How do you interpret and manage results from a right heart catheterization (RHC)?

Interpretation and Management of Right Heart Catheterization Results

Right heart catheterization (RHC) should be performed in patients with suspected pulmonary hypertension who have elevated tricuspid regurgitant jet velocity (TRJV) ≥2.5 m/s on echocardiogram along with reduced 6-minute walk distance (6MWD) and/or elevated NT-proBNP levels. 1

Key Hemodynamic Parameters to Measure During RHC

• Essential components of RHC include measurement of right atrial pressure, right ventricular pressure, pulmonary artery pressure (systolic, diastolic, and mean), pulmonary arterial wedge pressure, cardiac output/index, and pulmonary vascular resistance 1
• Oxygen saturations from superior vena cava, inferior vena cava, right ventricle, pulmonary artery, and systemic artery should be obtained to evaluate for intracardiac shunts 1
• Cardiac output should be measured in triplicate, preferably by thermodilution or by the Fick method if oxygen consumption is assessed 1
• Measurements should be taken over 2-3 respiratory cycles at end-exhalation when intrathoracic pressure is closest to atmospheric pressure to reduce respiratory variation 1

Diagnostic Criteria for Pulmonary Hypertension

• Pulmonary hypertension (PH) is defined hemodynamically as a mean pulmonary artery pressure >20 mmHg (recently reduced from >25 mmHg) 1
• Pulmonary arterial hypertension (PAH) requires additional criteria: pulmonary artery wedge pressure ≤15 mmHg and pulmonary vascular resistance ≥3 Wood units (240 dyn × seconds × cm−5) 1
• A pulmonary artery wedge pressure >15 mmHg excludes the diagnosis of pre-capillary PAH and suggests left heart disease as the cause of PH 1

Management Based on RHC Results

For Patients with Sickle Cell Disease:

• For patients with sickle cell disease (SCD) who do not have PAH confirmed by RHC, PAH-specific therapies should not be used 1
• For patients with SCD and RHC-confirmed PAH, PAH-specific therapies should be considered under the care of a PH specialist 1
• A multidisciplinary approach (hematology, PH specialist, pulmonary medicine, cardiology) is recommended when considering PAH-specific therapies in SCD patients with confirmed PAH 1

For Patients with Valvular Heart Disease:

• RHC is indicated when pulmonary artery pressure is out of proportion to the severity of mitral regurgitation as assessed by noninvasive testing 1
• RHC with left ventriculography and hemodynamic measurements is indicated when there is a discrepancy between clinical and noninvasive findings regarding severity of valve disease 1

Safety and Complications

• When performed at experienced centers, RHC procedures have low morbidity (1.1%) and mortality (0.055%) rates 1
• The most frequent complications are related to venous access (hematoma, pneumothorax), followed by arrhythmias and hypotensive episodes related to vagal reactions or pulmonary vasoreactivity testing 1, 2
• Injury to the tricuspid valve is the most commonly reported catheter-related complication 2

Special Considerations

• Consultation with a cardiologist, pulmonologist, or PH expert is recommended when referring patients for RHC, interpreting results, and considering therapeutic options 1
• RHC should be based on echocardiograms obtained during steady state and not during acute illness 1
• For patients with TRJV ≥2.5 m/s who are asymptomatic, the addition of NT-proBNP and 6MWD testing may help improve diagnostic accuracy for PH 1
• For patients with TRJV ≥2.5 m/s who have normal 6MWD and NT-proBNP, serial noninvasive monitoring with echocardiograms should be considered 1
• Consultation with a PH expert regarding the need for RHC should be considered for patients with TRJV >2.9 m/s even with normal 6MWD and NT-proBNP 1

Pitfalls to Avoid

• Avoid performing RHC in asymptomatic patients with isolated TRJV elevation (2.5-2.9 m/s) without other supporting evidence of PH 1
• Do not rely solely on a single hemodynamic measurement; repeat measurements may be necessary due to spontaneous variability in pulmonary artery pressure 1
• Avoid inaccurate cardiac output measurements, which can compromise the ability to calculate pulmonary vascular resistance and interpret acute vasodilator testing 1
• Do not initiate PAH-specific therapy without confirmation of PAH by RHC, as this may lead to inappropriate treatment 1
• Recognize that the diagnostic accuracy of using TRJV ≥2.5 m/s on screening echocardiogram as the sole criterion for identifying PH is suboptimal and has a high false-positive rate 1