A pilot randomised controlled trial investigating a mindfulness-based stress reduction (MBSR) intervention in individuals with pulmonary arterial hypertension (PAH): the PATHWAYS study

BACKGROUND

Pulmonary arterial hypertension (PAH) is an uncommon condition with progressive heart failure and premature death. Treatment costs up to £120,000 per patient per year, and the psychological burden of PAH is substantial. Mindfulness-based stress reduction (MBSR) is an intervention with the potential to reduce this burden, but to date, it has not been applied to people with pulmonary hypertension. We wished to determine whether a trial of MBSR for people with PAH would be feasible.

METHODS

A customised gentle MBSR programme of eight sessions was developed for people with physical disability due to PAH, and they were randomised to group-based MBSR or treatment as usual. The completeness of outcome measures including Beck Anxiety Index, Beck Depression Inventory and standard physical assessment at 3 months after randomisation were recorded. Health care utilisation was measured. Attendance at the sessions and the costs involved in delivering the intervention were assessed. Semi-structured interviews were conducted to explore the acceptability of the MBSR intervention and when appropriate the reasons for trial non-participation.

RESULTS

Fifty-two patients were recruited, but only 34 were randomised due to patients finding it difficult to travel to sessions. Twenty-two completed all questionnaires and attended all clinics, both routine and additional in order to collect outcomes measures. The MSBR sessions were delivered in Bristol, Cardiff and London, costing, on average, between £2234 (Cardiff) and £4128 (London) per patient to deliver. Attendance at each session averaged between two patients in Bristol and Cardiff and three in London. For those receiving treatment as usual, clinician blinding was achievable. Interviews revealed that people who attended MBSR found it interesting and helpful in managing their symptoms and minimising the psychological component of their disease.

CONCLUSIONS

We found that attendance at group MBSR was poor in people with chronic PAH within the context of a trial. Achieving better MBSR intervention attendance or use of an Internet-based programme might maximise the benefit of MBSR.

Capsaicin 8% patch for treprostinil subcutaneous infusion site pain in pulmonary hypertension patients

BACKGROUND

Treprostinil sodium improves haemodynamics and symptoms in pulmonary arterial hypertension (PAH) patients, but its subcutaneous (s.c.) administration can produce severe local site pain, and lead to discontinuation of vital treatment. Treprostinil is a prostacyclin analogue which stimulates prostacyclin receptors in skin nociceptor terminals, resulting in pain and cutaneous hypersensitivity, for which current pain remedies have limited effect. Capsaicin 8% patch relieves neuropathic pain for 3 months after a single 60 min cutaneous application; we investigated whether its pre-application can reduce s.c. trepostinil-induced pain.

METHODS

A single-centre, double-blind, randomized, placebo-controlled, crossover study was conducted to assess the safety and efficacy of a single capsaicin 8% patch pre-application for s.c. treprostinil pain in 11 PAH patients, relative to control patch with low-dose capsaicin 0.075% cream.

RESULTS

The primary efficacy endpoint, mean difference between the two treatment arms in an 11-point numerical pain rating scale from baseline to 2 weeks after patch applications, was significantly lower on the capsaicin 8% patch treatment arm [P=0.01, mean difference=-1.47 units, 95% credible interval (CI): -2. 59 to -0.38] in the patients who completed the study per protocol, although intention-to-treat analysis did not show significant difference (P=0.28). Heat pain thresholds were decreased (P=0.027, mean difference=5.43°C, 95% CI: 0.71-10.21) and laser Doppler flux increased (P=0.016, mean difference=370 units, 95% CI: 612 to 127.9) at the application site immediately after capsaicin 8% patch, confirming activity.

CONCLUSIONS

Further investigation of the efficacy of capsaicin 8% patch in this indication is warranted.

The responsiveness and validity of the CAMPHOR Utility Index

The aim of the present study was to validate and determine the minimal important difference (MID) and responsiveness of the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) Utility Index, a new tool enabling cost utility analyses. CAMPHOR, 6-min walking test (6MWT) and New York Heart Association (NYHA) data for 869 pulmonary hypertension patients (545 (63%) female; mean+/-SD age 56.6+/-15.4 yrs) from three centres were analysed. Utility was correlated with 6MWT data and calculated by NYHA class to assess validity. Effect sizes were calculated for those with two CAMPHOR assessments. Distribution and anchor-based MIDs were calculated. Analyses were carried out in patients receiving bosentan in order to determine whether or not those remaining in NYHA class III following treatment improved. The Utility Index distinguished between adjacent NYHA classes and correlated with 6MWT results. CAMPHOR subscales and utility were as responsive as the 6MWT (effect sizes ranged 0.31-0.69 for the CAMPHOR and 0.16-0.34 for the 6MWT). The within-group MID for the Utility Index was estimated to be approximately 0.09. Patients remaining in NYHA class III experienced, on average, a significant improvement (CAMPHOR Utility Index and functioning), which exceeded the MID. The CAMPHOR Utility Index is valid and responsive to change. Patients can experience significant and important improvements even if they do not improve on the basis of traditional outcomes, such as NYHA functional class.