What can my family member do to live a longer life with pulmonary hypertension?

Pulmonary HTN. It truly depends on the cause of pulmonary htn. If it is idiopathic (no clear cause) they should be referred to a pulmonologist (or cardiologist) that is comfortable treating it. The treatments are somewhat new and not all specialists are comfortable treating it.
Living with PH. Pulmonary hypertension (ph) has a variety of causes and the life expectancy may depend on the cause. Your relative should speak to their physician regarding specific therapies for ph. General recommendations may include ph medications, diuretics, salt and fluid restriction, and oxygen if the blood oxygen levels are low. Bottom line, encourage your family member to work with their doctor.
PH Center. Your relative should be treated in a ph center. This field is changing very rapidly and there are new medications that your relative can be treated with.