Severity of obstructive sleep apnea and extension of coronary artery disease.

PURPOSE: Obstructive sleep apnea (OSA) is highly prevalent among patients with coronary artery disease (CAD). The relationship between the severity of OSA and the severity of CAD has not been entirely established. The objective was to explore the type of correlation existent between the apnea-hypopnea index and the Gensini score, which provides granularity in terms of CAD extension and severity, in search of a dose-response relationship. METHODS: A cross-sectional study was conducted among patients that underwent cardiac catheterization due to the suspicion of CAD. Coronary lesions were classified according to one's Gensini score. The severity of OSA was determined by the apnea-hypopnea index (AHI), obtainable through a respiratory polysomnography. RESULTS: Eighty patients were eligible for the study. The mean age was 55 years, and 37% had AHI ≥ 15. Forty-four subjects (55%) had a Gensini score of 0, and five had a score < 2, indicating a 25% obstruction in a non-proximal artery; these individuals were considered non-CAD controls; and clinical characteristics were similar between them and CAD cases. Attempts to correlate the AHI with the Gensini score either converting both variables to square root (r = 0.08) or using Spearman's rho (rho = 0.13) obtained small, non-significant coefficients. AHI ≥ 15 was a predictor of a Gensini score ≥ 2 with a large effect size (OR 4.46) when adjusted for age ≥ 55 years, BMI ≥ 25 kg/m2, uric acid, and hypertension. CONCLUSIONS: In patients undergoing coronary angiography due to suspected CAD, moderate-severe OSA was associated with the presence of CAD but no significant correlation was found between the lesion severity and the AHI. Our results suggest that OSA influences CAD pathogenesis but a dose-response relationship is unlikely.

Elevated serum interleukin-6 is predictive of coronary artery disease in intermediate risk overweight patients referred for coronary angiography.

BACKGROUND: Interleukin-6 (IL-6) plays a central role in atherosclerosis and inflammation. It may improve risk prediction in patients at intermediate cardiovascular risk. OBJECTIVE: To analyze the impact of serum IL-6 in predicting early angiographic coronary artery disease in patients at intermediate cardiovascular risk with chest pain. METHODS: In a cross-sectional study, patients referred for coronary angiography due to suspected coronary artery disease (CAD) were included. Coronary artery disease was defined as the presence of at least 30% stenosis in one or more coronary artery. Severity of CAD was classified by the anatomic burden score. Performance of serum IL-6 assay was compared with ACC/AHA atherosclerotic cardiovascular disease (ASCVD) risk score and hs-CRP through receiver operating characteristic (ROC) curves. RESULTS: We have included 48 patients with a mean 10-year ASCVD risk of 10.0 ± 6.8%. The prevalence of CAD was 72.9%. The presence of CAD was associated with higher mean levels of IL-6 (p = 0.025). Patients with CAD had significantly more overweight than subjects without CAD. In 27% of patients, IL-6 was >1.0 pg/mL and 100% of these patients had CAD, while only 64% in those with IL-6 <1.0 pg/mL, corresponding to a positive predictive value of 100% (p = 0.015). The area under the receiver operating characteristic (ROC) curve of IL-6, hs-CRP and ASCVD were respectively 0.72, 0.60 and 0.54. Intermediate risk patients with IL-6 >1.0 pg/mL were further reclassified into ASCVD high risk due to the presence of coronary lesions. CONCLUSION: In intermediate risk patients referred for coronary angiography, a serum IL-6 level above 1 pg/mL is predictive of significant CAD. IL-6 determination may be useful to reclassify ASCVD intermediate risk patients into higher risk categories.

Influence of high risk of obstructive sleep apnea on adherence to antihypertensive treatment in outpatients.

