Benefits of obstructive sleep apnoea treatment in coronary artery disease: a long-term follow-up study.

AIM: The aim of this long-term prospective study was to evaluate the effect of treating obstructive sleep apnoea (OSA) on the rate of cardiovascular events in coronary artery disease (CAD). METHODS AND RESULTS: We prospectively studied 54 patients (mean age 57.3 +/- 10.1 years) with both CAD (> or = 70% coronary artery stenosis) and OSA (apnoea-hypopnoea index > or = 15). In 25 patients, OSA was treated with continuous positive airway pressure (n=21) or upper airway surgery (n=4); the remaining 29 patients declined treatment for their OSA. The median follow-up was 86.5 +/- 39 months. The two groups were similar at baseline in age, body mass index, smoking history, hypertension, hypercholesterolaemia, diabetes mellitus, number of diseased vessels, left ventricular ejection fraction, and CAD therapy. Treatment of risk factors other than OSA was similar in the two groups. The endpoint (a composite of cardiovascular death, acute coronary syndrome, hospitalisation for heart failure, or need for coronary revascularisation) was reached in 6 (6/25, 24%) and 17 (17/29, 58%) patients with and without OSA treatment, respectively (P<0.01). OSA treatment significantly reduced the risk of occurrence of the composite endpoint (hazard ratio 0.24; 95% confidence interval, 0.09-0.62; p<0.01) and of each of its components. CONCLUSIONS: Our data indicate that the treatment of OSA in CAD patients is associated with a decrease in the occurrence of new cardiovascular events, and an increase in the time to such events.     

An independent association between obstructive sleep apnoea and coronary artery disease.

Previous studies of sleep and breathing suggest an independent association between coronary artery disease (CAD) and obstructive sleep apnoea (OSA) in middle-aged males and females. These studies, however, were criticized because they did not properly adjust for all important confounding factors. In order to better control for the impact of these confounders, a case-control study was performed, matching for age, sex and body mass index (BMI), and additionally adjusting for hypertension, hypercholesterolemia, diabetes mellitus and current smoking. A consecutive selection of 62 patients (44 males and 18 females, mean age 69 yrs, range 44-88 yrs) requiring intensive care for angina pectoris or myocardial infarction at the County Hospital of Skaraborg, Sk?vde, Sweden, as well as 62 age-, sex- and BMI- matched control subjects without history or signs of heart disease underwent an overnight sleep/ventilatory monitoring study. The time interval between discharge from the intensive care unit and the overnight study ranged between 4 and 21 months. OSA, defined as a Respiratory Disturbance Index (RDI) of > or =10 x h(-1), was present in 19 CAD patients but only in eight control subjects (p=0.017). Using a univariate logistic regression analysis, current smoking (odds ratio (OR) 8.1, 95% confidence interval (CI) 2.2-29.0), diabetes mellitus (OR 4.2, 95% CI 1.1-16.1) and OSA (OR 3.0, 95% CI 1.2-7.5), but not hypertension (OR 1.5, 95% CI 0.7-3.2) and hypercholesterolaemia (OR 1.8, 95% CI 0.7-4.1) were significantly correlated with CAD. In a multiple logistic regression model, current smoking (OR 9.8, 95% CI 2.6-36.5), diabetes mellitus (OR 4.2, 95% CI 1.1-17.1) and OSA (OR 3.1, 95% CI 1.2-8.3) all remained independently associated with CAD. In summary, these data suggest a high occurrence of obstructive sleep apnoea in middle-aged and elderly patients with coronary artery disease requiring intensive care, which should be taken into account when considering risk factors for coronary artery disease.     

Increased incidence of cardiovascular disease in middle-aged men with obstructive sleep apnea: a 7-year follow-up

