Newest Pulmonary Hypertension Criteria Based on Echocardiography
According to the 2015 ESC/ERS guidelines, pulmonary hypertension probability is assessed using tricuspid regurgitation velocity (TRV) measurements and additional echocardiographic variables, with PH considered "likely" when TRV exceeds 3.4 m/s (corresponding to PA systolic pressure >50 mmHg). 1
Primary Diagnostic Criteria
Echocardiographic probability of PH is graded based on tricuspid regurgitation velocity (TRV) at rest and the presence of additional echocardiographic variables 1:
PH unlikely: TRV ≤2.8 m/s, PA systolic pressure ≤36 mmHg, and no additional echocardiographic variables suggestive of PH 1
PH possible: Either TRV ≤2.8 m/s with additional echocardiographic variables suggestive of PH, or TRV 2.9-3.4 m/s (PA systolic pressure 37-50 mmHg) with/without additional variables 1
PH likely: TRV >3.4 m/s, PA systolic pressure >50 mmHg, with/without additional echocardiographic variables 1
Additional Echocardiographic Signs
Signs from at least two different categories (A/B/C) should be present to alter the level of echocardiographic probability of PH 1:
Category A: The ventricles
Category B: Pulmonary artery
Category C: Inferior vena cava and right atrium
Clinical Application and Management
The recommended management based on echocardiographic probability of PH in symptomatic patients 1:
Low probability: Alternative diagnosis should be considered (without risk factors) or echocardiographic follow-up (with risk factors) 1
Intermediate probability: Alternative diagnosis and echocardiographic follow-up should be considered (without risk factors) or further assessment including right heart catheterization (RHC) should be considered (with risk factors) 1
High probability: Further investigation including RHC is recommended regardless of risk factors 1
Important Considerations
Exercise Doppler echocardiography is not recommended for screening of PH (Class III recommendation) 1
Right heart catheterization remains the gold standard for definitive diagnosis of PH 3, 4
The newest definition of PH has been revised to include patients with mean pulmonary artery pressure >20 mmHg (lowered from the previous threshold of 25 mmHg) measured by right heart catheterization, with pulmonary vascular resistance >2.0 Wood units also used for diagnosis 4
When TRV is technically difficult to measure, contrast echocardiography may improve the Doppler signal 1
Echocardiographic estimation of pulmonary pressures may be inaccurate in individual patients, particularly in those with severe tricuspid regurgitation where TRV may be significantly underestimated 1
Advanced echocardiographic techniques including 3D assessment of the right ventricle, RV free wall strain, and right atrial strain may provide additional prognostic information 3, 5
Pitfalls to Avoid
Do not rely solely on TRV or estimated PASP for diagnosis; consider the full clinical context and additional echocardiographic variables 1, 5
Avoid using a fixed value of 5 or 10 mmHg for RAP when calculating PASP; instead, estimate RAP based on IVC diameter and collapsibility 1
Do not use echocardiography alone to rule out PH when clinical suspicion is high; right heart catheterization is required for definitive diagnosis 3, 6
Be aware that PH cannot be reliably defined by a single cut-off value of TRV, and Doppler-derived pressure estimation may be inaccurate in individual patients 1