Moustafa, Amr

BACKGROUND: Fontan conversion (FC) is associated with a lower risk of atrial arrhythmias and thromboembolism, but it is unknown whether FC improves long-term survival. The purpose of this study was to assess the impact of FC on transplant-free survival. METHOD: Adults with Fontan palliation were divided into 3 groups: (1) atriopulmonary Fontan connection; (2) atriopulmonary Fontan and subsequent FC to total cavopulmonary connection (TCPC); (3) TCPC at initial Fontan operation. The risk of death/transplant was compared between the 3 groups using Cox regression analysis. RESULTS: We studied 534 patients (age 27±9 years; males [N=298; 56%]). Patients were divided into atriopulmonary Fontan group (N=199, 37%); FC-TCPC (N=138, 26%); and TCPC (N=197, 37%). The FC-TCPC and TCPC groups have similar 15-year incidence of death/transplant (42% versus 47%; P =0.8), even after excluding the 8% operative mortality in the FC-TCPC group (38% versus 47%; P =0.3). On multivariable analyses, neither FC nor the type of Fontan connection was associated with death/transplant. Rather, the risk factors for death/transplant were older age, hepatorenal dysfunction, heart failure, and higher Fontan pressures. The prevalence and severity of these comorbidities increased with age, suggesting that these factors reflect the duration of Fontan physiology, rather than the type of Fontan connection. CONCLUSIONS: These findings, in addition to the high operative mortality associated with FC, suggest that this may not be the optimal treatment option for most adults with atriopulmonary Fontan presenting with Fontan failure. Duration of Fontan physiology rather than the type of Fontan connection may be the main determinant of outcomes.

Abstract Aims Systemic ventricular (SV) strain imaging improves early detection of systolic dysfunction in patients with congenital heart disease and biventricular circulation. However, its role for risk stratification in the Fontan population has not been systematically studied. We hypothesized that among Fontan patients with normal SV ejection fraction (Echo_EF) at baseline, those with reduced SV longitudinal strain (Echo_LS) would have a higher risk of progressive SV systolic dysfunction, greater neurohormonal activation, and cardiovascular events (heart failure hospitalization/death/transplant) during follow-up. Methods and results We studied adults with Fontan palliation and normal SV systolic function (Echo_EF >50%) at baseline who underwent follow-up echocardiogram >36 months after the baseline echocardiogram. Echo_LS was assessed from the apical 4-chamber window using speckle tracking echocardiography. Patients were divided into reduced vs. normal Echo_LS groups, using −18% as the cut-off point. Echo_LS, Echo_EF, and NT-proBNP were assessed at baseline and follow-up encounters. Of 272 patients (age, 28 ± 8 years), 98 (36%) and 174 (64%) had reduced vs. normal Echo_LS. The reduced_Echo_LS group had progressive SV systolic dysfunction [worse temporal decline in Echo_EF (relative_Δ_Echo_EF −12.8% vs. −2.1%, P < 0.001)], and higher prevalence of new-onset SV systolic dysfunction [30% (29/98) vs. 8% (13/174), P < 0.001]. The reduced Echo_LS group also had greater neurohormonal activation [relative Δ_ NT-proBNP 36 (95%CI, 27–43) % vs. 17 (95%CI, 11–23) %, P < 0.001], and higher risk of cardiovascular events (adjusted hazard ratio 1.84, P = 0.009). Conclusion Echo_LS improves risk stratification in Fontan patients with normal Echo_EF and may provide an opportunity for early interventions to improve outcomes.

Background Atrial dysfunction is a risk factor for atrial arrhythmia and can be detected by atrial strain imaging in patients with biventricular circulation. However, the role of atrial strain imaging for risk stratification of atrial arrhythmia in patients with Fontan palliation has not been studied, despite the high prevalence and prognostic implications of atrial arrhythmia in this population. We hypothesized that pulmonary venous atrial strain was associated with new‐onset and recurrent atrial arrhythmia in Fontan physiology. Method and Results This is a retrospective study of adults with Fontan palliation and no prior history of atrial arrhythmia who underwent atrial strain imaging by speckle tracking echocardiography (2003–2023). New‐onset and recurrent atrial arrhythmias were ascertained from baseline encounter to last follow‐up. Of 404 patients, atrial reservoir strain assessment was feasible in 329 patients (81%), with modest intra‐ and interobserver agreement. The median atrial reservoir strain was 18% (interquartile range, 13%–24%), and atrial dysfunction (atrial reservoir strain <28%) was present in 294 (89%). Atrial reservoir strain <15% was associated with new‐onset atrial arrhythmia (adjusted hazard ratio [HR], 1.59 [95% CI, 1.09–2.34]; P =0.009), and recurrent atrial arrhythmia (adjusted HR, 2.01 [95% CI, 1.06–3.93]; P =0.003). Rhythm control therapy was associated with lower risk of recurrence compared with rate control therapy (adjusted HR, 0.92 [95% CI, 0.86–0.98]; P =0.003). Conclusions Atrial dysfunction was common and was associated with new‐onset and recurrent atrial arrhythmias. The higher prevalence of atrial arrhythmias in patients with reduced atrial strain and the apparent protective effect of rhythm control therapy suggest that rhythm control therapy may be the preferred treatment in patients with reduced atrial strain.

Abstract Background Six percent of patients presenting with acute myocardial infarction (MI) have MI with non-obstructed coronary artery disease (MINOCA). Coronary microvascular disease (CMD) is common in angina with non-obstructive coronary artery disease (ANOCA), but its prevalence and severity in MINOCA is undefined. Purpose Patients with CMD may have elevated risk of myocardial infarction despite no significant stenosis. We tested the hypothesis that patients with MINOCA have more significant burden of CMD than patients with ANOCA. Methods A retrospective case-control study was performed on patients who underwent invasive testing for signs of coronary ischemia and found to have non-obstructive disease (stenoses&lt; 50%). Cases of MI were classified as MINOCA (n=87) and compared to patients with ANOCA (n=552). Patients with spontaneous coronary artery dissection, myocarditis, Takotsubo cardiomyopathy or prior atherothrombotic MI were excluded. Coronary catheterization was performed followed by invasive provocation testing with adenosine and acetylcholine using a Doppler flow wire. CMD was subdivided into endothelium-independent, defined as coronary flow reserve (CFR) &lt; 2.5 with intra-coronary adenosine, and endothelium dependent, defined as &lt; 50% increase in coronary blood flow with acetylcholine. Epicardial vasoconstriction &gt; 90% with typical anginal symptoms was classified as epicardial vasospasm. Results There was no difference in age, sex or traditional coronary risk factors between the MINOCA and ANOCA groups (Table 1). Fifty (57%) of patients with MINOCA had type 2 MI secondary to supply-demand mismatch. Both MINOCA and suspected ANOCA patients had a high prevalence of CMD (71% vs 67%) and endothelium-independent CMD is more prevalent in MINOCA (64.5% vs 50.4%). Although odds of endothelium-dependent CMD were similar, the CFR within this group and CMD overall was worse in MINOCA patients (Figure 1). There was no difference in epicardial spasm. Conclusion Coronary microvascular disease and vasomotor dysfunction are common in patients with MINOCA, with a higher prevalence of endothelium-independent CMD and more severe CMD overall compared to patients with ANOCA. Treatment of CMD in patients with MINOCA may help reduce recurrence and warrants further investigation.