Connolly, Heidi M.

Abstract Aims The Fontan operation is associated with significant long-term morbidity and mortality, posing challenges in management. No haemodynamic classification has been established to aid management and prognostication of patients with Fontan palliation. Our aim was to assess haemodynamic profiles for Fontan patients and evaluate their relationships to prognosis. Methods and results Eighty-four adult Fontan patients without obstruction or significant valve disease undergoing cardiac catheterization for Fontan-related co-morbidities were divided into four different haemodynamic profiles based on normal/high Fontan pressures (FP) (< 15 or ≥ 15 mmHg) and low/normal cardiac index (CI) (< 2.5 or ≥ 2.5 L/min/m2). Fourteen patients had low CI/high FP (17%), 24 low CI/normal FP (29%), 20 normal CI/high FP (24%), and 26 normal CI/normal FP (31%). Demographic and clinical data were similar among groups except for a trend towards a higher prevalence of cirrhosis in the normal CI/high FP (50%) group. Systemic vascular afterload, assessed by systemic vascular resistance and effective arterial elastance, was higher in patients with low CI/high FP and low CI/normal FP as compared to normal CI profiles. Pulmonary vascular resistance indices were higher in patients with low CI/high FP than all other profiles. The normal CI/high FP haemodynamic profile was an independent predictor of mortality (hazard ratio 4.1, 95% confidence interval 1.2–11.5). Heterotaxy and protein-losing enteropathy were also predictors of mortality on the multivariate model. Conclusion The proposed haemodynamic classification provides prognostic information in adults post-Fontan with patients in the normal CI/high FP profile having worse survival. Whether this classification can guide management in these patients deserves further investigation.

Background Patients with tetralogy of Fallot ( TOF ) remain at risk for cardiovascular events despite successful repair. Some of the current risk stratification tools require advanced imaging and invasive studies, and hence are difficult to apply to routine patient care. A recent study showed that QRS fragmentation ( QRS ‐f) is predictive of mortality in patients with TOF. The current study aims to validate this result by assessing whether severity of QRS ‐f could predict all‐cause mortality in a different TOF population. Methods and Results The authors reviewed the Mayo Adult Congenital Heart Disease database for patients with TOF who had ECG from 1990–2017. QRS ‐f was defined as notches in QRS complex in ≥2 contiguous leads on ECG , not related to bundle branch block, and classified as none, mild (≤3 leads), moderate (4 leads), or severe (≥5 leads). Of 465 patients (age 37±14 years) in the study, QRS ‐f was present in 161 (35%): mild (n=43, 9%), moderate (n=77, 17%), and severe (n=41, 9%). There were 55 deaths (12%) during 13.6±8.2 years of follow‐up. Severity of QRS ‐f remained an independent predictor of all‐cause mortality after adjustment for other ECG parameters, patient demographics, and atrial and ventricular arrhythmia (hazard ratio, 1.74 per class; 95% confidence interval, 1.08–2.93 [ P =0.041]). Conclusions The presence of severe QRS ‐f may be used as complementary data to the usual clinical indices to determine whether interventions such as invasive electrophysiology study should be performed in patients with nonsustained ventricular tachycardia or to proceed with pulmonary valve replacement in patients with severe pulmonary regurgitation with ventricular volumes below the guideline‐directed threshold for intervention.

Background Aortic dilation and aortic valve disease are known long-term complication of tetralogy of Fallot (TOF), but the risk of aortic dissection and the indications for prophylactic aortic surgery are unknown in this population. The purpose of this study was to: (1) determine the prevalence of significant aortic valve disease and/or significant aortic aneurysm (AVD-AA); (2) determine the incidence of progressive aortic dilation and aortic dissection in patients with TOF. Methods Retrospective review of adults with repaired TOF, and no prior aortic valve/aorta surgery, who had ≥2 measurements of the thoracic aorta >12 months apart, 1990–2017. The aortic root and mid-ascending aorta were measured at the onset of QRS complex from leading edge to leading edge. Significant aortic valve disease was defined as the presence of ≥moderate aortic stenosis and/or ≥moderate aortic regurgitation. Significant aortic aneurysm was defined as aortic root or mid-ascending aorta dimension ≥50 mm. Progressive aortic dilation was defined as increase in aortic dimension ≥2 mm. Results Of the 453 consecutive patients (37±13 years, men 216 (49%)) in the study, aortic aneurysm was present in 312 (69%) based on normative data; progressive aortic dilation occurred in 40 (9%), and there was no case of aortic dissection. Significant AVD-AA occurred in 52 (12%) patients; and 15 of them (29%) underwent aortic surgery without any surgical mortality. Conclusions Although aortic aneurysm was common, progressive aortic dilation was uncommon and aortic dissection did not occur in our patients with TOF with significant aortic aneurysms who did not undergo aortic surgery. This has important clinical implication in deciding the frequency of imaging follow-up and timing of surgical intervention in this population.

