Use of eHealth in the management of pulmonary arterial hypertension: review of the literature

Introduction

Pulmonary arterial hypertension (PAH) is an incurable and progressive disease caused by the narrowing of the blood vessels of the lungs. This disease is characterised by high blood pressure in the pulmonary artery that, if maintained over time, may lead to right heart failure and premature death.1 PAH is a complex and multifactorial chronic disease2 that pervades the holistic functioning of the individuals and their quality of life (QoL).3 Over the past few years, the efficacy of combination drug therapy and the utilisation of diagnostic technologies (including imaging techniques and right heart catheterisation) have contributed to increasing the efficacy of therapeutic regimes, reducing morbidity and mortality in people with PAH.4 5

The management of PAH is complex and requires intense and regular communication, in the first place between the patient and caregivers, but also among all members of the highly specialised centre-based multidisciplinary care team6 and the external caregivers, including primary care centres, regional hospitals, supporting family and carers. In PAH care, all contributions to enhance communication can be of particular interest, for example, during the almost inevitable periods of drug modification or up-titration, or when drug side effects may potentially appear.7

Electronic Health (eHealth), which is referred to as a broad range of informatics applications for facilitating the management and delivery of healthcare,8 has been proposed to support the management of patients with chronic disease and as a possible tool to improve clinical outcomes in patients with heart failure (HF) and chronic obstructive pulmonary disease (COPD).9 10 The adoption of eHealth enables remote monitoring of patients and helps to identify early symptoms and respond promptly to exacerbations.11 In addition, eHealth innovations enable self-management and contribute to shifting the balance of power and responsibility from healthcare professionals to patients,12 which in turn is closely related to improvements in health-related QoL.13 In addition, mobile health (mHealth), which is a subset of eHealth and defined as the medical and public health practice supported by mobile devices, such as mobile phones, patient monitoring devices, personal digital assistants and other wireless devices,14 has been envisioned to play an important role for the management of chronic conditions.15 As the impact of eHealth needs to be established specifically for different targeted populations,16 the objective of this study was reviewing the existing literature in an attempt to better understand what types of eHealth solutions have been tested, and the possible benefits that eHealth has brought about for the management of people with PAH.

Methods

Results

The electronic search resulted in 1431 unique records. Of these, 1406 non-relevant records were filtered out at title/abstract screening, based on the exclusion criteria. The full text of 23 studies were inspected for eligibility. Of these, five papers were excluded either due to non-relevant study setting (eg, the purpose of the trial was not assessing eHealth) or non-relevant patient population (eg, patients with HF without PAH). Eighteen studies were considered eligible for inclusion in this review: 6 peer-reviewed journal papers and 12 conference papers published in scientific journals. The PRISMA flow diagram of study selection is shown in figure 1. To facilitate the analysis and the discussion of the findings of this review, we split the studies into two groups: one group includes the studies that aimed to test the validity and/or the reliability of a specific eHealth solution (table 1), and the other group includes the studies that evaluated eHealth as part of the medical management of PAH, with the possibility of reporting clinical endpoints such as hospitalisation and QoL (table 2).

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In the reviewed studies, four different eHealth solutions have been tested: (1) wireless implantable haemodynamic monitor (IHM) to measure pulmonary artery pressure, (2) wireless pedometers and smartphone apps for self-administered 6-minute walk test (6MWT), (3) step-oximetry devices to capture wireless information on exercise capacity and (4) ambulatory impedance cardiography to evaluate haemodynamic variables during all daytime activity. The findings are summarised as follows:

1. Benza et al explored the feasibility and safety of CardioMEMS® (Abbott Laboratories; Atlanta, USA) demonstrating that its use was safe at rest, during exercise21–23 and in combination with the use of cardiac MRI,24 and was associated with a greater pulmonary artery pressure reduction through medication changes in the ambulatory setting.25 The use of CardioMEMS was associated with a 36% reduction in heart failure–related hospitalisation rates (0.60 vs 0.94, HR 0.64, 95% CI 0.51 to 0.81, p=0.00020).26 In a retrospective analysis of the CHAMPION trial, 314 patients with HF who met the definition of pulmonary hypertension (PH) (151 with CardioMEMS vs 163 control) were followed for an average of 15 months. The CardioMEMS group experienced a reduction in a composite endpoint of death and HF hospitalisation (HR 0.74, 95% CI 0.55 to 0.99, p=0.04).27 Biederman et al showed that the use of CardioMEMS allowed reliable measurements of right ventricle cardiac output.28 Fruhwald et al used an early model of IHM (Chronicle, model 9520; Medtronic, USA) to demonstrate the need for improvement of treatment models with long-term aerosolised Iloprost.29 Raina et al conducted a retrospective analysis of the CHAMPION trial concluding that in patients with HF with marked limitation of their physical activity, those with pulmonary hypertension (Group 2 of the WHO classification) had higher hospitalisation rates than those without pulmonary hypertension (0.77/year vs 0.37/year, HR 0.49, 95% CI 0.39 to 0.61), and that in patients with and without PH, ongoing knowledge of CardioMEMS data resulted in a significant reduction in HF hospitalisation (HR 0.64, 95% CI 0.51 to 0.81 for patients with PH and HR 0.60, 95% CI 0.41 to 0.89 for non-PH). The relative risk reduction (RRR) was lowest in the patients with transpulmonary pressure gradient >15 mm Hg (RRR 30%) and pulmonary vascular resistance >3 Woods Units (RRR 33%). In addition, there was a non-significant trend towards improved survival with knowledge of CardioMEMS parameters (HR 0.78, 95% CI 0.50 to 1.22).30