The incidence of a cardiovascular disease (CVD) was explored in a consecutive sleep clinic cohort of 182 middle-aged men (mean age, 46.8 +/- 9.3; range, 30-69 years in 1991) with or without obstructive sleep apnea (OSA). All subjects were free of hypertension or other CVD, pulmonary disease, diabetes mellitus, psychiatric disorder, alcohol dependency, as well as malignancy at baseline. Data were collected via the Swedish Hospital Discharge Register covering a 7-year period before December 31, 1998, as well as questionnaires. Effectiveness of OSA treatment initiated during the period as well as age, body mass index (BMI), systolic blood pressure (SBP), diastolic blood pressure (DBP) at baseline, and smoking habits were controlled. The incidence of at least one CVD was observed in 22 of 60 (36.7%) cases with OSA (overnight oxygen desaturations of 30 or more) compared with in 8 of 122 (6.6%) subjects without OSA (p < 0.001). In a multiple logistic regression model, significant predictors of CVD incidence were OSA at baseline (odds ratio [OR] 4.9; 95% confidence interval [CI], 1.8-13.6) and age (OR 23.4; 95% CI, 2.7-197.5) after adjustment for BMI, SBP, and DBP at baseline. In the OSA group, CVD incidence was observed in 21 of 37 (56.8%) incompletely treated cases compared with in 1 of 15 (6.7%) efficiently treated subjects (p < 0.001). In a multiple regression analysis, efficient treatment was associated with a significant risk reduction for CVD incidence (OR 0.1; 95% CI, 0.0-0.7) after adjustment for age and SBP at baseline in the OSA subjects. We conclude that the risk of developing CVD is increased in middle-aged OSA subjects independently of age, BMI, SBP, DBP, and smoking. Furthermore, efficient treatment of OSA reduces the excess CVD risk and may be considered also in relatively mild OSA without regard to daytime sleepiness.     

Obstructive sleep apnea as a risk marker in coronary artery disease

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) is associated with a range of cardiovascular sequelae and increased cardiovascular mortality. The aim of our study was to assess the prevalence of OSA in patients with symptomatic angina and angiographically verified coronary artery disease (CAD). In addition, we analyzed the association of OSA and other coronary risk factors with CAD and myocardial infarction. METHODS: Overnight non-laboratory-monitoring-system recordings for detection of OSA was performed in 223 male patients with angiographically verified CAD and in 66 male patients with exclusion of CAD. A logistic regression analysis was performed to assess associations between risk factors and CAD and myocardial infarction. RESULTS: CAD patients were found to have OSA in 30.5%, whereas OSA was found in control subjects in 19.7%. The mean apnea/hypopnea index (AHI) was significantly higher (p < 0.01) in CAD patients (9.9 +/- 11.8) than in control subjects (6.7 +/- 7.3). Body-mass-index (BMI) was significantly higher in patients with CAD and OSA than in patients with CAD without OSA (28. 1 vs. 26.7 kg/m(2); p < 0.001). No significant difference was found with regard to other risk factors and left ventricular ejection fraction (LVEF) between both groups. Hyperlipidemia (OR 2.3; CI 1. 3-3.9; p < 0.005) and OSA defined as AHI >/=20 (OR 2.0; CI 1.0-3.8, p < 0.05) were independently associated with myocardial infarction. CONCLUSIONS: There is a high prevalence of OSA among patients with angiographically proven CAD. OSA of moderate severity (AHI >/=20) is independently associated with myocardial infarction. Thus, in the care of patients with CAD, particular vigilance for OSA is important.     

Respiratory disturbance index: an independent predictor of mortality in coronary artery disease

Cardiovascular mortality was prospectively investigated in consecutive coronary artery disease (CAD) patients with versus without obstructive sleep apnea (OSA) during a follow-up period of 5 yr. An overnight sleep/ventilatory study was performed in patients requiring intensive care (n = 62, mean age 67.6 +/- 10.4 yr, range 44 to 86) during a stable condition (New York Heart Association [NYHA] functional class I-II) 4 to 21 mo after discharge from the hospital. OSA, defined as a respiratory disturbance index (RDI) of 10/h or more was found in 19 patients (mean RDI 17.5 +/- 8.3). Three OSA subjects who were successfully treated with continuous positive airway pressure (CPAP) during the observation period were excluded from the final analysis. There was no statistically significant difference (Fisher two-tailed exact test) between the OSA and non-OSA patient groups in terms of number of elderly subjects (age >/= 65 yr), gender, obesity (body mass index [BMI] >/= 30 kg/m(2)), smoking history, presence of hypertension, diabetes mellitus, hypercholesterolemia, or history of myocardial infarction at the study start. During the follow-up period, cardiovascular death occurred in six of 16 OSA patients (37.5%) compared with 4 (9.3%) in the non-OSA group (p = 0.018). The univariate predictors of cardiovascular mortality were RDI (p = 0.007), OSA (p = 0.014), age at baseline (p = 0.028), hypertension at baseline (p = 0.036), history of never-smoking (p = 0.031), and digoxin treatment during the follow-up period (p = 0.013). In a Cox multiple conditional regression model, RDI remained as an independent predictor of cardiovascular mortality (exp beta = 1.13, 95% confidence interval [CI] 1.05 to 1.21, two-sided p < 0.001). We conclude that untreated OSA is associated with an increased risk of cardiovascular mortality in patients with CAD. Furthermore, it appears appropriate that RDI is taken into consideration when evaluating secondary prevention models in CAD.     

