estimated glomerular filtration rate (eGFR) (<50?ml/min/1.73?m²) and proteinuria (>5?g/day) at diagnosis (p?=?0.003). For the 2017 system, none of the patients progressed to dialysis in both stage 1 (24?h proteinuria to eGFR <30?mg/ml/min/1.73?m²) and stage 2 (24?h proteinuria to eGFR 30–99?mg/ml/min/1.73?m²). A significant difference in terms of requiring dialysis was seen only between stage 3 (24?h proteinuria to eGFR ≥100?mg/ml/min/1.73?m²) and the two other stages (p?=?0.008).

Conclusions: The prognostic value of the criteria based on eGFR and 24-hour proteinuria for predicting dialysis has been confirmed. These results might benefit guiding clinical treatment.     

Is obstructive sleep apnea syndrome in children season dependent?

Introduction

The most common cause of obstructive sleep apnea (OSA) in children is an enlargement of tonsils and/or adenoids. Previous studies have shown that the size of adenoids and tonsils is influenced by upper respiratory tract infections and exposure to allergens. The rate of exposure to bacteria, viruses, and allergens fluctuates from season to season. Therefore, we hypothesized that the rate of polysomnograms positive for OSA may vary according to season.

Objective

The objective of this study is to determine whether the prevalence of OSA in children, as determined by polysomnography, is affected by the season during which the study was performed.

Methods

We retrospectively reviewed polysomnography tests of 296 children, ages 0–12 years, referred for suspected OSA. We compared the Obstructive Apnea Hypopnea Index (OAHI) between the seasons and the rates of abnormal tests in each season according to the degree of severity.

Results

The mean OAHI did not significantly differ among the seasons (winter, 3.0?±?5.0; spring, 3.0?±?4.9; summer, 4.0?±?6.3; fall, 3.4?±?5.7, p?=?0.183). When dividing the OAHI by levels of severity, no seasonality was found in moderate (winter, 13.8 %; spring, 6.7 %; summer, 11.7 %; fall, 14.1 %, p?=?NS) and severe OSA (winter, 8.8 %; spring, 11.2 %; summer, 10 %; fall, 7.8 %, p?=?NS). There was a small increase in the frequency of mild OSA diagnoses in the summer compared to the other seasons.

Conclusion

In this study, season does not appear to affect the rate of diagnosis of significant OSA in children. Re-evaluation during a different season is unlikely to provide different results and may postpone surgery unnecessarily.

     

The variability and burden of severe sleep apnea and the relationship with atrial fibrillation occurrence: analysis of pacemaker-detected sleep apnea

Study objectives

This was a pilot study to evaluate the long-term variability and burden of respiratory disturbance index (RDI) detected by pacemaker and to investigate the relationship between RDI and atrial fibrillation (AF) event in patients with pacemakers.

Methods

This was a prospective study enrolling patients implanted with a pacemaker that could calculate the night-to-night RDI. The mean follow-up was 348?±?34 days. The RDI variability was defined as the standard deviation of RDI (RDI-SD). RDI burden was referred to as the percentage of nights with RDI?≥?26. The patient with RDI?≥?26 in more than 75% nights was considered to have a high sleep apnea (SA) burden. An AF event was defined as a daily AF duration?>?6 h.

Results

Among 30 patients, the mean RDI of the whole follow-up period was 24.5?±?8.6. Nine (30%) patients were diagnosed with high SA burden. Patients with high SA burden had a higher BMI (26.7?±?4.8 vs 23.2?±?3.9, p?=?0.036), a higher prevalence of hypertension (86% vs 39%, p?=?0.031), and a larger left ventricular diastolic diameter (49.2 mm vs 46.7 mm, p?=?0.036). The RDI-SD in patients with a higher burden was significantly greater than that in the patients with less burden (10.7?±?4.9 vs 5.7?±?1.4, p?=?0.036). Linear regression showed that participants with a higher RDI tended to have a higher SD (R?=?0.661; p?<?0.001). The mean RDI (OR?=?1.118, 95%CI 1.008–1.244, p?=?0.044) was associated with AF occurrence.

Conclusion

Using a metric such as burden of severe SA may be more appropriate to demonstrate a patient’s true disease burden.

     

Atrial involvement and progression of sinus node dysfunction in non-senile patients: evidences from electroanatomic mapping and long-term follow-up

Purpose

Sinus node inability or conduction disorders of its surrounding atrial myocardium cause sinus node dysfunction (SND). This study aimed to characterize right atrium (RA) substrates and long-term atrial lead performance after pacemaker implantation in non-senile SND patients.

