How does elevated right ventricular systolic pressure (RVSP) and a severely dilated left atrium affect eligibility for liver transplantation from a deceased donor or a live donor?

Impact of Elevated RVSP and Severely Dilated Left Atrium on Liver Transplant Eligibility

Elevated right ventricular systolic pressure (RVSP) and severely dilated left atrium significantly complicate both deceased donor and living donor liver transplantation eligibility, with severe pulmonary hypertension (mean PAP ≥35 mmHg or PASP ≥60 mmHg) representing a relative or absolute contraindication unless effectively controlled with medical therapy, while cardiac structural abnormalities require comprehensive evaluation to determine perioperative risk and candidacy. 1

Pulmonary Hypertension Assessment and Thresholds

Screening Requirements

• All liver transplant candidates must undergo screening echocardiography to identify pulmonary hypertension and assess cardiac structure, including left atrial size. 1
• Doppler echocardiography serves as the initial screening tool, but any PASP ≥45 mmHg on noninvasive testing should trigger confirmatory right heart catheterization due to the margin of error in echocardiographic measurements. 1

Critical Thresholds for Transplant Eligibility

• Severe pulmonary hypertension defined as mean pulmonary artery pressure >35 mmHg or PASP ≥60 mmHg is associated with markedly increased perioperative mortality and represents a contraindication to transplantation unless the condition can be effectively controlled with medical therapy. 1
• Patients with moderate pulmonary hypertension (PASP 45-59 mmHg) face increased but potentially acceptable risk if hemodynamics can be optimized preoperatively. 1
• The presence of elevated RVSP suggests underlying pulmonary hypertension that requires definitive hemodynamic assessment via right heart catheterization to measure mean PAP, pulmonary capillary wedge pressure, and pulmonary vascular resistance. 1

Left Atrial Dilation Considerations

Cardiac Structural Assessment

• A severely dilated left atrium indicates chronic left-sided cardiac dysfunction, volume overload, or valvular disease—all of which increase perioperative cardiovascular risk. 2
• Candidates with severely dilated left atrium require comprehensive cardiac evaluation including assessment of left ventricular ejection fraction, diastolic function, and exclusion of significant valvular disease. 1
• Volume-mediated pulmonary hypertension is particularly relevant in liver transplant candidates, as rapid intraoperative volume shifts can precipitate acute pulmonary hypertension in patients with underlying left ventricular dysfunction or elevated baseline pulmonary capillary wedge pressure. 3

Risk Stratification

• Patients with left atrial dilation who develop volume-dependent pulmonary hypertension have 2-fold higher baseline pulmonary capillary wedge pressure and are at increased risk for perioperative complications. 3
• If left ventricular ejection fraction is <50%, or there is evidence of ischemic left ventricular dilation, exercise-induced hypotension, or demonstrable ischemia, referral to cardiology for optimization is mandatory before transplant listing. 1

Deceased Donor Transplantation Eligibility

Absolute and Relative Contraindications

• Severe pulmonary hypertension that cannot be medically controlled represents a relative to absolute contraindication for deceased donor liver transplantation due to prohibitively high perioperative mortality. 1
• Patients must undergo medical optimization with pulmonary vasodilators (prostacyclins, endothelin receptor antagonists, phosphodiesterase-5 inhibitors) with documented hemodynamic improvement on repeat right heart catheterization before listing. 1

Preoperative Optimization Protocol

• Pulmonary artery catheter placement is recommended the day before surgery to measure real-time hemodynamics and guide perioperative management. 4
• Advanced intra- and postoperative hemodynamic monitoring plus transesophageal echocardiography is strongly recommended for recipients with significant cardiac disease. 2

Living Donor Liver Transplantation Considerations

Ethical and Safety Framework

• Living donor liver transplantation (LDLT) in patients with elevated RVSP and cardiac structural abnormalities raises significant ethical concerns regarding the "double equipoise" principle—the donor's risk must be justified by a reasonable expectation of recipient survival benefit. 1, 5
• LDLT must be restricted to centers of excellence with extensive experience in managing high-risk recipients, as donor safety cannot be compromised regardless of recipient need. 1, 6

Advantages in Selected Cases

• For carefully selected patients with optimized pulmonary hypertension, LDLT offers the advantage of elective timing, allowing for maximal medical optimization and use of a superior quality graft with minimal ischemia time. 4
• The ability to perform LDLT electively permits admission 24 hours prior to surgery for pulmonary artery catheter placement, hemodynamic optimization, and multidisciplinary team assessment of fitness for transplant. 4

Specific Requirements for LDLT Candidacy

• Pulmonary arterial hemodynamics must be optimized with documented improvement on medical therapy before considering LDLT. 4
• Right ventricular function must be preserved, as right heart failure perioperatively carries extremely high mortality. 4
• A multidisciplinary team including hepatology, cardiology, pulmonology, and transplant surgery must unanimously agree on candidacy after reviewing the most current clinical data. 4

Perioperative Risk Factors

Increased Complications

• Patients with cardiac structural abnormalities and pulmonary hypertension face higher rates of postreperfusion syndrome, characterized by severe hemodynamic instability, bradycardia, and potential cardiac arrest. 7
• Volume shifts during liver transplantation can precipitate acute decompensation in patients with underlying left ventricular dysfunction or elevated baseline filling pressures. 3
• The combination of elevated RVSP and left atrial dilation suggests biventricular dysfunction or significant valvular disease, both associated with increased perioperative mortality. 2

Common Pitfalls to Avoid

• Do not rely solely on echocardiographic estimates of pulmonary pressure—any PASP ≥45 mmHg requires confirmatory right heart catheterization with full hemodynamic assessment. 1
• Avoid listing patients with severe pulmonary hypertension without documented response to medical therapy, as perioperative mortality is unacceptably high. 1
• Do not proceed with LDLT in patients with significant cardiac disease without extensive multidisciplinary discussion and clear documentation that recipient survival benefit justifies donor risk. 1, 5
• Recognize that left atrial dilation may indicate occult coronary artery disease or valvular pathology requiring further investigation before transplant clearance. 1

Practical Algorithm for Evaluation

1. Initial screening: Perform transthoracic echocardiography on all candidates to assess RVSP, left atrial size, left ventricular function, and valvular disease. 1

2. If RVSP elevated (≥45 mmHg) or left atrium severely dilated: Proceed to right heart catheterization to measure mean PAP, PCWP, and calculate pulmonary vascular resistance. 1

3. If mean PAP >35 mmHg or severe left ventricular dysfunction: Initiate medical optimization with pulmonary vasodilators and/or cardiac medications, then reassess with repeat catheterization. 1, 4

4. If hemodynamics improve to acceptable range: Consider listing for deceased donor transplantation with plan for intensive perioperative monitoring, or evaluate for LDLT at experienced center with multidisciplinary approval. 4

5. If hemodynamics remain severely abnormal despite maximal therapy: Patient is not a transplant candidate due to prohibitive perioperative mortality risk. 1