Indexed Left Ventricular Dimensions Best Predict Survival After Aortic Valve Replacement in Patients With Aortic Valve Regurgitation

Outcomes of Watchful Waiting Strategy and Predictors of Postoperative Prognosis in Asymptomatic or Equivocally Symptomatic Chronic Severe Aortic Regurgitation With Preserved Left Ventricular Function

BACKGROUND

The optimal surgical timing for asymptomatic or equivocally symptomatic chronic severe aortic regurgitation with preserved left ventricular ejection fraction remains controversial.

METHODS AND RESULTS

Two hundred ten consecutive patients (median age 65 years) with asymptomatic or equivocally symptomatic chronic severe aortic regurgitation and left ventricular ejection fraction ≥50% were registered. First, the treatment plans (aortic valve replacement or watchful waiting) after initial diagnosis were investigated. Then, 2 studies were set: Study A (n=144) investigated the prognosis of patients who were managed under the watchful waiting strategy after initial diagnosis; Study B (n=99) investigated the postoperative prognosis in patients who underwent aortic valve replacement at initial diagnosis or after watchful waiting. The primary outcomes were all-cause death in Study A and postoperative cardiovascular events in Study B. In Study A, 3 died of noncardiovascular causes during a median follow-up of 3.2 years. In Kaplan-Meier analysis, the survival curve was similar to that of an age-sex-matched general population in Japan. In Study B, 9 experienced the primary outcome during a median follow-up of 5.0 years. In Cox regression analysis, preoperative left ventricular end-systolic diameter enlargement (hazard ratio, 1.11; P=0.048) and left ventricular end-systolic diameter >45 mm (hazard ratio, 12.75; P=0.02) were significantly associated with poor postoperative prognosis. In Kaplan-Meier analysis, left ventricular end-systolic diameter >45 mm predicted a higher risk of the primary outcome (P <0.01).

CONCLUSIONS

Watchful waiting was achieved safely in asymptomatic or equivocally symptomatic chronic severe aortic regurgitation with preserved left ventricular ejection fraction. Preoperative left ventricular end-systolic diameter >45 mm predicted a poor postoperative outcome and may be an optimal cut-off value for surgical indication.

Aortic Regurgitation: From Valvular to Myocardial Dysfunction

Chronic aortic regurgitation (AR) leads to volume overload in the left ventricle (LV), which is well tolerated for years. In this condition, the LV usually dilates with minimal reduction in the ejection fraction (EF), even in the absence of symptoms. Echocardiography is the primary imaging test used to quantify AR. However, no single assessment of Doppler measures is accurate and precise in individual patients; therefore, the integration of multiple parameters is necessary. Recent guidelines recommend surgical treatment for severe AR in patients who are symptomatic or have an LVEF < 55% and an end-systolic diameter > 50 mm. Nevertheless, advances in imaging technology have improved the quantification of AR and the assessment of LV subclinical dysfunction. It is widely recognized that patients who undergo aortic valve replacement/repair (AVR) due to symptoms or a low LVEF experience worse outcomes than those undergoing AVR for non-Class I indications. In fact, subclinical irreversible myocardial damage may occur in clinically well-compensated and closely monitored patients while awaiting formal surgical indications. This condition could be prevented by the use of multimodal imaging parameters, in particular longitudinal LV strain and magnetic resonance imaging. In addition, better cut-off values for mortality predictors should be established. This review aims to identify simple models that integrate several echocardiographic and cardiac magnetic resonance-derived parameters to predict the optimal timing of surgical treatment in asymptomatic patients with chronic severe AR.

Echocardiographic assessment of aortic regurgitation: a narrative review

Aortic regurgitation (AR) is the third most frequently encountered valve lesion and may be caused by abnormalities of the valve cusps or the aorta. Echocardiography is instrumental in the assessment of AR as it enables the delineation of valvular morphology, the mechanism of the lesion and the grading of severity. Severe AR has a major impact on the myocardium and carries a significant risk of morbidity and mortality if left untreated. Established and novel echocardiographic methods, such as global longitudinal strain and three-dimensional echocardiography, allow an estimation of this risk and provide invaluable information for patient management and prognosis. This narrative review summarises the epidemiology of AR, reviews current practices and recommendations with regards to the echocardiographic assessment of AR and outlines novel echocardiographic tools that may prove beneficial in patient assessment and management.

