Effect of Sleep Surgery on Blood Pressure in Adults with Obstructive Sleep Apnea: A Systematic Review and Meta-analysis

The Effect of Surgical Therapy for Obstructive Sleep Apnea on Blood Pressure and Peripheral Arterial Tonometry

OBJECTIVE

To determine the effect of upper airway surgery on cardiovascular function in patients with obstructive sleep apnea (OSA).

STUDY DESIGN

A prospective, self-controlled study from 2018 to 2023.

SETTING

Two academic medical centers.

METHODS

Seventy-four patients underwent surgery for OSA, including: tonsillectomy, adenoidectomy, epiglottidectomy, modified uvulopalatopharyngoplasty, maxillary expansion, and maxillomandibular advancement. Twenty-four-hour ambulatory blood pressure (BP), peripheral arterial tonometry (PAT)-based home sleep study, and sleep-related patient-reported outcomes (PROs) were captured preoperatively and at 6 months postoperatively. Paired T-tests evaluated changes in outcomes after surgery.

RESULTS

Forty-one patients successfully completed preoperative and postoperative assessments. Patients were generally middle-aged (43.8 ± 12.5 years), obese (BMI 33.0 ± 5.8 kg/m2), male (68%), White (71%), and had severe OSA (apnea-hypopnea index [AHI] 33.9 ± 29.5 events/h). The 4% oxygen desaturation index (ODI) decreased from 30.7 ± 27.1 to 12.2 ± 13.6 events/h (P < .01) after surgery. There was no significant difference in 24-h BP following surgery, though clinically meaningful reductions in nocturnal systolic (-1.95 [-5.34, 1.45] mmHg) and nocturnal diastolic (-2.30 [-5.11, 0.52] mmHg) blood pressure were observed. Stratified analysis showed patients undergoing skeletal surgery (n = 17) demonstrated larger average reductions compared to those undergoing soft tissue surgery in nocturnal systolic (-4.12 [-7.72, -0.51] vs -0.10 [-5.78, 5.58] mmHg) and nocturnal diastolic (-3.94 [-7.90, 0.01] vs -0.90 [-5.11, 3.31] mmHg) pressures. No meaningful changes were observed in PAT Autonomic Index (PAI) measurements.

CONCLUSION

Surgical therapy for OSA did not demonstrate statistically significant improvements in 24-h BP. However, clinically meaningful reductions in nocturnal BP were observed, particularly in skeletal surgery patients, supporting the need for larger studies of cardiovascular outcomes following OSA surgery.

Recommended assessment and management of sleep disordered breathing in patients with atrial fibrillation, hypertension and heart failure: Taiwan Society of Cardiology/Taiwan Society of sleep Medicine/Taiwan Society of pulmonary and Critical Care Medicine joint consensus statement

Sleep disordered breathing (SDB) is highly prevalent and may be linked to cardiovascular disease in a bidirectional manner. The Taiwan Society of Cardiology, Taiwan Society of Sleep Medicine and Taiwan Society of Pulmonary and Critical Care Medicine established a task force of experts to evaluate the evidence regarding the assessment and management of SDB in patients with atrial fibrillation (AF), hypertension and heart failure with reduced ejection fraction (HFrEF). The GRADE process was used to assess the evidence associated with 15 formulated questions. The task force developed recommendations and determined strength (Strong, Weak) and direction (For, Against) based on the quality of evidence, balance of benefits and harms, patient values and preferences, and resource use. The resulting 11 recommendations are intended to guide clinicians in determining which the specific patient-care strategy should be utilized by clinicians based on the needs of individual patients.

Sleep apnea multi-level surgery trial: long-term observational outcomes

STUDY OBJECTIVES

The sleep apnea multi-level surgery (SAMS) randomized clinical trial showed surgery improved outcomes at 6 months compared to ongoing medical management in patients with moderate or severe obstructive sleep apnea (OSA) who failed continuous positive airway pressure therapy. This study reports the long-term outcomes of the multi-level surgery as a case series.

METHODS

Surgical participants were reassessed >2 years postoperatively with the same outcomes reported in the main SAMS trial. Primary outcomes were apnea-hypopnea index (AHI) and Epworth sleepiness scale (ESS), with secondary outcomes including other polysomnography measures, symptoms, quality of life, and adverse events. Long-term effectiveness (baseline to long-term follow-up [LTFU]) and interval changes (6 month to LTFU) were assessed using mixed effects regression models. Control participants were also reassessed for rate of subsequent surgery and outcomes.

