Blood pressure in adults with a functionally univentricular circulation who underwent either a Fontan procedure or a total cavo-pulmonary connection in childhood. A systematic review and meta-analysis.

BACKGROUND

Adults with a Fontan procedure or total cavo-pulmonary connection (TCPC) have been shown to have abnormalities in their microcirculation (capillary rarefaction) and increased aortic stiffness. These are also a hallmark of essential hypertension. It remains unclear whether the blood pressure of Fontan patients differs from the general population. Therefore, we undertook a systematic review and meta-analysis in Fontan patients comparing blood pressure against healthy controls.

METHODS

A systematic search of peer-reviewed publications for "Fontan adults" studies, including patients >=16 years of age, with a previous Fontan/TCPC and containing blood pressure data for both Fontan adults and controls, was included. The trial strategy was registered in PROSPERO (CRD42022355781). MEDLINE, Embase, and Cochrane (CENTRAL) database searches yielded 2168 records. Heterogeneity was assessed with Higgins I2 statistic with a value >50% indicative of high heterogeneity and P values based on Cochran's Q test. A random-effects model was used to calculate the pooled effect size.

RESULTS

Eleven studies contained sufficient blood pressure data from 544 Fontan/TCPC adults. Their weighted mean systolic and diastolic blood pressure was 114 ± 14 mmHg and 69 ± 9 mmHg. Only four (130 patients) studies, were suitable for meta-analysis. Weighted mean difference in systolic BP was -1.36 mmHg (95% CI, -9 to 6.38) and in diastolic BP was +0.89 mmHg (95% CI, -2.92 to 4.70) between Fontan/TCPC patients and controls. A high level of heterogeneity in both SBP (P < 0.00001) and DBP (P < 0.003) was noted.

CONCLUSION

Neither systolic nor diastolic blood pressure in adults with a Fontan circulation differ from healthy controls. Overall weighted means of blood pressure were comparable for similar age groups. Arterial hypertension does not appear to explain the capillary rarefaction and aortic stiffness found in adults with a Fontan procedure or total cavo-pulmonary connection. Further studies are required to explore other causes of their vascular remodelling.