Left ventricular remodeling and improvement in diastolic function after balloon aortic valvuloplasty for congenital aortic stenosis

Left ventricular function assessment after aortic and renal intervention in Takayasu arteritis by speckle tracking echocardiography: a pilot study

Background

Overt left ventricular (LV) dysfunction and congestive heart failure are known entities in Takayasu arteritis (TA). Subclinical LV dysfunction may develop in these patients despite normal LV ejection fraction (LVEF). Moreover, effect of treatment of aortic or renal artery narrowing in such patients is unknown.

Methods

This study included 15 angiographically confirmed TA patients undergoing aortic and/or renal intervention. A comprehensive clinical, biochemical and echocardiographic (2-dimensional, speckle tracking and tissue doppler imaging) evaluation were done at baseline, 72 h, and six months post intervention.

Results

Six patients (40%) had reduced LVEF (<50%) at baseline while rest 9 (60%) patients had reduced global longitudinal strain (GLS) but normal EF. Diastolic filling pattern was abnormal in all the patients. In patients with baseline reduced EF, mean EF improved from 24.62 ± 12.14% to 45.6 ± 9.45% (p = 0.001), E/e’ ratio decreased from 15.15 ± 3.19 to 10.8 ± 2.56 (p = 0.005) and median NT pro BNP decreased from 1673 pg/ml (970–2401 pg/ml) to 80 pg/ml (40–354 pg/ml) (p = 0.001) at 6 months after interventional procedure. In patients with baseline normal EF, median NT pro BNP decreased from 512 pg/ml (80–898.5 pg/ml) to 34 pg/ml (29–70.8 pg/ml) (p < 0.01), mean GLS improved from −8.80 ± 0.77% to −16.3 ± 0.78% (p < 0.001) and mean E/e’ decreased from 12.93 ± 2.63 to 7.8 ± 2.73 (p = 0.005) at 6 months follow up.

Conclusion

LV dysfunction is common in patients with TA and obstructive lesions in aorta or renal arteries. GLS can be used to assess subclinical systolic dysfunction in these patients. Timely intervention can improve LV dysfunction and can even reverse the subclinical changes.

Increased prevalence of left ventricular diastolic dysfunction in adults with repaired coarctation of aorta

Background

Left ventricular (LV) pressure overload and coronary artery disease are common in patients with coarctation of aorta (COA), and they are risk factors for LV diastolic dysfunction. Patients with COA may have aortic vasculopathy that can result in LV pressure overload even in the absence of hemodynamically significant COA. We therefore hypothesized that patients with mild COA (without hemodynamically significant COA) will have more LV diastolic dysfunction compared to controls.

Methods

Adult patients with mild COA (Doppler peak velocity < 2.5 m/s) were matched 1:1 to patients without structural heart disease using propensity score method based on age, sex, body mass index, hypertension and blood pressure. The objective was to compare LV diastolic dysfunction (defined as E/e′ > 2 standard deviations above age-specific normative values) between adults with repaired COA and controls.

Results

Of 204 COA and 204 control patients (age 35 ± 12 years), patients with COA had higher septal and lateral E/e′ ratio (12 ± 4 vs 9 ± 4, p = 0.009) and (10 ± 3 vs 7 ± 3, p < 0.001), respectively. Compared to controls, the prevalence of LV diastolic dysfunction was higher in patients with COA for every age group: <40 years (63% vs 13%, p < 0.001); 41–60 years (87% vs 33%, p < 0.001); age > 60 years (82% vs 56%, p = 0.076). Left ventricular mass index (LVMI) was the strongest determinant of E/e′ (β = 2.71 per 10 g/m², standard error = 1.25, p < 0.001).

Conclusion

LV diastolic dysfunction was common in patients with COA, and the association with LVMI suggests that patients with COA may have ongoing LV pressure overload in the absence of hemodynamically significant re-coarctation.

Is Doppler echocardiography useful for estimating left ventricular filling pressures in pediatric heart transplant recipients?

LV E/E' ratio obtained using Doppler echocardiography is considered a surrogate for LV filling pressure in adults but has performed poorly in children. We hypothesized that LV E/E' ratio Z-score, adjusted for age, will relate more strongly to LV filling pressures than LV E/E' ratio in pediatric HT recipients. We analyzed 751 echocardiograms performed within 24 hours of a heart catheterization in 122 pediatric HT recipients (median age at HT 13 years, median 6 studies per patient). The primary end-point was PCWP, assessed both as a continuous and a binary variable. Associations with LV E/E' ratios and z-scores were assessed using generalized estimating equations models. PCWP, LV E/E' ratios (using E' from LV free wall, septum, and their average), and LV E/E' ratio Z-scores, all declined over time after HT. LV E/E' ratios and their Z-scores were significantly associated with PCWP assessed as a continuous variable (P < 0.001 for all); however, the relationship was weak (R² range, 0.083 to 0.121). LV E/E' ratios and their Z-scores were also significantly associated with PCWP as a binary variable (P < 0.001 for all) but with only modest ability to discriminate PCWP ≥15 mm Hg (c-statistic range, 0.660 to 0.695). The association between LV E/E' ratio and PCWP in pediatric HT recipients is modest. Using a LV E/E' ratio Z-score did not result in significantly improved association with PCWP. Current Doppler echocardiographic methods are unreliable for estimating LV filling pressures in pediatric HT recipients.

