The World Symposium on Pulmonary Hypertension (WSPH) convenes every 5 years to discuss updates in the field. The symposium is designed to create guidelines to improve clinical practice and to standardize both pathologic and clinical definitions. A consensus on standard of care therapy is difficult in an orphan disease but these guidelines help physicians better treat their patients. Noteworthy, it provides perspectives of future investigations.
During the 5th WSPH held in Nice, France, in 2013, the following points might be emphasized:
1.- The definition of PH did not change, defined as a mean pulmonary artery pressure (mPAP) ≥ 25 mmHg and wedge pressure ≤ 15 mmHg. The cutoff of mPAP 25 mmHg was chosen as was the valued used in all clinical trials and previous PAH registries. Pulmonary vascular resistance (PVR) will not be included, as was in Dana Point1.
2.-Exercise-induced PH remains controversial. Abnormal exercise-induced pulmonary pressures could allow for an earlier diagnosis of PH, but thus far, there is not conclusive evidence of a universal abnormal threshold in mPAP. Studies showed that in younger persons, < 50 years, mPAP ~ 35 mmHg can be considered normal during exercise2. More importantly, in contrast to pressures at rest, mPAP during exercise is largely age-dependent, presumably as a result of increasing stiffness of the left ventricle and the pulmonary vessels and mPAP ~ 30 mmHg during mild exercise have been seen in 50% of apparently healthy subjects aged > 50 yrs. The definition of a “normal” value for the wedge with exercise is also still debated. Without the appropriate data and consensus, no recommendation could be made on exercise hemodynamics.
3.-The general scheme of previous clinical classifications in five groups was maintained, with some updates and modifications, especially related to group 1 patients:
a) Persistent PH of the newborn (PPHN) has been withdrawn from Group 1 (PAH) because this entity carries more differences than similarities with other PAH subgroups. In the current classification, PPHN is designated 1.
b) In agreement with the pediatric classification3, congenital or acquired left-heart inflow/outflow obstructive lesions and congenital cardiomyopathies have been added to Group 2.
c) Pulmonary hypertension associated with chronic hemolytic anemia (sicle cell disease) appears significantly different from other forms of PAH in regard to pathological findings, hemodynamic characteristics, and response to PAH-specific therapies. Therefore, PH associated with sickle cell disease was moved from Group 1 (PAH) to Group 5 (unclear multifactorial mechanisms).
These guidelines provide current evidence, research gaps, and recommendations on pulmonary hypertension classification.
Of note, this updated clinical classification was the first to consider at the same time adult and pediatric patients. Groups 2, 3 and four remained unchanged.
In conclusion, the fifth WSPH provided the cutting-edge knowledge in the different fields of PH.
Corresponding author from original paper
Dr. Gérald Simonneau,
Department of Pneumology and ICU, University Hospital Bicêtre, AP-HP, 78 Avenue du Général Leclerc 92275, Le Kremlin Bicêtre, France.
1.- Galie N, Hoeper MM, Humbert M, et al. Guidelines on the diagnosis and treatment of pulmonary hypertension. Eur Heart J 2009; 34: 1219-1263.
2.- Kovacs G, Berghold A, Scheidl S,et al. Pulmonary arterial pressure during rest and exercise in healthy subjects: a systematic review. Eur Respir J 2009; 34: 888-894.
Gomberg-Maitland M, Dufton C, Oudiz R, et al. Compelling evidence of long-term outcomes in pulmonary arterial hypertension? J Am Coll Cardiol 2011;57:1053-1061
3- Ivy D, Abman SH, Barst RJ, et al. Pediatric pulmonary hypertension. J Am Coll Cardiol 2013;62 Suppl:D118–27.
Citation: Simonneau G, Gatzoulis MA, Adatia I, Celermajer D, Denton C, Ghofrani A, Gomez Sanchez MA, Krishna Kumar R, Landzberg M, Machado RF, Olschewski H, Robbins IM, Souza R.. Updated Clinical Classification of Pulmonary Hypertension J Am Coll Cardiol. 2013;62(25 Suppl):D34-41