Study Objectives: To assess the impact of cardiac rehabilitation for decreasing sleep-disordered breathing in patients with coronary artery disease. Methods: The study included 121 patients aged 60.01 ± 10.08 years, 101 of whom were men, with an increased pretest probability of OSA. The cardiac rehabilitation program lasted 21-25 days. The improvement in cardiorespiratory fitness was assessed using the changes in peak metabolic equivalents, the maximal heart rate achieved, the proportion of the age-and sex-predicted maximal heart rate, and the Six-Minute Walk Test distance. Level 3 portable sleep tests with respiratory event index assessments were performed in 113 patients on admission and discharge. Results: Increases were achieved in metabolic equivalents (Δ1.20; 95% confidence interval [CI], 0.95-1.40; P < .0001), maximal heart rate (-Δ7.5 beats per minute; 95% CI, 5.00-10.50; P <.0001), proportion of age-and sex-predicted maximal heart rate (Δ5.50%; 95% CI, 4.00-7.50; P <.0001), and the Six-Minute Walk Test distance (Δ91.00 m; 95% CI, 62.50-120.00; P <.0001). Sleep-disordered breathing was diagnosed in 94 (83.19%) patients: moderate in 28 (24.8%) patients and severe in 27 (23.9%) patients, with a respiratory event index of 19.75 (interquartile range, 17.20-24.00) and 47.50 (interquartile range, 35.96-56.78), respectively. OSA was dominant in 90.40% of patients. The respiratory event index reduction achieved in the sleep-disordered breathing group was -Δ3.65 (95% CI, -6.30 to -1.25; P = .003) and was in parallel to the improvement in cardiorespiratory fitness in the subgroups with the highest effort load and with severe sleepdisordered breathing: -Δ6.40 (95% CI, -11.40 to -1.90; P = .03) and -Δ11.00 (95% CI, -18.65 to -4.40; P = .003), respectively. Conclusions: High-intensity exercise training during cardiac rehabilitation resulted in a significant decrease in OSA, when severe, in parallel with an improvement in cardiorespiratory fitness in patients with coronary artery disease.

Obstructive sleep apnea (OSA) worsens prognosis after myocardial infarction (MI) but often remains undiagnosed. The study aimed to evaluate the usefulness of questionnaires in assessing the risk of OSA in patients participating in managed care after an acute myocardial infarction program. Study group: 438 patients (349 (79.7%) men) aged 59.92 ± 10.92, hospitalized in the day treatment cardiac rehabilitation department 7–28 days after MI. OSA risk assessment: A 4-variable screening tool (4-V), STOP-BANG questionnaire, Epworth sleepiness scale (ESS), and adjusted neck circumference (ANC). The home sleep apnea testing (HSAT) was performed on 275 participants. Based on four scales, a high risk of OSA was found in 283 (64.6%) responders, including 248 (56.6%) based on STOP-BANG, 163 (37.5%) based on ANC, 115 (26.3%) based on 4-V, and 45 (10.3%) based on ESS. OSA was confirmed in 186 (68.0%) participants: mild in 85 (30.9%), moderate in 53 (19.3%), and severe in 48 (17.5%). The questionnaires’ sensitivity and specificity in predicting moderate-to-severe OSA were: for STOP-BANG—79.21% (95% confidence interval; CI 70.0–86.6) and 35.67% (95% CI 28.2–43.7); ANC—61.39% (95% CI 51.2–70.9) and 61.15% (95% CI 53.1–68.8); 4-V—45.54% (95% CI 35.6–55.8) and 68.79% (95% CI 60.9–75.9); ESS—16.83% (95% CI 10.1–25.6) and 87.90% (95% CI 81.7–92.6). OSA is common in post-MI patients. The ANC most accurately estimates the risk of OSA eligible for positive airway pressure therapy. The sensitivity of the ESS in the post-MI population is insufficient and limits this scale’s usefulness in risk assessment and qualification for treatment.

