Effects of High-Intensity Aerobic Interval Training on Cardiopulmonary Function in Patients With Chronic Heart Failure at The University Teaching Hospital, Lusaka, Zambia

Chronic heart failure patients present with various symptoms, such as fatigue and dyspnea, adversely affecting their quality of life. Heart failure is a complex disease and a major cause of morbidity and mortality in developed and developing countries, including Zambia. Through studies undertaken, high-intensity aerobic interval training has been recommended in patients with chronic heart failure to help improve symptoms and, consequently, the quality of life. Minimal research pertaining to the effectiveness of aerobic exercise on various physiological parameters such as peripheral oxygen saturation, cardiopulmonary capacity and quality of life have been done in Africa and Zambia. This study evaluated the physiological effects of high-intensity aerobic interval training on the cardiopulmonary function in New York Heart Association (NYHA) Class II and III chronic heart failure patients with a focus on peripheral oxygen delivery/saturation, cardiopulmonary capacity and the quality of life. This study utilised the Randomised Clinical Trial (RCT) study design, and the study population was selected from the University Teaching Hospital-Heart Clinic in Lusaka, Zambia.A total number of 42 patients participated and were randomly assigned to the two arms of the study. Twenty-one (21) were assigned to the interventional group (IG) and 21 to the control group (CG), respectively. The IG underwent a 12-week aerobic HIIT exercise-training programme, while the CG was subjected to 30 minutes of walking on a treadmill for the same period of 12 weeks. The expected primary outcomes were the baseline to endline differences in oxygen delivery/saturation readings, cardiopulmonary capacity test readings and the quality of life (measured using the Minnesota questionnaire) for both groups. The results obtained from the pulse oximeter readings showed an increase in the oxygen saturation readings (97.90 to 98.62%), 6-minute walk distance readings (360.05 m to 429 m) and the questionnaire score totals of the different dimensions (physical, emotional/mental and socio-psychological factors) of the questionnaire (p-value;0.0001) of the IG. The CG oxygen saturation readings (97.38 % to 97.90%) and 6-minute walk test scores (359.14 to 370.9 m) showed minimal change. While the questionnaire scores showed a statistical difference in the emotional/mental (p-value < 0.0001), physical (p=0.005) and socio-psychological factors (p-value < 0.0001). High-intensity aerobic interval training has shown to improve peripheral oxygen delivery, cardiopulmonary capacity and quality of life in chronic heart failure patients; hence, it must be considered an adjunct therapy aside from pharmacological management in stable chronic heart failure patients in Zambia.