Cardiovascular diseases in obstructive sleep apnea

Obstructive sleep apnea (OSA) affects approximately 5% of women and 15% of men in the middle-aged adults, and associated with adverse health outcomes. Cardiovascular disturbances are the most serious complications of OSA. These complications include heart failure, left/right ventricular dysfunction, acute myocardial infarction, arrhythmias, stroke, systemic and pulmonary hypertension. All these cardiovascular complications increase morbidity and mortality of OSA. Several epidemiologic studies have demonstrated that sleep related breathing disorders are an independent risk factor for hypertension, probably resulting from a combination of intermittent hypoxia and hypercapnia, arousals, increased sympathetic activity, and altered baroreflex control during sleep. Arterial hypertension, obesity, diabetes mellitus and coronary artery disease (CAD) which are independent predictors of left ventricular dysfunction, often have co-existence with OSA. Especially severe OSA patients having diastolic dysfunction might have an increased risk of heart failure, since diastolic dysfunction might be combined with systolic dysfunction. Early recognition and appropriate therapy of ventricular dysfunction is advisable to prevent further progression to heart failure and death. Patients with acute myocardial infarction, especially if they had apneas and hypoxemia without evident heart failure should be evaluated for sleep disorders. So, patients with CAD should be evaluated for OSA and vice versa. Early recognition and treatment of OSA may improve cardiovascular functions. Continuous positive airway pressure (CPAP) applied by nasal mask, is still the gold standard method for treatment of the disease and prevention of complications.     

鼾症老年人睡眠呼吸暂停症与心血管疾病的相关性

目的　观察鼾症老年人中睡眠呼吸暂停症 (SAS)与部分心血管异常改变的相关性及经鼻持续气道正压通气(nCPAP)对SAS的有关疗效。方法　采用多导睡眠仪将 6 7例 6 0岁以上老年鼾症者分为SAS组和非SAS组 ,同时通过Holter心电及血压检测仪就两组间血压昼夜节律、高血压、心率变异性、部分心律失常、冠心病的状况作出比较。在SAS组中将接受nCPAP治疗 5～ 7d后的以上有关心血管状况与治疗前加以比较。结果　鼾症老人中SAS的发病率较高 (47.8% ) ;在SAS组中 ,高血压、血压昼夜节律消失、冠心病心绞痛对扩冠药疗效不佳、睡眠期心率变异性降低、心律失常及动脉血氧饱和度 (SaO2 )降低的发生率均明显高于非SAS组。经nCPAP治疗后睡眠期不仅鼾声消除、SaO2 明显增高和呼吸暂停 /低通气指数明显降低 ;而且心率变异性 (HRV)和血压昼夜节律恢复。结论　SAS在老年心血管疾病的发生和发展上有着不可忽视的相关性 ,应用nCPAP不仅对SAS有较满意的疗效 ,而且对改善其并存的心血管病变也有重要的作用。     

Influence of obstructive sleep apnoea in coronary artery disease: A 10-year follow-up

In patients with coronary artery disease (CAD) the prevalence of obstructive sleep apnoea (OSA) is found to be about 14-65%. In this study, the influence of OSA in 50 patients with CAD was prospectively compared during a follow-up period of 10 years. In the follow-up period 4 of 25 patients with OSA and 5 of the 25 without OSA died by cardiovascular complications. The proportion survival curve showed no significant difference for patients with CAD and with versus without OSA. The results of this rather small 10-year follow-up study failed to give further evidence for an increased mortality in patients with CAD and OSA.     

Cardiovascular risk factors in patients with obstructive sleep apnoea syndrome.