Methods

Eighteen SND patients (53.3?±?9.6 years) controlled by 18 age-matched supraventricular tachycardia patients were consecutively enrolled. The P-wave amplitude (PWA) and P-wave duration (PWD) were measured on surface electrocardiography. Electroanatomic mapping was conducted to assess the bipolar voltage, complex signals, volume, and activation time of RA. Pacemaker implantation was performed in SND patients after mapping.

Results

Compared with controls, SND patients showed significant PWA reduction (0.13?±?0.02 vs. 0.16?±?0.04 mV, p?=?0.017) and PWD prolongation (120.8?±?15.2 vs. 105.2?±?8.6 ms, p?=?0.001). The RA endocardial voltage was lower (1.56?±?0.78 vs. 2.57?±?0.55 mV, p?<?0.001) and activation time was longer (112.1?±?14.9 vs. 90.8?±?12.4 ms, p?<?0.001) in the study group. Atrial lead was anchored at the lower atrial septum in one patient and failed in another due to extensive atrial scarring. During a median follow-up of 86 (57–88) months, one patient lost atrial capturing, and overall atrial sensing was significantly decreased (2.44?±?1.16 vs. 1.87?±?1.01 mV, p?=?0.003).

Conclusions

Atrial involvement was proved and the process was progressive in non-senile SND patients, as demonstrated by diffused RA lower voltage, slower conduction, and the decrease of the atrial lead sensing.

     

Serum uric acid and progression of diabetic nephropathy in type 1 diabetes

Aims

Uric acid (UA) is a risk factor for CKD. We evaluated UA in relation to change in GFR in patients with type 1 diabetes.

The effect of renal hyperfiltration on urinary inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes mellitus

Aims/hypothesis

High intraglomerular pressure causes renal inflammation in experimental models of diabetes. Our objective was to determine whether renal hyperfiltration, a surrogate for intraglomerular hypertension, is associated with increased excretion of urinary cytokines/chemokines in patients with type 1 diabetes mellitus.

Methods

Blood pressure, renal haemodynamic function (inulin and para-aminohippurate clearances for glomerular filtration rate (GFR) and effective renal plasma flow (ERPF), respectively) and urine samples were obtained during clamped euglycaemia in individuals with type 1 diabetes with either hyperfiltration (GFR determined using inulin [GFR_INULIN] ≥135 ml? min^?1 1.73 m^?2, n?=?28) or normofiltration (n?=?21) and healthy control individuals (n?=?18).

Results

Baseline clinical characteristics, dietary sodium and protein intake and blood pressure levels were similar in the diabetic and healthy control groups. In addition, HbA_1c levels were similar in the two diabetic groups. As expected baseline GFR was higher in hyperfilterers than either normofiltering diabetic patients or healthy control patients (165?±?9 vs 113?±?2 and 116?±?4 ml min^?1 1.73 m^?2, respectively, p?<?0.01). ERPF and renal blood flow were also comparatively higher and renal vascular resistance was lower in hyperfiltering patients (p?<?0.01). Hyperfiltering diabetic patients had higher excretion rates for eotaxin, IFNα2, macrophage-derived chemokine, platelet-derived growth factor (PDGF)-AA, PDGF-AB/BB and granulocyte-macrophage colony-stimulating factor (p?≤?0.01). Urinary monocyte chemoattractant protein (MCP)-1 and RANTES (regulated on activation, normal T expressed and secreted) excretion was also higher in hyperfiltering vs normofiltering diabetic individuals (p?<?0.01) and fibroblast growth factor-2, MCP-3 and CD40K excretion was elevated in hyperfiltering diabetic individuals vs healthy controls (p?<?0.01).

Conclusions/interpretation

Renal hyperfiltration is associated with increased urinary excretion of inflammatory cytokines/chemokines in patients with uncomplicated type 1 diabetes.     

3.0 T magnetic resonance imaging scanning on different body regions in patients with pacemakers

Purpose

Magnetic resonance imaging (MRI) at 3.0 T is becoming more common, but there is a lack of sufficient evidence on the safety of a 3.0 T scan in patients with pacemakers. This study aimed to investigate the safety and practical concerns of 3.0 T scans for patients with MR-conditional pacemakers.

Methods

Twenty consecutive patients were enrolled. A standardized protocol was developed by cardiologists, pacemaker engineers, and radiologists. Pacemaker interrogation was performed immediately before and after the scan. Scan-related adverse events were documented, and imaging quality was graded as level 1 to 4 by radiologists.