2. Brooks et al and Gregorietti et al showed the feasibility and accuracy of a smartphone-based self-administered 6-MWT (6MWTApp) and a digital pedometer in measuring physical activity level and exercise capacity. The number of footsteps during the 6MWT correlated with clinical and laboratory parameters of prognostic relevance in patients with PH such as pro-BNP levels and WHO functional class and provided valuable data for the evaluation and the follow-up of people with PH.31–34

3. Fox et al demonstrated that a step oximetry system equipped with pressure sensors and pulse oximeter linked to a computer provided useful information on the functional capacity of patients with WHO group 1 PAH (idiopathic form of PAH) and group 4 PAH (chronic thromboembolic PH), strongly correlating with functional class and 6MWT walk distance.35 36

4. Arelli et al showed a real-time wireless impedance cardiography (Physioflow Enduro; Manatec Biomedical, Paris, France) for non-invasive determination of haemodynamic parameters in pulmonary hypertension patients during their 6MWT. Stroke volume, cardiac output and cardiac index increased with activity in direct relation to the distance walked, providing valuable insights into the haemodynamic changes during exercise.37 Other authors (Tonelli et al) used this portable device to enable continuous non-invasive evaluation of haemodynamic variables on a beat-to-beat basis during all daytime activity. In another study, the same researchers demonstrated that the acceleration and decay of the heart rate slopes during a 6MWT exercise in patients with PAH were different compared with lung airway diseases and healthy controls.38 39

Discussion

To our knowledge, this is the first literature review investigating the use of eHealth in PAH. In general, the reported eHealth solutions have demonstrated to be safe, accurate and reliable, and could contribute to the clinical management of people with pulmonary hypertension. In particular, the reported association between CardioMEMS and a reduction in hospitalisations rates in PAH Group 2 (patients with left-sided HF and concomitant PH) appears promising. In another study (based on the same HF population), the use of this device was associated with a reduction in a composite endpoint of death and HF hospitalisation, although without any difference in survival. CardioMEMS combined with CMR could also contribute to providing an accurate calculation of non-invasive cardiac output, necessary to estimate non-invasive pulmonary vascular resistance, a key feature in the diagnosis of patients with PAH.

The smartphone-based self-administered 6MWT app (SA-6MWT App) demonstrated to be accurate and reliable at clinics and at home. A digital footstep counting and a computerised step-pulse oximeter during the 6MWT added valuable data for evaluation and follow-up of these patients, showing a strong correlation to clinical and laboratory parameters of prognostic relevance in PAH. The ambulatory impedance cardiography increased the value of 6MWT providing valuable insights into the haemodynamic changes that occur during exercise in patients with PAH, under treatment and in comparison, with other lung diseases and healthy controls.

In general, this review highlights a lack of studies assessing the impact of eHealth on hard clinical endpoints (such as mortality and hospitalisations) and on QoL. This makes it difficult to draw further conclusions on the effects that the introduction of eHealth may have for the people living with PAH, their health professionals and their families. However, based on promising reports in the HF domain,40 41 possible benefits of using eHealth in the management of PAH can be postulated.

In particular, some additional observations may be considered. First, looking at the characteristics of the study participants, most participants pertained to Group 2 of the WHO classification, haemodynamically referred to as post-capillary PAH. This is a crucial observation as the patients with left-sided HF have a completely different management (and treatment) compared with the WHO Group 1 of patients with PAH (haemodynamically referred to as pre-capillary PAH). This type of PAH includes, along with the idiopathic form of the disease, the connective tissue disease–associated PAH. Both conditions are considered rare diseases42 (or perhaps underdiagnosed).43 These entities present a management challenge for PAH services and health organisations derived from a high dependency of frequent visits at tertiary centres and highly specialised care, with close supervision of health measures, as well as symptoms and treatment monitoring. We propose that any future attempt to trial the impact of eHealth in PAH should only recruit patients with precapillary PAH, excluding participants with PH associated with HF or severe chronic obstructive lung disease.

Second, one of the most important factors determining the success versus failure of an eHealth intervention may be dependent on delivery of an effective medical intervention and the presence or absence of required medical action. Thus, it is important to examine the whole workflow that the eHealth intervention will support and the impact on the clinical management.44 In the present review, only two studies25 30 considered the use of eHealth as part of the medical management (table 2). In both cases, most of the patients pertained to the post-capillary form of PAH, which represents a serious limitation in terms of validating the usefulness of these eHealth interventions in patients living with precapillary forms of PAH.

Third, in the two studies referred to in table 2, the use of eHealth showed reductions in hospitalisation and, in one of them, a non-significant trend towards improved survival.26 30 Again, it was not possible to extrapolate this positive outcome to the patients with the precapillary form of the disease, as most of the participants included in these studies were patients with post-capillary PH.

Lastly, none of these studies assessed the impact that eHealth has on the well-being of the patients, usually represented by the assessment of QoL. Hence, the assessment of QoL is of great interest in PAH,44 as in any other incurable disease where new treatments with small survival benefits may be offset by QoL deterioration.45 Thus, specific tools have been developed to measure QoL in people with PAH.46

Conclusion

The evidence on the use of eHealth in patients with PAH is scant and mainly envisioned to validate the accuracy and reliability of specific technology tools. However, the potentials of using eHealth to improve the management of patients with PAH needs to be considered. A comprehensive analysis of the impact that the utilisation of eHealth may have on hard clinical outcomes and QoL needs to be addressed. We see this study as a general call for researchers to investigate the impact that eHealth may have on the holistic management of people with PAH.