Effect of phrenic nerve stimulation on patients with central sleep apnea: A meta-analysis.

Patients with central sleep apnea (CSA) have a lower quality of life and higher morbidity and mortality. Phrenic nerve stimulation (PNS) is a novel treatment for CSA that has been shown to be safe. However, the effects of PNS on sleep changes are still under debate. This meta-analysis was performed to evaluate the efficacy of PNS in patients with CSA. PubMed, Scopus, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL) and Web of Science databases were searched for relevant studies published. We performed random-effects meta-analyses of the changes in apnea-hypopnea index (AHI), central apnea index (CAI), Arousal Index, percent of sleep with O2 saturation <90% (T90), Epworth Sleepiness Scale (ESS) and sleep efficiency. Ten studies with a total of 580 subjects were analyzed. Overall meta-analysis showed AHI [SMD: -2.24, 95% confidence interval (CI): was -3.11 to -1.36(p＜0.00001)], CAI [SMD: -2.32, 95% CI: -3.17 to -1.47 (p＜0.00001)] and Arousal Index (p = 0.0002, SMD (95% CI) -1.79 (-2.74 to -0.85)) significantly reduced after PNS. No significant changes were observed in T90, ESS and sleep efficiency (p > 0.05). Meta-analysis of observational studies demonstrated AHI, CAI and Arousal Index had a decreasing trend between before and after PNS (all, p＜0.05). However, ESS and T90 did not change significantly after PNS (p > 0.05). Meta-analysis of RCTs showed that CSA patients had trends of a lower AHI (I2 = 0%), CAI (I2 = 74%), Arousal Index (I2 = 0%), T90 (I2 = 0%) and ESS (I2 = 0%) after PNS (all, p＜0.05). The use of PNS appears to be safe and feasible in patients with CSA. However, larger, independent RCTs are required to investigate the efficacy and long-term effect of PNS and more attention should be paid to T90 and ESS.

Effects of sacubitril-valsartan on central and obstructive apneas in heart failure patients with reduced ejection fraction.

OBJECTIVE: This study aimed to evaluate the effect of sacubitril-valsartan (SV) on central apneas (CA) and obstructive apneas (OA) in patients with heart failure with reduced ejection fraction (HFrEF). METHODS: In patients with HFrEF, SV initiation was titrated to the highest tolerable dosage. Patients were evaluated with portable apnea monitoring, echocardiography, and cardiopulmonary exercise testing at baseline and 3 months later. RESULTS: Of a total of 18 patients, 9 (50%) had OA, 7 (39%) had CA, and 2 (11%) had normal breathing. SV therapy was related to a reduction in NT-pro BNP and an improvement in LV function after 3 months. Portable apnea monitoring revealed a significant decrease of the respiratory event index (REI) after treatment with SV (20 ± 23 events/h to 7 ± 7 events/h, p = 0.003). When subgrouping according to type of apneas, REI, and time spent below 90% saturation (T90) decreased in patients with CA and OA (all p < 0.05). CONCLUSION: In this prospective study, SV treatment for 3 months in patients with CA and OA is associated with a significant decrease in REI.

Phrenic nerve stimulation for the treatment of central sleep apnea in patients with heart failure.

OBJECTIVE: Central sleep apnea (CSA) is associated with increased morbidity and mortality in patients with heart failure (HF). We aimed to explore the effectiveness of phrenic nerve stimulation (PNS) on CSA in patients with HF. METHODS: This was a prospective and non-randomized study. The stimulation lead was inserted into the right brachiocephalic vein and attached to a proprietary neurostimulator. Monitoring was conducted during the implantation process, and all individuals underwent two-night polysomnography. RESULTS: A total of nine subjects with HF and CSA were enrolled in our center. There was a significant decrease in the apnea-hypopnea index (41 ± 18 vs 29 ± 25, p = 0.02) and an increase in mean arterial oxygen saturation (SaO2) (93% ± 1% vs 95% ± 2%, p = 0.03) after PNS treatment. We did not observe any significant differences of oxygen desaturation index (ODI) and SaO2 < 90% (T90) following PNS. Unilateral phrenic nerve stimulation might also categorically improve the severity of sleep apnea. CONCLUSION: In our non-randomized study, PNS may serve as a therapeutic approach for CSA in patients with HF.

