A treatment-related adverse event was any untoward medical occurrence attributed to sildenafil citrate in a participant who received sildenafil citrate. Relatedness to sildenafil citrate was assessed by the physician/investigator. Participants with treatment related adverse events were counted by disease type to assess whether it was risk factor for the treatment related adverse events.

* indicates "Associated Pulmonary Arterial Hypertension (APAH)". ** refers to "Pulmonary Veno Occlusive Disease/Pulmonary Capillary Hemangiomatosis".

A treatment-related adverse event was any untoward medical occurrence attributed to sildenafil citrate in a participant who received sildenafil citrate. Relatedness to sildenafil citrate was assessed by the physician/investigator. Participants with treatment related adverse events were counted by severity (WHO functional classification for PAH range;This system grades PAH severity according to the functional status of the patient. The grades range from Functional Class (FC) I, where the patient's disease does not affect their day-to-day activities, to FC IV, where patients are severely functionally impaired, even at rest. This functional classification system links symptoms with activity limitations, and allows clinicians to quickly predict disease progression and prognosis, as well as the need for specific treatment regimens, irrespective of the underlying etiology of PAH) to assess whether it was risk factor for the treatment related adverse events.

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by age were counted to assess whether it contributes to the clinical effectiveness.

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by gender were counted to assess whether it contributes to the clinical effectiveness.

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by disease type were counted to assess whether it contributes to the clinical effectiveness.

* indicates "Associated Pulmonary Arterial Hypertension (APAH)". ** refers to "Pulmonary Veno Occlusive Disease/Pulmonary Capillary Hemangiomatosis".

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by severity (WHO functional classification of PAH;The grades range from Functional Class (FC) I, where the patient's disease does not affect their day-to-day activities, to FC IV, where patients are severely functionally impaired, even at rest. This functional classification system links) were counted to assess whether it contributes to the clinical effectiveness.

Categorization of PAH in the study. * indicates "Associated Pulmonary Arterial Hypertension (APAH)". ** refers to "Pulmonary Veno Occlusive Disease/Pulmonary Capillary Hemangiomatosis".

This system grades PAH severity according to the functional status of the patient. The grades range from Functional Class (FC) I, where the patient's disease does not affect their day-to-day activities, to FC IV, where patients are severely functionally impaired, even at rest. This functional classification system links symptoms with activity limitations, and allows clinicians to quickly predict disease progression and prognosis, as well as the need for specific treatment regimens, irrespective of the underlying etiology of PAH.

A treatment-related adverse event was any untoward medical occurrence attributed to sildenafil citrate in a participant who received sildenafil citrate. Expectedness of the adverse event was determined according to the Japanese package insert. Relatedness to sildenafil citrate was assessed by the physician/investigator.

The safety analysis set comprised of participants who satisfied the inclusion criteria and had received sildenafil citrate at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to sildenafil citrate in a participant who received sildenafil citrate. Relatedness to sildenafil citrate was assessed by the physician/investigator. Participants with treatment related adverse events were counted by age to assess whether it was risk factor for the treatment related adverse events.

The safety analysis set comprised of participants who satisfied the inclusion criteria and had received sildenafil citrate at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to sildenafil citrate in a participant who received sildenafil citrate. Relatedness to sildenafil citrate was assessed by the physician/investigator. Participants with treatment related adverse events were counted by gender to assess whether it was risk factor for the treatment related adverse events.

The safety analysis set comprised of participants who satisfied the inclusion criteria and had received sildenafil citrate at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to sildenafil citrate in a participant who received sildenafil citrate. Relatedness to sildenafil citrate was assessed by the physician/investigator. Participants with treatment related adverse events were counted by disease type to assess whether it was risk factor for the treatment related adverse events.

* indicates "Associated Pulmonary Arterial Hypertension (APAH)". ** refers to "Pulmonary Veno Occlusive Disease/Pulmonary Capillary Hemangiomatosis".

The safety analysis set comprised of participants who satisfied the inclusion criteria and had received sildenafil citrate at least once.

A treatment-related adverse event was any untoward medical occurrence attributed to sildenafil citrate in a participant who received sildenafil citrate. Relatedness to sildenafil citrate was assessed by the physician/investigator. Participants with treatment related adverse events were counted by severity (WHO functional classification for PAH range;This system grades PAH severity according to the functional status of the patient. The grades range from Functional Class (FC) I, where the patient's disease does not affect their day-to-day activities, to FC IV, where patients are severely functionally impaired, even at rest. This functional classification system links symptoms with activity limitations, and allows clinicians to quickly predict disease progression and prognosis, as well as the need for specific treatment regimens, irrespective of the underlying etiology of PAH) to assess whether it was risk factor for the treatment related adverse events.

The safety analysis set comprised of participants who satisfied the inclusion criteria and had received sildenafil citrate at least once.

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by age were counted to assess whether it contributes to the clinical effectiveness.

The effectiveness analysis set comprised of participants in the safety analysis set who had effectiveness evaluation (overall evaluation by the physician/investigator based upon change in clinical symptoms and laboratory findings) at least once. Participants with observed effectiveness data were included in table.

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by gender were counted to assess whether it contributes to the clinical effectiveness.

The effectiveness analysis set comprised of participants in the safety analysis set who had effectiveness evaluation (overall evaluation by the physician/investigator based upon change in clinical symptoms and laboratory findings) at least once. Participants with observed effectiveness data were included in table.

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by disease type were counted to assess whether it contributes to the clinical effectiveness.

* indicates "Associated Pulmonary Arterial Hypertension (APAH)". ** refers to "Pulmonary Veno Occlusive Disease/Pulmonary Capillary Hemangiomatosis".

The effectiveness analysis set comprised of participants in the safety analysis set who had effectiveness evaluation (overall evaluation by the physician/investigator based upon change in clinical symptoms and laboratory findings) at least once. Participants with observed effectiveness data were included in table.

Clinical effectiveness rate, which was defined as the percentage of participants who achieved clinical effectiveness over the total number of assessable effectiveness analysis population, was presented. Clinical effectiveness of sildenafil citrate was assessed as "effective," "ineffective" or "unassessable" by the physician/investigator. Overall effectiveness of sildenafil citrate was determined by the physician/investigator based on clinical symptoms, laboratory values, and other examinations such as echocardiogram. Participants achieved clinical effectiveness by severity (WHO functional classification of PAH;The grades range from Functional Class (FC) I, where the patient's disease does not affect their day-to-day activities, to FC IV, where patients are severely functionally impaired, even at rest. This functional classification system links) were counted to assess whether it contributes to the clinical effectiveness.

The effectiveness analysis set comprised of participants in the safety analysis set who had effectiveness evaluation (overall evaluation by the physician/investigator based upon change in clinical symptoms and laboratory findings) at least once. Participants with observed effectiveness data were included in table.