Diastolic function predicts outcome after aortic valve replacement in patients with chronic severe aortic regurgitation

Incidence and Risk Factors for Long-Term Persistence of Diastolic Dysfunction after Aortic Valve Replacement for Aortic Stenosis Compared with Aortic Regurgitation

(1) Background: Severe left ventricular (LV) diastolic dysfunction with a restrictive diastolic pattern (LVDFP) is generally associated with a worse prognosis. Its evolution and reversibility in the short- and medium-term after aortic valve replacement (AVR) has been little-studied. We aimed to evaluate the evolution of LV remodeling and LV systolic and diastolic function after AVR in aortic stenosis (AS) patients compared to aortic regurgitation (AR). Moreover, we tried to identify the main predictive parameters for postoperative evolution (cardiovascular hospitalization or death and quality of life) and the independent predictors for the persistence of restrictive LVDFP after AVR. (2) Methods: A five-year prospective study on 397 patients undergoing AVR for AS (226 pts) or AR (171 pts), evaluated clinically and by echocardiography preoperatively and until 5 years postoperatively. (3) Results: 1. In patients with AS, early post AVR, LV dimensions decreased and diastolic filling and LV ejection fraction (LVEF) improved more rapidly compared to patients with AR. At 1 year postoperatively, persistent restrictive LVDFP was found especially in the AR group compared to the AS group (36.84% vs. 14.16%). 2. Cardiovascular event-free survival at the 5-year follow-up was lower in the AR group (64.91% vs. 87.17% in the AS group). The main independent predictors of short- and medium-term prognosis after AVR were: restrictive LVDFP, severe LV systolic dysfunction, severe pulmonary hypertension (PHT), advanced age, severe AR, and comorbidities. 3. The persistence of restrictive LVDFP after AVR was independently predicted by: preoperative AR, the E/Ea ratio > 12, the LA dimension index > 30 mm/m², an LV endsystolic diameter (LVESD) > 55 mm, severe PHT, and associated second-degree MR (p < 0.05). (4) Conclusions: AS patients had an immediate postoperative evolution in terms of LV remodeling, and LV systolic and diastolic function were more favorable compared to those with AR. The restrictive LVDFP was reversible, especially after the AVR for AS. The main prognostic predictors were the presence of restrictive LVDFP, advanced age, preoperative AR, severe LV systolic dysfunction, and severe PHT.

Valvular heart disease: shifting the focus to the myocardium

Adverse cardiac remodelling is the main determinant of patient prognosis in degenerative valvular heart disease (VHD). However, to give an indication for valvular intervention, current guidelines include parameters of cardiac chamber dilatation or function which are subject to variability, do not directly reflect myocardial structural changes, and, more importantly, seem to be not sensitive enough in depicting early signs of myocardial dysfunction before irreversible myocardial damage has occurred. To avoid irreversible myocardial dysfunction, novel biomarkers are advocated to help refining indications for intervention and risk stratification. Advanced echocardiographic modalities, including strain analysis, and magnetic resonance imaging have shown to be promising in providing new tools to depict the important switch from adaptive to maladaptive myocardial changes in response to severe VHD. This review, therefore, summarizes the current available evidence on the role of these new imaging biomarkers in degenerative VHD, aiming at shifting the clinical perspective from a valve-centred to a myocardium-focused approach for patient management and therapeutic decision-making.

Diastolic versus Systolic Left Ventricular Dysfunction as Independent Predictors for Unfavorable Postoperative Evolution in Patients with Aortic Regurgitation Undergoing Aortic Valve Replacement