Longitudinal Assessment of the Doppler-Estimated Maximum Gradient in Patients With Congenital Valvar Aortic Stenosis Pre- and Post-Balloon Valvuloplasty

BACKGROUND

Aortic stenosis has been reported to manifest a slow rate of progression in mild disease, with a greater likelihood of progression in patients with moderate-severe disease. The natural history of the Doppler-estimated maximum gradient (DEMG) in patients after balloon aortic valvuloplasty (BAVP) has not previously been studied on a large scale.

METHODS AND RESULTS

A retrospective review was performed of 360 patients from 1984 to 2012 with aortic stenosis, providing a total of 2059 echocardiograms both before and after BAVP. Patients were excluded if they had an intervention within the first 30 days of life. The relationships between the aortic stenosis DEMG and several predictors (age at initial study, body surface area, valve morphology, and initial DEMG) were explored using linear mixed effect models. Patients with a unicommissural aortic valve had a significantly higher rate of progression compared with those with a bicommissural aortic valve (0.81 and 0.45 mm Hg/year; P<0.001). The median rate of progression in the post-BAVP group was significantly lower than the median pre-BAVP rate of progression (n=34; pre-BAVP 3.97 [1.69-8.7] mm Hg/year; post-BAVP 0.40 [-1.80 to 3.88] mm Hg/year; P<0.008). When adjusted for body surface area, there was no significant increase in the DEMG (-0.03 mm Hg/m² per year; P<0.001).

CONCLUSIONS

There is a statistically significant increase in the DEMG over time in patients with aortic stenosis. After balloon dilation, the DEMG rate of change is reduced compared with that pre-dilation. Given the effect of body surface area on DEMG progression, more frequent observation should be made during periods of rapid somatic growth.

Early hemodynamic changes after fetal aortic stenosis valvuloplasty predict biventricular circulation at birth

OBJECTIVE

To describe the early hemodynamic changes after fetal aortic valvuloplasty (FAV) for evolving hypoplastic left heart syndrome due to mid-gestational aortic stenosis and to assess whether these early changes predict biventricular (BiV) circulation at neonatal discharge.

METHOD

We retrospectively reviewed all technically successful FAV cases resulting in live birth between 2000 and 2015 (n = 93, 45% BiV circulation at neonatal discharge). Paired testing methods were used to compare pre-intervention and post-intervention measures of left ventricular hemodynamics. Logistic regression was used to determine whether these changes were predictive of post-natal outcome.

RESULTS

Measures of left heart physiology were markedly abnormal pre-FAV and improved significantly post-FAV. No subjects had systolic antegrade transverse aortic arch flow pre-FAV and 65% of subjects had antegrade flow post-FAV. The number of subjects with abnormal left-to-right patent foramen ovale flow decreased, and the number with biphasic mitral valve inflow increased. The median left ventricular ejection fraction improved after intervention. Amongst the pre-post changes, gaining partially or exclusively antegrade systolic arch flow was the most significant independent predictor of BiV circulation (OR 9.80 and 19.83, respectively, both P < 0.001).

CONCLUSION

Technically successful FAV is associated with immediate improvements in left heart physiology that are predictive of BiV circulation at neonatal discharge.

Utility of Cardiovascular Magnetic Resonance-Derived Wave Intensity Analysis As a Marker of Ventricular Function in Children with Heart Failure and Normal Ejection Fraction

OBJECTIVE

This study sought to explore the diagnostic insight of cardiovascular magnetic resonance (CMR)-derived wave intensity analysis to better study systolic dysfunction in young patients with chronic diastolic dysfunction and preserved ejection fraction (EF), comparing it against other echocardiographic and CMR parameters.

BACKGROUND

Evaluating systolic and diastolic dysfunctions in children is challenging, and a gold standard method is currently lacking.