Obstructive sleep apnea (OSA) is a common cause of high blood pressure (BP). Many patients, however, have uncontrolled BP because of nonadherence to antihypertensive medication. The possibility that OSA influences adherence has not been investigated to date. The authors sought to explore the possible association between high risk of OSA and nonadherence. This study was carried out in a hypertension outpatient clinic. Adherence to medication, high risk of OSA, and sleepiness were evaluated in a cross-sectional study. These variables were identified using the eight-item Morisky, STOP-Bang, and Epworth scales, respectively. A total of 416 patients with hypertension were enrolled (32% male, aged 65±11 years). Nonadherence was identified in 71 (17%) individuals. The prevalence of high risk of OSA was 323 (78%) and of somnolence was 136 (33%). High risk of OSA was associated with nonadherence, showing a prevalence ratio (PR) of 2.6 (95% confidence interval [CI], 1.3-5.6) and retained significance after adjustment for sleepiness (PR, 2.3; 95% CI, 1.1-4.9 [P=.011]). Sleepiness was also associated with nonadherence (PR, 1.7; 95% CI, 1.1-2.6 [P=.003]). High risk of OSA and sleepiness are associated with nonadherence. These conditions, if treated, may allow for achieving better outcomes and improvement of adherence to medication.

Influence of sleep apnea severity on blood pressure variability of patients with hypertension.

PURPOSE: Obstructive sleep apnea (OSA) is a risk factor for the development of hypertension and cardiovascular disease. Apnea overloads the autonomic cardiovascular control system and may influence blood pressure variability, a risk for vascular damage independent of blood pressure levels. This study investigates the hypothesis that blood pressure variability is associated with OSA. METHODS: In a cross-sectional study, 107 patients with hypertension underwent 24-h ambulatory blood pressure monitoring and level III polysomnography to detect sleep apnea. Pressure variability was assessed by the first derivative of blood pressure over time, the time rate index, and by the standard deviation of blood pressure measurements. The association between the apnea-hypopnea index and blood pressure variability was tested by univariate and multivariate methods. RESULTS: The 57 patients with apnea were older, had higher blood pressure, and had longer duration of hypertension than the 50 patients without apnea. Patients with apnea-hypopnea index (AHI) ≥ 10 had higher blood pressure variability assessed by the standard deviation than patients with AHI < 10 during sleep (10.4 ± 0.7 versus 8.0 ± 0.7, P = 0.02) after adjustment for age, body mass, and blood pressure. Blood pressure variability assessed by the time rate index presented a trend for association during sleep (P = 0.07). Daytime blood pressure variability was not associated with the severity of sleep apnea. CONCLUSION: Sleep apnea increases nighttime blood pressure variability in patients with hypertension and may be another pathway linking sleep abnormalities to cardiovascular disease.

Neck circumference and central obesity are independent predictors of coronary artery disease in patients undergoing coronary angiography.

Excess of adiposity is a risk factor for coronary artery disease, but it remains unclear if the distribution of fat is an effect modifier or if the risk is mediate by hypertension, diabetes and dyslipidemia. We investigated the association of central in addition to general obesity with coronary artery disease (CAD). A case-control study was conducted in 376 patients, aged 40 years or more, with chronic coronary disease, undergoing elective coronary angiography. Excess of adiposity was evaluated by the Body Mass Index (BMI), waist circumference, waist-hip ratio, and neck circumference. Cases (n=155) were patients referred for coronary angiography with at least 50% of coronary stenosis in at least one epicardial vessels or their branches, with diameter greater than 2.5 mm. Controls (n=221) were patients referred for coronary angiography without significant coronary disease. Odds ratios and 95%CI for significant coronary stenosis were calculated using multiple logistic regression, controlling for age, sex, years at school, smoking, hypertension, HDL-cholesterol, diabetes mellitus, and an adiposity index. There was a predominance of men and individuals older than 50 years among cases. The waist-hip ratio increased four times the chance of CAD, even after the control for confounding factors, including BMI. Neck circumference above the 90(th) Percentile doubled the chance of CAD, after adjustment for traditional risk factors. Neck circumference and waist-hip ratio are independent predictors of CAD, even taking into account traditional risk factors for CAD. These findings highlight the need of anthropometric assessment among patients with suspected coronary artery disease.

Erectile dysfunction and coronary artery disease: an association of higher risk in younger men.

