Correlation of anatomic and hemodynamic features with aortic valve leaflet deformity in doubly committed subarterial ventricular septal defect

Incidence of Aortic Regurgitation in Association with Type of Ventricular Septal Defects and its Immediate and Intermediate Outcome after Surgical Closure

Introduction Ventricular septal defect (VSD) is one of the more common congenital heart defects, and aortic regurgitation (AR) is its major complication if it remains unrepaired. We aim to determine the AR incidence in various types of VSD, its immediate and intermediate six to 12-month post-VSD repair outcomes of AR. Methods We conducted a retrospective review of medical records of all children aged 18 years or younger who were diagnosed with single VSD at our institution from 2016 to 2018. VSD was classified according to its location and relation to the tricuspid annulus and semilunar valve. AR severity grading was done according to the American Society of Echocardiography, and vena contracta width (VC) was taken as the main parameter for severity. We defined trivial-to-mild AR as VC width less than 0.3 cm, moderate AR was 0.3-0.6 cm VC width, and severe AR was VC width of more than 0.6 cm. Immediate and intermediate outcomes of surgical closure, such as residual VSD and AR, were observed. Results One hundred ninety patients with isolated single VSD were included in the study. Of those, 114 patients had perimembranous VSD (60.0%), 64 patients had muscular VSD (33.7%), and 12 patients had supracristal VSD (6.3%). The median age of our study cohort was six months, with a male to female ratio of 1.3:1. Aortic valve prolapse (28.9%; n = 55) and AR (23.2%; n = 44) were the most common findings on echocardiographic evaluation of VSD patients. Most cases of VSD with AR had trivial-to-mild AR, (68.2%; n = 30). AR was most commonly seen in supracristal VSD (83.3%; n = 10) followed by perimembranous VSD (28.9%; n = 33). VSD closed spontaneously in 34 patients (17.9%) and 98 patients (51.6%) patients underwent surgery. Residual VSD after surgical closure was present in 57.1% (56) and 17.3% (17) of the patients immediate postoperatively and six- to 12-month postoperative follow-up, respectively. Similarly, residual AR after surgical closure of VSD was present in 32.7% (32) and 15.3% (15) of the patients immediate postoperatively and six- to 12-month postoperative follow-up, respectively. Conclusion The incidence of AR with VSD was very high in our study; AR was most commonly associated with supracristal VSD. After surgical repair, mild AR decreased with time. Early corrective surgery of VSD can prevent this complication and help improve outcomes.

Vulnerability of Coronary Circulation After Norwood Operation

BACKGROUND

We hypothesized that the myocardial oxygen supply-demand balance is impaired in patients after a Norwood procedure and that an abnormal oxygen supply-demand balance is associated with pronounced activation of the renin-angiotensin-aldosterone system and worse clinical outcome after this procedure.

METHODS

To investigate the myocardial oxygen supply-demand balance, the subendocardial viability ratio (SEVR) was measured in 29 hypoplastic left heart syndrome patients after the Norwood procedure, in 27 patients with pulmonary atresia whose pulmonary blood flow was supplied from the aortopulmonary (AP) shunt, and in 30 control patients who were considered to have normal biventricular circulation. The SEVR in Norwood (0.57 ± 0.18) and AP shunt (0.66 ± 0.10) patients was significantly reduced compared with that in controls (0.94 ± 0.25, p < 0.001 vs Norwood and AP shunt).

RESULTS

After controlling for heart rate, the SEVR was significantly lower in Norwood than in AP shunt patients (p < 0.001). Importantly, the SEVR was significantly lower in Norwood patients with poor clinical outcomes (cardiac arrest before second-stage operation, progressive tricuspid regurgitation, or reduction of ejection fraction <0.35) than in the remaining Norwood patients (0.51 ± 0.12 vs 0.69 ± 0.22, p < 0.01). An SEVR of less than 0.52 had a more than 76% probability of having a poor outcome (p < 0.05). Furthermore, a lower SEVR was significantly correlated with more pronounced renin-angiotensin-aldosterone system activation and elevated natriuretic peptides in serum. Multiple regression analysis revealed that increased aortic stiffness and a smaller neoaorta relative to the native descending aorta were independent determinants of reduced SEVR.

CONCLUSIONS

Myocardial oxygen supply-demand imbalance is intrinsic to Norwood circulation but may be improved by technical refinement of aortic reconstruction or afterload-reducing medication with renin-angiotensin-aldosterone system blockade.