Endovascular Treatment Versus Best Medical Management in Acute Basilar Artery Occlusion Strokes: Results From the ATTENTION Multicenter Registry.

BACKGROUND: The authors compare the effectiveness and safety of endovascular treatment (EVT) versus best medical management (BMM) in strokes attributable to acute basilar artery occlusion (BAO). METHODS: The present analysis was based on the ongoing, prospective, multicenter ATTENTION (Endovascular Treatment for Acute Basilar Artery Occlusion) trial registry in China. Our analytic sample comprised 2134 patients recruited at 48 sites between 2017 and 2021 and included 462 patients who received BMM and 1672 patients who received EVT. We performed an inversed probability of treatment weighting analysis. Qualifying patients had to present within 24 hours of estimated BAO. The primary clinical outcome was favorable functional outcome (modified Rankin Scale score, 0-3) at 90 days. We also performed a sensitivity analysis with the propensity score matching-based and the instrumental variable-based analysis. RESULTS: In our primary analysis using the inversed probability of treatment weighting-based analysis, there was a significantly higher rate of favorable outcome at 90 days among EVT patients compared with BMM-treated patients (adjusted relative risk, 1.42 [95% CI, 1.19-1.65]; absolute risk difference, 11.8% [95% CI, 6.9-16.7]). The mortality was significantly lower (adjusted relative risk, 0.78 [95% CI, 0.69-0.88]; absolute risk difference, -10.3% [95% CI, -15.8 to -4.9]) in patients undergoing EVT. Results were generally consistent across the secondary end points. Similar associations were seen in the propensity score matching-based and instrumental variable-based analysis. CONCLUSIONS: In this real-world study, EVT was associated with significantly better functional outcomes and survival at 90 days. Well-designed randomized studies comparing EVT with BMM in the acute BAO are needed. REGISTRATION: URL: www.chictr.org.cn; Unique identifier: ChiCTR2000041117.

Management of Obstructive Sleep Apnea in Patients With Heart Failure.

Sleep apnea is traditionally classified as obstructive sleep apnea (OSA), which occurs when the upper airway collapses due to the relaxation of oropharyngeal musculature, and central sleep apnea occurs when the brainstem cannot stimulate breathing. Most sleep apnea in patients with heart failure (HF) results from coexisting OSA and central sleep apnea (CSA), or complex sleep apnea syndrome. OSA and CSA are common in HF and can be involved in its progression by exposure to the heart to intermittent hypoxia, increased preload and afterload, activating sympathetic, and decreased vascular endothelial function. A majority of treatments have been investigated in patients with CSA and HF; however, less or short-term randomized trials demonstrated whether treating OSA in patients with HF could improve morbidity and mortality. OSA could directly influence the patient's recovery. This review will focus on past and present studies on the various therapies for OSA in patients with HF and summarize CSA treatment options for reasons of reference and completeness. More specifically, the treatment covered include surgical and non-surgical treatments and reported the positive and negative consequences for these treatment options, highlighting possible implications for clinical practice and future research directions.

Feasibility of Transcatheter Caval Valve Implantation to Improve Sleep-Disordered Breathing in Patients With Severe Tricuspid Regurgitation-A Pilot Study.

Transcatheter caval valve implantation (CAVI) has been evaluated as a treatment option for inoperable patients with severe symptomatic tricuspid regurgitation (TR). We studied the effect of CAVI on sleep disorder breathing (SDB) in patients with right heart failure and TR. Twenty right heart failure patients with severe symptomatic TR who underwent portable monitoring of SDB (ApneaLink), echocardiography, cardiopulmonary exercise (CPET), and laboratory testing were enrolled. This was a single-center, nonblinded study. There were no significant changes in sleep variables, echocardiographic parameters, laboratory results, lung function, and CPET after CAVI. In conclusion, these data suggest that CAVI may not have an effect on SDB; however, additional follow-up fully powered studies with appropriate statistical analyses are needed.

