The objective of this study is to evaluate the incidence of adverse events in Japanese pulmonary arterial hypertension subjects treated with epoprostenol injection based on prescribing information under the conditions of general clinical practice and also to grasp the following items;

1. Unknown adverse reactions (especially, significant adverse reactions)
2. Adverse reaction onset status under practical drug use conditions
3. Factors possibly influential on safety
4. Factors possibly influential on efficacy
5. Patient's prognosis, efficacy and safety in long-term use

Inclusion Criteria:

• Subjects with cardiovascular disease

Exclusion Criteria:

• Subjects with hypersensitivity to epoprostenol
• Subjects with right cardiac failure during an acute exacerbation
• Subjects with severe left ventricular systolic dysfunction
• Subjects with serious left ventricular dysfunction
• Subjects whose pulmonary edema getting worse during dose initiation

All Japanese subjects with pulmonary arterial hypertension who are treated with epoprostenol injection