Background: Sleep-disordered breathing (SDB) is a risk factor for bradyarrhythmia, which is reversible with positive airway pressure therapy. Aims:The study aims to evaluate the occurrence and number of severe sinus bradycardia and advanced atrioventricular block (AVB) in patients with cardiovascular diseases and SDB risk factors. Methods:The analysis covered 207 patients with cardiovascular diseases aged 59.4 (standard deviation [SD], 10.49) years, including 177 men (85.51%), hospitalized in the Department of Electrocardiology and the Day Stay Cardiac Rehabilitation Ward Upper-Silesian Medical Centre in Katowice, Poland. The inclusion criterion was a high risk of SDB, in particular obstructive sleep apnea (OSA), in one of the following questionnaires: the Four-Variable Screening Tool, the STOP-Bang Questionnaire, and the Epworth Sleepiness Scale. Both level-3 portable sleep tests and electrocardiogram Holter recordings were made simultaneously.Results: SDB was confirmed in 175 (84.5%) patients, including severe in 74 (35.7%), moderate in 42 (20.3%), and mild in 59 (28.5%) participants. The dominant type of SDB was OSA, which was found in 158 (76.3%) participants. The severe SDB was a predictor of third-degree AVB (odds ratio [OR], 11.61; 95% confidence interval [CI], 1.37-98.60), second-degree AVB type 2 (Mobitz) (OR, 4.51; 95% CI, 1.17-18.08), pauses above 3 seconds (OR, 10.26; 95% CI,, and sinus bradycardia below 40 bpm (OR, 3.00; 95% CI, 1.36-6.60) during sleep.Conclusions: SDB, with particular emphasis on OSA, is a risk factor for sinus bradycardia and advanced AVB during sleep, which may lead to a hasty qualification for pacemaker implantation. The severity of SDB determines the frequency and number of bradyarrhythmic episodes.

Cardiac arrhythmias during sleep are reported in almost half of the population suffering from obstructive sleep apnea (OSA). The most common are bradyarrhythmias and atrial fibrillation whereas premature ventricular contractions and nonsustained ventricular tachycardia are less frequent. The risk of arrhythmia is proportional to the body mass index (BMI), number of respiratory events per hour of sleep described with apnea/hypopnea index (AHI) and the level of oxygen desaturation during these episodes. Continuous positive airway pressure (CPAP) treatment in OSA reduces the incidence of cardiac arrhythmias therefore reduce mortality and morbidity from cardiovascular disease.

Background According to the 2018 ACC/AHA/HRS Bradycardia Clinical Practice Guidelines an effective treatment of obstructive sleep apnea (OSA) can prevent the need to implant a pacemaker. The aim of the study was to create a prediction model of high risk of OSA in patients with bradycardia or conduction disorders during sleep and referred for pacemaker implantation. Methods and results The polysomnography was performed in 118 (20 female) high-cardiovascular risk patients; aged 60.1±11.7 years; body mass index (BMI) 32.65±7.1. Sleep-disordered breathing (SDB) as an apnea/hypopnea index (AHI) ≥5 per hour was observed in 101 (85.6%) subjects including moderate SDB (AHI≥15) in 28 (27.7%) and severe SDB (AHI≥30) in 43 (42.6%) subjects. The risk of severe SDB increased with increasing BMI; if ≥30kg/m2 (AUC=0.725, sensitivity 81.4%, specificity 55.4%, p<0.0001), the neck size; if ≥43cm (AUC=0.74, sensitivity 60.0%, specificity 75.7%, p<0.0001). The ECG Holter was performed in 93 patients and revealed in 27 of them bradycardia and/or conduction disorders during sleep: episodes of bradycardia <40 beats per minute in 19 (20.4%), sinus arrest in 7 (7.5%) and an atrioventricular block in 8 (8.6%). The neck size, BMI and AHI in these patients were larger: 45.8±4.0 vs. 42.6±3.0 cm (p=0.081), 37.5±8.4 vs. 30.4±5.5kg/m2 (p=0.0003) and 38.0±22.5 vs. 21.7±21.4 (p=0.0016) respectively. When age, sex, BMI and neck size were taken into consideration using multivariate modeling the BMI and sex if male were revealed as independent predictors of clinically significant SDB (AHI ≥15); (p=0.0001, AUC for model 0.820) (figure 1). Figure 1. Receiver-operating characteristic curve showed the best cut-off value of BMI >34,9 kg/m2 (sensitivity 72,73, specificity 78,12) to predict nocturnal bradycardia or conduction disorders in patients with sleep apnea and AHI index ≥15. Conclusions In patients who are being considered for a pacemaker implantation for bradycardia or conduction disorders during sleep, with BMI >30kg/m2 or the neck size over 43cm screening for sleep apnea syndrome is reasonable.