Pujol C, Schiele S, Maurer SJ, Hock J, Fritz C, Hager A, Ewert P, Tutarel O.
J Clin Med. 2020 Dec 18;9(12):4085. doi: 10.3390/jcm9124085.
PMID: 33352831 Free PMC article
Take Home Points:
- Patients over 40 years with single ventricular physiology are burdened with morbidity and mortality.
- This group of patients frequently has arrhythmia and required cardioversion, pacemakers, or antiarrhythmic medications.
- The presence of renal disease is associated with mortality.
Commentary from Dr. M.C. Leong (Kuala Lumpur, Malaysia), section editor of ACHD Journal Watch: The survival of single ventricular hearts has improved over the years owing to improved surgical techniques, understanding of the underlying physiology and follow-up care. However, the long-term morbidities and mortality remain unresolved and is largely due to the limitations of the Fontan circulation. These morbidities become more evident as the patients age.
In this article, Pujol and colleagues reported on the outcome data from their cohort of patients with single ventricle physiology above the age of 40 years. In this cohort, 49 patients (19 female, mean age 49.2 ± 6.4 years, median follow up duration: 4.9 years, IQR: 1.8–8.5) were identified. Baseline characteristics were as tabulated in Table 1.
Strikingly, although over 80% of these patients were in NYHA functional class I-II, 35 (71.4%) of patients had a prior hospital admission for heart failure. Many of them were plagued with comorbidities. Arrhythmias were a frequent challenge. 23 (53%) of these patients had lost sinus rhythm; amongst them, 13 patients required pacemakers. Another 8 patients required pacemakers during the follow-up period. On follow-up, 9 (18.4%) of patients underwent electrophysiological procedures. Cardioversion was required in 20 (40.8%) patients, amongst them, 14 patients required multiple episodes of cardioversion. In relation to the frequency of atrial arrythmias, the type of Fontan circulation was not specified (Atriopulmonary, lateral tunnel or extra-cardiac conduit). Arrhythmias in patients with severely dilated atria are notoriously difficult to control and often they affect the quality of lives of these patients despite medications.
During the follow-up, there were 10 (20.4%) mortalities. The authors subsequently analysed the factors associated with death in this cohort (Table 2). On univariate analysis, renal disease and liver cirrhosis were predictors of all-cause mortality. However, on multivariate analysis, only renal disease (HR: 12.5, 95% CI: 1.5–106.3, p = 0.021) remained as an independent predictor (Figure 1). End organ damage has commonly been found to be a good surrogate marker for disease progression. The cause for end organ damage may be attributed to the chronic elevation of systemic venous pressure, low perfusion to the end organs due to chronic heart failure and possibly, repeated episodes of end organ injuries during acute heart failure which may be triggered by acute arrhythmias, surgeries or infections. Renal disease is a useful predictor of mortality and thus aids in the planning of follow-up and risk stratification of these patients.
In summary, this is a study looking at the outcome of a special cohort of older patients with Fontan palliation. Although this data highlights the burden of morbidities and mortality, it is difficult to draw the same conclusion to the younger cohort who has mostly undergone the extracardiac type of Fontan palliation which, hopefully, has a low burden of arrhythmia. On the other hand, this younger cohort of Fontan population may have a poorer substrate i.e., heterotaxies and hypoplastic left heart syndromes, which may give rise to a different set of morbidities and mortality risk.