Sleep duration and architecture during ASV for central sleep apnoea in systolic heart failure.

BACKGROUND: Adaptive servoventilation (ASV) effectively treats nocturnal respiratory events in patients with heart failure and reduced ejection fraction (HFrEF) and central sleep apnoea (CSA), but increased mortality has been reported. This study investigated changes in sleep architecture during ASV treatment in HFrEF patients. METHODS: A retrospective analysis of polysomnographic datasets for 30 ASV-treated patients with stable HFrEF and moderate-to-severe CSA was performed, including blinded analyses of total sleep time (TST), and percentage of REM and non-REM sleep (stages N1-N3). RESULTS: Follow-up was 109 ±â€¯32 days; mean device usage was 6.0 ±â€¯1.1 h/day. During ASV there was reduction of N1 (34 ±â€¯20%/TST to 13 ±â€¯5%/TST, p < 0.001) and N3 sleep (4 ±â€¯6%/TST to 1 ±â€¯4%/TST, p = 0.020), and increase of N2 (44 ±â€¯14%/TST to 62 ±â€¯7%/TST, p < 0.001) and REM-sleep (18 ±â€¯8%/TST to 24 ±â€¯6%/TST, p = 0.002). CONCLUSIONS: Disturbances of sympatho-vagal balance during ASV might help explain increased mortality during ASV. Since sympathetic tone is highest in REM-sleep and vagal predominance occurs during N3 sleep, these findings generate new hypotheses for the increased mortality seen in SERVE-HF.

Adaptive servo-ventilation to treat central sleep apnea in heart failure with reduced ejection fraction: the Bad Oeynhausen prospective ASV registry.

BACKGROUND: Central sleep apnea (CSA) is highly prevalent in heart failure patients with reduced left ventricular ejection fraction (HF-REF). The Bad Oeynhausen Adaptive Servo-ventilation (ASV) registry (NCT01657188) was designed to investigate whether treatment of CSA with ASV improved survival in HF-REF patients; the effects of ASV on symptoms and cardiopulmonary performance were also investigated. METHODS AND RESULTS: From January 2004 to October 2013, the registry prospectively enrolled HF-REF patients [NYHA class ≥ II, left ventricular ejection fraction (LVEF) ≤ 45%] with moderate to severe predominant CSA [apnea-hypopnea index (AHI) ≥ 15/h]. ASV-treated patients were followed up at 3, 6, 12 and 24 months, including natriuretic peptide concentrations, blood gas analyses, echocardiography, 6-min walk distance (6MWD), and cardiopulmonary exercise (CPX) testing. 550 patients were included [age 67.7 ± 10 years, 90% male, 52% in NYHA class ≥ III, LVEF 29.9 ± 8%, AHI 35.4 ± 13.6/h, and time with nocturnal oxygen saturation < 90% (T < 90%) 58 ± 73 min]; ASV was prescribed to 224 patients. Over a median follow-up of 6.6 years, 109 (48.7%) ASV-treated patients and 191 (58.6%) controls died (adjusted Cox modelling hazard ratio of 0.95, 95% confidence interval 0.68-1.24; p = 0.740); older age, lower LVEF, impaired renal function, low sodium concentration, and nocturnal hypoxemia were significant predictors of mortality. Patient reported NYHA functional class improved in the ASV group, but LVEF, CPX, 6MWD, natriuretic peptides and blood gases remained unchanged. CONCLUSIONS: Long-term ASV treatment of predominant CSA in HF-REF patients included in our registry had no statistically significant effect on survival. ASV improved HF symptoms, but had no significant effects on exercise capacity, LVEF, natriuretic peptide concentrations or blood gases during follow-up as compared to control patients.

Second generation cryoballoon ablation for persistent atrial fibrillation: an updated meta-analysis.

BACKGROUND: Catheter ablation is an established treatment option for patients with symptomatic atrial fibrillation (AF). The cornerstone of AF ablation is pulmonary vein isolation (PVI). The second-generation cryoballoon (2G-CB) has shown non-inferiority to radiofrequency (RF) ablation in paroxysmal AF in several trials. Growing evidence suggests that 2G-CB is also effective in patients with persistent AF (perAF). The aim of this study was to summarize and analyze available data on safety and mid-term (≥ 12 months) efficacy of PVI using 2G-CB in patients with perAF. METHODS: We did a search in PubMed, Web of Science, Cochrane Library, and clinicaltrials.gov in December 2016 for studies of 2G-CB ablation for perAF. Studies reporting clinical success rates at a follow-up (FU) of ≥ 12 months were included. Success was defined as freedom from any atrial arrhythmia lasting > 30 s after an initial blanking period of 3 months. Acute success and complication rates were also assessed. Data were analyzed applying random-effects model. RESULTS: A total of 917 patients from 11 studies meeting study inclusion criteria were analyzed. After a mean FU of 16.7 ± 3.0 months, 68.9% were free from recurrences [95% confidence interval (CI) 63.4-74.7%]. Overall acute success rate was 99.7% (95% CI 99.2-100%). Complications occurred in 5.5% (95% CI 2.4-9.6%). Vascular access complications were the most frequent 3.3% (95% CI 1.5-5.6%). The rate of phrenic nerve palsy/injury was 2.09% (95% CI 0.8-3.9%). No death, stroke or myocardial infarction was reported. CONCLUSION: The 2G-CB seems to be safe and effective in the treatment of perAF in the mid-term.

