Impact of undiagnosed obstructive sleep apnea on atrial fibrillation recurrence following catheter ablation (OSA-AF study)

Prediction model and scoring system for the risk of atrial fibrillation recurrence in patients with atrial fibrillation and obstructive sleep apnoea syndrome: a retrospective case-control study

BACKGROUND

The high prevalence of atrial fibrillation (AF) and obstructive sleep apnea syndrome (OSAS) imposes a substantial disease burden on public healthcare, making it a significant health concern in the current era. However, there is currently a lack of risk assessment tools for AF recurrence in patients with AF and OSAS. Therefore, this study aims to explore the factors influencing AF recurrence in patients with AF and OSAS, and to establish a predictive model and scoring system for AF recurrence rates.

METHODS

The study included a total of 423 patients with AF and OSAS, who were randomly divided into train set (n = 296) and test set (n = 127) in a ratio of 7:3. Afterwards, the train set was split into a recurrence group and a non-recurrence group for further analysis of indicators while in hospital.

RESULTS

Following Lasso regression screening, 8 variables were selected from a pool of 62 variables from patients with AF and OSAS. Additionally, the study incorporated the CHA2DS2-VASc score and its components of interest, the severity of OSAS and hypoxemia, and whether patients received catheter ablation (CA). Multivariable Cox regression analysis revealed: Hb < 115 g/L (HR = 2.27), P > 1.51mmol/L (HR = 3.77), PCT > 2ng/ml (HR = 15.72) as independent risk factors. Hb > 150 g/L (HR = 0.66), TT4 < 66 nmol/L (HR = 0.16) were identified as independent protective factors. The train set showed AUC values of 0.65, 0.71, and 0.71 at the 1st, 3rd, and 5th year, respectively, while the validation set displayed AUC values of 0.60, 0.59, and 0.64 at the 1st, 3rd, and 5th year, respectively, indicating good predictive performance of the model. The AF recurrence rate scoring system categorized patients in the train and test sets into low-risk, medium-risk, and high-risk groups, with HR values of 2.36 and 6.79 for AF recurrence rates in the medium-risk and high-risk groups of the train set, and an HR value of 2.77 for the medium-risk group in the test set.

CONCLUSION

The predictive models and scoring systems developed in this study demonstrate good predictive ability in assessing the recurrence of AF in patients with OSAS, offering invaluable clinical guidance and references.

CLINICAL TRIAL NUMBER

Not applicable.

Association Between Body Mass Index and the Efficacy of Calcium Channel Blockers for Hypertension in Cardiovascular Disease Patients

BACKGROUND

Hypertension, or high blood pressure, is a major risk factor for cardiovascular diseases (CVDs) worldwide. Variations in body mass index (BMI) may influence the efficacy of calcium channel blockers (CCBs) by affecting drug metabolism, vascular resistance, and inflammatory responses associated with adipose tissue.

OBJECTIVE

This study aims to evaluate the association between BMI and the short-term efficacy of CCBs in managing hypertension among patients with CVDs over a six-month follow-up period.

METHODOLOGY

This prospective observational study was conducted at the Department of General Internal Medicine, Royal Alexandra Hospital, Glasgow, UK, from June 2023 to June 2024, enrolling 220 patients diagnosed with hypertension and at least one underlying cardiovascular condition, such as coronary artery disease, heart failure, or atrial fibrillation. Patients were categorized into BMI groups based on the World Health Organization (WHO) classification, and all were prescribed CCBs either as monotherapy or in combination with other antihypertensive medications. Blood pressure was measured using an automated sphygmomanometer with follow-up ambulatory monitoring, while lipid levels were assessed via fasting blood samples.

RESULTS

The study involved 220 participants, categorized into four BMI groups: underweight (n = 40), normal weight (n = 60), overweight (n = 60), and obese (n = 60). Underweight patients had a baseline systolic/diastolic blood pressure of 150/95 mmHg, which decreased to 135/85 mmHg, showing a reduction of 15/10 mmHg. Normal weight patients experienced a drop from 145/90 mmHg to 130/80 mmHg, overweight patients from 155/95 mmHg to 140/85 mmHg, and obese patients from 160/100 mmHg to 145/90 mmHg, all with the same reduction of 15 mmHg in systolic and 10 mmHg in diastolic pressure. Low-density lipoprotein (LDL) levels decreased in all groups, with a reduction of 5 mg/dL in the underweight (130 to 125 mg/dL) and normal weight (125 to 120 mg/dL) groups, while the overweight (140 to 130 mg/dL) and obese (150 to 140 mg/dL) groups showed a greater reduction of 10 mg/dL. High-density lipoprotein (HDL) levels improved in all categories, increasing by 5 mg/dL in each group. LDL reduction was more pronounced in overweight and obese groups, likely due to metabolic changes associated with higher body fat. Adverse effects, including peripheral edema and dizziness, were more common in higher BMI groups, with a noticeable decline in medication adherence in obese patients. These results suggest that BMI may influence treatment efficacy, particularly in lipid regulation and the occurrence of adverse effects.