Background and Objectives: Chronic severe aortic valve disease is associated with important changes in left ventricle (LV) performance associated with eccentric or concentric LV hypertrophy. We aimed to assess the immediate prognostic implications of the type of the LV diastolic filling pattern (LVDFP) compared with LV systolic performance in patients with severe aortic regurgitation (AR) undergoing aortic valve replacement (AVR) and to define the independent echographic predictors for the immediate and long-term prognoses. Materials and Methods: We performed a prospective study enrolling 332 AR patients undergoing AVR, divided into two groups: Group A—201 pts with normal LV systolic function, divided into two subgroups (A1: 129 pts with a nonrestrictive LVDFP and A2: 72 pts with restrictive LVDFP), and Group B—131 pts with LV systolic dysfunction (LV ejection fraction LVEF < 50%), divided into two subgroups (B1: 83 pts with a nonrestrictive LVDFP and B2: 48 pts with restrictive LVDFP). Results: The early postoperative mortality rate was higher in patients with a restrictive LVDFP (11.12% in A2 and 12.5% in B2) compared with normal LV filling (2.32% in A1 and 7.63% in B1, p < 0.0001), regardless of the LVEF. The restrictive LVDFP—defined by at least one of the following echographic parameters: an E/A > 2 with an E wave deceleration time (EDt) < 100 ms; an isovolumetric relaxation time (IVRT) < 60 ms; or an S/D ratio < 1 in the pulmonary vein flow—was an independent predictor for early postoperative mortality, increasing the relative risk by 8.2-fold. Other independent factors associated with early poor prognosis were an LV end-systolic diameter (LVESD) > 58 mm, an age > 75 years, and the presence of comorbidities (chronic obstructive pulmonary disease-COPD or diabetes mellitus). On a medium-term, an unfavorable evolution was associated with: an age > 75 years (RR = 8.1), an LV end-systolic volume (LVESV) > 95 cm3 (RR = 6.7), a restrictive LVDFP (RR = 9.8, p < 0.0002), and pulmonary hypertension (RR = 8.2). Conclusions: The presence of a restrictive LVDFP in patients with AR undergoing AVR is associated with both increased early and medium-term mortality rates. The LV diastolic function is a more reliable parameter for prognosis than LV systolic performance (RR 9.2 versus 2.1). Other independent predictors for increased early postoperative mortality rate were: an age > 75 years, an LVESD > 58 mm, and comorbidities (diabetes mellitus, COPD), and for unfavorable evolution at 2 years postoperatively: an age > 75 years, an LVESV > 95 cm3, and severe pulmonary hypertension.

Prognostic value of diastolic function parameters in significant aortic regurgitation: the role of the left atrial strain

BACKGROUND

The management of patients with asymptomatic significant aortic regurgitation (sAR) is often challenging and appropriate timing of aortic valve surgery remains controversial. Prognostic value of diastolic parameters has been demonstrated in several cardiac diseases. The aim of this study was to analyze the prognostic significance of the diastolic function evaluated by echocardiography, in asymptomatic patients with sAR.

METHODS

A total of 126 patients with asymptomatic sAR evaluated in the Heart Valve Clinic were retrospective included. Conventional echocardiographic systolic and diastolic function parameters were assessed. Left atrial (LA) auto-strain analysis was performed in a sub-group of 57 patients. A combined end-point of hospital admission due to heart failure, cardiovascular mortality, or aortic valve surgery was defined.

RESULTS

During a median follow-up of 34.1 (interquartile range 16.5-48.1) months, 25 (19.8%) patients reached the combined end-point. Univariate analysis showed that LV volumes, LV ejection fraction (LVEF), LV-GLS, E wave, E/e' ratio, LA volume and LA reservoir strain (LASr) were significant predictors of events. Multivariate analysis that tested all classical echocardiographic variables statistically significant in the univariate model showed that LVEDV (HR = 1.02; 95% CI 1.01-1.03; p < 0.001) and E/e' ratio (HR = 1.12; 95% CI 1.03-123; p = 0.01) were significant predictors of events. Kaplan-Meier curve, stratified by median value of LASr, showed that lower LASr values (less than median of 34%) were associated with higher rates of events (p = 0.013).

CONCLUSION

In this population of asymptomatic patients with sAR and normal LV systolic function, baseline diastolic parameters were prognostic markers of cardiovascular events; among them, LASr played a significant predictor role.

Prognostic implications of left atrial dilation in aortic regurgitation due to bicuspid aortic valve

OBJECTIVE

To investigate the prognostic value of left atrial volume index (LAVI) in patients with moderate to severe aortic regurgitation (AR) and bicuspid aortic valve (BAV).

