Improvement in Quality of Life in Chronic Thromboembolic Pulmonary Hypertension With Balloon Pulmonary Angioplasty

Chronic thromboembolic pulmonary hypertension (CTEPH) is caused by occlusion and/or thrombi of the pulmonary arteries with organized thrombi, resulting in reduced pulmonary artery flow and compensatory PH to drain pulmonary flow normally. Although CTEPH is sometimes a sequela of acute pulmonary embolus, it is more prevalent that thrombus organization in the pulmonary arteries progresses more insidiously and induces chronic PH states like pulmonary arterial hypertension (PAH), especially in Japan. Usually, CTEPH advances very slowly but tends to aggravate more rapidly when it becomes more serious. The prognosis is not so bad when mean pulmonary arterial pressure (mPAP) is <30 mmHg, but it is very grave when mPAP is >30 mmHg.¹ Regarding treatment, the gold standard has long been surgical pulmonary endarterectomy (PEA), in which the mortality rate has been >5% and 20–40% of affected patients cannot undergo the treatment.^2,3 Catheter treatment with balloon (balloon pulmonary angioplasty: BPA) was started in early 2000,⁴ has been improved,⁵ developed rapidly and now established as a safe and effective treatment.⁶ Reports on the effects of this treatment, such as hemodynamic⁶ and anatomic⁷ improvement, have been published, but to date an assessment of the quality of life (QOL) after catheter treatment has not been done.

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In this issue of the Journal, Darocha et al report on their study of the benefit of BPA.⁸ They used the 36-item Short Form (SF-36v2) questionnaire, which evaluates QOL on 8 scales: physical functioning (PF), role-physical (RP), bodily pain (BP), general health (GH), vitality (VT), social functioning (SF), role-emotional (RE) and mental health (MH). The appropriate scales combined into groups summarize 4 parameters for evaluating the physical sphere (physical component summary: PCS) and 4 parameters for evaluating the mental sphere (mental component summary: MCS). However, this grouping is not acknowledged in Japan because of social differences. As another way of evaluating QOL, the 6-min walk test (6MWT) was performed. After enrolling 25 patients with CTEPH, these tests were done before and after BPA, and the scores were compared.

The results were as following. At baseline, 64% of the patients described their general health status as unsatisfactory. After BPA, 44% described their general health status as good, and 80% reported a significant improvement compared with the previous year (P<0.05). Baseline QOL among the CTEPH patients was significantly worse compared with the healthy population. After BPA, a significant improvement was observed in QOL on all the scales, except for pain experience (Table). Hemodynamic variables were also significantly improved (Figure), but that improvement did not correlate well with improvement in PCS or MCS. However, the 6MWT improvement significantly correlated with MCS.

Table. Change in SF-36v2 Scale Scores⁸ Among Patients With Chronic Thromboembolic Pulmonary Hypertension

	Scale score			Normalized scale score
	Before BPA	After BPA	P value	Before BPA	After BPA	P value
PF	29	62.4	0.001	26.9	41.3	0.001
RP	9	57	0.001	29.6	44	0.001
BP	57.3	66.3	0.185	44.6	48.3	0.186
GH	30.6	46.1	0.001	31.3	38.7	0.001
VT	35	62.4	0.001	39.2	52.5	0.001
SF	52	77	0.001	35.8	47.1	0.001
RE	33.3	74.6	0.001	35	47.3	0.008
MH	55.6	73.9	0.001	39.2	49.3	0.001
PCS	29.5	39.4	0.001	–	–	–
MCS	41	51.9	0.024	–	–	–

BP, bodily pain; BPA, balloon pulmonary angioplasty; GH, general health; MCS, mental component summary; MH, mental health; PCS, physical component summary; PF, physical functioning; RE, role-emotional; RP, role-physical; SF, social functioning; VT, vitality.

Figure.

Hemodynamic parameters before and after balloon pulmonary angioplasty in patients with chronic thromboembolic pulmonary hypertension. CI, cardiac index; mPAP, mean pulmonary artery pressure; mRAP, mean right atrial pressure; PVR, pulmonary vascular resistance. Adapted with permission from Darocha S, et al.⁸

One characteristic of this study is that hemodynamic improvement is not as prominent as in other studies, specifically when compared with the results reported in Japanese centers.^5,6,9 Despite this, a significant improvement in QOL was revealed and the results for the 6MWT correlated with a QOL questionnaire item but not with any hemodynamic variables, meaning that not hemodynamic improvement but physical fitness improvement is more directly correlated with how patients feel in their daily lives. Therefore, the aim of BPA is to ameliorate QOL by increasing exercise capacity once patients achieve the goal of mPAP <30 mmHg, securing greater life expectancy. Moreover, exercise therapy to recover exercise capacity after successful BPA sessions is also imperative to enhance QOL, the final goal in the treatment in general, in addition to the improvement in prognosis. Only the 6MW distance correlated with QOL, conversely signifying that dyspnea on exertion is the most important subjective symptom for CTEPH patients.

This study used the SF-36v2 QOL questionnaire, which has been the most widely used to date and is the best authorized tool for measuring QOL. It is not specific to individual diseases, general health condition is well analyzed and plenty of data has already accumulated that includes healthy people, making a comparison with healthy people possible. As QOL improvement becomes the next treatment goal after a good prognosis has been attained with treatment in patients with PH, comparison of QOL among various PH etiologies will be a very interesting study, using the SF-36v2 QOL questionnaire, in terms of contemplating QOL improvement in PH patients.

In conclusion, although hemodynamic improvement was not so remarkable after BPA in this study, QOL improved significantly according to an analysis using the SF-36v2 QOL questionnaire and correlated with an improvement in 6MW distance. This study leads us to consider the goal of PH treatment in general, and future directions in the treatment of CTEPH in particular.

References

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