Current controversies in aortic valve-preserving surgery

The clinical outcome of severe aortic regurgitation (AR) remains suboptimal, but surgery has been shown to have survival benefit over medical therapy. Postoperative survival is inferior in patients with reduced left ventricular function, and therefore early surgical intervention is recommended. Aortic valvuloplasty (AVP) is an attractive option to avoid the major drawbacks of prosthetic valves but has not been widely adopted. The etiology of AR is classified functionally into three groups: normal leaflet motion (type I), cusp prolapse (type II), and restriction (type III). Type I with dilatation of the sinus of Valsalva (type Ib) can be repaired by aortic valve reimplantation or aortic root remodeling with similar valve stability. Type I with dilatation of the aortic annulus (type Ic) can be managed by annuloplasty. Type II can be corrected by plication or resuspension techniques. Pericardial patch is necessary in AVP for type Id (perforation/fenestration) and type III but is associated with risk of recurrence. Bicuspid aortic valve is classified according to commissure angle: symmetrical, asymmetrical, and very asymmetrical. Tricuspidization is recommended for repair of very asymmetrical valves to avoid postoperative stenosis. Recent progress has achieved similar reoperation rates between bicuspid and tricuspid aortic valve repair. For Marfan syndrome, valve-sparing root replacement is advantageous compared to Bentall operation regarding late survival, thromboembolic and hemorrhagic events, and endocarditis. Similar findings have been reported in acute aortic dissection. Both remodeling and reimplantation procedures provide similar favorable outcomes in these settings. Recent advances in AVP are summarized by quantitative assessment of cusp configuration (effective height and geometric height), graft size decision, use of template to cut the graft, and videoscopic assessment of post-repair cusp configuration. Due to these advances, AVP shows superior results to replacement surgery. Further concrete evidence with larger case volumes and longer observation periods are necessary to popularize AVP.

Long-term outcomes after aortic valve surgery in patients with aortic regurgitation with preserved ejection fraction and left ventricular dilation

OBJECTIVES

This study aims to assess the long-term outcomes and prognostic predictors of asymptomatic patients with severe aortic regurgitation (AR) accompanied by left ventricular ejection fraction (LVEF) ≥ 55% and left ventricular end-diastolic diameter (LVEDD) > 65 mm undergoing aortic valve replacement (AVR).

METHODS

We retrospectively studied 291 consecutive asymptomatic patients with severe AR accompanied by LVEF ≥ 55% and LVEDD > 65 mm undergoing AVR from January 2000 to December 2013. The long-term outcomes and prognostic predictors were evaluated.

RESULTS

There were 2 (0.7%) in-hospital deaths caused by multiple organ failure. The overall survival rate was 95.2% at 5 years, 89.9% at 10 years, 85.9% at 15 years, and 85.9% at 20 years. The left ventricular end-systolic volume index (LVESVi) was an independent predictor of overall mortality, with 59 ml/m² being the best cut-off value. The left ventricular (LV) dimension decreased within 1 year after surgery and sustained thereafter. There were 15.5% of patients had incomplete LV reverse remodeling. LVESVi was an independent predictor of incomplete LV reverse remodeling, with 56 ml/m² being the best cut-off value.

CONCLUSIONS

AVR can be performed with an acceptable outcome in patients with severe AR accompanied by LVEF ≥ 55% and LVEDD > 65 mm. The LVESVi has the best predictive value for prognosis and the cut-off value is 59 ml/m², and has the best predictive value for incomplete LV reverse remodeling and the cut-off value is 56 ml/m².

Valve-sparing Root Reimplantation In Patients With Left Ventricular Dilation

OBJECTIVES

The purpose of this study was to evaluate the association between left ventricular (LV) dilation and outcomes following valve-sparing root reimplantation.

METHODS

Patients with an indexed left ventricular internal diameter during systole (iLVIDS) of ≥ 2.0 cm/m2 were categorized as having LV dilation. Outcomes were post-operative aortic insufficiency (AI), re-intervention, and all-cause mortality. The cumulative incidence of each outcome was computed using the Kaplan-Meier estimator. Adjusted comparisons between strata were performed for each outcome using a Cox proportional-hazards model. Where possible, the competing risk of death was accounted for. Multilevel mixed-effects ordered logistic regression was performed for AI grade at follow-up.

RESULTS

There were 295 patients of whom 52 had LV dilation. Operative outcomes were excellent; there were no significant differences between groups. Patients with LV dilation demonstrated significant improvement in iLVIDS overtime. There was no association between LV dilation and post-operative AI grade >2 (HR 0.88, 95% CI 0.21 to 3.67, p = 0.89) or odds of increased AI grade overtime (OR = 0.76, 95% CI 0.30 to 1.93, p = 0.57). There were no re-interventions among those with LV dilation. Adjusted mortality was significantly higher among those with LV dilation (HR 5.56, 95% CI 1.56 to 19.9), however, deaths were unrelated to aortic valve dilation.