RESULTS

36/48 (75%) of surgical participants were reevaluated (mean (standard deviation)) 3.5 (1.0) years following surgery, with 29 undergoing polysomnography. AHI was 41/h (23) at preoperative baseline and 21/h (18) at follow-up, representing persistent improvement of -24/h (95% CI -32, -17; p < 0.001). ESS was 12.3 (3.5) at baseline and 5.5 (3.9) at follow-up, representing persistent improvement of -6.8 (95% CI -8.3, -5.4; p < 0.001). Secondary outcomes were improved long term, and adverse events were minor. Interval change analysis suggests stability of outcomes. 36/43 (84%) of the control participants were reevaluated, with 25 (69%) reporting subsequent surgery, with symptom and quality of life improvements.

CONCLUSION

Multi-level upper airway surgery improves OSA burden with long-term maintenance of treatment effect in adults with moderate or severe OSA in whom conventional therapy failed.

CLINICAL TRIAL

Multi-level airway surgery in patients with moderate-severe obstructive sleep apnea (OSA) who have failed medical management to assess change in OSA events and daytime sleepiness; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366019&isReview=true; ACTRN12614000338662.

Hypoglossal Nerve Stimulation and Cardiovascular Outcomes for Patients With Obstructive Sleep Apnea: A Randomized Clinical Trial

Importance

Sham-controlled trials are needed to characterize the effect of hypoglossal nerve stimulation (HGNS) therapy on cardiovascular end points in patients with moderate-severe obstructive sleep apnea (OSA).

Objective

To determine the effect of therapeutic levels of HGNS, compared to sham levels, on blood pressure, sympathetic activity, and vascular function.

Design, Setting, and Participants

This double-blind, sham-controlled, randomized crossover therapy trial was conducted from 2018 to 2022 at 3 separate academic medical centers. Adult patients with OSA who already had an HGNS device implanted and were adherent and clinically optimized to HGNS therapy were included. Participants who had fallen asleep while driving within 1 year prior to HGNS implantation were excluded from the trial. Data analysis was performed from January to September 2022.

Interventions

Participants underwent a 4-week period of active HGNS therapy and a 4-week period of sham HGNS therapy in a randomized order. Each 4-week period concluded with collection of 24-hour ambulatory blood pressure monitoring (ABPM), pre-ejection period (PEP), and flow-mediated dilation (FMD) values.

Main Outcomes and Measures

The change in mean 24-hour systolic blood pressure was the primary outcome, with other ABPM end points exploratory, and PEP and FMD were cosecondary end points.

Results

Participants (n = 60) were older (mean [SD] age, 67.3 [9.9] years), overweight (mean [SD] body mass index, calculated as weight in kilograms divided by height in meters squared, 28.7 [4.6]), predominantly male (38 [63%]), and had severe OSA at baseline (mean [SD] apnea-hypopnea index, 33.1 [14.9] events/h). There were no differences observed between active and sham therapy in 24-hour systolic blood pressure (mean change on active therapy, -0.18 [95% CI, -2.21 to 1.84] mm Hg), PEP (mean change on active therapy, 0.11 [95% CI, -5.43 to 5.66] milliseconds), or FMD (mean change on active therapy, -0.17% [95% CI, -1.88% to 1.54%]). Larger differences between active and sham therapy were observed in a per-protocol analysis set (n = 20) defined as experiencing at least a 50% reduction in apnea-hypopnea index between sham and active treatment.

Conclusions and Relevance

In this sham-controlled HGNS randomized clinical trial, mean 24-hour systolic blood pressure and other cardiovascular measures were not significantly different between sham and active HGNS therapy. Several methodologic lessons can be gleaned to inform future HGNS randomized clinical trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT03359096.

White matter microstructure and connectivity changes after surgery in male adults with obstructive sleep apnea: recovery or reorganization?

Study objectives

Obstructive sleep apnea (OSA) is a prevalent clinical problem significantly affecting cognitive functions. Surgical treatment is recommended for those unable to use continuous positive airway pressure. We aimed to investigate the therapeutic effect of upper airway surgery on the white matter (WM) microstructure and brain connectivity in patients with OSA.

