Patients with symptoms and characteristics consistent with obstructive sleep apnea are at a higher risk for acute and subacute stent thrombosis after percutaneous coronary stent implantation: a single-center case-control study

Diagnostic accuracy and suitability of instruments that screen for obstructive sleep apnoea, insomnia and sleep quality in cardiac patients: a meta-analysis

BACKGROUND

A number of clinical guidelines recommend that all cardiac rehabilitation patients should be screened for potential sleep disorders with a validated screening instrument. There is currently no consensus on what specific tools should be used.

OBJECTIVE

To identify tools that are practical to use in the clinical environment and have high diagnostic accuracy.

METHODS

We systematically searched online databases to identify patient reported outcome instruments that have been used in published research studies to assess the likelihood of obstructive sleep apnoea (OSA) in cardiac patients. In studies that provided diagnostic data, these data were extracted and verified via an evidence-based diagnostic calculator. Where sufficient numbers of studies were available, a meta-analysis was conducted to determine pooled estimates of specificity, sensitivity and diagnostic odds ratios. Selected papers were qualitatively assessed using the Standards for Reporting Diagnostic accuracy studies (STARD).

RESULTS

Of the 21 instruments identified, six detected likelihood of OSA, two assessed daytime sleepiness, five assessed insomnia and eight examined sleep quality. A meta-analysis of 14 studies that assessed diagnostic accuracy of moderate OSA, revealed moderate sensitivity for the Berlin Questionnaire, Sens = 0.49 (95% CI 0.45-0.52) and good sensitivity for the Stop-BANG, Sens = 0.93 (95% CI 0.87-0.96) but poor specificity at standard cut-off criteria.

CONCLUSION

There are promising practical tools available to screen patients with OSA and other sleep disorders in cardiac rehabilitation settings, but specificity could be improved. Additional assessment of sleep quality may enhance prognostic ability with both OSA and insomnia screening.

Obstructive sleep apnoea in acute coronary syndrome

Obstructive sleep apnoea (OSA) syndrome affects about 13% of the male and 7–9% of the female population. Hypoxia, oxidative stress and systemic inflammation link OSA and cardiovascular and metabolic consequences, including coronary artery disease. Current research has identified several clinical phenotypes, and the combination of breathing disturbances during sleep, systemic effects and end-organ damage might help to develop personalised therapeutic approaches. It is unclear whether OSA is a risk factor for acute coronary syndrome (ACS) and might affect its outcome. On the one hand, OSA in patients with ACS may worsen prognosis; on the other hand, OSA-related hypoxaemia could favour the development of coronary collaterals, thereby exerting a protective effect. It is unknown whether positive airway pressure treatment may influence adverse events and consequences of ACS. In non-sleepy patients with OSA and stable coronary artery disease, randomised controlled trials failed to show that continuous positive airway pressure (CPAP) treatment protected against cardiovascular events. Conversely, uncontrolled studies suggested positive effects of CPAP treatment in such patients. Fewer data are available in subjects with ACS and OSA, and results of randomised controlled studies on the effects of CPAP are expected shortly. Meanwhile, the search for reliable markers of risk continues. Recent studies suggest that daytime sleepiness may indicate a more severe OSA phenotype with regard to cardiovascular risk. Finally, some studies suggest sex-related differences. The picture is still incomplete, and the potential role of OSA in patients with ACS awaits confirmation, as well as clear definition of subgroups with different degrees of risk.

Evidence suggests a high prevalence of OSA in ACS. While some studies suggest hypoxia may have a protective effect, the majority show increased adverse cardiac outcomes. Treatment effectiveness on ACS outcome crucially depends on patients' adherence.http://bit.ly/2Id97ec

Impact of Obstructive Sleep Apnea on Platelet Function Profiles in Patients With Acute Coronary Syndrome Taking Dual Antiplatelet Therapy

Background Obstructive sleep apnea ( OSA ) is a novel risk factor for acute coronary syndrome ( ACS ). Several studies have shown OSA to be associated with induced platelet reactivity. However, whether OSA have effects on platelet function profiles in ACS patients taking dual antiplatelet therapy remains unexplored. Methods and Results This was a cross-sectional observational study, in which ACS patients taking maintenance aspirin and clopidogrel therapy were included. OSA was defined as an apnea-hypopnea index ≥15 events/hour. The inhibitory rate of arachidonic acid or adenosine diphosphate pathway were assessed with thrombelastography and defined patients with high residual on-treatment platelet reactivity. Platelet indices were obtained from routine analysis of blood samples using an automated blood cell counter. A total of 127 ACS patients taking dual antiplatelet therapy were analyzed. Platelet volume indices, including mean platelet volume and platelet large cell ratio, were significantly increased in patients with OSA . Patients with OSA (n=68) had significantly lower inhibitory rate of adenosine diphosphate receptor pathway ( P=0.028) compared with those without (n=59). After adjustment for potential confounders, patients with OSA were more likely to have high residual on-treatment platelet reactivity after clopidogrel therapy (adjusted odds ratio: 3.25, 95% confidence interval: 1.19-8.87, P=0.021). Conclusions In ACS patients taking dual antiplatelet therapy, OSA is associated with an increased level of platelet volume indices, reduced clopidogrel-induced antiplatelet effects and a greater prevalence of high residual on-treatment platelet reactivity.