CONCLUSION

BMI does not significantly affect the blood pressure-lowering efficacy of CCBs in patients with hypertension and CVDs. However, a greater reduction in LDL levels was observed in overweight and obese groups, suggesting that BMI may influence lipid metabolism differently than blood pressure regulation.

A new telemedicine-based sleep service using WatchPAT® ONE for patients with suspected OSA: what does the patient experience?

PURPOSE

Obstructive Sleep Apnea is a widespread disease but is very underdiagnosed and undertreated. The aim of this study is to assess the effectiveness and patient satisfaction of using the WatchPAT® ONE, a disposable home sleep apnea test device, within a telemedicine-based management pathway.

METHODS

All patients who used the telemedicine services for OSA diagnosis using the WatchPAT® ONE were prospectively enrolled in the study. Patients receive the device at home and download its associated application to learn how to perform the test autonomously at night. Clinicians then review automated results transmitted by the cloud and conduct the follow-up visit via telemedicine, providing diagnostic and therapeutic guidance.

RESULTS

The study included 167 patients (78% male; mean age 55 ± 14 years; BMI: 27.5 ± 4.5 kg/cm²), with a mean distance of 147.29 ± 172.35 km from our hospital. The median time from test request to result delivery was 5 working days. The study cohort showed a median pAHI of 16.7 events/h, a median pODI was 7.9 events/h, and an pRDI of 20.7 events/h. 99% of respondents were satisfied with the remote management. Half of the subjects found both the application installation and the device operation extremely easy, and 60% of them were willing to recommend the use of WatchPAT® ONE.

CONCLUSION

The telemedicine pathway represents an efficient and patient-friendly method for diagnosing OSA. This approach improves diagnostic ease and accessibility while reducing time to diagnosis and societal and healthcare costs. Further large-scale studies are necessary to confirm these results.

Rethinking appropriate blanking period after atrial fibrillation ablation

BACKGROUND

Early recurrence (ER) within a 90-day blanking period (BP) in catheter ablation (CA) for atrial fibrillation (AF) is a risk factor for late recurrence (LR) after 90 days postoperatively. However, few reports have examined them in the second CA and compared them to the first CA. Moreover, in recent years, there have been reports suggesting that BP should be reduced from 90 to 30 days. Therefore, the association between ER and LR in the first and the second CA was examined, and the validity of a 30-day BP was evaluated.

METHODS

A total of 511 consecutive patients undergoing the first CA and 116 of these patients undergoing the second CA for AF at a single institution from November 2016 to December 2020 were analyzed retrospectively.

RESULTS

When ER within a 90-day BP was divided into 0-30 days and 31-90 days according to the timing of the last ER episode, the hazard ratios on LR of them relative to no ER were 2.7 {95% confidence interval (CI) 1.7-4.2} and 9.7 (95% CI 6.6-14.3), respectively, for the first CA and 15.3 (95% CI 4.7-50.1) and 44.1 (95% CI 14.0-139.4), respectively, for the second CA.

CONCLUSIONS

ER was strongly associated with LR, especially in patients with the last episode of ER more than 30 days after CA. This was pronounced in cases after the second CA, when PVI appeared to be completed. With the current improvement in PVI durability, BP may be acceptable for 30 days.

Radiofrequency Catheter Ablation for Atrial Fibrillation Patients on Hemodialysis (From the Kansai Plus Atrial Fibrillation Registry) - Clinical Impact of Early Recurrence

BACKGROUND

Catheter ablation (CA) for atrial fibrillation (AF) in patients on hemodialysis (HD) is reported to have a high risk of late recurrence (LR). However, the relationship between early recurrence (ER) within a 90-day blanking period after CA in AF patients and LR in HD patients remains unclear.