Down-regulated miR-21 promotes learning-memory recovery after brain injury.

BACKGROUND: MicroRNA is anendogenous non-coding single strand RNA which consists of 22 nt. It post-transcriptionally regulates gene expression and development. MicroRNA 21 plays an important role in repairing injured brain tissues. Thus, in this research, we explored the function of miR-21 in learning-memory recovery after brain injury. METHOD: 3 days old newborn SD rats were separated into three groups: Sham operation group (Sham), inflammation-sensitized hypoxic-ischemic brain injury (LPS+HI) group and miR-21 inhibitor group. 28 days later, the learning and memory capability was assayed by water maze. H&E staining and Nissl's staining were used to assay pathologic changes and TUNEL was used to assay neuron apoptosis in brain tissue. RESULTS: Water maze assay showed that the capability of positioning navigation in the IH-HI group was worse than in the Sham group and miR-21 inhibition group, and the Sham group wass better than miR-21 group. Both of the comparisons had statistical significance (P < 0.05). H&E staining in the sham group showed that the neurons were arranged well in hippocampus. In LPS+HI group, some neurons in hippocampus had vacuolar degeneration and the neurons were not well arranged well. In the hippocampus of miR-21 inhibitor group, the neuron cell layers were decreased but the neurons were arranged better than in the LPS+HI group. Nissl's staining in LPS+HI group showed neuronal edema, neurons decreased, and Nissl's bodies decreased in the cytoplasm compared with the sham group. However, compared with the LPS+HI group, Nissl's staining in miR-21 inhibitor group showed that the neuronal edema was alleviated and neurons were better arranged. TUNEL assay showed that the apoptosis rate of LPS+HI group was higher than in the miR-21 inhibitor group and miR-21 inhibitor group was higher than the sham group. CONCLUSION: Down-regulated miR-21 can alleviate LPS+HI injury in the brain.

Multiple intracranial arterial stenosis influences the long-term prognosis of symptomatic middle cerebral artery occlusion.

BACKGROUND: Large intracranial occlusive vascular disease is a major contributor to the incidence of stroke worldwide, especially when it involves the middle cerebral artery (MCA). The data on the prognosis of symptomatic atherosclerotic MCA occlusions (MCAO) with concomitant intracranial arterial disease (MCAO-AIS) are limited. MCAO-AIS may reflect the extent of the atherosclerotic intracranial disease, we hypotheses that coexisting intracranial arterial disease influenced the prognosis of MCAO. METHODS: Patients having survived at least one month after the initial ischemic stroke who suffered from atherosclerotic occlusion of the MCA were enrolled. According to their concomitant atherosclerotic intracranial arterial disease, the patients were assigned to one of two groups: the MCAO or the MCAO-AIS. All of the patients' cerebrovascular risk factors were recorded. Recurrent ischemic stroke and death were the end-point events during the follow-up. RESULTS: A total of 232 patients (mean age 57.68 ± 9.50 years; 69% male) were analyzed. The mean follow-up time was 17.65 months. The end-point events occurred in 35 (15.09%) patients, resulting in an annual rate of 10.26%. The presence of MCAO- AIS was an independent risk factor associated with the patient's prognosis in the cohort (OR = 3.426, 95% CI 1.261 to 9.308; p = 0.016), as well as gender and diabetes mellitus. The MCAO-AIS were more likely to experience ipsilateral ischemic strokes, but the difference was not statistically significant. CONCLUSION: Concomitant intracranial arterial disease may influence the prognosis of patients with atherosclerotic MCAO. The result warrants further research in larger sample population.