The efficacy and safety of herbal formulas for adults with pulmonary hypertension combined with chronic obstructive pulmonary disease: a systematic review and meta-analysis involving 1,865 participants.

BACKGROUND

There is currently no effective treatment for the majority of patients with chronic obstructive pulmonary disease combined with pulmonary hypertension (COPD-PH). Numerous clinical trials have demonstrated the use of traditional Chinese medicine (TCM) herbal formulas in combination with routine western pharmacotherapy (WP) for the treatment of COPD-PH, with positive results. This meta-analysis was designed to evaluate the efficacy and safety of TCM herbal formulas in the treatment of COPD-PH.

METHODS

A systematic literature search was conducted using Web of Science, PubMed, Chinese National Knowledge Infrastructure (CNKI), WanFang, and Chinese Science and Technology Journal (VIP) from database inception until October 2023. The primary outcome was pulmonary artery pressure parameters, including pulmonary artery systolic pressure (PASP) and mean pulmonary artery pressure (mPAP). Secondary outcomes included pulmonary ventilation function parameters, such as forced expiratory volume in one second (FEV1) and the ratio of FEV1 to forced vital capacity (FEV1/FVC%), as well as functional capacity assessments measured by the six-minute walk distance (6MWD). Reviewer Manager software was used for both random-effects and fixed-effects meta-analyses. We registered the protocol for this study with the International Platform of Registered Systematic Review and Meta-analysis Protocols (INPLASY, registry number: INPLASY2022100041).

RESULTS

Twenty randomized control trials with a total of 1,865 patients were included in the meta-analysis. The results of our meta-analysis revealed that TCM herbal formulas in combination with basic WP significantly reduced pulmonary artery pressure in patients with COPD-PH, including PASP [mean difference (MD) =-4.50 mmHg, 95% confidence interval (CI): -6.04, -2.95] and mPAP (MD =-4.47 mmHg, 95% CI: -5.07, -3.88). Additionally, pulmonary ventilation function and 6MWD (MD =48.13 m, 95% CI: 39.92, 56.34) were also improved in COPD-PH patients. Pulmonary ventilation function was reflected by FEV1 (MD =0.83 L, 95% CI: 0.35, 1.30) and FEV1/FVC% (MD =4.76, 95% CI: 3.75, 5.77). A total of six studies reported adverse events in detail, and all claimed that no adverse events were observed in COPD-PH patients using TCM herbal formulas.

CONCLUSIONS

The combination of TCM herbal formulas and basic WP might be more effective in improving the quality of life and exercise capacity of patients with COPD-PH than basic WP alone. However, the firm conclusions of our study were hampered by the low quality of the evidence.