What are the indications and guidelines for right heart catheterization (RHC)?

Right Heart Catheterization: Indications and Guidelines

Primary Diagnostic Indications

Right heart catheterization (RHC) is mandatory to confirm the diagnosis of pulmonary arterial hypertension (Group 1 PAH) and must be performed before initiating treatment decisions. 1

Class I Indications (Must Perform)

• Confirming Group 1 PAH diagnosis - RHC is the gold standard for measuring pulmonary artery pressures and establishing the diagnosis of pulmonary arterial hypertension before any treatment is initiated 1, 2

• Chronic thromboembolic pulmonary hypertension (CTEPH, Group 4) - RHC is required to confirm diagnosis and guide treatment decisions including surgical candidacy 1

• Congenital cardiac shunts - RHC is necessary to support decisions regarding surgical correction, particularly to assess pulmonary vascular resistance and shunt hemodynamics 1

• Pre-transplant evaluation - RHC is mandatory in patients with PH due to left heart disease (Group 2) or lung disease (Group 3) when organ transplantation is being considered 1

• Heart failure with angina - Coronary angiography (left heart catheterization) should be performed as this combination strongly suggests revascularizable coronary disease 3, 4

Class IIa Indications (Should Consider)

• Assessing treatment response - RHC should be considered in Group 1 PAH to evaluate the effect of drug therapy 1

• Unreliable wedge pressure - When pulmonary artery wedge pressure (PAWP) measurements are unreliable, left heart catheterization should be performed to measure left ventricular end-diastolic pressure (LVEDP) directly 1

• Sickle cell disease with elevated TRJV - For patients with tricuspid regurgitant jet velocity ≥2.5 m/s plus reduced 6-minute walk distance and/or elevated NT-BNP, RHC should be performed to confirm PAH 1

• Acute heart failure with persistent symptoms - RHC is useful for carefully selected patients with uncertain fluid status, low systolic pressure despite treatment, worsening renal function, or requirement for parenteral vasoactive agents 3, 4

Class IIb Indications (May Consider)

• Differential diagnosis in Groups 2-3 PH - RHC may be considered in patients with suspected PH and left heart disease or lung disease to assist in differential diagnosis and support treatment decisions 1

Critical Procedural Requirements

All RHC procedures in patients with pulmonary hypertension must be performed at expert centers due to technical complexity and potential for serious complications. 1

Safety Considerations

• RHC should only be performed by experienced operators (median experience >450 procedures) to minimize complications 5

• Patients with severe left ventricular dysfunction (EF ≤35%) represent high-risk populations and should be studied as inpatients with prolonged monitoring available 3

• The overall complication rate is approximately 1.7% when performed by experienced operators, including carotid puncture, bradycardia, and heart block 5

• Major complications are uncommon but can include tricuspid valve injury, arteriovenous fistula formation, and rarely pulmonary hemorrhage 6

Hemodynamic Definitions

Pulmonary hypertension is defined as mean pulmonary artery pressure >20 mmHg (recently reduced from ≥25 mmHg). 1

PAH-Specific Criteria

For the diagnosis of pulmonary arterial hypertension, all three criteria must be met 1:

• Mean pulmonary artery pressure >20 mmHg
• Pulmonary artery wedge pressure ≤15 mmHg
• Pulmonary vascular resistance ≥3 Wood units (240 dyn·sec·cm⁻⁵)

Vasoreactivity Testing

Vasoreactivity testing is indicated ONLY in expert centers and ONLY for patients with idiopathic PAH, heritable PAH, or drug-induced PAH to identify candidates for high-dose calcium channel blocker therapy. 1

Testing Protocol

• Nitric oxide is the recommended agent for performing vasoreactivity testing 1

• Intravenous epoprostenol is an acceptable alternative 1

• Adenosine should be considered as an alternative option 1

• A positive response is defined as: reduction of mean PAP ≥10 mmHg to reach an absolute value ≤40 mmHg with increased or unchanged cardiac output 1

Critical Contraindications for Vasoreactivity Testing

• Do NOT perform vasoreactivity testing in PAH associated with connective tissue disease, portal hypertension, HIV, or congenital heart disease 1

• Do NOT perform vasoreactivity testing in PH Groups 2,3,4, or 5 1

• Oral or intravenous calcium channel blockers are contraindicated for acute vasoreactivity testing 1

When RHC is NOT Indicated

• Isolated elevated TRJV (2.5-2.9 m/s) without other risk factors - RHC is not recommended in sickle cell disease patients with isolated TRJV elevation 1

• Asymptomatic severe LV dysfunction - Patients with EF ≤35% without angina or high-risk features do not require routine catheterization 3

• Normotensive acute heart failure responding to diuretics - Routine invasive hemodynamic monitoring is not recommended in patients with symptomatic response to standard therapy 4

Common Pitfalls to Avoid

• Never perform RHC outside expert centers for pulmonary hypertension evaluation, as this is technically demanding and associated with serious complications when performed by inexperienced operators 1

• Do not use PAWP alone to exclude left heart disease - when measurements are unreliable, directly measure LVEDP with left heart catheterization 1

• Do not perform ambulatory catheterization in patients with NYHA class III-IV heart failure, severe pulmonary hypertension, or suspected active endocarditis 1, 3, 4

• Do not rely solely on echocardiography to diagnose PAH - RHC confirmation is mandatory before initiating PAH-specific therapies 1, 2