Please assess the completion status of the following clinical trial:

Trial Title: Crossover Study From Macitentan or Bosentan Over to Ambrisentan

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: CROSSOVER
- Observational Model: None
- Primary Purpose: TREATMENT
- Time Perspective: None
- Masking: NONE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Diagnosis of a Connective Tissue Disease (CTD)~* Age range: 18-80 years old~* Previous Right Heart Catheterization (RHC) demonstrating PAH~* Forced vital capacity (FVC) greater than 50%~* Carbon Monoxide Diffusing Capacity (DLCO) greater than 50%~* World Health Organization (WHO) functional class II or III~* Able to perform a 6 minute walk test (6MWT)~* Stable dose of antihypertensive medications~* Non-pregnant females~* Have to be currently on stable dose of bosentan for at least 3 months~* Adequate acoustic images to allow for transthoracic echocardiography to be performed~Exclusion Criteria:~* Exercise limitation related to a non-cardiopulmonary reason (e.g. arthritis)~* Severe systemic hypertension greater than 170/95~* Patients with a prior history of cardiovascular disease~* WHO functional class IV status~* Patients with severe other organ disease felt by investigators to impact on survival during the course of the study.~* FVC less than 50% of predicted~* DLCO less than 50% of predicted

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: 80 Years
- Healthy Volunteers: f

Study Arms:
- Switch to Letairis from Bosentan (Type: EXPERIMENTAL): Subjects will be switching treatments from Bosentan (Tracleer) to Ambrisentan (Letairis)
- Switch to Letairis from Macitentan (Type: EXPERIMENTAL): Subjects will be switching treatments from Macitentan (Opsumit) to Ambrisentan (Letairis)

Based on this trial design, predict the completion outcome and termination type (if applicable).