Pulmonary arterial hypertension (PAH) is a progressive disease that leads to right heart failure and eventually death. The pathological mechanisms of pulmonary hypertension are complex and involve genetic mechanisms including bone morphogenetic protein receptor II (BMPR2), Activin-like kinase type-1, 5-hydroxytryptamine transport factor (5-HTT), and molecular cellular mechanisms of prostacyclin, endothelin, abnormal endothelial cell function, nitric oxide (NO) pathway, 5-hydroxytryptamine (5-HT), inflammation, and thrombotic alterations. According to the pathogenesis of pulmonary hypertension, WHO classifies it into: arterial pulmonary hypertension, pulmonary hypertension associated with left heart disease, pulmonary hypertension associated with hypoxia and lung disease, pulmonary hypertension associated with chronic thrombosis and/or embolic disease, and pulmonary hypertension caused by other rare diseases. In recent years, there have been great advances in the treatment of PAH, including basic therapy, new drug therapy to address the pathogenesis, interventional and surgical treatment, and other treatments. In particular, pharmacological treatment of PAH has made great strides. In a retrospective analysis of 557 patients with IPAH, Sibton et al. concluded that a decrease in mean pulmonary artery pressure (mPAP) of ≥10 mmHg or mPAP ≤40 mmHg with no change in cardiac output after the use of vasodilators was considered a positive vasodilator response. Patients with idiopathic pulmonary arterial hypertension (IPAH) can be treated with Ca2+ channel blockers if they have a positive test response. Long-acting nifedipine or amlodipine are recommended; isoptin is not recommended due to negative inotropic effects. The safety and efficacy of treatment with Ca2+ channel blockers should be monitored. If the functional class (FC) of IPAH patients does not reach grade I or II (FC I or FC II) after the use of Ca2+ channel blockers, other treatment options need to be considered. Prostacyclin Intravenous epoprostenol improves FC, 6-minute walking distance (6MWD, exercise tolerance test), improves hemodynamics, and prolongs survival time in patients with IPAH. An open, randomized study of 81 patients with FC III and FC IV IPAH demonstrated the benefits of intravenous epoprostenol in significantly increasing patient 6MWD and improving hemodynamics as well as prolonging survival. Similarly, observational studies have demonstrated the long-term efficacy of long-term intravenous epoprostenol in patients with IPAH: Sitbon et al. reported that 178 patients with FC III and FCA IV IPAH who received long-term intravenous epoprostenol had 1-, 2-, 3-, and 5-year survival rates of 85%, 70%, 63%, and 55%, respectively, which were significantly higher than in patients not previously treated with prostacyclin. patients. Similarly et al. observed 162 cases of FC III and FC IV IPAH with intravenous epoprostenol, and the 1-, 2-, 3-, and 5-year survival rates were 88%, 76%, 63%, and 56%, respectively, with significant improvements in FC, exercise tolerance, and hemodynamics. There are observational studies demonstrating that intravenous epoprostenol improves 6MWD and hemodynamics in patients with connective tissue disease (CTD)-associated PAH, but has a non-significant effect on mortality change during the observation period. Similarly, studies have demonstrated the beneficial effects of this treatment in patients with congenital heart disease, HIV, and hypertension-related PAH. Epoprostenol treatment requires that a central venous catheter be placed in the patient and that the drug be continuously administered into the vein via a special continuous infusion pump device. The dose is started at 2 ng/(kg?min) and adjusted gradually according to the patient’s symptom improvement and adverse effects. The optimal dose for long-term treatment is 25 to 40 ng/(kg?min). Long-term overdose can lead to high output heart failure. General adverse effects include headache, jaw pain, facial flushing, nausea, diarrhea, rash, myalgia; infections and other adverse effects can be fatal, so caution is needed in its use. The FDA has currently approved intravenous epoprostenol for FC III and FC IV IPAH and scleroderma-associated PAH. Treprostinil is a stable prostacyclin-mimetic drug, first developed for continuous subcutaneous injection. A randomized, placebo-controlled study of 470 patients with FC II, FC III and FC IV PAH and CTD, congenital heart disease-associated PAH over a 12-week period showed that subcutaneous administration of treprostinil achieved a statistically significant increase in 6MWD of 16 m. The improvement in 6MWD was dose-related, with the highest dose of the drug resulting in a 6MWD improved by up to 40m (interquartile). However, 85% of patients experienced pain and erythema at the injection site. Other adverse effects were headache, diarrhea, rash, and nausea. treprostinil was approved by the FDA in 2002 for FC II, III, and IV PAH. has potential benefit over IV epoprostenol and has a long half-life. Intravenous treprostinil has been developed and FDA approved intravenous treprostinil in 2004 for patients with FC II, III, and FC IV PAH who cannot tolerate subcutaneous