PH Care Centers

Diagnostic Shortcomings Due to Lack of Awareness and Adherence to Diagnostic Algorithm

Despite advances in diagnostic technology and targeted treatment options, pulmonary arterial hypertension (PAH) continues to suffer from both under-diagnosis and misdiagnosis.

As a rare disease with a prevalence of approximately 15-25 cases per million people, PAH remains under-appreciated in the medical community. Delays in diagnosis are also due to the non-specific nature of presenting symptoms, such as:

  • Dyspnea
  • Dizziness
  • Angina pectoris
  • Syncope and near-syncope
  • Edema
  • Cough

Lack of awareness leads to nearly three out of four patients being delivered a PAH diagnosis with very advanced symptomatology (New York Heart Association Functional Class III or IV):

Late Diagnosis Graph 4

Late diagnosis is not a new phenomenon. The percentage of patients being diagnosed in NYHA/WHO Functional Class III and IV has remained around 70 percent since the 1980’s according to a comparison of several patient registries1,2,3.

PHCC Functional Class Presentation

This delay in diagnosis is not inconsequential. Advanced functional class has correlated to significantly worse patient outcomes when studied longitudinally4.

Despite advances in diagnosic technology and targeted treatment options, evidence-based diagnostic algorithms are not consistantly followed.

To ensure the correct diagnosis is made and the primary cause of the patient’s elevated pulmonary vascular resistance identified, an evidence-based diagnostic algorithm must be followed. There are many nuances to interpreting the results, which requires expertise and a well-trained, multidisciplinary team.

Evidence shows that this algorithm is not being consistantly followed, leading to an increased risk of misdiagnosis and mismanagement.

For example, analysis of the QuERI project revealed the following proportions on tests, recommended by multiple evidence-based diagnostic algorithms, that were not completed at study baseline5.

Essential Blood Work 1.8%
Echocardiogram 3.3%
Right Heart Catheterization 9.0%
Chest X-ray 11.7%
Pulmonary Function Tests 16.9%
ECG 18.3%
Exercise Capacity 21.0%
Ventilation/Profusion (V/Q) Scan 42.7%
Oximetry 58.5%

Patients referred to PH center are frequently received with misdiagnoses

A recent study, the multicenter RePHerral study, demonstrates the volume of pulmonary arterial hypertension (PAH) misdiagnosis in the medical community. In an analysis of PH referrals to three tertiary care centers, fifty-one percent of patients had a change in diagnosis after a complete, evidence-based workup by the receiving center6. Thirty percent of patients were being received by the tertiary care centers already on PAH-targeted therapy and, after full workup, forty-five percent of those on Group 1 PAH-targeted therapy were classified as “non-Group 1”6.

Reclassification of patients referred to tertiary care centers on PAH-targeted therapies after workup by the receiving center
Group 1 55%
Group 2 14%
Group 3 21%
Group 4 2%
No PH 7%
1 – Badesch DB, Raskob GE, Elliott CG, Krichman AM, et al. Pulmonary Arterial Hypertension: Baseline Characteristics from the REVEAL Registry. Chest. 2010 Feb; 137(2):376-87. doi: 10.1378/chest.09-1140.
2 – Humbert M, Sitbon O, Chaouat A, Bertocchi M, et al. Pulmonary Arterial Hypertension in France: Results from a National Registry. Am J Respir Crit Care Med. 2006 May 1; 173(9):1023-30. doi: 10.1164/rccm.200510-16680C.
3 – Rich S, Dantzker DR, Ayres SM, Bergofsky EH, et al. Primary Pulmonary Hypertension. A National Prospective Study. Ann Intern Med. 1987 Aug;107(2):216-23. doi: 10.7326/0003-4819-107-2-216.
4 – Humbert M, Sitbon O, Chaouat A, Bertocchi M, et al. Survival in Patients with Idiopathic, Familial, and Anorexigen-Associated Pulmonary Arterial Hypertension in the Modern Management Era. Circulation. 2010 Jul 13; 122(2):156-63. doi: 10.1161/CIRCULATIONAHA.109.911818.
5 – McLaughlin VV, Langer A, Tan M, Clements PJ, et al. Contemporary Trends in the Diagnosis and Management of PAH: An Initiative to Close the Care Gap. Chest. 2013;143(2):324-32. doi: 10.1378/chest.11-3060.
6 – Deaño RC, Glassner-Kolmin C, Rubenfire M, Frost A, et al. Referral of Patients with Pulmonary Hypertension Diagnoses to Tertiary Pulmonary Hypertension Centers: The Multicenter RePHerral Study. JAMA Intern Med. 2013;173(10)887-893. doi: 10.1001/jamainternmed.2013.319.