Cardiovascular disorders are common in patients with obstructive sleep apnoea syndrome (OSAS) but there is debate as to whether OSAS is an independent risk factor for their development, since OSAS may be associated with other disorders and risk factors that predispose to cardiovascular disease. In an effort to quantify the risk of OSAS patients for cardiovascular disease arising from these other factors, the authors assessed the future risk for cardiovascular disease among a group of 114 consecutive patients with established OSAS prior to nasal continuous positive airway pressure therapy, using an established method of risk prediction employed in the Framingham studies. Patients were 100 males, aged (mean+/-SD) 52+/-9.0 yrs, and 14 females, aged 51+/-10.4 yrs, with an apnoea/hypopnoea index of 45+/-22 x h(-1). Based on either a prior diagnosis, or a mean of three resting blood pressure recordings >140 mmHg systolic and/or 90 diastolic, 68% of patients were hypertensive. Only 18% were current smokers, while 16% had either diabetes mellitus or impaired glucose tolerance, and 63% had elevated fasting cholesterol and/or triglyceride levels. The estimated 10-yr risk of a coronary heart disease (CHD) event in males was (mean+/-SEM) 13.9+/-0.9%, 95% confidence interval (95% CI) 12.1-16.0, and for a stroke was 12.3+/-1.4%; 95% CI 9.4-15.1, with a combined 10 yr risk for stroke and CHD events of 32.9+/-2.7%; 95% CI 27.8-38.5 in males aged >53 yrs. These findings indicate that obstructive sleep apnoea syndrome patients are at high risk of future cardiovascular disease from factors other than obstructive sleep apnoea syndrome, and may help explain the difficulties in identifying a potential independent risk from obstructive sleep apnoea syndrome.     

Mild renal dysfunction associated with incident coronary artery disease in young males.

AIMS: Although impaired renal function is associated with adverse cardiovascular outcomes, it is unknown whether this association exists in young, healthy adults with normal or mildly impaired renal dysfunction. METHODS AND RESULTS We calculated the baseline creatinine clearance of young males without antecedent diabetes mellitus, coronary artery disease (CAD), or renal dysfunction, and examined their subsequent diagnosis of CAD, defined as coronary artery diameter stenosis of at least 50% and/or myocardial infarction. The 23 964 males, 32.5 +/- 5.9 years old, had a baseline estimated creatinine clearance of 107.9 +/- 0.6 mL min(-1) per 1.73 m(2) (60-150 mL min(-1) per 1.73 m(2)). During a mean follow-up of 3.5 +/- 1.9 years, 77 subjects were diagnosed with CAD. After age adjustment, there was a progressive increase in the risk for CAD as the estimated creatinine clearance decreased [hazard ratio (HR) 4.77, 95% confidence interval 3.22-7.06, P < 0.001 for comparison between the fifth and first quintiles]. This association also persisted after further adjustments for conventional and ancillary risk factors for CAD (HR 2.10, 95% confidence interval 1.40-3.14, P < 0.001). Conclusion Reduced renal function in the normal to mildly impaired range is independently associated with increased risk for CAD among young, healthy males.     

Altered blood rheology in obstructive sleep apnea as a mediator of cardiovascular risk

BACKGROUND: Cardiovascular complications are common in patients with obstructive sleep apnea (OSA). Blood rheology is a major determent of coagulation and an established risk factor for cardiovascular events. Since nocturnal hypoxemia could influence parameters of blood rheology, we hypothesized that OSA alters blood rheology independent of other cardiovascular risk factors. METHODS: One hundred and ten consecutive patients admitted to the sleep laboratory were included. The association of plasma fibrinogen and viscosity (as parameters of blood rheology) with OSA was evaluated. RESULTS: One hundred and ten patients aged 61.4+/-10.1 years (body mass index 28.4+/-4.1 kg/m2) were included. OSA was confirmed in 63 patients (57.2%) with an apnea-hypopnea index (AHI) of 28.7+/-14.9 events/hour. Patients with OSA showed higher levels of plasma viscosity (1.36+/-0.09 vs. 1.31+/-0.08 mPas, p=0.005). Nevertheless, hypertensive apneics have even higher levels of plasma viscosity than nonapneics (1.38+/-0.091 vs. 1.32+/-0.028 mPas, p=0.018). Similar results were found in patients with coronary artery disease, where OSA was associated with elevated plasma viscosity (1.36+/-0.076 vs. 1.31+/-0.081 mPas, p=0.007). Plasma fibrinogen was correlated with nocturnal minimal oxygen saturation (r=-0275, p=0.0036) and AHI (r=0.297, p=0.001). OSA was associated with higher plasma fibrinogen (353+/-83 vs. 317+/-62 mg/dl, p=0.015). These differences persist with control for cardiovascular risk factors. CONCLUSIONS: Patients with OSA have elevated morning fibrinogen levels and a higher plasma viscosity, which correlate positively with indices of sleep apnea severity. These changes in blood rheology are independent of cardiovascular risk factors, and therefore, might be specific mechanisms of OSA. This supports the pathophysiological concept that sleep apnea is a cardiovascular risk factor.     