METHODS AND RESULTS

Of the 5,010 patients in the Kansai Plus Atrial Fibrillation Registry, 5,009 were included in the present study. Of these patients, 4,942 were not on HD (non-HD group) and 67 were on HD (HD group). HD was an independent risk factor for LR after the initial CA (adjusted hazard ratio 1.6; 95% confidence interval 1.1-2.2; P=0.01). In patients with ER, the rate of sinus rhythm maintenance at 3 years after the initial CA was significantly lower in the HD than non-HD group (11.4% vs. 35.4%, respectively; log-rank P=0.004). However, in patients without ER, there was no significant difference in the rate of sinus rhythm maintenance at 3 years between the HD and non-HD groups (67.7% vs. 74.5%, respectively; log-rank P=0.62).

CONCLUSIONS

ER in HD patients was a strong risk factor for LR. However, even HD patients could expect a good outcome without ER after the initial CA.

Impact of Body Mass Index in the Cardioverter Efficacy of Amiodarone in Persistent Atrial Fibrillation

BACKGROUND

Amiodarone is an anti-arrhythmic drug that has extensive tissue distribution and substantial storage in the fat tissue. Different studies have described some implications of body fat composition in its pharmacokinetics and pharmacodynamics. However, no clinical studies have described its implications for clinical efficacy.

METHODS

We studied 878 patients with persistent atrial fibrillation (AF) treated with a regimen of amiodarone and referred to electrical cardioversion (ECV), included prospectively in two Spanish registries. We analyzed the influence of body mass index (BMI), as well as overweight and obesity, in the efficacy of amiodarone for achieving pharmacologic cardioversion to sinus rhythm (SR) before ECV.

RESULTS

A total of 185 patients (21.1%) reverted to SR before ECV. Patients who reverted to SR had a lower BMI than those who did not revert (27.45 ± 4.36 kg/m2 vs. 29.11 ± 4.09 kg/m2; p < 0.001). We observed a progressively lower probability of reverting to SR in overweight and obese patients (normal weight 28.3%, overweight 21.3%, obesity 13.1%; p < 0.001). In the logistic regression, BMI (kg/m2) adjusted for other related variables remained as the main factor inversely related to reversion to SR (OR = 0.904 × kg/m2); CI 75% 0.864-0.946).

CONCLUSIONS

We observed a negative relationship between an increased BMI and the efficacy of amiodarone for reversion to SR, suggesting a negative clinical impact of excess body fat in its efficacy.

Breathless nights and heart flutters: Understanding the relationship between obstructive sleep apnea and atrial fibrillation

There is an extraordinary and increasing global burden of atrial fibrillation (AF) and obstructive sleep apnea (OSA), two conditions that frequently accompany one another and that share underlying risk factors. Whether a causal pathophysiologic relationship connects OSA to the development and/or progression of AF, or whether shared risk factors promote both conditions, is unproven. With increasing recognition of the importance of controlling AF-related risk factors, numerous observational studies now highlight the potential benefits of OSA treatment in AF-related outcomes. Physicians are regularly faced with caring for this important and increasing population of patients despite a paucity of clinical guidance on the topic. Here, we review the clinical epidemiology and pathophysiology of AF and OSA with a focus on key clinical studies and major outstanding questions that should be addressed in future studies.

Optimization of procedural sedation and analgesia during atrial fibrillation ablation

PURPOSE OF REVIEW

This mini-review is aimed to provide an overview and discuss procedural sedation and analgesia for atrial fibrillation (AF) ablation with focus at qualification of staff, patient evaluation, monitoring, medication and postprocedural care.

RECENT FINDINGS

Sleep-disordered breathing is highly prevalent in patients with AF. Impact of often used STOP-BANG questionnaire to detect sleep-disordered breathing in AF patients is limited due to its restricted validity. Dexmedetomidine is a commonly used drug in sedation, but is shown not to be superior to propofol in sedation during AF-ablation. Alternatively use of remimazolam has characteristics that makes it a promising drug for minimal to moderate sedation for AF-ablation. High flow nasal oxygen (HFNO) has shown to reduce the risk of desaturation in adults receiving procedural sedation and analgesia.

SUMMARY

An optimal sedation strategy during AF ablation should be based on AF patient characteristics, the level of sedation needed, the procedure (duration and type of ablation) and the education and experience of the sedation provider. Patient evaluation and post procedural care are part of sedation care. More personalized care based on use of various sedation strategies and types of drugs as related to the type of AF-ablation is the way to further optimize care.