CONCLUSIONS

Left ventricular dilation is not associated with poorer operative outcomes, post-operative AI, or re-intervention. It is associated with increased risk of mortality, though not from valvular dysfunction. LV dilation should not deter VSRR when otherwise indicated.

The usefulness of C-reactive protein to predict improving left ventricular function after aortic valve replacement in patients with aortic regurgitation

Background

We aimed to clarify the predictive factors for left ventricular (LV) function after aortic valve replacement (AVR) in patients with aortic regurgitation (AR).

Methods and results

Among 555 patients who underwent AVR at our institution from January 2015 to December 2020, we enrolled 44 patients for whom only AVR (or AVR + aortic replacement) was performed. We defined LV dysfunction under any of the following criteria: LV ejection fraction (LVEF) <50 %, LV diastolic dimension >65 mm, LV systolic dimension (LVDs) >50 mm, or LVDs/body surface area > 25 mm/m2. Multivariable logistic regression analysis revealed high natural logarithm (ln) C-reactive protein (CRP) and low LVEF in the pre-AVR period significantly associated with LV dysfunction after AVR (ln CRP: odds ratio [OR] 4.15, 95 % confidence interval [CI] 1.44-11.98, p < 0.01; LVEF: OR 0.79, 95%CI 0.65-0.97, p < 0.05). Receiver-operating characteristic analysis revealed an area under curve of CRP and LVEF in the pre-AVR period for LV dysfunction after AVR of 0.84 and 0.83, respectively. Upon dividing the patients into four groups according to cutoff values of CRP (0.13 mg/dL) and LVEF (50 %) in the pre-AVR period, no patients (0/19) had LV dysfunction in the low CRP (<0.13 mg/dL) and high LVEF (≥50 %) group, and all patients (5/5) in the high CRP (≥0.13 mg/dL) and low LVEF (<50 %) group had LV dysfunction after AVR.

Conclusion

High CRP level was significantly and independently associated with LV dysfunction after AVR. Combination of CRP and LVEF values might be useful for predicting improvement in LV function after AVR.

Relationship between enlarged cardiac silhouette on chest X-ray and left ventricular size on transthoracic echocardiography

The diagnostic accuracy of the cardiothoracic ratio on chest X-ray to detect left ventricular (LV) enlargement has not been well defined despite its traditional association with cardiomegaly. We aimed to determine whether the cardiothoracic ratio can accurately predict LV enlargement based on indexed linear measurements of the LV on transthoracic echocardiography (TTE). We included consecutive patients who had a TTE and a posteroanterior chest X-ray performed within 90 days of each other at a tertiary care center. LV size was determined by measuring the LV end-diastolic dimension (LVEDD) and LV end-diastolic dimension indexed (LVEDDI) to body surface area. The cardiothoracic ratio was calculated by dividing the maximum transverse diameter of the cardiac silhouette by the maximum transverse diameter of the right and left lung boundaries. 173 patients were included in the study (mean age 68 ± 15 years, 49.1% female). Mean cardiothoracic ratio was 0.56 ± 0.09, and the mean LVEDD and indexed LVEDDI were of 47 ± 8.6 mm and dimension of 27 ± 4.5 mm/m2 respectively. There was no significant correlation between the cardiothoracic ratio measured on chest X-ray and either the LVEDD or LVEDDI measured on TTE (r = 0.011, p = 0.879; r = 0.122, p = 0.111). The ability of the cardiothoracic ratio to predict LV enlargement (defined as LVEDDI > 30 mm/m2) was not statistically significant. The cardiothoracic ratio on chest X-ray is not a predictor of LV enlargement based on indexed linear measurements of the LV by TTE.

Optimal Management of Chronic Severe Aortic Regurgitation - How to Determine Cutoff Values for Surgical Intervention?

Aortic regurgitation (AR) is a common valvular heart disease, but the optimal timing of surgical intervention remains controversial. In the natural history of chronic severe AR, sudden death is rare, and the annual mortality rate is comparatively low. Considering the hemodynamic features of combined volume and pressure overload and long-term compensation in patients with chronic AR, symptoms related to AR do not frequently occur. Therefore, the progression of left ventricular (LV) dysfunction is a key factor in determining the timing of surgical intervention in patients with severe chronic AR. In addition to symptoms, an ejection fraction <50% and an LV endsystolic diameter (LVESD) >45 mm are appropriate cutoff values for surgical intervention in Japanese patients, whereas LV end-diastolic diameter is not a good indicator. An LVESD index of 25 mm/m²is controversial, because adjusting for body size may cause overcorrection in Japanese patients who have a small body size compared with Westerners. Accumulation of data from the Japanese population is indispensable for establishing guidelines on optimal management of patients with chronic AR.