Pulmonary arterial wall stiffness and its impact on right ventricular afterload in patients with repaired tetralogy of Fallot

BACKGROUND

Recent histologic studies involving patients with tetralogy of Fallot (TOF) have revealed a reduction in normal elastic fibers in the pulmonary trunk. Such histologic changes may significantly alter the mechanical properties of the arterial wall and may thereby augment the pulsatile afterload on the right ventricle (RV) and propagate RV dilation and dysfunction.

METHODS

We studied 29 patients with repaired TOF (median age, 5.9 years) and 29 age-matched controls. Pulmonary arterial hemodynamics were investigated by measuring the pulmonary input impedance during cardiac catheterization.

RESULTS

Patients with TOF had higher characteristic impedance (p = 0.0002), lower total pulmonary vascular compliance (p < 0.0001), and enhanced wave reflection (p < 0.0001). Consistent with these changes, patients with TOF were subject to higher pulsatile load, measured by fundamental frequency impedance (p < 0.0001), which was significantly related to both reduced RV output and increased RV end-diastolic volume (p = 0.006 and 0.003, respectively). Moreover, pulmonary arterial compliance was strongly related to RV end-diastolic volume (r = -0.69, p = 0.0001). In multivariate analysis, pulmonary arterial compliance was a significant predictor of RV dilation independent of pulmonary regurgitation and pulmonary stenosis (p = 0.03).

CONCLUSIONS

In line with known histologic changes, pulmonary arterial stiffness is increased and is significantly related to reduced RV ejection and RV enlargement in patients with repaired TOF. These results suggest that not only pulmonary valvular function (pulmonary regurgitation/pulmonary stenosis) but also pulmonary vascular pulsatile properties can be an important therapeutic target to improve prognosis in this population.

Marked disparity in mechanical wall properties between ascending and descending aorta in patients with tetralogy of Fallot

OBJECTIVES

Recent studies have linked abnormal aortic medial pathology to progressive aortic root dilatation in patients with tetralogy of Fallot (TOF). To explore whether the aortic medial pathology in TOF is linked to aortic mechanical property, the present study tested the hypothesis that the distribution of impaired aortic elasticity corresponds to the known distribution of abnormal medial pathology (confined to the ascending aorta) in TOF.

METHODS

Pulse wave velocity (PWV) of the proximal and distal aortas was measured with a high-fidelity micromanometer in 98 TOF patients (64 with repaired TOF and 34 with unrepaired TOF) and 63 control subjects.

RESULTS

PWV of the proximal aorta was significantly higher in TOF than in the control, but similar in repaired and unrepaired TOF (repaired: 588 ± 205 cm/s, unrepaired: 680 ± 288 cm/s, control: 439 ± 101 cm/s, P < 0.001 for each TOF group vs. control, P = 0.07 for repaired vs. unrepaired TOF). In contrast, PWV of the distal aorta was almost identical among the three groups (repaired: 441 ± 189 cm/s, unrepaired: 430 ± 114 cm/s, control: 461 ± 164 cm/s, P = 0.73, analysis of variance), indicating that abnormal aortic mechanical property is confined to the proximal aorta regardless of the operative status of TOF. This was also confirmed by comparison within the group; PWV of the proximal aorta was significantly higher than that of the distal aorta in both TOF groups (P < 0.001, each), whereas there was no difference in PWV between the proximal and distal aortas in the control subjects (P = 0.61).

CONCLUSIONS

Consistent with the known histopathological disparity between the media of the ascending and descending aortas, aortic stiffness is markedly increased in the proximal but not in the distal aorta of TOF. These results suggest that aortic wall stiffness is a potentially useful clinical marker of aortic dilation in patients with TOF.

Findings in the pulmonary vascular bed in the remote phase after Kawasaki disease

Kawasaki disease (KD) is a form of systemic vasculitis that causes chronic changes in arterial walls, including pulmonary arteries. The aim of this study was to test the hypothesis that pulmonary arterial wall properties and hemodynamics are abnormal after the resolution of KD. Pulmonary arterial input impedance was measured during cardiac catheterization (4.8 ± 4.5 years after disease onset) in 47 consecutive patients (mean age 7.8 ± 5.7 years) with KD and coronary artery lesions (CALs) in the acute phase and 42 control patients (mean age 6.7 ± 4.6 years). Patients with KD were subdivided into 2 groups: 28 with persistent CALs and 19 with regressed CALs. There were no significant differences in characteristic impedance and peripheral vascular resistance between patients with KD and controls. Compared with controls, patients with persistent CALs had significantly lower pulmonary arterial compliance, suggesting increased wall stiffness of the peripheral pulmonary vascular bed (p <0.05, analysis of variance). Patients with persistent CALs also exhibited increased wave reflection compared with other groups (p <0.05, analysis of variance). In conclusion, unlike patients with regressed CALs, patients with persistent CALs have abnormal mechanical properties and hemodynamics of the pulmonary artery after KD. Together with previous reports of abnormal properties of coronary and systemic arteries, these data suggest that KD vasculitis causes chronic changes in arterial wall properties in the entire arterial system to varying degrees and extent. The fate of these abnormalities in the pulmonary bed and other arterial systems and their potential adverse effects must be monitored in long-term follow-up.

