Effect of obstructive sleep apnoea and its treatment with continuous positive airway pressure on the prevalence of cardiovascular events in patients with acute coronary syndrome (ISAACC study): a randomised controlled trial.

BACKGROUND: Despite the improvement in the prognosis of acute coronary syndrome (ACS), substantial morbidity and mortality remain. We aimed to evaluate the effect of obstructive sleep apnoea (OSA) and its treatment with continuous positive airway pressure (CPAP) on the clinical evolution of patients with ACS. METHODS: We designed a multicentre, open-label, parallel-group, randomised controlled trial of patients with ACS at 15 hospitals in Spain. Eligible non-sleepy patients were men and women aged 18 years and older, admitted to hospital for documented symptoms of ACS. All patients underwent respiratory polygraphy during the first 24-72 h after admission. OSA patients were randomly assigned (1:1) to CPAP treatment plus usual care (CPAP group) or usual care alone (UC group) by a computerised system available 24 h a day. A group of patients with ACS but without OSA was also included as a reference group. Because of the nature of the intervention, the trial intervention could not be masked to either investigators or patients. Patients were monitored and followed for a minimum of 1 year. Patients were examined at the time of inclusion; after 1 month, 3 months, 6 months, 12 months, 18 months, 24 months, 30 months, and 36 months; and every 12 months thereafter, if applicable, during the follow-up period. The primary endpoint was the prevalence of a composite of cardiovascular events (cardiovascular death or non-fatal events [Acute myocardial infarction, non-fatal stroke, hospital admission for heart failure, and new hospitalisations for unstable angina or transient ischaemic attack]) in patients followed up for a minimum of 1 year. The primary analysis was done according to the intention-to-treat principle. This study is registered with Clinicaltrials.gov, NCT01335087 and is now closed. FINDINGS: Between April 25, 2011, and Feb 2, 2018, a total of 2834 patients with ACS had respiratory polygraphy, of whom 2551 (90·01%) were recruited. 1264 (49·55%) patients had OSA and were randomly assigned to the CPAP group (n=633) or the UC group (n=631). 1287 (50·45%) patients did not have OSA, of whom 603 (46·85%) were randomly assigned to the reference group. Patients were followed up for a median of 3·35 years (IQR 1·50-5·31). The prevalence of cardiovascular events was similar in the CPAP and UC groups (98 events [16%] vs 108 events [17%]; hazard ratio [HR] 0·89 [95% CI 0·68-1·17]; p=0·40) during follow-up. Mean time of adherence to CPAP treatment was 2·78 h/night (SD 2·73). The prevalence of cardiovascular events was similar between patients in the reference group (90 [15%] events) and those in the UC group (102 (17%) events) during follow-up (1·01 [0·76-1·35]; p=0·93). The prevalence of cardiovascular events seem not to be related to CPAP compliance or OSA severity. 464 (74%) of 629 patients in the CPAP group had 1538 serious adverse events and 406 (65%) of 626 patients in the UC group had 1764 serious adverse events. INTERPRETATION: Among non-sleepy patients with ACS, the presence of OSA was not associated with an increased prevalence of cardiovascular events and treatment with CPAP did not significantly reduce this prevalence. FUNDING: ResMed (Australia), Fondo de Investigación Sanitaria (Fondo Europeo de Desarrollo Regional), the Spanish Respiratory Society, the Catalonian Cardiology Society, Esteve-Teijin, Oxigen Salud, and ALLER.

Impact of environmental air pollutants on disease control in asmathic patients.