Results

Twenty-three MRI scans of different body regions (brain?=?13, lumbar spine?=?4, cervical spine?=?2, and heart?=?4) were performed, and the average time of a scan was 25?±?11 min. No significant changes in sensing amplitude (atrial 3.1?±?1.1 mV vs. 2.9?±?1.2 mV, P?=?0.71; ventricular 9.3?±?3.5 mV vs. 10.2?±?3.4 mV, P?=?0.46), lead impedances (atrial 647?±?146 Ω vs. 627?±?151 Ω, P?=?0.7; ventricular: 780?±?247 Ω vs.711?±?226 Ω, P?=?0.36), or pacing threshold (atrial 0.6?±?0.2 V/0.4 ms vs. 0.6?±?0.2 V/0.4 ms, P?=?0.71; ventricular 0.7?±?0.3 V/0.4 ms vs. 0.7?±?0.2 V/0.4 ms, P?=?0.85) were observed pre- and postscan. No adverse events were detected. Image quality review showed grade 1 quality in 16 patients and grade 2 quality in 4 patients with artifacts of pulse generators and leads in cardiac MRI scan and no impact on diagnostic value.

Conclusion

Our initial data indicated that 3.0 T scanning might be feasible under a standardized protocol with good diagnostic imaging quality irrespective of body region in patients with MR-conditional pacemakers.

     

The effects of continuous positive airway pressure and mandibular advancement therapy on metabolic outcomes of patients with mild obstructive sleep apnea: a randomized controlled study

Background

Moderate and severe obstructive sleep apnea (OSA) have been independently associated with dyslipidemia. The results of metabolic improvement with continuous positive airway pressure (CPAP) have been controversial. Less evidence exists regarding this issue in mild OSA. A current treatment for mild OSA is mandibular advancement device (MAD) therapy, but its effectiveness on the metabolic profile needs to be compared with CPAP. The purpose of this study was to compare MAD vs CPAP vs no treatment on the metabolic profile during 6 and 12 months of follow-up in patients with mild OSA.

Methods

The inclusion criteria were patients with mild OSA, both genders, ages 18 to 65 years, and body mass index (BMI) of < 35 Kg/m². Patients were randomized in 3 groups (CPAP, MAD, and control). The evaluations included physical examination, metabolic profile, and full polysomnography at baseline, 6 months, and 12 months of follow-up.

Results

Seventy-nine patients with mild OSA were randomized in three treatment groups, with mean age (± SD) of 47?±?9 years, 54% men, and AHI 9.5?±?2.9 events/h. MAD and CPAP reduced AHI at 6 and 12 months compared to the control group. MAD adherence was higher than CPAP at 6 and 12 months. Despite lower adherence compared to MAD, CPAP was more effective in reducing total cholesterol over 12 months (baseline 189.3?±?60.2 mg/dl to 173.4?±?74.3 mg/dl) and low-density lipoprotein cholesterol (LDL-c, baseline 112.8?±?54.9 mg/dl to 94.5?±?67.4 mg/dl).

Conclusions

After 1 year of treatment, CPAP was superior to MAD in reducing total cholesterol and LDL-c in patients with mild OSA.

     

Lack of association between obstructive sleep apnea syndrome and specular microscopic features of the corneal endothelium

Background

Obstructive sleep apnea syndrome (OSAS) is characterized by recurrent episodes of hypoxemia and hypercapnia during sleep. The aim of this study was to determine whether OSAS causes significant changes in corneal endothelium detectable by specular microscopy.

Methods

This prospective, cross-sectional study compared the specular microscopic features of the corneal endothelium of patients with OSAS and age-and gender-matched controls. Patients diagnosed with OSAS by polysomnography in the sleep unit were classified using apnea-hypopnea indexes into two groups as mild-moderate OSAS group and severe OSAS group. All participants were divided into three age groups: 30–45, 46–60, and >?60 years. Corneal endothelial cell density (ECD), percentage of hexagonal cells (Hex), and coefficient of variation of cell area (CV) were obtained using a non-contact specular microscope. The measurements of each group were compared statistically.

Results

A total of 66 patients (51.1?±?9.4 years) and 88 controls (49.2?±?10.5 years) were examined. The mild-moderate OSAS group and the severe OSAS group had no significant differences in measures of specular microscopy compared with the controls (ECD, p?=?0.84; Hex, p?= 0.18; CV, p?=?0.41). The mean values of ECD, Hex, and CV were 2552.56?±?302.49 cells/mm², 54.13?±?8.13%, and 36.41?±?5.92, respectively, in the mild-moderate OSAS group; 2510.52?±?377.12 cells/mm², 54.85?±?8.68%, and 34.77?±?5.02, respectively, in the severe OSAS group; 2543.37?±?286.94 cells/mm², 51.89?±?9.09%, and 36.03?±?5.32, respectively, in the control group.

Conclusions

There were no significant differences in corneal endothelial features between patients and controls. Although OSAS causes systemic hypoxia, its effects do not appear to result in corneal endothelial alterations detectable by specular microscopy.