Impact of lifestyle interventions in cardiac rehabilitation for individuals with ischaemic heart disease: a prospective cohort study

Background/Aims Lifestyle interventions are recommended in cardiac rehabilitation guidelines to reduce cardiovascular risk and prevent heart attacks. Therefore, it is important to investigate their effectiveness in primary healthcare settings to improve outcomes in individuals with ischaemic heart disease. The aim of this study was to examine the association between adherence and completion of cardiac rehabilitation and outcomes related to waist circumference and physical performance in primary healthcare settings. Methods A total of 514 individuals diagnosed with ischaemic heart disease were enrolled from ten primary healthcare settings in the Central Denmark Region to participate in cardiac rehabilitation. Participants were categorised based on the completion of a dietary intervention. Changes in waist circumference from baseline to the 12-week follow-up were measured. Adherence to the exercise intervention was assessed based on participation in >= 80% or <80% of training sessions. Changes in physical performance, specifically a 10% improvement in the Watt-max bicycle test, were evaluated over the same period. Linear and logistic regression analyses were conducted, both crude and adjusted for potential confounders. Results Of the 514 participants, 317 (70.8%) who completed the dietary intervention experienced an average reduction of -1.32 cm (95% confidence interval: -1.91 to -0.74 cm) in waist circumference, compared to -0.50 cm for non-completers (P=0.019). Additionally, 276 (56.2%) participants adhered to >= 80% of the exercise intervention, with 237 (66.7%) showing an improvement of >= 10% in Watt-max from baseline to follow-up. Individuals who adhered to >= 80% of the exercise intervention were twice as likely to achieve a >= 10% improvement in Watt-max compared to those with <80% adherence (P=0.334). Conclusions Both dietary and exercise interventions administered in primary healthcare settings were associated with positive changes in waist circumference and physical performance. Implications for practice Dietitians should focus on motivating patients to complete dietary interventions, which can significantly reduce waist circumference. Physiotherapists should emphasise the importance of adherence to exercise programmes. Encouraging patients to meet adherence targets, both in structured rehabilitation and home-based activities, is vital to achieve long-term health benefits.