Postoperative changes in left ventricular systolic function after combined mitral and aortic valve replacement in patients with rheumatic heart disease

BACKGROUNDS

We sought to identify short- and long-term changes in postoperative left ventricular systolic function in patients with rheumatic heart disease (RHD) who underwent combined aortic and mitral valve replacement.

METHODS

We analyzed 146 patients according to their preoperative left ventricular ejection fraction (LVEF) (113 with preoperative LVEF ≥50% and 33 with preoperative LVEF <50%). A restricted cubic spline model was used to assess the effect of time on the postoperative changes in echocardiographic parameters.

RESULTS

There were no significant difference in preoperative and immediately postoperative LVEF before discharge in either group. During median follow-up of 3.2 years (interquartile range: 1.3-4.7 years) after surgery, postoperative LVEF increased slightly and then plateaued in patients with preoperative LVEF ≥50%, whereas it increased over 3-4 years after surgery and then gradually decreased in patients with preoperative LVEF <50% (p < .001).

CONCLUSION

Long-term postoperative LVEF showed a downward trend in RHD patients with reduced preoperative LVEF, whereas it reached a plateau in RHD patients with normal preoperative LVEF.

Reverse remodelling after aortic valve replacement for chronic aortic regurgitation

OBJECTIVES

This study aimed to assess the long-term outcomes and investigate the factors related to left ventricular (LV) reverse remodelling after aortic valve replacement (AVR) in patients with chronic aortic regurgitation (AR).

METHODS

A total of 246 patients who underwent AVR for chronic AR at our institution were included in this retrospective study. Primary end-points included all-cause mortality, cardiac mortality and major adverse cerebral and cardiovascular events. Secondary end-points included cardiac function on echocardiography 1 year after surgery. We explored the predictive factors for reverse remodelling 1 year after surgery.

RESULTS

The 10-year survival rate was 86.0%, with no cardiac deaths in 93.8% and no major adverse cerebral and cardiovascular events in 79.9% of patients. Postoperative LV function and symptoms were significantly improved 1 year after surgery, but 34 patients (13.8%) did not recover normal function and structure. A significant negative correlation was found between the incidence of cardiac death and major adverse cerebral and cardiovascular events and reverse remodelling. Multivariate logistic regression identified preoperative LV ejection fraction (P = 0.001, odds ratio = 1.057) and LV end-systolic dimension index (P = 0.038, odds ratio = 0.912) as significant predictive factors of reverse remodelling 1 year after surgery.

CONCLUSIONS

Preoperative LV ejection fraction and LV end-systolic dimension index were predictive factors for reverse remodelling after surgery, which was associated with late outcomes. Earlier surgery may thus help to restore normal LV function and achieve better late outcomes after AVR for AR.

Preoperative left ventricular end-systolic dimension predicts occurrence of aortic insufficiency following aortic valve preservation and repair surgery

BACKGROUND

Preoperative left ventricular (LV) end-systolic dimension (LVESD) ≥5.0 cm is a class IIa indication for surgical intervention for aortic insufficiency (AI); however, the effect of LV dilatation on the longevity of the aortic valve (AV) has not yet been investigated. This study aimed to assess the impact of preoperative LV dimension on the long-term outcome of AV preservation surgery.

METHODS

Between 2009 and 2019, 256 patients underwent AV preservation surgery at a single center. The median duration of follow-up was 5 years. The primary outcome was the development of >1+ AI at 6 years; secondary outcomes include long-term mortality, freedom from >2+ AI, and freedom from AV reoperation. Cox proportional hazard analysis was performed to identify predictors of AV deterioration.

RESULTS

In-hospital mortality was 0.8%, and mean survival at 8 years was 85.5 ± 3.4%. Mean freedom from >1+ AI at 6 years was 71.1 ± 3.4%. Patients with preoperative indexed LVESD (LVESDi) ≥2.0 cm/m² were at greater risk of developing >1+ AI at 6 years compared with patients with preoperative LVESDi of 1.5 to 1.9 cm/m² and ≤1.4 cm/m² (50.3 ± 0.1% vs 80.9 ± 0.1% vs 92.2 ± 0.1%, respectively; P < .01). On risk-adjusted multivariable analysis, preoperative LVESDi was an independent predictor for recurrence of >1+ AI (hazard ratio, 2.2; 95% confidence interval, 1.5-3.4).

