Demographic and clinical data of the study population before introduction of continuous positive airway pressure
| OSA (n=158) | ComplexSA (n=34) | p Value | |
| Male, n (%) | 134 (79.2) | 33 (97.1) | 0.79 |
| Age, years | 64.8±9.8 | 65.6±10.0 | 0.72 |
| Ischaemic cause, n (%) | 92 (0.58) | 18 (0.53) | 0.48 |
| CRT device implanted, n (%) | 93 (0.59) | 18 (0.53) | 0.63 |
| Body mass index | 29.4±5.3 | 28.2±4.7 | 0.23 |
| Nocturia | 1.4±1.6 | 1.5±2.6 | 0.57 |
| NYHA class | 2.5±0.6 | 2.7±0.7 | <0.01 |
| Heart rate | 72±13 | 72±16 | 0.83 |
| Systolic blood pressure | 115±23 | 118±20 | 0.38 |
| Diastolic blood pressure | 74±12 | 69±13 | 0.02 |
| Atrial fibrillation, n (%) | 31 (19.6) | 8 (23.5) | 0.79 |
| Arterial hypertension, n (%) | 126 (79.7) | 26 (76.5) | 0.84 |
| Diabetes, n (%) | 47 (29.7) | 6 (17.6) | 0.10 |
| Medication, n (%) | |||
| β-Blockers | 143 (90.5) | 33 (97.1) | 0.41 |
| ACE/AT1 inhibitors | 156 (98.7) | 33 (97.1) | 0.95 |
| Aldosterone blockers | 103 (65.2) | 21 (61.8) | 0.88 |
| Amiodarone | 42 (26.6) | 10 (29.4) | 0.86 |
| Digitalis glycosides | 57 (36.1) | 14 (41.2) | 0.74 |
| Diuretics | 151 (95.5) | 27 (79.4) | <0.01 |
| Blood gas analysis and sleep studies | |||
| pH | 7.428±0.03 | 7.442±0.03 | 0.03 |
| pco2, mm Hg | 40.3±4.5 | 37.0±4.0 | <0.001 |
| po2, mm Hg | 75.6±10.0 | 77.6±11.6 | 0.34 |
| BE | 2.5±3.1 | 1.9±2.7 | 0.41 |
| AHI, /h | 33.1±15.1 | 30.4±13.2 | 0.32 |
| Mean oxygen saturation (%) | 91.9±3.1 | 92.6±3.0 | 0.54 |
| Maximum oxygen desaturation (%) | 80.5±6.5 | 80.7±6.5 | 0.89 |
| Average oxygen desaturation (%) | 5.6±5.2 | 5.8±4.0 | 0.70 |
| Longest apnoea duration, s | 38.5±21.3 | 35.5±19.3 | 0.43 |
| Longest hypopnoea duration, s | 53.1±27.1 | 51.2±22.0 | 0.67 |
| Echocardiography | |||
| LVEF (%) | 31.6±7.4 | 30.1±7.5 | 0.31 |
| LVEDD, mm | 70.0±9.0 | 69.5±11.9 | 0.21 |
| LAD, mm | 50.0±8.8 | 50.2±7.5 | 0.89 |
| sPAP | 36.7±13.0 | 42.3±13.9 | 0.12 |
| Cardiopulmonary exercise testing and six-minute walk | |||
| Duration, min | 7.5±3.0 | 7.4±2.4 | 0.91 |
| Maximum workload, watts | 82.5±35.2 | 90.6±32.5 | 0.25 |
| Vo2-AT, ml/min/kg | 12.9±3.7 | 12.7±3.1 | 0.79 |
| Vo2 peak, ml/min/kg | 14.7±4.1 | 14.4±3.9 | 0.73 |
| Vo2 predicted, % | 60.3±18.3 | 63.7±17.6 | 0.32 |
| VE/Vco2 slope | 30.5±4.0 | 33.7±5.3 | 0.001 |
| Six-minute walk test, m | 379±111 | 382±85 | 0.90 |
| Laboratory measurement | |||
| NT-proBNP, pg/ml | 1662±3157 | 2789±3940 | 0.14 |
| Hb, /ml | 13.5±2.6 | 14.0±1.3 | 0.11 |
| Sodium, μg/l | 137.3±5.9 | 139.6±7.9 | 0.41 |
| Creatinine, μg/l | 1.3±0.5 | 1.3±0.4 | 0.70 |
| CRP, ng/ml | 0.8±0.9 | 0.8±0.8 | 0.92 |
| HCVR, l/min/mm Hg | 2.52±1.49 | 4.60±3.66 | <0.001 |
ACE/AT1, angiotensin-converting enzyme/angiotensin 1 receptor; AHI, apnoea– hypopnoea index; BE, base excess; CRP, C-reactive protein; CRT, cardiac resynchronisation therapy; ComplexSDA, complex sleep apnoea; Hb, haemoglobin; HCVR, hyperoxic, hypercapnic ventilatory response; LAD, left atrium dimension; LVEDD, left ventricular end-diastolic dimension; LVEF, left ventricular ejection fraction; NT-proBNP, N-terminal pro-brain natriuretic peptide; NYHA, New York Heart Association; OSA, obstructive sleep apnoea; pco2, partial pressure of CO2; po2, partial pressure of O2; sPAP, systolic pulmonary artery pressure; VE/Vco2 slope, the relationship between minute ventilation and the rate of CO2 elimination; Vo2, oxygen consumption; Vo2-AT, oxygen consumption at the individual aerobic–anaerobic threshold.