Doubly committed ventricular septal defect: single-centre experience and midterm follow-up

BACKGROUND

Doubly committed ventricular septal defect (dcVSD) is the least common type of VSD. Because published studies are rather scarce, this study aimed at evaluating the midterm outcome of dcVSDs.

METHODS

The records of all patients registered in the database of Paediatric and Congenital Cardiology, University Hospitals Leuven, with a dcVSD at 16 years of age were reviewed. Clinical, electrocardiographic and transthoracic echocardiographic changes from baseline, defined as of the age of 16 years, until the latest follow-up were compared.

RESULTS

Thirty-three patients (20 males, median age 26 years, interquartile range 12) were followed for a median time of 7.9 years (interquartile range 9.8, time range 2-25.9). No deaths occurred. In 15 patients (45%), the defect remained patent at baseline. During follow-up, two spontaneous closures (13%) occurred. Eighteen patients (55%) required closure before the age of 16 years. Five (28%) needed reoperation. In the dcVSD closure group, left ventricular ejection fraction decreased from 69 ± 12 to 61 ± 6% (p = 0.028). No significant changes in pulmonary arterial hypertension were noticed.

CONCLUSIONS

Patients with persistently patent dcVSD remained nearly event free during follow-up. Event-free survival after dcVSD closure was markedly lower. These patients developed reduced left ventricular function and had a high risk of reintervention.

Aortic stiffness and aortic dilation in infants and children with tetralogy of Fallot before corrective surgery: evidence for intrinsically abnormal aortic mechanical property

OBJECTIVE

The present study tested the hypothesis that there is an intrinsic abnormality of aortic elasticity in infants/children with tetralogy of Fallot (TOF) before corrective surgery. The study also determined the independent and quantitative effects of aortic volume load on aortic dilation in this group of TOF patients.

METHODS

Aortic stiffness (pulse wave velocity; PWV) and aortic volume load (aortic volume flow) were measured during catheterization in 37 infants and children with TOF before corrective surgery and in 55 control subjects.

RESULTS

PWV was significantly higher in TOF patients than in controls, irrespective of age, sex, hemodynamic burden on the aortic wall, and existence of aorto-pulmonary shunt. Aortic diameter was also significantly greater in TOF patients than in controls. Multivariate regression analysis identified aortic volume load as an independent determinant of aortic dilation (aortic diameter = 0.72 aortic flow + 26.1 body surface area + 2.79, r(2) = 0.58, p < 0.001). Increased aortic-wall stiffness correlated with the increase in aortic diameter in patients with dominant left-to-right shunt (without aortic volume load); aortic diameter = 0.007 PWV + 13.5 body surface area (BSA) + 6.3 (r(2) = 0.73, p < 0.05).

CONCLUSIONS

The present study highlighted the intrinsic abnormality of the mechanical property of the aortic wall as a feature of aortopathy in TOF. The study also indicated that aortic volume overload and, to a lesser extent, intrinsically high aortic stiffness correlated significantly with aortic dilation in TOF.

Ventricular–Vascular Stiffening in Patients With Repaired Coarctation of Aorta

Background— Despite successful repair, patients with coarctation of the aorta (COA) often show persistent hypertension at rest and/or during exercise. Previous studies indicated that the hypertension is mainly due to abnormalities in the arterial bed and its regulatory systems. We hypothesized that ventricular systolic stiffness also contributes to the hypertensive state in these patients in addition to increased vascular stiffness.