CONCLUSIONS

Preoperative LVESDi ≥2 cm/m² is associated with increased risk of recurrent >1+ AI following AV preservation surgery. Further investigation of the appropriate operative threshold for AI may be warranted.

Time course of left ventricular remodelling and mechanics after aortic valve surgery: aortic stenosis vs. aortic regurgitation

Aims

Pressure overload in aortic stenosis (AS) and both pressure and volume overload in aortic regurgitation (AR) induce concentric and eccentric hypertrophy, respectively. These structural changes influence left ventricular (LV) mechanics, but little is known about the time course of LV remodelling and mechanics after aortic valve surgery (AVR) and its differences in AS vs. AR. The present study aimed to characterize the time course of LV mass index (LVMI) and LV mechanics [by LV global longitudinal strain (LV GLS)] after AVR in AS vs. AR.

Methods and results

Two hundred and eleven (61 ± 14 years, 61% male) patients with severe AS (63%) or AR (37%) undergoing surgical AVR with routine echocardiographic follow-up at 1, 2, and/or 5 years were evaluated. Before AVR, LVMI was larger in AR patients compared with AS. Both groups showed moderately impaired LV GLS, but preserved LV ejection fraction. After surgery, both groups showed LV mass regression, although a more pronounced decline was seen in AR patients. Improvement in LV GLS was observed in both groups, but characterized by an initial decline in AR patients while LV GLS in AS patients remained initially stable.

Conclusion

In severe AS and AR patients undergoing AVR, LV mass regression and changes in LV GLS are similar despite different LV remodelling before AVR. In AR, relief of volume overload led to reduction in LVMI and an initial decline in LV GLS. In contrast, relief of pressure overload in AS was characterized by a stable LV GLS and more sustained LV mass regression.

Current trends in aortic valve-preserving surgery

The natural history of aortic regurgitation is not as benign as once believed, even in asymptomatic patients with preserved left ventricular function. Aortic valve surgery can prolong survival in these patients. However, both mechanical and biological aortic valve replacement have major disadvantages, especially in young patients. Aortic valve-preserving surgery has attracted a great deal of attention because it has a significant survival benefit over replacement. Nonetheless, aortic valve-preserving surgery has not been widely adopted due to the complexity of the technique and assessment (i.e., long learning curve). With recent technical and theoretical advances, aortic valve-preserving surgery has increasingly been performed with better outcomes, and therefore earlier surgical intervention in cases of aortic regurgitation has been considered. Recent advances in aortic valve-preserving surgery include repair-oriented classification of the etiology of aortic regurgitation, objective assessment of the cusp configuration (i.e., effective height and geometric height), use of aortic annuloplasty, introduction of two reproducible valve-sparing root replacement procedures (i.e., aortic valve reimplantation and aortic root remodeling techniques), standardization of aortic valve-preserving surgery, and assessment of cusp configuration with aortoscopy. A number of prospective multicenter studies are currently underway and will clarify the role of aortic valve-preserving surgery in the treatment of aortic regurgitation in the near future.

Prognostic factors associated with postoperative adverse outcomes in patients with aortic valve prolapse

BACKGROUND AND AIM

Aortic valve (AV) cusp prolapse and subsequent aortic insufficiency (AI) are 2 of factors leading to left ventricular (LV) enlargement and decreased LV function. Aortic valve replacement (AVR) has been the standard surgical procedure for AI. However, few data is available on the prognosis of these patients undergoing AVR procedure, especially in Chinese population. The study aims to evaluate the potential risk factors affecting the mid-term adverse outcomes after AVR.

METHODS

One hundred thirty-four patients (mean age: 46.7 years old) with AV cusp prolapse and severe AI who all received surgical aortic valve replacement were recruited in our hospital between January 1, 2009 and December 30, 2017. The clinical characteristics, echocardiography parameters, as well as operative parameters were obtained. The primary endpoint included death, heart failure development, and reoperation.

RESULTS

There were 14 adverse events altogether with the primary endpoint during a median follow-up of 8.6 (6-10) months. The multivariable Cox regression analysis revealed that baseline LVEDD (hazard rate, HR = 1.08, 95% CI: 1.01-1.15, P = .021), moderate pulmonary hypertension (HR = 9.36, 95% CI: 1.81-48.28, P = .008), and the time of assisted mechanical ventilation (HR = 1.01, 95% CI: 1.00-1.01, P = .022) were independently associated with the primary endpoint. Kaplan-Meier survival curve showed a significant worse survival free of the endpoint for patients with LVEDD≥70 mm, indexed LVEDD≥37.3 mm/m (the mean in this study), indexed LVESD≥25 mm/m or baseline LVEF <50% (all P<.05).