Methods

Twenty-one male patients with moderate-to-severe OSA were recruited for multi-level upper airway surgery. Overnight polysomnography (PSG), neuropsychiatric tests, and brain MRI scans were acquired before and 6.1 ± 0.8 months after surgery. Nineteen male patients with untreated OSA were also included as a reference group. We calculated the longitudinal changes of diffusion tensor imaging (DTI) parameters, including fractional anisotropy (ΔFA) and mean/axial/radial diffusivity (ΔMD/AD/RD). We also assessed changes in network properties based on graph theory.

Results

Surgically treated patients showed improvement in PSG parameters and verbal memory after surgery. Globally, ΔFA was significantly higher and ΔRD was lower in the surgery group than in the untreated group. Especially ΔFA of the tracts involved in the limbic system was higher after surgery. In network analysis, higher Δbetweenness and lower Δclustering coefficients were observed in the surgical group than in the untreated group. Finally, the improvement of verbal memory after surgery positively correlated with ΔFA in superior thalamic radiation (p = 0.021), fronto aslant tracts (p = 0.027), and forceps minor tracts (p = 0.032).

Conclusion

Surgical treatment of OSA can alleviate alterations in WM integrity and disruptions in local networks, particularly for the tracts involved in the limbic system. These findings may further explain the cognitive improvement observed after the treatment of OSA.

Management of hypertension in obstructive sleep apnea

Obstructive sleep apnea (OSA) plays an important role in the development of hypertension. Thus, this review summarizes pharmacological and non-pharmacological approaches to blood pressure (BP) control in patients with OSA. Current treatments for OSA, such as continuous positive airway pressure, are effective at lowering BP. However, they only provide a modest BP reduction, and pharmacological treatment remains important for achieving optimal BP control. Furthermore, current guidelines for the treatment of hypertension do not make specific recommendations on pharmacological treatment protocols for controlling BP in patients with OSA. Moreover, the BP-lowering effects of various classes of antihypertensives may be different in hypertensive patients with OSA than in those without OSA due to the underlying mechanisms that promote hypertension in OSA. The acute and chronic increase in sympathetic nerve activity in patients with OSA explain the effectiveness of beta blockers in controlling BP in these patients. As activation of the renin-angiotensin-aldosterone system may also promote hypertension in OSA, angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers have generally been found effective for lowering BP in hypertensive patients with OSA. The aldosterone antagonist spironolactone also produces a good antihypertensive response in patients with OSA and resistant hypertension. However, there are limited data available that compare the effects of various classes of antihypertensive medication on BP control in those with OSA, and most data have been obtained from small-scale studies. This demonstrates the need for large-scale randomized controlled trials to evaluate a range of BP-lowering regimens in patients with OSA and hypertension.

Effect of Sleep Surgery on Inflammatory Cytokines in Adult Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate whether sleep surgery is associated with inflammatory cytokine changes. This study hypothesizes cytokines may change after surgery in adult obstructive sleep apnea (OSA).

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

The study protocol was registered on PROSPERO (CRD42020154425). Two authors independently searched PubMed, Embase, and Cochrane review databases from their inception to June 2021. The keywords used were sleep apnea, inflammatory markers, cytokines, and surgery. The effects of sleep surgery on the apnea-hypopnea index (AHI) and inflammatory cytokines were evaluated using a random-effects model. Both mean difference (MD) and standardized mean difference (SMD) of the changes in cytokines were calculated.

RESULTS

Nine studies with 235 adults were included (mean age: 43 years; 82% were men). After sleep surgery, AHI significantly reduced by -11.3 events/h (95% confidence interval [CI], -15.8 to -6.9). In total, 8 and 6 studies were pooled for examining tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels, respectively. Sleep surgery significantly reduced TNF-α levels, with an MD of -2.8 pg/ml (95% CI, -5.1 to -0.6) and an SMD of -0.56 (95% CI, -0.85 to -0.27). Furthermore, sleep surgery reduced IL-6 levels, with an MD of -0.6 pg/ml (95% CI, -1.0 to -0.2) and an SMD of -0.66 (95% CI, -0.89 to -0.43). No covariates were identified to be correlated with cytokine changes in subgroup and meta-regression analyses. Funnel plots showed possible publication bias in current data.

CONCLUSIONS

In adults, OSA treatment with sleep surgery improves inflammatory cytokines. Laryngoscope, 2022.