Background National prevalence and outcomes of Fontan operation in the USA is unknown. Study objective was to determine trends (temporal change) in the annual volume of Fontan operations, in-hospital mortality, postoperative complications and type of hospital discharge. Methods Review of the Nationwide Inpatient Sample for patients that underwent Fontan operation from 2001 to 2014 using the International Classification of Diseases-Ninth Revision, Clinical Modification procedure code for Fontan operation, that is, 35.94. To evaluate for change in patients’ demographics over the years, we divided the patient population into four groups based on procedure year (2001–2004, 2005–2008, 2009–2011 and 2012–2014). Results An estimated 15 934 Fontan operations were performed in the USA from 2001 to 2014. Median (Q1–Q3) age was 3 (2–4) years and 39.8% were female. Hypoplastic left heart syndrome was the most common (29%) congenital heart disease diagnosis. An estimated 1175 procedures were performed in 2001 and 1340 in 2014, but there was no significant change in the number of procedures per year (p=0.47). There was significant decline in in-hospital mortality from 4.5% (53/1175) in 2001 to 1.1% (15/1340) in 2014 (p=0.009). When we compared event rates between 2001–2004 and 2012–2014 periods, there was significant decline in postoperative cardiac complications (12.6% (459/3640) to 8% (378/4706), p=0.007) and respiratory complications (17.1% (623/3640) to 10.2% (481/4706), p<0.001). However, there was increase in the number of patients discharged to home with healthcare assistance or transferred to another acute care facility (5.8% (211/3640) to 9.4% (443/4706), p=0.01) and inflation-adjusted hospitalisation cost (US$46 978 to US$60 383, p<0.001), but no significant change in length of stay (p=0.73). Conclusion On the average, 1062 Fontan operations are performed annually in the USA with no change in volume of procedures but a decrease in in-hospital mortality and postoperative complications over a 15-year period.

Background Tachyarrhythmias and bradyarrhythmias affect 20%–50% of adult patients with tetralogy of Fallot (TOF) and some of these patients will require cardiac implantable electronic devices (CIED) such as pacemaker and/or internal cardioverter defibrillator. Methods The Mayo Adult Congenital Heart Disease database was queried for patients with repaired TOF and history of CIED implantation, 1990–2017. The study objectives were: (1) determine the occurrence of device-related complications defined as lead failure, lead recall, device infection and lead thrombus; and (2) determine the occurrence and risk factors for defibrillator shock. Results There were 99 patients (age 46±14 years and 66 (66%) men) with CIED, and the CIEDs were 41 (41%) pacemakers and 73 (73%) defibrillators. Indication for defibrillator implantation was for primary prevention in 28 (38%) and secondary prevention in 45 (62%). Device-related complications occurred in 20 (20%) patients (lead failure 17, lead recall 4, device infection 12 and thrombus 3). Twenty-five per cent of all device infections occurred within 30 days from the time of device generator change. Annualised rates of appropriate and inappropriate shocks were 5.7% and 6.2%, respectively. The use of class III antiarrhythmic drug was protective against defibrillator shock. Conclusion The current study provides useful outcome data to aid patient counselling and clinical decision-making. Further studies are required to explore ways to decrease the risk of postprocedural infection after device generator change, and to determine which patients will benefit from empirical antiarrhythmic therapy as a strategy to decrease incidence of inappropriate defibrillator shock.

Background Nonpulsatile pulmonary blood flow in Fontan circulation results in pulmonary vascular disease, but the potential relationships between pulmonary vascular resistance index (PVRI) and Fontan failure have not been studied. The objective was to determine whether the absence of subpulmonary ventricle in the Fontan circulation would make patients more vulnerable to even low-level elevations in PVRI, and when coupled with low cardiac index, this would identify patients at increased risk of Fontan failure. Methods and Results Two hundred sixty-one adult Fontan patients underwent cardiac catheterization; age 26±3 years, men 146 (56%), atriopulmonary Fontan 144 (55%). Patients were divided into 2 groups: those with high PVRI (>2 WU·m 2 ) and low cardiac index <2.5 L min −1 m −2 (group 1, n=70, 30%), and those with normal PVRI and normal cardiac index (group 2, n=182, 70%). Fontan failure was defined by the composite of all-cause mortality, listing for heart transplantation, or initiation of palliative care. There were 68 (26%) cases of Fontan failure during a mean follow-up of 8.6±2.4 years. When compared with group 2, freedom from Fontan failure was significantly lower in group 1: 66% versus 89% at 5 years. The combination of high PVRI and low cardiac index was an independent risk factor for Fontan failure (hazard ratio, 1.84; 95% confidence interval, 1.09–2.85). Conclusions When coupled with low cardiac index, even mild elevations in PVRI identify patients at high risk of Fontan failure. This suggests that pulmonary vascular disease is a key mechanism underlying Fontan failure and supports further studies to understand the pathophysiology and target treatments to pulmonary vascular tone in this population.