CONCLUSION

Baseline enlarged LV dimensions, low LV function, moderate pulmonary hypertension, and prolonged assisted mechanical ventilation may predict the poor mid-term postoperative outcomes for AV cusp prolapse patients undergoing AVR procedure.

Persistence of Reduced Left Ventricular Function after Aortic Valve Surgery for Aortic Valve Regurgitation: Bicuspid versus Tricuspid

OBJECTIVE

 Long-term prognosis of patients with aortic regurgitation (AR) and reduced left ventricular ejection fraction (LVEF) who undergo aortic valve surgery (AVS) is unknown. Due to the congenital origin, bicuspid aortic valve (BAV) morphotype might be associated with a more severe cardiomyopathy. We aimed to evaluate the LVEF recovery after aortic valve replacement (AVR) surgery in patients with AR and reduced preoperative LVEF.

METHODS

 This retrospective analysis included 1,170 consecutive patients with moderate to severe AR who underwent AVS at our institution between January 2005 and April 2016. Preoperative echocardiography revealed 154 (13%) patients with predominant AR and baseline LVEF < 50%. A total of 60 (39%) patients had a BAV (BAV group), while the remaining 94 (61%) patients had a tricuspid morphotype (tricuspid aortic valve [TAV] group). Follow-up protocol included clinical interview using a structured questionnaire and echocardiographic follow-up.

RESULTS

 A total of 154 patients (mean age 63.5 ± 12.4 years, 71% male) underwent AVS for AR in the context of reduced LVEF (mean LVEF 42 ± 8%). Fifteen (10%) patients had a severely reduced preoperative LVEF ≤ 30%. Mean STS (Society of Thoracic Surgeons) score was 1.36 ± 1.09%. Mean follow-up was comparable between both the study groups (BAV: 50 ± 40 months vs. TAV: 40 ± 38 months, p = 0.140). A total of 25 (17%) patients died during follow-up. Follow-up echocardiography demonstrated similar rate of postoperatively reduced LVEF in both groups (i.e., 39% BAV patients vs. 43% TAV patients; p = 0.638). Cox's regression analysis showed no significant impact of BAV morphotype (i.e., as compared with TAV) on the postoperative LVEF recovery (odds ratio [OR]: 1.065; p = 0.859). Severe left ventricular (LV) dysfunction at baseline (i.e., LVEF ≤ 30%) was a strong predictor for persistence of reduced LVEF during follow-up (OR: 3.174; 95% confidence interval: 1.517-6.640; p = 0.002). Survival was significantly reduced in patients with persisting LV dysfunction versus those in whom LVEF recovered (log rank: p < 0.001).

CONCLUSION

 Our study demonstrates that reduced LVEF persists postoperatively in 40 to 45% patients who present with relevant AR and reduced LVEF at baseline. Postoperative LVEF recovery is independent of aortic valve morphotype (i.e., BAV vs. TAV). Severe LV dysfunction (LVEF ≤ 30%) at baseline is a strong predictor for persistence of reduced LVEF in patients with AR and results in significantly reduced long-term survival.

Effect of Left Ventricular Reverse Remodeling on Long-term Outcomes After Aortic Valve Replacement

There have been few studies with a large number of patients on the effect of left ventricular (LV) reverse remodeling and long-term outcomes after aortic valve replacement (AVR). This study aimed to investigate long-term outcomes and the prognostic impact of follow-up echocardiographic parameters after AVR. We evaluated 456 consecutive patients from a retrospective multicenter registry in Japan (J-PROVE-Retro) who underwent AVR for aortic valve diseases (predominantly aortic stenosis [AS]; 326 patients and aortic regurgitation [AR]; 130 patients). Preoperative and follow-up echocardiography at 1 year after AVR was evaluated. The primary outcome measure was a composite of cardiac death or hospitalization due to heart failure. The median follow-up period was 9.2 years in AS group and 9.7 years in AR group. The freedom rate from the primary outcome was 92% at 5 years and 79% at 10 years in AS, and 97% at 5 years, and 93% at 10 years in AR. LV end-diastolic and end-systolic diameters, and the LV mass index decreased and LV ejection fraction increased after AVR in both AS and AR, and LV mass index was normalized in more than half of the patients. In the Cox proportional hazard model, echocardiographic parameters at 1 year after AVR were more strongly related to long-term outcomes than preoperative echocardiographic parameters. In conclusion, echocardiographic parameters at 1 year after AVR are more important as predictors of long-term outcomes than preoperative parameters in both AS and AR. More attention should be paid on early postoperative remodeling for long-term follow-up of patients after AVR.