METHODS

Patients with presumed diastolic dysfunction [n = 18; nine aortic stenosis (AS), five hypertrophic, and four restrictive cardiomyopathies] were compared with age-matched control subjects (n = 18). All patients had no mitral or aortic incompetence, significant AS, or reduced systolic EF. E/A ratio, E/E' ratio, deceleration time, and isovolumetric contraction time were assessed on echocardiography, and indexed left atrial volume (LAVi), acceleration time (AT), ejection time (ET), and wave intensity analyses were calculated from CMR. The latter was performed on CMR phase-contrast flow sequences, defining a ratio of the peaks of the early systolic forward compression wave (FCW) and the end-systolic forward expansion wave (FEW).

RESULTS

Significant differences between patients and controls were seen in the E/E' ratio (8.7 ± 4.0 vs. 5.1 ± 1.3, p = 0.001) and FCW/FEW ratio (2.5 ± 1.6 vs. 7.2 ± 4.2 × 10^-5 m/s, p < 0.001), as well as-as expected-LAVi (80.7 ± 22.5 vs. 51.0 ± 10.9 mL/m², p < 0.001). In particular, patients exhibited a lower FCW (2.5 ± 1.6 vs. 7.2 ± 4.2 × 10^-5 m/s, p < 0.001) in the face of preserved EF (67 ± 11 vs. 69 ± 5%, p = 0.392), as well as longer isovolumetric contraction time (49 ± 7 vs. 34 ± 7 ms, p < 0.001) and ET/AT (0.35 ± 0.04 vs. 0.27 ± 0.04, p < 0.001).

CONCLUSION

This study shows that the wave intensity-derived ratio summarizing systolic and diastolic function could provide insight into ventricular function in children, on top of CMR and echocardiography, and it was here able to identify an element of ventricular dysfunction with preserved EF in a small group of young patients.

Assessment of Diastolic Function in Single-Ventricle Patients After the Fontan Procedure

BACKGROUND

Patients with functional single ventricles after the Fontan procedure have abnormal cardiac mechanics. The aims of this study were to determine factors that influence diastolic function and to describe associations of diastolic function with current clinical status.

METHODS

Echocardiograms were obtained as part of the Pediatric Heart Network Fontan Cross-Sectional Study. Diastolic function grade (DFG) was assessed as normal (grade 0), impaired relaxation (grade 1), pseudonymization (grade 2), or restrictive (grade 3). Studies were also classified dichotomously (restrictive pattern present or absent). Relationships between DFG and pre-Fontan variables (e.g., ventricular morphology, age at Fontan, history of volume-unloading surgery) and current status (e.g., systolic function, valvar regurgitation, exercise performance) were explored.

RESULTS

DFG was calculable in 326 of 546 subjects (60%) (mean age, 11.7 ± 3.3 years). Overall, 32% of patients had grade 0, 9% grade 1, 37% grade 2, and 22% grade 3 diastolic function. Although there was no association between ventricular morphology and DFG, there was an association between ventricular morphology and E', which was lowest in those with right ventricular morphology (P < .001); this association remained significant when using Z scores adjusted for age (P < .001). DFG was associated with achieving maximal effort on exercise testing (P = .004); the majority (64%) of those not achieving maximal effort had DFG 2 or 3. No additional significant associations of DFG with laboratory or clinical measures were identified.

CONCLUSIONS

Assessment of diastolic function by current algorithms results in a high percentage of patients with abnormal DFG, but few clinically or statistically significant associations were found. This may imply a lack of impact of abnormal diastolic function on clinical outcomes in this cohort, or it may indicate that the methodology may not be applicable to pediatric patients with functional single ventricles.

Determinants and Regression Equations for the Calculation of z Scores of Left Ventricular Tissue Doppler Longitudinal Indexes in a Healthy Italian Pediatric Population

Aim. We investigated the predictors of tissue Doppler left ventricular (LV) longitudinal indexes in a healthy Italian pediatric population and established normative data and regression equations for the calculation of z scores. Methods and Results. A total of 369 healthy subjects aged 1–17 years (age of 6.4 ± 1.1 years, 49.1% female) underwent echocardiography. LV peak longitudinal velocity at systole (s^'), early diastole (e^'), and late diastole (a^') was determined by tissue Doppler. The ratio of peak early diastolic LV filling velocity to e^' was calculated. Age was the only independent determinant of s^' (β = 0.491, p < 0.0001) and the strongest determinant of e^' (β = 0.334, p < 0.0001) and E/e^' (β = −0.369, p < 0.0001). Heart rate was the main determinant of a^' (β = 0.265, p < 0.0001). Male gender showed no effects except for a weak association with lateral s^', suggesting no need of gender-specific reference ranges. Age-specific reference ranges, regression equations, and scatterplots for the calculation of z scores were determined for each index. Conclusion. In a pediatric Italian population, age was the strongest determinant of LV longitudinal dynamics. The availability of age-specific normality data for the calculation of z scores may allow for correctly detecting LV dysfunction in pediatric pathological populations.

