Adult Congenital Heart Disease

Modified Ventricular Global Function Index Correlates With Exercise Capacity in Repaired Tetralogy of Fallot View Article Ta HT, Critser PJ, Alsaied T, Germann J, Powell AW, Redington AN, Tretter JT. J Am Heart Assoc. 2020 Jul 21;9(14):e016308. doi: 10.1161/JAHA.120.016308. Epub 2020 Jul 7. PMID: 32633206 Take Home Points: Establishing RV effective Global function index (eGFI) as a novel and more robust predictor of hard clinical end points in patients with rTOF. RV eGFI may be a more comprehensive marker of poor myocardial health and exercise intolerance than currently used indices. The association between reduced RV eGFI with impaired exercise performance establishes biologic plausibility which may form the basis of larger scale studies assessing the value of preoperative eGFI in timing of PVR , Commentary by Dr. Soha Romeih (Aswan, Egypt), section editor of ACHD Journal Watch: Despite improvements in early survival in rTOF, there continues to be a high incidence of impaired functional status, heart failure, arrhythmias, and death, which often occur in the setting of RV dysfunction with either volume- and/or pressure-loading of the RV. To improve these outcomes, PVR is often performed in symptomatic patients or asymptomatic patients who have significant RV dilation or RV systolic dysfunction. However, using current guidelines, PVR does not lead to survival benefit or reduce other major adverse postoperative events. Recent investigations have shown that preoperative RV hypertrophy and dysfunction, not ventricular volumes, particularly in patients approaching their 3rd decade of life, are associated with worse outcomes—highlighting the importance of maintaining myocardial health. CMR derived ventricular global function index (GFI), has been proposed as a better marker of ventricular function because it incorporates structural, mechanical, and preload indices. Establishing eGFI, or the lesion-specific modification described in the current study, as a novel and more robust predictor of hard clinical end points in patients with rTOF will require prospective testing in a large, likely multi-center, study after biologic plausibility has been established. To do the latter, this "proof-of-principle" study leverages the known association between impaired exercise capacity as assessed by cardiopulmonary exercise testing (CPET) and poorer outcomes in patients with rTOF. Methods 75 patients with rTOF who underwent CMR were identified. Clinical variables were recorded and biventricular GFI calculated. RV effective GFI (eGFI) was derived by incorporating effective stroke volume. 35 pediatric patients were matched with 29 age-matched healthy controls. 25 patients completed cardiopulmonary exercise tests within 6 months of CMR. RV effective Global function index Results: Median age at CMR was 20 years (interquartile range, 13–28). Pediatric rTOF patients had lower RV eGFI (P < 0.001), RV-EF (P=0.002), but higher indexed RV EDV and ESV (P < 0.001, P < 0.001) compared with controls. Univariate analysis demonstrated a correlation between indexed peak VO2 with RV eGFI (R2=0.32, P=0.004), but with neither RVGFI, RV ejection fraction, indexed RV volumes nor RV mass.  RV eGFI remained significantly associated with indexed peak VO2 during multivariable modeling Discussion This study demonstrates that the novel modification of the GFI, incorporating effective stroke volume rather than total stroke volume (eGFI), may be a useful non-invasive method to assess myocardial health in patients with rTOF. Reduced RV eGFI was associated with impaired exercise capacity in patients with rTOF, while RV EF, RV GFI using the total RV stroke volume, indexed RV volumes and mass were not. While preoperative RV volumes and EF are the most commonly used indices to determine the need for PVR in asymptomatic patients, their optimal thresholds continue to be debated, and they do not appear to be related to hard clinical end points such as death, heart failure or ventricular tachycardia after PVR. Patients had significantly lower RV function as measured by both RV EF and RV eGFI values compared with controls. Importantly, in multivariate analysis, RV eGFI but neither RV GFI, RV EF, nor RV volume indices was correlated with exercise performance. Those finding of an association between reduced RV eGFI with impaired exercise performance is important for 2 reasons—first, impaired exercise performance correlates with poor outcomes; and second, this establishes biologic plausibility may form the basis of larger scale studies of the value of preoperative GFI in defining potential thresholds for PVR and predicting outcomes thereafter. This data disagrees somewhat with the findings of Rashid and colleagues who evaluated a larger cohort of similarly aged patients with rTOF who underwent CPET and CMR. Similar to current findings, RV size did not correlate with peak VO2 in their study, but indices of RV systolic function including RV EF and stroke volume index did correlate significantly. Of note, patients in current had lower indexed RV volumes and higher RV EF when compared with the study by Rashid and are consistent with a study in younger patients with rTOF that demonstrated only a weak association between RV EF and exercise performance. Limitations There were several limitations to this study including its retrospective nature from a single center. Conclusions Patients with rTOF had lower RV eGFI compared with age-matched controls. Reduced RV eGFI was associated with reduced exercise capacity, while RV EF, indexed RV volumes, and mass were not. This supports RV eGFI as a potentially valuable non-invasive marker of cardiac function in the rTOF population.