injections; intravenous dosing has been shown to be more effective in improving 6MWD, hemodynamics. Inhalation and oral dosage forms are in development. iloprost is a stable prostacyclin for inhalation 6-9 times daily. iloprost has been approved by the FDA for use in FC III and FC IV PAH. studies have demonstrated significantly better short-term efficacy than placebo in improving FC and 6MWD in patients with a variety of PAH; fewer long-term efficacy observations have been made. A 12-week randomized, double-blind, placebo trial demonstrated significant effects in improving 6MWD, but a 12-month dosing observation trial found a significant improvement in 6MWD at 3-6 months of dosing, and this effective effect did not last for 9-12 months, so the long-term efficacy is yet to be further confirmed. It has been marketed in Japan and Korea. Endothelin receptor antagonist Bosentan is an oral dosage form, active, non-selective endothelin receptor antagonist. In a placebo-controlled study of patients with FC III or IV IPAH and CTD-related PAH taking bosentan, Channick found a 36m increase in 6MWD in patients taking bosentan PAH, with significant improvements in mPAP, cardiac index, and pulmonary vasospasm in the dosing group compared to the placebo group; also in the high-profile BREATHE-1 trial, patients in the bosentan group A long-term observational study found that long-term bosentan treatment patients had significantly longer survival than that documented by the NIH (National Institutes of Health). The FDA has approved bosentan for the treatment of FCIII and FCIV PAH, which requires monthly monitoring of liver function, quarterly review of peripheral blood work, and monthly observation in women approaching delivery. Sitaxsentan is a selective ETA antagonist, and the STRIDE-1 trial included 178 patients with FC II, III and IV PAH, including IPAH or CTD, congenital heart disease-related PAH, with maximal oxygen consumption measured after cardiopulmonary exercise as the observation index. The maximum oxygen consumption in the 100 mg dose group did not improve; 6MWD improved significantly in both dose groups, and hemodynamics improved appropriately. The common adverse effects were headache, peripheral edema, nausea, epistaxis, and drowsiness. interaction between Sitaxsentan and warfarin; transaminases >3 times the upper limit of normal occurred in 5% and 21% of patients on 100 mg and 300 mg Sitaxsentan, respectively. Ambrisentan is a selective ETA antagonist. 64 patients with IPAH, CTD and drug, HIV-associated PAH were randomized to receive 4 doses of ambrisentan (1, 2.5, 5 and 10 mg per day). 12 weeks of treatment increased 6MWD by 36m in each group, reduced mean pulmonary artery pressure and increased cardiac index increased; 3.1% of patients showed transaminases 3 times higher than the upper limit of normal. Controlled studies between various doses and placebo are ongoing. Phosphodiesterase inhibitor Sildenafil: The SUPER trial demonstrated that Sildenafil is an effective, highly selective PDE-5 inhibitor that improves exercise capacity, FC, and hemodynamics in patients with PAH. This randomized, double-blind, placebo-controlled trial included 278 patients with symptomatic PAH, including IPAH and CTD, and preconditioning-associated PAH. Patients were randomized to 20, 40, and 80 mg of sildenafil three times daily, and 6MWD improved by 45, 46, and 50 m for 12 weeks at the three doses, with no significant change in the number of acute exacerbations The main adverse effects were headache, facial flushing, dyspepsia, and epistaxis. sildenafil was approved by the FDA in 2005 for the treatment of PAH at the recommended dose of 20 mg three times daily. Treatment methods under research and development In addition to the above described drug treatments, there are some new treatment options being researched, developed and expected to be applied in clinical practice in the near future. Vasoactive intestinal peptide belongs to the family of secretory glucagon-related growth factor releasing factors, which can inhibit platelet activation and vascular smooth muscle cell proliferation, and has significant pulmonary vasodilatory effects. An open trial confirmed that eight patients with inhaled vasoactive intestinal peptide IPAH showed significant improvement in their condition. New anti-pulmonary hypertension drugs currently act on the angiopoeitin and serotonin pathways, while growth factor inhibitors are also one of the new anti-pulmonary hypertension research directions. Gene therapy is still in the enlightened stage of research, but may hold great promise for effective control of PAH. Transfection of endothelin precursor cells with nitric oxide synthase in a PAH mouse model resulted in decreased right ventricular pressure and prolonged survival in PAH mice. In conclusion, research in the treatment of pulmonary hypertension has progressed rapidly, and physicians should consider all aspects of therapeutic use, including cardiopulmonary hemodynamics, the presence or absence of heart failure and drug interactions and adverse effects. Quantification of the patient’s cardiopulmonary function classification also has an important impact on the selection of drugs and drug efficacy.