Left ventricular response to pressure afterload in children: aortic stenosis and coarctation: a systematic review of the current evidence

Congenital aortic stenosis (CAS) and Coarctation of Aorta (CoA) represent two forms of pressure afterload that affect the left ventricle (LV), hence require regular echocardiographic monitoring. Subclinical dysfunction of the LV exists even in asymptomatic patients with preserved left ventricular ejection fraction (EF), implying low sensitivity of EF in predicting optimum time for intervention. In this article we review patterns of LV myocardial deformation before and after correction of CAS and CoA in infants, children and adolescents, showing their important role in monitoring the course of LV dysfunction. A systematic search using PubMed was performed and suitable studies are presented on a narrative form. Normal EF and/or fractional shortening (FS), with subclinical myocardial dysfunction are reported in all studies before intervention. The short-term results, after intervention, were related to the type of procedure, with no improvement or further deterioration related to surgery but immediate improvement after balloon intervention. Long term follow-up showed further improvement but still subnormal function. Thus correction of CAS and CoA before irreversible LV dysfunction is vital, and requires longitudinal studies in order to identify the most accurate parameter for function prognostication. Until then, conventional echocardiographic parameters together with myocardial velocities and deformation parameters should continue to provide follow-up reproducible measures of ventricular function.

Mixed aortic valve disease in the young: initial observations

The short-term surgical results for mixed aortic valve disease (MAVD) and the long-term effects on the left ventricle (LV) are unknown. Retrospective review identified patients with at least both moderate aortic stenosis (AS) and aortic regurgitation (AR) before surgical intervention. A one-to-one comparison cohort of patients with MAVD not referred for surgical intervention was identified. The 45 patients in this study underwent surgical management for MAVD. A control group of 45 medically managed patients with MAVD also was identified. Both groups had elevated LV end-diastolic volume (EDV), elevated LV mass, a normal LV mass:volume ratio (MVR), and a normal ejection fraction. Both groups had diastolic dysfunction shown by early diastolic pulsed-Doppler mitral inflow/early diastolic tissue Doppler velocity z-score. The LV end-diastolic pressure (EDP) was correlated with age (R = 0.4; p = 0.03) and LV MVR (R = 0.4; p = 0.03) but not with AS, AR, or the score combining gradient and LV size. As shown by 6- to 12-month postoperative echocardiograms, aortic valve gradients and AR significantly improved (gradient 65 ± 17 to 28 ± 18 mmHg, p = 0.01; median regurgitation grade moderate to mild; p < 0.01), LV EDV normalized, and LV mass significantly improved (p < 0.01). Diastolic dysfunction was unchanged. Symptoms did not correlate with any measured parameter, but the preoperative symptoms resolved. In conclusion, despite diastolic dysfunction, systolic function is invariably preserved, and symptoms are not correlated with aortic valve function or LV EDP. Current surgical practice preserves LV mechanics and results in short-term improvement in valve function and symptoms.

Left ventricular diastolic function and characteristics in fetal aortic stenosis

Fetal aortic balloon valvuloplasty (FAV) has shown promise in averting progression of midgestation aortic stenosis (AS) to hypoplastic left heart syndrome in a subset of patients. Patients who achieve biventricular circulation after FAV frequently have left ventricular (LV) diastolic dysfunction (DD). This study evaluates DD in fetuses with AS by comparing echocardiographic indices of LV diastolic function in fetuses underwent FAV (n = 20) with controls (n = 40) and evaluates for LV factors associated with DD in patients with FAV. We also compared pre-FAV and post-FAV DD variables (n = 16). Median gestational age (24 weeks, range 18 to 29 weeks) and fetal heart rate were similar between FAV and controls. Compared with controls, patients with FAV had universally abnormal LV diastolic parameters including fused mitral inflow E and A waves (p = 0.008), higher E velocity (p <0.001), shorter mitral inflow time (p = 0.001), lower LV lateral annulus E' (p <0.001), septal E' (p = 0.003), and higher E/E' (p <0.001) than controls. Patients with FAV had abnormal right ventricular mechanics with higher tricuspid inflow E velocity (p <0.001) and shorter tricuspid inflow time (p = 0.03). Worse LV diastolic function (lower LV E') was associated with higher endocardial fibroelastosis grade (r = 0.74, p <0.001), large LV volume (r = 0.55, p = 0.013), and sphericity (r = 0.58, p = 0.009) and with lower LV pressure by mitral regurgitation jet (r = -0.68, p <0.001). Post-FAV, fewer patients had fused mitral inflow E and A than pre-FAV (p = 0.05) and septal E' was higher (=0.04). In conclusion, fetuses with midgestation AS have evidence of marked DD. Worse DD is associated with larger, more spherical LV, with more extensive endocardial fibroelastosis and lower LV pressure.