Predicting the Risk of Adverse Events in Pregnant Women With Congenital Heart Disease View Article Chu R, Chen W, Song G, Yao S, Xie L, Song L, Zhang Y, Chen L, Zhang X, Ma Y, Luo X, Liu Y, Sun P, Zhang S, Fang Y, Dong T, Zhang Q, Peng J, Zhang L, Wei Y, Zhang W, Su X, Qiao X, Song K, Yang X, Kong B. J Am Heart Assoc. 2020 Jul 21;9(14):e016371. doi: 10.1161/JAHA.120.016371. Epub 2020 Jul 14. PMID: 32662348 Commentary from Dr. Helen Parry (Leeds UK), section editor of ACHD Journal Watch: The aim of this paper was to produce a model to improve the accuracy of risk assessment in pregnant women with congenital heart disease. Method A total of 318 pregnancies in women with congenital heart disease were included in the study.  These were divided into a development cohort, used to create the risk model (n=213) and validation cohort, used to test whether the models were accurate (n=105).  Models were created to assess both maternal risk and neonatal risk to the baby.  Patients were excluded if maternal death occurred prior to delivery or if spontaneous abortion occurred prior to 28 weeks gestation. A regression analysis model was used to identify independent risk factors for poor outcome.  Variables were regarded as significant if the p-value was <0.10.  Once the model was established, this was tested on the validation cohort and assess for positive predictive value, negative predictive value, sensitivity and specificity. Results Ten per cent of patients gave birth vaginally.  Forty-one (12.9%) of the women experienced adverse maternal events whilst 93 (29.3%) of neonates experienced adverse events.  A number of risk factors for worse outcomes for the mother or neonate were identified including pulmonary hypertension, Eisenmenger’s syndrome, higher NYHA functional class, left heart obstruction, significant impairment in left ventricular function, oxygen saturations and sinus tachycardia. There were 13 maternal deaths, 2 of which were due to heart failure developing after Caesarean section to remove the fetus following intrauterine death. Conclusion The risk models will help guide clinicians when looking after patients with congenital heart disease. Critique Positive aspects: N=318 is a reasonable sample size, especially in a study examining patients with congenital heart disease, which are notorious for small samples. There was an indication of sinus tachycardia being a risk factor for adverse outcome, which I don’t believe is quite so widely recognised as the other risk factors identified. Negative aspects: Although the overall sample size is reasonable, there are actually very small numbers of patients in some of the subgroups. For example, there were only 8 patients with Eisenmenger’s syndrome in the validation cohort and it is difficult to conclude that the model is valid for this group with a sample of this size.  It is recognised that studying large numbers of patients with Eisenmenger’s syndrome who become pregnant is incredibly challenging given that these patients would generally be advised not to conceive as they are too high risk.  It raises the possibility that this is actually a self-selecting group of patients with relatively good physiology within the Eisenmenger’s group; otherwise, they would be unlikely to carry the pregnancy beyond the 28 week gestation period required for the inclusion criteria. The lack of inclusion of pregnancies that did not continue to the 28 week stage means the data cannot be used when counselling patients regarding risk of early miscarriage and is likely to exclude some of the highest risk mothers. The same is true of exclusion if maternal death occurred before delivery. The cut off value for statistical significance was p<0.10. This is unusually high; most papers do not regard a p-value of >0.05 as statistically significant. It is unclear whether the conclusions actually add anything to the assessment and management of patients with congenital heart disease who become pregnant. The risk factors identified are in keeping with those categorised under the modified WHO categorization and there are other obstetric scoring systems that already take these factors into account. It is difficult to see how management improves as a result of the risk scores generated as we already knew about the risk factors and the paper provides no information on whether intervention reduces risk. Does beta-blockade in patients with sinus tachycardia reduce their risk or is it detrimental as it impedes an appropriate response to reduced cardiac output? Of note, it is interesting there is such a low proportion of vaginal deliveries. In our centre, vaginal delivery is preferred if at all possible.

