Fontan Patients with a Systemic Left Ventricle Have Greater Exercise Capacity than those with a Systemic Right...

Area of Science:

• Cardiology
• Exercise Physiology
• Congenital Heart Disease

Background:

• Cardiopulmonary exercise testing (CPET) is crucial for assessing functional capacity and prognosis in Fontan circulation patients.
• Systemic ventricular morphology (left vs. right ventricle) may significantly influence the interpretation of CPET results in this population.

Purpose of the Study:

• To systematically review and conduct a meta-analysis on the impact of systemic ventricular morphology on CPET outcomes in Fontan circulation.
• To compare exercise performance metrics between Fontan patients with a systemic left ventricle (SLV) and those with a systemic right ventricle (SRV).

Main Methods:

• Systematic literature search of PubMed, Embase, and Cochrane databases up to December 2024.
• Inclusion criteria: Fontan circulation, CPET (treadmill/cycle ergometer), and outcomes stratified by systemic ventricle.
• Extracted outcomes included peak VO2, O2-pulse, VE/VCO2 slope, and VO2 at anaerobic threshold (VAT); analyzed using a random-effects model.

Main Results:

• Twenty-seven studies (2972 participants) met inclusion criteria, with most having low risk of bias.
• Fontan patients with SLV demonstrated superior exercise performance compared to those with SRV across all metrics.
• Key findings include higher peak VO2 (% predicted), greater O2-pulse, higher VO2 at VAT, and a lower VE/VCO2 slope in SLV patients.

Conclusions:

• Systemic ventricular morphology significantly impacts CPET outcomes in Fontan circulation, with SLV associated with better exercise performance.
• These findings necessitate careful consideration of ventricular morphology when interpreting CPET results in Fontan patients.
• Further prospective research is recommended to explore the influence of ventricular morphology on long-term outcomes like transplant timing and mortality.