Impact of the Rudimentary Chamber on Outcomes in Fontan Patients

• Published in: World journal for pediatric & congenital heart surgery 2024-05, Vol.15 (3), p.270-276
• Main Authors: Miwa, Koji, Tsumura, Sanae, Kanaya, Tomomitsu, Kido, Takashi, Tominaga, Yuji, Kawai, Shota, Teguri, Yuta
• Format: Article
• Language: English
• Subjects: Adolescent; Cardiac Catheterization; Child; Child, Preschool; Exercise Tolerance - physiology; Female; Follow-Up Studies; Fontan Procedure; Heart Defects, Congenital - surgery; Heart Ventricles - abnormalities; Heart Ventricles - physiopathology; Heart Ventricles - surgery; Humans; Male; Retrospective Studies; Treatment Outcome
• ISSN: 2150-1351; 2150-136X
• DOI: 10.1177/21501351241227882

Background: We sought to evaluate the influence of the rudimentary ventricle on long-term outcomes after the Fontan operation, focusing on exercise capacity and cardiac performance. Methods: Between 1995 and 2021, 290 patients underwent a total cavopulmonary connection. “Two-ventricle” Fontan circulation was defined as a rudimentary ventricle >30% of the dominant ventricle or >50% of its predicted normal value. This cohort was compared with patients with single-ventricle Fontan circulation. The primary endpoint was Fontan failure, and the secondary endpoints were VO2 and cardiac catheterization data at ten years postoperatively. Results: The median follow-up after the Fontan operation was 7.9 years (interquartile range: 1.9-13.9). No significant difference was found in Fontan failure-free survival between the “two-ventricle” Fontan circulation group and the single-ventricle Fontan circulation group (83/91, 93% vs 156/199, 78%), respectively at 20 years; P = .11). No significant difference was found in VO2 or cardiac performance except cardiac index, with 2.9 (2.3-4.8) versus 2.5 (2.3-4.3) L/min/m2 (P = .047). Fifty-one patients in the “two-ventricle” Fontan circulation group were followed up for over ten years after the Fontan operation. In the subgroup analysis of this cohort, the rudimentary ventricular end-diastolic volume/dominant ventricular end-diastolic volume ratio showed a significant positive correlation with dominant ventricular end-diastolic pressure (r = 0.58 [95% CI 0.35-0.74], P = .002) and a significant negative correlation with VO2 (r = −0.61 [95% CI −0.80 to −0.28], P = .001). Conclusions: The rudimentary ventricle was not significantly associated with any clinical disadvantages regarding Fontan failure. However, a large rudimentary ventricle was significantly associated with higher end-diastolic pressure and lower exercise capacity.