Echocardiographic Identification of Pulmonary Artery Flow Reversal: An Indicator of Adverse Outcomes in Single Ventricle Physiology. View Article Spearman AD, Ginde S, Goot BH, Schaal AM, Feng M, Pan AY, Frommelt MA, Frommelt PC. Pediatr Cardiol. 2020 Jul 24. doi: 10.1007/s00246-020-02421-z. Online ahead of print. PMID: 32710282 Take Home Points: Pulmonary artery flow reversal in patients with palliated single ventricular physiology is the continuous reversal of blood flow from the pulmonary artery into the contralateral pulmonary artery. Compared to patient without pulmonary artery flow reversal, patients with such physiology were associated with: Longer length of stay post superior cavopulmonary connection surgery; Less probability of eventual Fontan completion; and Lower 10-year transplant-free survival Commentary from Dr. MC Leong (Kuala Lumpur), section editor of ACHD Journal Watch:  In the absence of a forward pulmonary arterial flow, palliated single ventricle, either in the form of a superior cavopulmonary connection (Glenn shunt) or a total cavopulmonary connection (Fontan), is non-pulsatile and unidirectional, i.e. from the cavopulmonary shunt into the pulmonary arteries. Pulmonary artery flow reversal is the continuous reversal of blood flow from the pulmonary artery into the contralateral pulmonary artery as detected by Color Doppler (Figure 1). The authors retrospectively reviewed all patients seen at their centre from 1999-2019 with single ventricle congenital heart disease and superior cavopulmonary connection and compared the clinical outcomes between those with reversal of blood flow and those without (Table 1). A total of 560 patients (21, 3.8% with pulmonary artery flow reversal) were recruited. Over the median follow up period of 8.2 years (median 5.3[range 0.2-20.2] years for the pulmonary artery reversal group and median 8.2 years [range <0.1-20.5] years for the non-reversal group, patients with flow pulmonary artery reversal was associated with a poorer outcome. They are associated with a poorer 10-year transplant-free survival, a longer post-operative length of stay (Figure 2-3). However, the 10-year overall survival and the post-operative length of Fontan stay were comparable to those of the non-reversal group. Of patients older than 2 years old who had pulmonary artery flow reversal, only 4 out of 11 (36.4%) proceeded to Fontan completion. They either died (n=4), underwent orthotopic heart transplant (n=1) or remain with superior cavopulmonary connection physiology (n=2). Heterotaxy was not found to be associated with pulmonary artery flow reversal. In the article, the authors mentioned that they detected pulsatile retrograde flow into the pulmonary artery suggesting the presence of aorto-pulmonary collateral arteries. The authors demonstrated that patients who had pulmonary artery flow reversal had a poorer clinical outcome. The study could pave the way for a new noninvasive indicator to predict patients with poorer long-term prognosis and aid in decision making and clinical management. Pulmonary artery flow reversal is easy to diagnose and is cost-efficient. The logic behind its occurrence is plausible. Ipsilateral pulmonary artery which is high in pressure or obstructed tended to receive less pulmonary blood flow and hence blood tends flow to the contralateral pulmonary artery. Unfortunately, the incidence of pulmonary artery flow reversal is not high, the study may not have the power to associate it with poorer long term outcomes convincingly. We may have to await more studies before this concept translates into a solid evidence.

Terol C, Kamphuis VP, Hazekamp MG, Blom NA, Ten Harkel ADJ.Pediatr Cardiol. 2020 May 4. doi: 10.1007/s00246-020-02355-6. Online ahead of print.PMID: 32363435   Abstract Surgical repair of Tetralogy of Fallot (ToF) is usually performed in the first months of life with low early postoperative mortality. During long-term follow-up, however, both right (RV) and left ventricular (LV) performances may deteriorate. Tissue Doppler imaging (TDI) and speckle tracking echocardiography (ST) can unmask a diminished RV and LV performance. The objective of the current study was to assess the cardiac performance before and shortly after corrective surgery in ToF patients using conventional, TDI and ST echocardiographic techniques. Thirty-six ToF patients after surgery were included. Transthoracic echocardiography including TDI and ST techniques was performed preoperatively and at hospital discharge after surgery (10 days to 4 weeks after surgery). Median age at surgery was 7.5 months [5.5-10.9]. Regarding the LV systolic function there was a significant decrease in interventricular septum (IVS) S' at discharge as compared to preoperatively (pre IVS S' = 5.4 ± 1.4; post IVS S' = 3.9 ± 1.2; p < 0.001) and in global longitudinal peak strain (GLS) (pre = - 18.3 ± 3.4; post = - 14.2 ± 4.1; p = 0.003); but not in the fractional shortening (FS). Both conventional and TDI parameters showed a decrease in diastolic function at discharge. Tricuspid Annular Plane Systolic Excursion and RV S' were significantly lower before discharge. When assessing the RV diastolic performance, only the TDI demonstrated a RV impairment. There was a negative correlation between age at surgery and postoperative LV GLS (R = - 0.41, p = 0.031). There seems to be an impairment in left and right ventricle performance at discharge after ToF corrective surgery compared to preoperatively. This is better determined with TDI and ST strain imaging than with conventional echocardiography.   Fig. 1 Longitudinal strain of a male patient with Tetralogy of Fallot: a before surgery (GLS − 17.1%) and b before discharge after surgery (GLS − 10.8%). GLS global longitudinal peak strain   source:https://pubmed.ncbi.nlm.nih.gov/32363435/