Does continuous positive airway pressure therapy benefit patients with coronary artery disease and obstructive sleep apnea? A systematic review and meta‐analysis

The prevalent co‐morbidity of coronary artery disease (CAD) and obstructive sleep apnea (OSA) has attracted great interest. However, effects of continuous positive airway pressure (CPAP) in patients with OSA and CAD for cardiovascular outcomes and deaths are still controversial. Usage of CPAP among patients with CAD and OSA could decrease the risk of cardiovascular events and death in adults. PubMed, EMBASE, Web of science, and Cochrane Library were systematically searched. Studies that described association of CPAP treatment with cardiovascular events in CAD and OSA patients were included. The main outcome was the major adverse cardiovascular events (MACE), including all‐cause death, cardiovascular death, myocardial infarction (MI), stroke, and repeat revascularization. Summary relative risks (risk ratios [RRs]) and 95% confidence intervals (CIs) of outcomes were pooled and heterogeneity was assessed with the I² statistic. Nine studies enrolling 2590 participants with OSA and CAD were included and extracted data. There was significant association of CPAP with reduced risk of MACE (RR, 0.73, 95% CI [0.55, 0.96]), particularly among those with AHI less than 30 events/h (RR, 0.43, 95% CI [0.22, 0.84]). Similarly, the same result was found in all‐cause death (RR, 0.66, 95% CI, [0.46, 0.94]) and cardiovascular death (RR, 0.495, 95% CI [0.292, 0.838]). Our data suggested that CPAP usage, compared to usual care, was associated with reduced risks of cardiovascular outcomes or death in patients with OSA and CAD, particularly in the subgroup with AHI less than 30 events/h, which still needs further studies to confirm.     

Adhesion molecules in patients with coronary artery disease and moderate-to-severe obstructive sleep apnea

STUDY OBJECTIVES: It has been suggested that obstructive sleep apnea (OSA)-induced hypoxic stress might contribute to cardiovascular disorders by promoting expression of soluble adhesion molecules. The reported increase of circulating adhesion molecules in patients with OSA remains controversial because confounders such as cardiovascular risk factors and left ventricular function have not been adequately controlled for. We hypothesized that soluble intercellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, L-selectin, and E-selectin levels are correlated with OSA independent of coexisting coronary artery disease (CAD). SETTINGS: University-affiliated teaching hospitals. DESIGN AND PARTICIPANTS: A prospective study of 61 consecutive subjects with angiographically proven CAD deemed to have stable angina. INTERVENTIONS: Fifteen patients (mean +/- SD) 61.2 +/- 1.9 years old with moderate-to-severe OSA (apnea-hypopnea index [AHI] > or = 20/h) were matched to a control group (AHI < or = 5/h) for age, gender, body mass index, and severity of CAD. Venous blood samples were collected the morning of the sleep study and assayed for human ICAM-1, VCAM-1, L-selectin, and E-selectin with commercially available enzyme-linked immunosorbent assay kits. RESULTS: All but L-selectin were significantly increased in the OSA group compared to the control subjects (ICAM-1, 367.4 +/- 85.2 ng/mL vs 252.8 +/- 68.4 ng/mL, p = 0.008; VCAM-1, 961.5 +/- 281.7 ng/mL vs 639.1 +/- 294.4 ng/mL, p = 0.004; E-selectin, 81.0 +/- 30.4 ng/mL vs 58.1 +/- 23.2 ng/mL, p = 0.03, respectively). The increased levels of adhesion molecules correlated with the AHI and the oxygen desaturation index but not with the severity of hypoxemia or the frequency of arousals. CONCLUSIONS: These findings suggest that OSA modulates the expression of proinflammatory mediators. Further studies should evaluate the influence of adhesion molecules on cardiovascular outcome in CAD patients with OSA.     

