Impact of cardiac resynchronisation therapy on physical ability and quality of life in patients with chronic heart failure

Abstract

Background: Chronic heart failure (CHF) is a serious public health problem associated with high rates of morbidity and mortality. Cardiac resynchronisation therapy (CRT) is a well established treatment for selected patients who do not respond to optimal drug treatment of CHF.
Aim: To assess the impact of CRT on the physical ability and quality of life (QoL) of patients with CHF.
Methods: The study group consisted of 60 patients (mean age: 66.3 ± 8.7 years, 57 males and three females) with CHF classified as NYHA class III or IV (despite optimal pharmacotherapy for more than three months), a left ventricular end-diastolic diameter ≥ 55 mm, ejection fraction (LVEF) ≤ 35%, and a QRS duration ≥ 130 ms. Just before CRT, and three months after the procedure, patients were assessed using echocardiography and the 6-minute walk test (6-MWT), while their QoL was assessed by the Psychological General Well-Being index (PGWB). Three months after CRT, a 10% increase in baseline values of the 6-MWT constituted a positive response — patients who improved in this manner were classified as responders. Changes of at least ± 10% from baseline values of the PGWB total index were considered as improvement or worsening in QoL.
Results: During the follow-up, three men died, and so 57 patients were included in the final analysis. At the end of the study, an increase in the walking distance during the 6-MWT (298.0 ± 107.4 m vs 373.1 ± 127.2 m; p < 0.001) was observed. After three months, 38 (66.7%) patients were classified as responders while 19 (33.3%) subjects were classified as non-responders to CRT. Concurrently, after CRT we observed an improvement in QoL in 34 (59.6%) patients, while 23 (41.4%) patients showed no such effect. Patients who demonstrated an increased QoL at three months after CRT were characterised by lower baseline values of the total PGWB index as well as its dimensions (with the exception of the general health dimension). Improvement in QoL after CRT was observed only in the responders group (p < 0.01).
Conclusions: The implementation of CRT leads to a reduction of heart failure related symptoms and an increase in physical ability in roughly two thirds of patients. Improvement in QoL after CRT pertains only to patients who demonstrate simultaneously an improvement in their 6-MWT. None of the other baseline clinical and echocardiographic parameters were useful in predicting better QoL and exercise capacity after CRT implementation.