METHODS

554 individuals (45 (IQR 33-57) years, 80% male) with BAV and moderate or severe AR were selected from an international, multicentre registry. The association between LAVI and the combined endpoint of all-cause mortality or aortic valve surgery was investigated with Cox proportional hazard regression analyses.

RESULTS

Dilated LAVI was observed in 181 (32.7%) patients. The mean indexed aortic annulus, sinus of Valsalva, sinotubular junction and ascending aorta diameters were 13.0±2.0 mm/m², 19.4±3.7 mm/m², 16.5±3.8 mm/m² and 20.4±4.5 mm/m², respectively. After a median follow-up of 23 (4-82) months, 272 patients underwent aortic valve surgery (89%) or died (11%). When compared with patients with normal LAVI (<35 mL/m²), those with a dilated LAVI (≥35 mL/m²) had significantly higher rates of aortic valve surgery or mortality (43% and 60% vs 23% and 36%, at 1 and 5 years of follow-up, respectively, p<0.001). Dilated LAVI was independently associated with reduced event-free survival (HR=1.450, 95% CI 1.085 to 1.938, p=0.012) after adjustment for LV ejection fraction, aortic root diameter, LV end-diastolic diameter and LV end-systolic diameter.

CONCLUSIONS

In this large, multicentre registry of patients with BAV and moderate to severe AR, left atrial dilation was independently associated with reduced event-free survival. The role of this parameter for the risk stratification of individuals with significant AR merits further investigation.

Prognostic Markers and Long-Term Outcomes After Aortic Valve Replacement in Patients With Chronic Aortic Regurgitation

Background

The objectives of the present study were (1) to evaluate the echocardiographic prognostic factors associated with improved left ventricular (LV) systolic function after aortic valve replacement, and (2) to compare the long‐term outcomes after aortic valve replacement in chronic aortic regurgitation (AR) patients with or without LV dysfunction.

Methods and Results

A total of 280 patients who underwent aortic valve replacement because of chronic aortic regurgitation were studied. Patients with reduced LV systolic function (LV ejection fraction [LVEF] <50%; group reduced LVEF [rEF]; N=80) were compared with those with preserved LV systolic function (LVEF ≥50%; group preserved LVEF; N=200). Postoperative clinical outcomes, overall survival, and freedom from cardiac death were compared. Postoperative echocardiographic examinations were reviewed, and changes in echocardiographic parameters were analyzed. The parameters related to LVEF improvement or normalization were evaluated, and risk factors affecting long‐term survival were identified. Follow‐up was complete in 100% of patients, with a median follow‐up of 104.8 months. Overall and cardiac mortality‐free survival rates at postoperative 10 years were 80.1% and 92.9% and 87.3% and 97.2% in groups rEF and preserved LVEF, respectively (P=0.036 and P=0.058, respectively). LVEF tended to decrease in the early postoperative period but improved thereafter in both groups. Preoperative early diastolic transmitral flow velocity/mitral annular tissue velocity ratio was a parameter of postoperative improvement or normalization of LVEF in all patients (area under the curve, 0.719; P=0.003) and in group rEF patients (area under the curve, 0.726; P=0.011) with a cutoff value of 12.73. Preoperative early diastolic transmitral flow velocity/mitral annular tissue velocity ratio also was the parameter of overall survival in all patients (hazard ratio [HR], 1.08; P=0.001) and in group rEF patients (HR, 1.08; P=0.005).

Conclusions

Long‐term outcomes and survival after aortic valve replacement were related to preoperative LV function in patients with chronic aortic regurgitation. Preoperative early diastolic transmitral flow velocity/mitral annular tissue velocity ratio was correlated with the postoperative improvement or normalization of LVEF and long‐term survival, especially in group rEF patients.

Mitochondrial Reversible Changes Determine Diastolic Function Adaptations During Myocardial (Reverse) Remodeling

BACKGROUND

Often, pressure overload-induced myocardial remodeling does not undergo complete reverse remodeling after decreasing afterload. Recently, mitochondrial abnormalities and oxidative stress have been successively implicated in the pathogenesis of several chronic pressure overload cardiac diseases. Therefore, we aim to clarify the myocardial energetic dysregulation in (reverse) remodeling, mainly focusing on the mitochondria.