Aortic valve repair for aortic regurgitation and preoperative echocardiographic assessment

Aortic valvuloplasty (AVP) has been performed less frequently than mitral valvuloplasty. The survival benefit of AVP over replacement has been demonstrated. Therefore, standardization of AVP is crucial for its widespread adoption. The hemodynamic advantage of AVP of preserving the native aortic valve may be one reason for the survival benefit. Recent guidelines still recommend AVP in selected cases compared with the less restricted recommendation for mitral valvuloplasty, although recent studies have proposed earlier indication for surgical intervention. Indication for aortic root replacement is also still conservative, especially in Japan. However, more liberal root replacement should be recommended for better repair when AVP is indicated. Theoretically, all aortic regurgitation lesions can be repaired with acceptable durability. However, restricted cusp should be extended by a pericardial patch, which itself has emerged as a risk of recurrence. Therefore, indications for aortic regurgitation for type III lesions should be determined carefully. Special consideration is crucial for bicuspid aortic valve repair; prevention of postoperative stenosis is especially important. Arrangement of the commissure position is the most important consideration for this purpose, although it remains controversial. Therefore, detailed diagnosis is important in planning AVP, and echocardiography plays a key role in this process.

Timing of Surgical Intervention for Aortic Regurgitation

OPINION STATEMENT

Aortic regurgitation is a frequently encountered condition, in which traditional measurements of severity have proven to be of limited value in identifying those who would be best served by aortic valve replacement. Novel methods of assessing severity are vital, particularly as an entirely new paradigm of aortic regurgitation has surfaced, with the advent of transcatheter aortic valve replacement (TAVR), and the adverse events that are being observed with varying degrees of aortic regurgitation. With that in mind, a comprehensive assessment of aortic regurgitation should now include indexed left ventricular systolic volumes and a comprehensive assessment of right ventricular function, in addition to the quantitative measures that are currently recommended. Cardiac MRI also provides valuable information and should be strongly considered, particularly in challenging cases. The incremental value of additional echocardiographic parameters such as strain imaging, speckle tracking imaging, and tissue Doppler imaging remains unclear, and evidence for their utility is not, as yet, compelling. However, the field of aortic regurgitation assessment has been reinvigorated by the prevalence of paravalvular regurgitation post-TAVR, and many of the abovementioned parameters may need to be re-visited so that we can more accurately determine prognosis and risk stratify patients in a more reliable and evidence-based manner.

Aortic valve replacement for severe aortic regurgitation in asymptomatic patients with normal ejection fraction and severe left ventricular dilatation

OBJECTIVES

According to current guidelines, aortic valve surgery is a Class II indication for asymptomatic patients with severe aortic regurgitation (AR) accompanied by left ventricular (LV) ejection fraction (LVEF) ≥ 50% and left ventricular end-diastolic dimension (LVEDD) >70 mm. This study aims to assess the postoperative outcomes of asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD >70 mm after aortic valve replacement (AVR) and to identify prognostic indicators of the surgery, especially in terms of LV ejection fraction and degree of LV dilatation.

METHODS

We retrospectively identified 192 consecutive asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD > 70 mm who underwent isolated AVR from January 2003 to December 2013. Postoperative outcomes and prognostic indicators were evaluated and analysed.

RESULTS

Patients had a mean age of 52.4 ± 16.1 years, and 69.3% were male. The mean LVEF and the mean LVEDD were 58.6 ± 6.6% and 76.0 ± 6.9 mm, respectively. The in-hospital mortality rate was 2.1% and survival rates at 5 and 10 years were 94.5 and 86.6%, respectively. Multivariable analysis indicated that postoperative mortality was associated with age [hazard ratio (HR) 1.059, 95% confidence interval (CI): 1.010-1.125, P = 0.049], preoperative LVEF (HR 0.860 95% CI: 0.748-0.989, P = 0.035) and LVEDD (HR 1.094 95% CI: 1.008-1.188, P = 0.032). Receiver-operating characteristic analysis showed that preoperative LVEF < 55% and LVEDD ≥ 81 mm were the best cut-off values for predicting postoperative mortality. By subgroup analysis, patients with 50 ≤ LVEF < 55% had poorer 5- and 10-year survival rates of 87.4 and 74.8% compared with 97.3% and 91.7% for patients with LVEF ≥ 55% (P = 0.023). Patients with LVEDD ≥ 81 mm had poorer 5- and 10-year survival rates of 85.6 and 72.6% compared with 98.2% and 85.6% for those with LVEDD < 81 mm (P = 0.027).