Snoring and excessive daytime somnolence and risk of cardiovascular diseases

Snoring and excessive daytime somnolence (EDS) are very common in middle-age adults. The goal of the investigation was to assess links between those symptoms and risk for cardiovascular diseases (CVD). The population studied included 1186 inhabitants of Warsaw (mean age 52 years), participants of the international multicentre study of cardiovascular disease MONICA II, who completed the sleep disordered breathing (SDB) questionnaire. Snoring was reported by 78% of males (48% habitual and 30% occasional) and 59% of females (27% habitual and 32% occasional). Every fourth (26.8%) subject declared observed apnoeas, in 9.2% apnoeas were observed every night. EDS was declared by 28.7% of studied sample. The results of the questionnaire were compared to the results of MONICA study. Snorers had significantly higher systolic and diastolic blood pressure (133.2 +/- 23/84.6 +/- 13 mm Hg) compared to non-snorers (126.4 +/- 22/80.4 +/- +/- 12 mm Hg) (p < 0.0001). The high total serum cholesterol (> or = 200 mg%) and triglycerides (> or = 200 mg%) concentration, and also obesity (BMI > or = 30 kg/m2) were more prevalent in snorers. Subjects reporting apnoeas more often had coronary artery disease (p < 0.001) or history of stroke (p = 0.002) compared to non-apnoeics. There was no relationship between EDS and risk of cardiovascular disorders, and also between diabetes and SDB. In conclusion, snoring was strongly associated with hyperlipidaemia, obesity or hypertension, well known risk factors for development of cardiovascular disorders. Reported apnoeas were related to risk of coronary artery disease.     

Impact of obstructive sleep apnea on clinical and angiographic outcomes following percutaneous coronary intervention in patients with acute coronary syndrome

There has been growing evidence associating obstructive sleep apnea (OSA) with cardiovascular pathogenesis. We hypothesized that OSA may affect outcomes after percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS). We performed a sleep study in 89 consecutive patients with ACS who were successfully treated with PCI. Patients with an apnea hypopnea index > or =10/hour were considered to have OSA. Co-morbidity of OSA with ACS was found in 51 patients (57%). There were no differences in baseline demographics between patients with and without OSA, except for significantly higher high-sensitivity C-reactive protein levels (0.59 +/- 0.75 vs 0.29 +/- 0.20 mg/dl, p = 0.019) in patients with OSA. Patients were followed for a mean period of 227 days. The incidence of major adverse cardiac events (cardiac death, reinfarction, and target vessel revascularization) was significantly higher in patients with OSA (23.5% vs 5.3%, p = 0.022). By multivariate analysis, the presence of OSA was an independent predictor for major adverse cardiac events (hazard ratio 11.61, 95% confidence interval 2.17 to 62.24, p = 0.004). In addition, quantitative coronary angiography at 6-month follow-up depicted significantly greater late loss (1.28 +/- 0.84 vs 0.69 +/- 0.81 mm, p = 0.003) and a higher binary restenosis rate (36.5% vs 15.4%, p = 0.026) in patients with OSA compared with those without OSA. In conclusion, the present study showed a high prevalence of OSA among patients with ACS. Moreover, OSA appeared to be an independent predictor for clinical and angiographic outcomes after PCI.     

The sympathetic nervous system and catecholamines metabolism in obstructive sleep apnoea

Obstructive sleep apnoea (OSA) is the most common sleep disorder of breathing in middle-aged and overweight subjects. It features recurrent episodes of upper airway total (apnoea) o partial (hypopnea) collapse during sleep, which are associated with a reduction in blood oxygen saturation and with arousal from sleep to re-establish airway patency. An association of OSA with dysregulation of the autonomous nervous system (ANS) and altered catecholamines (CAs) metabolism has been contended for years. However, the pathophysiology mechanisms underlying these alterations remain to be fully clarified. Nonetheless, these alterations are deemed to play a key pathogenic role in the established association of OSA with several conditions besides arterial hypertension (HT), including coronary artery disease, stroke, and, more in general, with increased risk of cardiovascular (CV) events. Hence, in this review we will analyse the relationship between the sleep disturbances associated with OSA and the altered function of the ANS, including CAs metabolism.     