METHODS

Thirty-five Wistar Han male rats randomly underwent sham or ascending (supravalvular) aortic banding procedure. Echocardiography revealed that banding induced concentric hypertrophy and diastolic dysfunction (early diastolic transmitral flow velocity to peak early-diastolic annular velocity ratio, E/E': sham, 13.6±2.1, banding, 18.5±4.1, P=0.014) accompanied by increased oxidative stress (dihydroethidium fluorescence: sham, 1.6×10⁸±6.1×10⁷, banding, 2.6×10⁸±4.5×10⁷, P<0.001) and augmented mitochondrial function. After 8 to 9 weeks, half of the banding animals underwent overload relief by an aortic debanding surgery (n=10).

RESULTS

Two weeks later, hypertrophy decreased with the decline of oxidative stress (dihydroethidium fluorescence: banding, 2.6×10⁸±4.5×10⁷, debanding, 1.96×10⁸±6.8×10⁷, P<0.001) and diastolic dysfunction improved simultaneously (E/E': banding, 18.5±4.1, debanding, 15.1±1.8, P=0.029). The reduction of energetic demands imposed by overload relief allowed the mitochondria to reduce its activity and myocardial levels of phosphocreatine, phosphocreatine/ATP, and ATP/ADP to normalize in debanding towards sham values (phosphocreatine: sham, 38.4±7.4, debanding, 35.6±8.7, P=0.71; phosphocreatine/ATP: sham, 1.22±0.23 debanding, 1.11±0.24, P=0.59; ATP/ADP: sham, 6.2±0.9, debanding, 5.6±1.6, P=0.66). Despite the decreased mitochondrial area, complex III and V expression increased in debanding compared with sham or banding. Autophagy and mitophagy-related markers increased in banding and remained higher in debanding rats.

CONCLUSIONS

During compensatory and maladaptive hypertrophy, mitochondria become more active. However, as the disease progresses, the myocardial energetic demands increase and the myocardium becomes energy deficient. During reverse remodeling, the concomitant attenuation of cardiac hypertrophy and oxidative stress allowed myocardial energetics, left ventricle hypertrophy, and diastolic dysfunction to recover. Autophagy and mitophagy are probably involved in the myocardial adaptation to overload and to unload. We conclude that these mitochondrial reversible changes underlie diastolic function adaptations during myocardial (reverse) remodeling.

Clinical and echocardiographic features of paradoxical low-flow and normal-flow severe aortic stenosis patients with concomitant mitral regurgitation

Mitral regurgitation (MR) coexists in a significant proportion of patients with severe aortic stenosis (AS), and portends inferior therapeutic outcomes. In severe AS, MR is thought to contribute to a low-flow state by decreasing forward stroke volume. We investigated concomitant MR on the clinical and echocardiographic features of patients with "paradoxical" low-flow (PLF) and normal-flow (NF) severe AS. Clinical and echocardiographic profiles of 886 consecutive patients with index echocardiographic diagnosis of severe AS (AVA < 1.0 cm²) were analysed retrospectively. All patients had preserved ejection fraction (LVEF  ≥ 50%, n = 645), and were divided into PLF (stroke volume index, SVI < 35 mL/m²) and NF AS. They were then further subdivided based on the presence or absence of moderate-or-severe MR (msMR). A higher prevalence of concomitant msMR was observed in patients with PLF AS (14.9%; n = 33/221) compared to those with NF AS (8.0%; n = 34/424). Concomitant msMR was associated with echocardiographic features of increased diastolic dysfunction in both PLF AS and NF AS patients, as evidenced by increased LA diameter (PLF AS 52.9 ± 12.5 to 43.9 ± 8.9 mm; NF AS 29.6 ± 10.8 to 42.4 ± 8.8 mm; p < 0.001) and increased transmitral E/A ratio (PLF AS 1.26 ± 0.56 to 0.92 ± 0.43; NF AS 1.19 ± 0.63 to 0.94 ± 0.45; p = 0.004). Amongst patients with NF AS, msMR was additionally associated with increased E:e' ratio (25.5 ± 15.1 vs 19.3 ± 10.8; p = 0.025). Concomitant MR was more common in PLF AS compared to NF. Although possibly related to the MR, patients severe AS and MR appeared to have more severe diastolic dysfunction. Further studies are warranted to evaluate prognosis and guide management.