Methods and Results— The study involved 43 patients with successfully repaired COA and 45 age-matched control subjects. Ventricular systolic stiffness (end systolic elastance) and arterial stiffness (effective arterial elastance) were measured invasively by ventricular pressure–area relationship during varying preload before and after β-adrenergic stimulation. The mean systolic blood pressure was significantly higher with concomitant increases in both end systolic elastance and effective arterial elastance in patients with COA compared with control subjects (113.2±16.8 versus 91.0±9.1 mm Hg, 44.5±17.0 versus 19.2±6.7 mm Hg/mL/m 2 , and 27.8±11.4 versus 20.2±4.8 mm Hg/mL/m 2 , respectively; P <0.01 for each). End systolic elastance and effective arterial elastance of patients with COA showed exaggerated responses to β-adrenergic stimulation, further amplifying blood pressure elevation. Quantification analyses assuming that ventricular systolic stiffness of patients with COA is equal to that of the control revealed that ventricular systolic stiffness accounts for approximately 50% to 70% of the elevated blood pressure in patients with COA. Furthermore, combined ventricular–arterial stiffening amplified systolic pressure sensitivity to increased preload during abdominal compression and limited stroke volume gain/relaxation improvement induced by β-adrenergic stimulation.

Conclusions— Increased ventricular systolic stiffness, coupled with increased arterial stiffness, plays important roles in hypertension in patients with repaired COA. Thus, ventricular systolic stiffness is a potentially suitable target for reduction of blood pressure and improvement of prognosis of patients with COA.

Aortic valvar involvement in patients undergoing closure of ventricular septal defect via the pulmonary trunk

BACKGROUND

To determine how often the aortic valve is involved in doubly-committed ventricular septal defect in a surgical series, and when to intervene to minimize aortic valvar impediments.

METHODS

The defect was surgically closed in 415 patients via the pulmonary trunk, age at operation ranging from 2 months to 76 years old. In infants, pulmonary hypertension or pulmonary high flow was the exclusive indication. Any progressive deformity of the aortic leaflet or aortic regurgitation was an alternative principal indication in older children or adolescents. No additional manoeuvres were employed for the aortic root unless aortic regurgitation is more than slight. Otherwise, the aortic valve was repaired or replaced. When the sinus of Valsalva was significantly deformed or ruptured, the structure was surgically restored.

RESULTS

Significant aortic regurgitation or the ruptured sinus of Valsalva was increasingly found beyond the paediatric age. Bacterial endocarditis was seen in 8% of adults or adolescents. Silent herniation of the aortic leaflet was not uncommon after 4 years old, seen in more than 40% of patients. Need of aortic valvar repair was rare before 2 years old, and in approximately 10% between 2 and 15 years old. Freedom from reoperation was 89% at 10 years and 78% at 25 years after aortic valvar repair, and 91% and 84%, respectively, after replacement, versus 100% and 99.4%, respectively, after no additional valvar procedure.

CONCLUSION

Aortic valvar involvement was rare, and ventricular septal defect was closed without impediments, before 2 years old. Surgery should be arranged before any additional aortic valvar manoeuvre is needed.

Progression of aortic regurgitation after surgical repair of outlet-type ventricular septal defects

BACKGROUND

Progression of aortic regurgitation (AR) in repaired outlet ventricular septal defects (VSDs) remains unclear, especially for muscular outlet and perimembranous outlet VSDs. We tried to identify the risk factors for AR progression and aortic valve replacement (AVR) at long-term follow-up.

METHODS

Four hundred patients with complete follow-up after the repair of their outlet VSD between 1987 and 2002 were studied.

RESULTS

Juxta-arterial VSD, perimembranous outlet VSD, and muscular outlet VSD were noted in 190, 148, and 62 patients, respectively. There were 377 patients with none to mild AR (group I) and 23 with moderate to severe AR (group II) preoperatively. Aortic valve replacement was performed on 11 patients (all from group II), with 10 having received AVR concomitantly with VSD repair and 1 having received it 4 years later. Only severity of preoperative AR and older age (>15 years) at VSD repair were significant predictors of AVR. With a total follow-up of 2230 person-years, the 10-year freedom from AVR after VSD repair for group I was 100% and that for group II was 50.2%. In group I, AR progressed in 4 patients only (1.2%, 2 juxta-arterial and 2 perimembranous outlet) and aortic valvular (aortic valve prolapse or ruptured sinus Valsalva aneurysm) or subvalvular anomalies were present in all. The event-free (AR or AVR) survival rates among the 3 outlet-type VSDs however showed no difference.

CONCLUSIONS

Aortic regurgitation progression modes after surgical VSD repair were similar among the 3 outlet-type VSDs. Aortic valve replacement was rarely necessary for patients who were operated on when they were younger than 15 years. Aortic regurgitation of a less-than-moderate degree preoperatively rarely progressed after VSD repair.