阻塞性睡眠呼吸暂停与冠心病的相关性及临床特点

目的了解国人阻塞性睡眠呼吸暂停(OSA)患者中冠心病(CAD)的发生率,并探讨两者之间关系和临床特点。方法对2009年01月-2010年6月以胸痛待查入住阜外医院心内科五区行冠状动脉造影(CAG)的患者,进行多导睡眠呼吸监测,收集其临床资料和常规生化指标。结果 257例患者入选,无OSA组、轻度OSA、中度OSA和重度OSA中,经CAG确诊CAD的患者分别为44.6%:60.0%:70.5%:72.1%(P0.01);Logistic回归分析,最低血氧饱和度与CAD的发生显著相关(P=0.024)。结论 CAD的发生率在OSA患者中明显增加,随着OSA的严重程度呈递增趋势;多元回归分析,OSA是冠心病的独立危险因素。     

OSA: the new cardiovascular disease Part II: overview of cardiovascular diseases associated with obstructive sleep apnea

Obstructive sleep apnea (OSA), present in 5–15% of adults, is strongly associated with the incidence and poor outcome of hypertension, coronary artery disease, arrhythmia, heart failure, and stroke. Treatment of OSA completely reverses its cardiovascular consequences. In this review, we discuss the clinical evidence for the strong association between OSA and cardiovascular disease and present an argument for approaching OSA as a cardiovascular disease. We particularly focus on the causative relationship between OSA and hypertension, and on the increasingly recognized relationship between OSA and heart failure.     

Coronary calcium by spiral computed tomography predicts cardiovascular events in high-risk hypertensive patients

OBJECTIVE: The ability of coronary artery calcium (CAC) to predict coronary events has been shown in several studies. We aimed to investigate the hypothesis that CAC as assessed by dual slice spiral computed tomography (DSCT), is an independent risk factor for cardiovascular events in hypertensive patients. METHODS: We followed 446 participants of INSIGHT (International Nifedipine Study Intervention as Goal for Hypertension Therapy) calcification study, for the incidence of cardiovascular events as a function of CAC and other factors. All were hypertensive, without coronary artery disease (CAD), ages > 55 years and with at least one more major cardiovascular risk factor. All underwent a baseline DSCT and were followed for a mean period of 3.8 +/- 0.4 years. All events were documented while the scheduled visits and confirmed by the INSIGHT critical event committee. RESULTS: Follow-up was conducted on all participants. 294 patients (66%) had CAC at baseline. Forty-seven patients experienced a first cardiovascular event: acute myocardial infarction (MI), 16; sudden cardiac death, two; unstable angina resulting in revascularization, 14; stroke, 15. The incidence of first cardiovascular events was 3.7 times higher among those who had CAC at baseline than among those who had no CAC (14.5% (41 of 294) versus 3.9% (6 of 152)). Patients who experienced an event were more likely to be males, had had higher prevalence of peripheral vascular disease, longer duration of hypertension, and had higher levels of systolic blood pressure (SBP), glucose, creatinine and uric acid. Adjusting for these covariates, CAC (total coronary calcium score (TCS) > 0) independently predicted cardiovascular events with an odds ratio (OR) of 2.76 [95% confidence interval (CI) 1.09-6.99, P = 0.032]. CONCLUSION: The presence of CAC predicts cardiovascular events in high-risk asymptomatic hypertensive patients.     

Influence of obstructive sleep apnea and treatment with continuous positive airway pressure on fractional flow reserve measurements for coronary lesion assessment

Obstructive sleep apnea (OSA) and sleep‐disordered breathing have been implicated in the progression of cardiovascular disease and with increased risk of coronary artery disease, congestive heart failure, and stroke. Fractional flow reserve (FFR) is used to evaluate the physiological significance of coronary artery stenosis, and this technique is largely thought to be independent of systemic hemodynamic changes. Herein, we describe a case of OSA and sleep‐disordered breathing cyclically altering FFR measurements from normal to abnormal in a patient with coronary artery disease. More specifically, we show that the abnormal FFR across a coronary lesion in a patient with sleep disordered apnea improves (to a normal threshold) with the initiation of continuous positive airway pressure (CPAP). This finding may have implications for the mechanisms of cardiac dysfunction in patients with OSA. © 2009 Wiley‐Liss, Inc.