Baseline characteristics
| Characteristic | IHHT group (n=40), abs. (%) | RIP group (n=40), abs. (%) | Control group (n=40), abs. (%) | P values |
| Gender, male | 30 (75%) | 33 (82.5%) | 31 (77.5%) | NS |
| Age, years | 63±8.4 | 64±8.1 | 64±7.6 | NS |
| HHB | 38 (95%) | 37 (92.5%) | 37 (92.5%) | NS |
| DM type 2 | 11 (27.5%) | 10 (25%) | 10 (25%) | NS |
| Smoking | 28 (70%) | 31 (77.5%) | 25 (62.5%) | NS |
| Angina pectoris, FC: | ||||
| II | 12 (30%) | 13 (32.5%) | 12 (30%) | NS |
| III | 15 (37.5%) | 19 (47.5%) | 17 (42.5%) | NS |
| IV | 8 (20%) | 5 (12.5%) | 7 (17.5%) | NS |
| Silent myocardial ischaemia | 5 (12.5%) | 3 (7.5%) | 4 (10%) | NS |
| Postinfarction cardiosclerosis | 21 (52.5%) | 20 (50%) | 25 (62.5%) | NS |
| Coronary artery bypass/PCI in the medical history | 7 (17.5%) | 8 (20%) | 6 (15%) | NS |
| Paroxysmal AF | 5 (12.5%) | 5 (12.5%) | 6 (15%) | NS |
| COPD without respiratory failure | 8 (20%) | 11 (27.5%) | 5 (12.5%) | NS |
| No of bypass grafts (median) | 2.58±0.81 | 2.5±0.91 | 2.52±0.82 | NS |
| 1 | 3 (7.5%) | 6 (15%) | 4 (10%) | NS |
| 2 | 16 (40%) | 13 (32.5%) | 15 (37.5%) | NS |
| 3 | 16 (40%) | 16 (40%) | 17 (42.5%) | NS |
| 4 | 5 (12.5%) | 5 (12.5%) | 4 (10%) | NS |
ABS, absolute number of patients; AF, atrial fibrillation; COPD, chronic obstructive pulmonary disease; DM, diabetes mellitus; FC, functional class; HHB, hypertensive heart disease; IHHT, intermittent hypoxic–hyperoxic training; NS, no significant difference between all three groups; PCI, percutaneous coronary intervention; RIP, remote ischaemic preconditioning.