CAMPHOR score: patient-reported outcomes are improved by pulmonary endarterectomy in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Pulmonary endarterectomy (PEA) is the recommended treatment for eligible patients with chronic thromboembolic pulmonary hypertension (CTEPH). The Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) score is an internationally validated patient-reported outcome (PRO) measure for CTEPH. It assesses three domains: activity, quality of life (QoL) and symptoms. We assessed PROs in patients with CTEPH undergoing PEA. METHODS: This retrospective observational study of consecutive CTEPH patients undergoing PEA at the UK national PEA centre between 2006 and 2017 assessed change in CAMPHOR score from baseline (pre-PEA) until up to 5 years post-PEA. CAMPHOR scores were compared between 1) those with and without clinically significant residual pulmonary hypertension and 2) those undergoing PEA and propensity-matched CTEPH patients who were not operated on. The minimally clinically important difference (MCID) was calculated using an anchor-based method. RESULTS: Out of 1324 CTEPH patients who underwent PEA, 1053 (80%) had a CAMPHOR score recorded pre-PEA, 934 (71%) had a score recorded within a year of PEA and 784 (60%) had both. There were significant improvements between pre- and post-PEA in all three CAMPHOR domains (median±interquartile range activity -5±7, QoL -4±8, symptoms -7±8; all p<0.0001). Improvements in CAMPHOR score were greater and more sustained in those without clinically significant residual pulmonary hypertension. CTEPH patients undergoing PEA had better CAMPHOR scores than those not operated on. The MCID in CAMPHOR score was -3±5 for activity, -4±7 for QoL and -6±7 for symptoms. CONCLUSIONS: PROs are markedly improved by PEA in patients with CTEPH, more so in those without clinically significant residual pulmonary hypertension.

A minimal clinically important difference measured by the Cambridge Pulmonary Hypertension Outcome Review for patients with idiopathic pulmonary arterial hypertension.

Several patient-reported outcome measures have been developed to assess health status in pulmonary arterial hypertension. The required change in instrument scores needed, to be seen as meaningful to the individual, however remain unknown. We sought to identify minimal clinically important differences in the Cambridge Pulmonary Hypertension Outcome Review (CAMPHOR) and to validate these against objective markers of functional capacity. Minimal clinically important differences were established from a discovery cohort (n = 129) of consecutive incident cases of idiopathic pulmonary arterial hypertension with CAMPHOR scores recorded at treatment-naïve baseline and 4-12 months following pulmonary arterial hypertension therapy. An independent validation cohort (n = 87) was used to verify minimal clinically important differences. Concurrent measures of functional capacity relative to CAMPHOR scores were collected. Minimal clinically important differences were derived using anchor- and distributional-based approaches. In the discovery cohort, mean (SD) was 54.4 (16.4) years and 64% were female. Most patients (63%) were treated with sequential pulmonary arterial hypertension therapy. Baseline CAMPHOR scores were: Symptoms, 12 (7); Activity, 12 (7) and quality of life, 10 (7). Pulmonary arterial hypertension treatment resulted in significant improvements in CAMPHOR scores (p < 0.05). CAMPHOR minimal clinically important differences averaged across methods for health status improvement were: Symptoms, -4 points; Activity, -4 points and quality of life -3 points. CAMPHOR Activity score change ≥minimal clinically important difference was associated with significantly greater improvement in six-minute walk distance, in both discovery and validation populations. In conclusion, CAMPHOR scores are responsive to pulmonary arterial hypertension treatment. Minimal clinically important differences in pulmonary hypertension-specific scales may provide useful insights into treatment response in future clinical trials.