Acute improvement of pulmonary hemodynamics does not alleviate Cheyne-Stokes respiration in chronic heart failure-a randomized, controlled, double-blind, crossover trial.

OBJECTIVES: This randomized, controlled trial aimed to investigate whether acute improvement of pulmonary congestion would reduce the severity of Cheyne-Stokes respiration (CSR) in patients with chronic heart failure (CHF). METHODS: Twenty-one consecutive patients with CHF and CSR (apnea-hypopnea index [AHI] ≥15/h) underwent right heart catheterization with titration of intravenous (IV) glyceryltrinitrate (GTN) to a maximum tolerable dosage and inhalation of iloprost 10 µg/mL after a washout phase. Maximum tolerable dosages of GTN and iloprost were randomly applied during full cardiorespiratory polysomnography within two split-night procedures and compared with IV or inhaled sodium chloride (NaCl) 0.9 %, respectively. RESULTS: GTN (6.2 ± 1.5 mg/h) and iloprost significantly lowered \mean pulmonary artery pressure (20.1 ± 9.0 to 11.6 ± 4.2 mmHg, p < 0.001 and 16.9 ± 7.9 to 14.2 ± 6.4 mmHg, p < 0.01, respectively). Pulmonary capillary wedge pressure was only reduced by GTN (14.0 ± 5.6 to 7.2 ± 3.9 mmHg, p < 0.001), and there was no significant change in the cardiac index. Sleep studies revealed no significant improvement in markers of CSR severity, including AHI, central apnea index, and CSR cycle length following GTN or iloprost treatment. Significant decreases in blood pressure, mean oxygen saturation, and S3 sleep were documented during GTN infusion. CONCLUSIONS: Acute improvement of pulmonary congestion by GTN had no immediate impact on CSR severity. Future investigations must therefore include longer treatment periods and treatment regimens that have positive, rather than negative, additional effects on peripheral and central chemoreceptors and sleep structure. TRIAL REGISTRATION: German Clinical Trial Registry-ID:DRKS00000467 ( www.germanctr.de ).

Nocturnal hypoxaemia is associated with increased mortality in stable heart failure patients.

AIM: This study investigated the prognostic value of sleep-disordered breathing (SDB) in a large cohort of patients with heart failure with reduced left ventricular function (HF-REF), with focus on the role of nocturnal hypoxaemia. METHODS: This single-centre prospective cohort study enrolled patients with chronic stable HF-REF (NYHA ≥II) receiving guideline-based treatment. Unattended in-hospital polygraphy was performed to determine the apnoea-hypopnoea index (AHI). Pulse oximetry was used to determine hypoxaemic burden [time with oxygen saturation <90% (T90)], and all-cause mortality was recorded. RESULTS: Complete data were available for 963 of 1249 patients. At baseline, 58% of patients had moderate-to-severe SDB. The median follow-up was 7.35 years; 480 of 963 (49.8%) patients died. Mortality rate (per 100 person-years) was 8.1 [95% confidence interval (CI) 7.0-9.4] in patients with no or mild SDB, but 12.2 (95% CI 10.9-13.7) in moderate-to-severe SDB. Apnoea-hypopnoea index was significantly associated with time to death from any cause in a simple Cox model [hazard ratio (HR) 1.011, P < 0.001], but was no longer significant after adjustment for confounding factors (HR 1.005, P = 0.085). T90 was significantly (P < 0.001) associated with time to death from any cause even after adjustment for confounding factors. The risk of death increased by 16.1% (95% CI 8.6-24.2) per hour of T90. Five-year survival probabilities for patients in T90 quartiles 1, 2, 3, and 4 were 70, 63, 60, and 50%, respectively. CONCLUSION: Hypoxaemic burden was a robust and independent predictor of all-cause mortality in chronic stable HF-REF patients. Whether or not targeting nocturnal hypoxaemia is associated with beneficial effects on mortality in HF-REF patients remains to be determined.

Trilevel adaptive servoventilation for the treatment of central and mixed sleep apnea in chronic heart failure patients.

BACKGROUND: Sleep-disordered breathing (SDB) in patients with heart failure (HF) is of major prognostic impact, though treatment of simultaneously occurring central and mixed apnea events is challenging. The objective was to examine long-term effects of a new trilevel adaptive servoventilation (ASV) therapy in patients with systolic or diastolic HF. METHODS: A total of 45 consecutive patients with a history of HF, elevated N-terminal prohormone of brain natriuretic peptide levels, objective signs of cardiac dysfunction, and moderate to severe SDB (apnea-hypopnea index [AHI] > or =15/h) with combined central and mixed respiratory events were included in this study and ASV therapy (SOMNOvent CR, Weinmann) was offered. RESULTS: In 38 patients (84%), ASV therapy was successfully initiated, with 23 (51%) patients showing appropriate compliance (device use > or = 4 h/night for > or = 5d/w) after 3.6±1.2 months. In these patients ASV therapy and HF status were re-evaluated. A sustained reduction was achieved in AHI (42.8±17.5/h vs 8.9±5.8/h; p<0.001) and oxygen saturation. Improvements also were recorded in New York Heart Association (NYHA) functional class (2.4±0.5-1.9±0.4; p<0.001) and oxygen uptake during cardiopulmonary exercise testing (VO2 peak, 13.64±3.5-15.8±5.8 ml/kg/min; p<0.002). CONCLUSION: In selected HF patients, trilevel ASV therapy is able to treat SDB with combined central and mixed respiratory events. This treatment is associated with an improvement in HF symptoms and objective cardiopulmonary performance.