PURPOSE: Asthmatics are adversely affected by the presence of air pollutants, the concentrations of which can nowadays be measured. However, the utility of this information in clinical practice has not been defined in a group of asthmatics in stable condition. Our objective was to determine what impact the level of air pollutants had on the control of their asthma and the degree of airway inflammation. METHODS: We performed a cross-sectional study of adult asthmatics in stable condition. From the regional environmental authority, we obtained the concentrations of ambient nitric oxide (NO2), ozone (O3), suspended particulate matter up to 10 micrometers in diameter (PM10) and sulphur dioxide (SO2) at fixed geographical points. Disease control was assessed using asthma control test (ACT) scores, and airway inflammation using fraction of exhaled nitric oxide (FeNO) values. Correlation and linear regression studies were performed using ACT scores as the dependent variable. RESULTS: The study included 99 asthmatics, aged 39 years (SD 8), 55% women. Mean ACT value was 17.2 (SD 6.5), and FeNO 33.7 (SD 16). Of the pollutants studied, only NO2 was correlated with ACT scores (CC = 0.45, p < 0.001). We found no relationship between pollutants and airway inflammation. Multivariate analysis showed that ACT score was predicted by ambient air NO2 concentration and, to a lesser extent, mean FeNO. CONCLUSIONS: Information on the concentration of ambient NO2 in our environment can help the clinician to interpret the evolution of asthmatic patients.

Nasal versus oronasal mask in home mechanical ventilation: the preference of patients as a strategy for choosing the interface.

INTRODUCTION: In home mechanical ventilation (HMV), the mask is a key factor for patient comfort and therapeutic adherence. There is no evidence on the best strategy for choosing the mask in HMV. OBJECTIVE: To explore patient preference when prescribing the mask for HMV treatment and assess its relationship with effectiveness. METHODS: A prospective study with repeated measures in stable patients receiving home nocturnal ventilation. Alternating oronasal mask (ONM) and nasal mask (NM) were tested in day and overnight sessions, with arterial blood gas measured and S(pO(2)) monitored. At the end of each evening session, patients rated interface comfort using a visual analog scale. At 3 months we evaluated adherence and effectiveness of the treatment. RESULTS: Twenty-nine subjects (mean ± SD age 65 ± 13 y, 44% male) completed the study. Initial functional values were P(CO(2)) 57.4 ± 5.2 mm Hg and time with S(pO(2)) < 90% (T90) 81.5 ± 9.5%. Both ONM and NM significantly decreased P(CO(2)) and T90. Over a third (38%) of our subjects preferred ONM, while NM was deemed more comfortable in general. At 3 months, effectiveness and adherence showed no differences between those treated with NM or ONM. CONCLUSIONS: Patient choice is an effective criterion for selecting the interface in HMV treatment.

Nocturnal home pulse oximetry: variability and clinical implications in home mechanical ventilation.

BACKGROUND: Nocturnal home pulse oximetry (NHPO) provides information by measuring a series of variables: time spent with SaO(2) <90% expressed as percentage (T90) or in minutes (Tm90), mean SaO(2) (MnS), and lowest SaO(2) (LwS.) The presence of significant nocturnal desaturation has been proposed as a parameter in decision making with regard to initiating home mechanical ventilation (HMV) or monitoring HMV effectiveness. However, there is limited information on the possible variability of the test, and this could influence the interpretation of results. OBJECTIVES: To explore the variability between 2 consecutive measurements of NHPO and to determine clinical applications in HMV. METHODS: The patients presented diseases susceptible to HMV treatment and were enrolled in stable condition without respiratory failure. NHPO was conducted on 2 consecutive nights. The variables analyzed were: T90, Tm90, Mns, and LwS. The coefficient of variation (CV), a concordance coefficient (CC), and the Bland-Altman method were used in order to explore the variability. RESULTS: We studied 40 cases. Two were excluded, and the remaining 38 were aged 58 ± 16 years (19 males). Eighteen were receiving HMV. CV values exceeded 100% for T90 and Tm90 and were below 5% for MnS and LwS. The CC for T90, Tm90, and LwS showed confidence intervals with lower limits below 0.5, while for MnS the value was 0.88 (0.79-0.93). CONCLUSIONS: There is a wide variability in NHPO recordings for T90, Tm90, and LwS, so a single determination to detect nocturnal desaturation may not be valid for decision making; the parameter with the least interindividual variability and intraindividual variability was MnS.