One problem two issues! Left ventricular systolic and diastolic dysfunction in aortic stenosis

Reports suggested that immediate post-aortic valve replacement (AVR); left ventricular (LV) dysfunction may be an important risk for morbidity and mortality in patients requiring positive inotropic support. Several factors have been identified as significant prognostic factors i.e., LV systolic dysfunction, LV diastolic dysfunction (LV-DD), heart failure and myocardial infarction (MI). Specific to pathophysiological changes associated with AS, markers of systolic LV function (e.g., LVEF) have been extensively studied in management, yet only a few studies have analysed the association between LV-DD and immediate post-operative LV dysfunction This review brings together the current body of evidence on this issue.

Left ventricular diastolic function in children and young adults with congenital aortic valve disease

Young patients with congenital aortic valve disease are at risk of left ventricular (LV) diastolic dysfunction (DD). We evaluated LV remodeling and the prevalence of, and risk factors for, DD in patients with aortic stenosis (AS), pure aortic regurgitation (AR), and AS+AR. Patients aged 8 to 39 years with congenital AS (n = 103), AR (n = 36), or AS+AR (n = 107) were identified. Cross-sectional assessment of the LV remodeling pattern and diastolic function was performed. A diastolic function score (DFS; range 0 to 4) was assigned to each patient, with 1 point for an abnormal value in each of 4 categories: mitral inflow (E/A and E-wave deceleration time), tissue Doppler E', E/E', and left atrial volume. Patients with a DFS of ≥2 were compared to those with a DFS <2. Concentric hypertrophy was the most common remodeling pattern in those with AS (51%), mixed/physiologic hypertrophy in those with AS+AR (48%) and eccentric hypertrophy in those with AR (49%) predominated. In the entire cohort, 91 patients (37%) had a DFS of ≥2. Patients with AS or AS+AR had greater DFS than those with pure AR (p <0.001). On multivariate analysis, a greater LV mass z-score and previous aortic valve balloon dilation were associated with a DFS of ≥2. In patients with catheterization data (n = 65), E/E' correlated with LV end-diastolic pressure. Those with a DFS of ≥2 had a greater LV end-diastolic pressure and mean pulmonary artery pressure than those with a DFS <2. In conclusion, DD is common in young patients with AS and AS+AR but not in those with pure AR. A greater LV mass and previous aortic valve dilation were associated with DD.

Anti-hypertensive drugs have different effects on ventricular hypertrophy regression

OBJECTIVES

There is a direct relationship between the regression of left ventricular hypertrophy (LVH) and a decreased risk of mortality. This investigation aimed to describe the effects of anti-hypertensive drugs on cardiac hypertrophy through a meta-analysis of the literature.

METHODS

The Medline (via PubMed), Lilacs and Scielo databases were searched using the subject keywords cardiac hypertrophy, antihypertensive and mortality. We aimed to analyze the effect of anti-hypertensive drugs on ventricle hypertrophy.

RESULTS

The main drugs we described were enalapril, verapamil, nifedipine, indapamina, losartan, angiotensin-converting enzyme inhibitors and atenolol. These drugs are usually used in follow up programs, however, the studies we investigated used different protocols. Enalapril (angiotensin-converting enzyme inhibitor) and verapamil (Ca(++) channel blocker) caused hypertrophy to regress in LVH rats. The effects of enalapril and nifedipine (Ca(++) channel blocker) were similar. Indapamina (diuretic) had a stronger effect than enalapril, and losartan (angiotensin II receptor type 1 (AT1) receptor antagonist) produced better results than atenolol (selective beta1 receptor antagonist) with respect to LVH regression.

CONCLUSION

The anti-hypertensive drugs induced various degrees of hypertrophic regression.