Effect of cardiopulmonary bypass reoxygenation on myocardial dysfunction following pediatric tetralogy of Fallot repair.

BACKGROUND: Little is known regarding the effect of cardiopulmonary bypass (CPB) reoxygenation on cardiac function following tetralogy of Fallot repair. We hypothesized that hyperoxic reoxygenation would be more strongly associated with myocardial dysfunction in children with tetralogy of Fallot. METHODS: We investigated the association of perfusate oxygenation (PpO2) associated with myocardial dysfunction among children aged 6-72 months who underwent complete repair of tetralogy of Fallot in 2012-2018. Patients were divided into two groups: lower PpO2 group (≤ 250 mmHg) and higher PpO2 (> 250 mmHg) group based on the highest value of PpO2 during aortic occlusion. The odd ratio (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression models. RESULTS: This study included 163 patients perfused with lower PpO2 and 213 with higher PpO2, with median age at surgery 23.3 (interquartile range [IQR] 12.5-39.4) months, 164 female (43.6%), and median body mass index 15.59 (IQR 14.3-16.9) kg/m2. After adjustment for baseline, clinical and procedural variables, patients with higher PpO2 were associated with higher risk of myocardial dysfunction than those with lower PpO2 (OR 1.770; 95% CI 1.040-3.012, P = 0.035). Higher PpO2, lower SpO2, lower pulmonary annular Z-score, and longer CPB time were independent risk factors for myocardial dysfunction. CONCLUSIONS: Association exists between higher PpO2 and myocardial dysfunction risk in patients with tetralogy of Fallot, highlighting the modulation of reoxygenation during aortic occlusion to reduce cardiovascular damage following tetralogy of Fallot repair. TRIAL REGISTRATION: Clinical Trials. gov number NCT03568357. June 26, 2018.

Association of perfusate oxygenation with cardiovascular disorder in tetralogy of fallot children: A nested case-control study.

BACKGROUND: Little is known regarding whether hyperoxic reoxygenation was associated with higher risk of cardiovascular disorder following tetralogy of Fallot repair. METHODS: We performed a nested case-control study among patients aged 1 month-18 years undergoing complete repair of tetralogy of Fallot in 2012-2018. We measured the highest perfusate oxygenation (PpO2) during aortic occlusion in 107 cardiovascular disorder cases and in 321 controls matched 1:3 to the cases on date of surgery, sex, and area of residence. We analyzed the association between PpO2 and outcome using multivariable conditional logistic regression adjusted for covariates. We further identified and integrated the risk covariates to build prediction nomograms. RESULTS: Cases had higher percentage of exposure to PpO2 > 200 mmHg (86.0% vs. 76.1%, p = .019) than controls. Patients with PpO2 > 200 mmHg had an increased risk of cardiovascular disorder compared to those with PpO2 ≤ 200 mmHg (odd ratio [OR] = 2.075, 95% confidence interval [CI] = 1.035, 4.158, p = .039) adjusted for matching, clinical and procedural covariates. Categorical PpO2, lower body mass index, lower SpO2, untreated minor aortopulmonary collateral arteries, high immediately postoperative central venous pressure, and longer cardiopulmonary bypass time were independent risk factors for cardiovascular disorder (all p < .05). Combining PpO2 nomogram slightly improved discrimination compared with covariate-based nomogram alone for training cohort (area under receiver operating characteristic curve [AUC] = 0.768 vs. 0.761) and for internal validation (AUC = 0.759 vs. 0.753). CONCLUSION: Our findings suggest association exists between high PpO2 during aortic occlusion and cardiovascular disorder risk, and nomogram integrating clinical and procedural factors may be useful in management of patients with tetralogy of Fallot.