Enhanced external counterpulsation treatment in patients with refractory angina pectoris with emphasis on physical capacity, health-related quality of life and safety : An explorative and interventional study

Background: Patients with refractory angina pectoris (RAP) suffer from debilitating symptoms with considerable limitation of functional capacity and impaired health-related quality of life (HRQoL) despite optimised medical therapy. In addition, frequent angina symptoms are strongly associated with psychological distress. The challenging management of RAP and the severe limitations and symptomatology experienced by these patients underscore the need for further research in more novel treatment approaches. Enhanced external counterpulsation (EECP) is a potential non-invasive treatment that can decrease limiting symptoms in patients with RAP and is generally given as 35 one-hour sessions (i.e., one course) over seven weeks. Aim: The overall aim was to obtain a deeper understanding of patients’ experiences undergoing EECP treatment and to evaluate the effects of the treatment with focus on physical capacity, HRQoL and safety. Methods: An explorative and interventional study comprising both qualitative (paper I) and quantitative (papers II, III, and IV) study designs were performed. In paper I, semi-structured interviews took place with 15 strategically selected patients who had finished an EECP course at the two existing EECP clinics in Sweden. Data were analysed using inductive qualitative content analysis. In paper II, a quasi-experimental study with one-group pre-test/post-test design with a six-month follow-up was performed with 50 patients who had undergone one EECP course. The following pre- and post-treatment data were collected: medication use, six-minute walk test (6MWT), functional class according to the Canadian Cardiovascular Society (CCS), self-reported (i.e., questionnaire data) cardiac anxiety, and HRQoL. The questionnaires were also completed at a six-month follow-up. In paper III and IV, sociodemographic, medical, and clinical data related to EECP were collected by reviewing medical records of 119 patients with RAP who had undergone one EECP course and a 6MWT pre- and post-treatment. An increased walking distance by 10% post treatment, measured with 6MWT, was considered an adequate treatment response. Results: In paper I, the findings were divided into four content areas, each comprising three categories: (1) experiences before EECP was initiated comprised of uncharted territory, be given a new opportunity and gain insight; (2) experiences during EECP sessions comprised physical discomfort, need of distraction, and sense of security; (3) experiences between EECP sessions comprised physical changes, socializing, and coordinating everyday life; and (4) experiences after one course of EECP treatment comprised improved physical well-being, improved mental well-being and maintaining angina in check. In paper II, patients used significantly less short-acting nitrates (p <. 001), walking distance increased on average by 46 m (p < .001), and CCS class improved after one EECP course (p < .001). In addition, all but one subscale of cardiac anxiety and all HRQoL components improved significantly, and the positive effects were maintained at the six-month follow-up (p < .05). In paper III, 49 (41.2%) of the 119 patients, were responders to EECP. CCS class ≥ 3, left ventricle ejection fraction < 50%, and previous revascularisation (i.e., ≤ one type of intervention) were predictors of response (p < .05). In paper IV, the treatment completion rate was high, and the occurrence of adverse events (AE) was low. Most device-related AE required nursing actions, while medical actions were needed more in the non-device-related AE. The AE distribution did not differ between responders and non-responders. Skin lesion/blister occurred mostly in responders and paraesthesia occurred mostly in non-responders. Conclusions: The EECP treatment was perceived as an unknown option among these patients but also as be given a new opportunity to get better. The presence and care provided by the cardiac nurse contributed to a sense of security during treatment. The treatment resulted in reduced symptom burden, improved physical capacity and HRQoL, and less cardiac anxiety, leading to increased physical activity and enhanced life satisfaction for patients with RAP. Moreover, the EECP should be considered preferentially for patients who have a greater functional impairment, evidence of systolic left ventricular dysfunction, and exposure to fewer types of revascularisation. The EECP treatment appears to be a safe and well-tolerated treatment option in patients with RAP