Intermittent Hypoxia Therapy in Cardiac Rehabilitation

Because the improvement of exercise tolerance reduces mortality in elderly patients affected by cardiovascular disease, intermittent hypoxia therapy (IHT) - defined as repeated episodes of hypoxia interspersed with normoxic periods delivered by an ad hoc device - might be a valuable tool to be associated to structured cardiac rehabilitation (CR) interventions.

The present study is a pilot, monocentric, randomized (randomization ratio 1:1), parallel group study to assess the effect of IHT on functional capacity vs conventional care in old patients with functional impairment admitted to a phase 2 in-hospital cardiac rehabilitation program.

The study will enroll cardiac patients of both genders, ≥ 75 years and with a functional impairment assessed by a Short Physical Performance Battery (SPPB) score < 7.

The effect of IHT on functional capacity will be evaluated on top of the conventional multidisciplinary CR intervention, by means of SPPB score variation; variations in quality of life and cognitive status will also be evaluated as secondary goals of the study.

The total amount of IHT sessions per patient will be 10, 1 per day over 2 weeks, the duration of each single procedure will be 45 min and the Hypoxic O2 conc.% will be 14-10. The study was approved by local ethic committee.

Inclusion criteria

• Admission to a Phase 2 in-hospital cardiac rehabilitation program because of a recent index event;
• Provision of signed and dated informed consent form;
• Age ≥ 75 years;
• Basic venous blood oxygen saturation (SpO2) level > 93% measured at the fingertip;
• SPPB score < 7;
• New York Heart Association (NYHA) Class I-III.

Exclusion criteria

• Inability to give informed consent (diminished understanding or comprehension);
• Age < 75 years;
• SPPB Score ≥ 7;
• NYHA Class IV and/or concomitant i.v. therapy with cardiovascular active drugs;
• Uncontrolled angina pectoris;
• Uncontrolled arterial hypertension;
• Uncontrolled atrial or ventricular arrhythmias;
• Active pericarditis or myocarditis;
• Need of continuous or intermittent O2 therapy;
• Hb < 10 g/dl;
• Severe concomitant non-cardiac diseases such as cancer or any other systemic disease limiting to participate in the study
• Acute inflammatory diseases;
• Acute non-cardiac somatic diseases, or somatic diseases with symptoms of decompensation;
• Currently implanted left ventricular assist device;
• Inability to accept the procedure of breathing via facial mask.