INTRODUCTION: The association between erectile dysfunction (ED) and coronary artery disease (CAD) has been described in various settings, but it is unclear if there is an independent interaction with age. AIM: To investigate the interaction of age in the association between ED and CAD. METHODS: This case-control study was conducted among 242 patients referred for elective coronary angiography. One hundred fourteen patients with significant CAD were identified as cases and 128 controls without significant CAD. ED was evaluated by the erectile function domain of the International Index of Erectile Function (IIEF) questionnaire, determined by a score ≤ 25 points. MAIN OUTCOME MEASURES: Significant CAD was based on stenosis of 50% or greater in the diameter in at least one of the major epicardial vessels or their branches. The analysis was conducted in the whole sample and according to the age strata, controlling for the effects of cardiovascular risk factors, testosterone, and C-reactive protein. Results. Patients had on average 58.3 ± 8.9 years. CAD and ED were associated exclusively in patients younger than 60 years (ED in 68.8% of patients with CAD vs. 46.7% of patients without CAD, P = 0.009). The association was independent of cardiovascular risk factors, testosterone and C-reactive protein (risk ratio 2.3, 95% confidence interval from 1.04 to 5.19). Severity of CAD was higher in patients younger than 60 years with ED. CONCLUSIONS: Men with less than 60 years of age who report ED presented a higher risk of having chronic CAD and more severe disease diagnosed by coronary angiography.

Lack of association between plasma myeloperoxidase levels and angiographic severity of coronary artery disease in patients with acute coronary syndrome.

OBJECTIVE: To evaluate the association between plasma myeloperoxidase (MPO) levels and angiographic severity of coronary atherosclerotic lesions in patients with non-ST elevation acute coronary syndrome (ACS). DESIGN AND METHODS: This cross-sectional study examined high-risk ACS patients who underwent coronary angiography within 72 h of the onset of symptoms by measuring their plasma MPO levels after sheath insertion. Gensini score was used to evaluate angiographic severity of coronary artery disease. RESULTS: A total of 48 patients were included in the study. Median MPO levels and Gensini scores were 6.9 ng/mL (4.4-73.5 ng/mL) and 10 (0-87.5), respectively. Spearman's correlation coefficient did not show a significant association between MPO levels and Gensini scores (r (s) = 0.2; p = 0.177). There was no correlation between MPO and age, hypertension, diabetes, leukocyte count, troponin I, CK-MB ≥ 2 × ULN (upper limit of normal), TIMI risk score ≥ 4 and Gensini score in the multivariate analysis. CONCLUSION: Our findings indicate that MPO expression is not associated with anatomical severity of coronary lesions in ACS.

Risk for Obstructive Sleep Apnea by Berlin Questionnaire, but not daytime sleepiness, is associated with resistant hypertension: a case-control study.

BACKGROUND: Obstructive Sleep Apnea Syndrome (OSAS) is a risk factor for resistant hypertension. Overnight polysomnography and portable sleep monitors are not generally available and questionnaires may be useful for screening OSAS. In a case-control study, we investigate the association between resistant hypertension and sleep disorders evaluated by the Berlin Questionnaire and Epworth Sleepiness Scale (ESS). METHODS: Cases were 63 patients with resistant hypertension (either systolic blood pressure (BP) > or =140 mm Hg or diastolic BP > or =90 mm Hg using at least three BP-lowering drugs, including a diuretic). Controls were 63 patients with controlled BP under drug treatment. All the patients were submitted to ambulatory BP monitoring and level III polysomnography by means of a portable monitor. The prevalence of high risk in the Berlin Questionnaire and high score in the ESS (>10) was compared between the groups. Diagnostic performance for OSAS of both questionnaires was calculated. RESULTS: The prevalence of high score in ESS was 44% in both groups. There was a higher prevalence of high risk for OSAS in Berlin Questionnaire in the cases group (78% vs. 48%; P < 0.001). In a logistic regression model, high risk for OSAS in Berlin Questionnaire was independently associated with resistant hypertension (odds ratio 4.1; confidence interval 95% 1.80-9.31; P < 0.01). Sensitivity and specificity for the diagnosis of OSAS was 85.5% (75.3-92.0%) and 65.0% (52.0-76.0%), respectively. CONCLUSIONS: High risk for OSAS assessed by the Berlin Questionnaire is highly prevalent and associated with resistant hypertension. This questionnaire may be used as screening for OSAS in patients with this clinical condition.

Plasma endothelin-1 levels after coronary stenting in humans.

Endothelin (ET)-1 levels were analyzed in patients who underwent elective coronary stenting. There was a significant increase in systemic ET-1 levels immediately after the procedure, which is probably a marker of endothelial dysfunction that is associated with arterial injury. However, there was no association between ET-1 levels and in-stent restenosis in humans.