The prevalence of mild PR among patients with normal anatomy of the pulmonary valve is 40% to 78%. Among patients born with congenital heart disease, 20% of patients have associated abnormalities of the pulmonary valve or the right ventricular outlet obstruction. The incidence and prevalence of PR increases with age. 24% of the deaths due to valvular heart disease are attributed to tricuspid valve and pulmonic valve abnormalities combined. There is one study supporting the increased prevalence of PR among women. In developing countries Pulmonary hypertension (PAH) is primarily due to rheumatic heart disease (RHD) which is rare in developed countries. PAH is a major cause of secondary PR.

• The prevalence of valvular heart disease in U.S. population is estimated to be 2.5%. About 13% of U.S population born before 1943 have valvular heart disease.^{_cdc.gov-1|[1]}
• The prevalence of mild PR among patients with normal anatomy of the pulmonary valve is 40% to 78%.^[2][3][4][5]
• In 1987, the prevalence of PR among patients with structurally normal hearts was estimated to be 5% in Boston area population, USA.^[2]
• In 1990, the prevalence of PR among normal patients (21 – 82 years) was estimated to be 31%.^[5]
• In 1992, the prevalence of PR among children (birth- 14 years) with structurally normal hearts was estimated to be 21.9% in Jerusalem, Israel population. Pulmonic regurgitation was the most common of all valvular regurgitations detected among children.^[6]
• In 1993, the prevalence of rheumatic fever in the developing countries was estimated to be 18.6/1000.^[7] Rheumatic fever is still a significant cause of PR in developing countries.
• There is a 50% chance of cardiac involvement in carcinoid syndrome.^[8] A large US case series on carcinoid syndrome reported that 81% of individuals demonstrated PR. ^[9]

• Among patients born with congenital heart disease, 20% of patients have associated abnormalities of the pulmonary valve or the right ventricular outlet obstruction.^[2]
• Rheumatic heart disease (RHD), a rare cause of PR in developed countries but developing world still shares the burden of the disease.
  • In 1989, the incidence rate of rheumatic fever in developing countries was estimated to be 100 per 100,000 young individuals.^[10]
  • In 1993, the incidence rate of rheumatic fever in the developing countries was estimated to be 206/100,000.^[7]
  • In 2013, 120 deaths were attributed to RHD in a referral cardiac center of northern India (Patna).^[11]
• Among patients with mechanical heart valves, the incidence of major thromboembolic events has been estimated to be approximately:
  • In the absence of antithrombotic therapy, 4 per 100 patient-years.^[12]
  • In the absence of systemic anticoagulation, 23 per 100 patient-years.^[13]

• In 2017, CDC reported that 24% of deaths due to valvular heart disease were attributed to tricuspid valve and pulmonic valve abnormalities combined.^{_cdc.gov-1|[1]}

• The prevalence of pulmonary regurgitation (PR) is estimated to have two demographic peaks. The first peak is among young patients with repaired congenital pulmonary stenosis. The second peak is among patients with pulmonary arterial hypertension (PAH).^[14] The multitude of causes makes the determination of exact prevalence of PR difficult.^{_Radiology_Reference_Article_|_Radiopaedia.org-15|[15]}
• In the U.S population, the prevalence of valvular heart disease is higher among older adults.^{_cdc.gov-1|[1]}
• In 1989, a meta‐analysis reported that 29% of the patients with isolated congenital PR develop symptoms within 40 years. The risk of development of symptoms demonstrated an increase with age, particularly after 40 years.^[16]
• In 1990, the incidence of mild degree valvular regurgitation in normal subjects was estimated to increase with age.^[5]
• In 2017, the incidence of PR among Tibetans (one of the highest cities in the world) was speculated to increase with age.^[17]
• Carcinoid symptoms typically appear at a mean age of 55–60 years and usually takes 2 years before symptoms due to valvular disease develop.^[8]

• There is no racial or ethnic predilection for pulmonary regurgitation.

• In 2017, Pulmonic regurgitation (PR) was speculated to be more prevalent among Tibetan women.^[17]

• Among developed countries such as the United States, Pulmonary hypertension (PAH) is primarily due to left heart disease. Other conditions that cause PAH include sickle cell disease; pulmonary embolus, and chronic obstructive pulmonary disease (COPD).^{_NHLBI,_NIH-18|[18]} PAH is a major cause of secondary PR.
• Rheumatic heart disease (RHD) is not a common cause of PAH or PR among developed countries. Due to the early detection and development of treatment strategies RHD is rare among developed countries.^[19][20]

• Among developing countries Pulmonary hypertension (PAH) is primarily due to rheumatic heart disease (RHD), schistosomiasis, congenital heart disease, hemolytic diseases. PAH is a major cause of secondary PR. The burden of PAH is greater among developing than developed countries.^[19][21]