CONCLUSIONS

AVR can be performed with satisfactory outcomes for severe aortic regurgitation in asymptomatic patients with severe AR accompanied by LVEF ≥ 50% and LVEDD > 70 mm. It is observed that 50% ≤ LVEF < 55% or LVEDD ≥ 81 mm are associated with poorer prognosis in patients undergoing AVR.

Detection of subtle left ventricular systolic dysfunction in patients with significant aortic regurgitation and preserved left ventricular ejection fraction: speckle tracking echocardiographic analysis

AIMS

The aim of this study was to characterize left ventricular (LV) mechanics in symptomatic and asymptomatic patients with moderate-to-severe or severe aortic regurgitation (AR) and preserved ejection fraction (left ventricular ejection fraction) using two-dimensional speckle tracking echocardiography (2D-STE). The association between baseline LV strain and development of indications for surgery in asymptomatic patients was also evaluated.

METHODS AND RESULTS

A total of 129 patients with moderate-to-severe or severe AR and LVEF >50% (age 55 ± 17 years, 64% male, 53% asymptomatic at baseline) were included. Standard echocardiography and 2D-STE were performed at baseline. Compared with asymptomatic patients, symptomatic patients had significantly impaired LV longitudinal (-14.9 ± 3.0 vs. -16.8 ± 2.5%, P < 0.001), circumferential (-17.5 ± 2.9 vs. -19.3 ± 2.8%, P = 0.001), and radial (35.7 ± 12.2 vs. 43.1 ± 14.7%, P = 0.004) strains. Among 49 asymptomatic patients who were followed up, 26 developed indications for surgery (symptoms onset or LVEF ≤50%). These patients had comparable LV volumes, LVEF, and colour Doppler assessments of AR jet at baseline, but more impaired LV longitudinal (P = 0.009) and circumferential (P = 0.017) strains compared with patients who remained asymptomatic. Impaired baseline LV longitudinal (per 1% decrease, HR = 1.21, P = 0.04) or circumferential (per 1% decrease, HR = 1.22, P = 0.04) strain was independently associated with the need for surgery.

CONCLUSION

Multidirectional LV strain was more impaired in symptomatic than in asymptomatic patients with moderate-to-severe or severe AR, despite preserved LVEF. In asymptomatic AR patients, longitudinal and circumferential strains identified patients who would require surgery during follow-up.

Long term results and predictors of left ventricular function recovery after aortic valve replacement for chronic aortic regurgitation

OBJECTIVES

In most patients with aortic regurgitation (AR), aortic valve replacement (AVR) improves left ventricular (LV) function, but some patients will not have favorable remodeling. Our objectives were to review long term clinical results of AVR for AR and to examine what factors affect the normalization of LV function after AVR for chronic AR.

METHODS

Between 1989 and 2010, 177 patients underwent isolated AVR for chronic pure AR. The patients were divided into 2 groups based on indexed end-systolic LV diameter (iESD): Group L (iESD) ≥25 mm/m(2)) (130 patients) and Group S (iESD <25 mm/m(2)) (47 patients).

RESULTS

There was no significant difference between groups in late mortality, freedom from cardiac-related death and rehospitalization for heart failure at late follow up after operation. At postoperative follow-up, 16% of patients had not recovered normal LV systolic function. By means of multivariate analysis, iESD and cardiac index (CI) were independent predictors of recovery of LV function and iESD >26.7 mm/m(2) and CI <2.71 l/min/m(2) were the best cut-off values.

CONCLUSIONS

Early and late surgical results of AVR for chronic AR were good, but for the preservation of postoperative normal LV function, AVR for AR patients should be performed before iESD reaches 26.7 mm/m(2).

Timing of aortic valve intervention in pediatric chronic aortic insufficiency

The timing of aortic valve intervention (AVI) in pediatric patients with chronic aortic insufficiency (AI) is largely based on adult experience, which is fraught with uncertainty and controversy. Current adult guidelines in the absence of symptoms use left ventricular (LV) systolic function and LV dimensions to guide AVI timing, with few studies translating these recommendations to pediatric patients. This article reviews the current guidelines for AVI timing in chronic AI along with the emerging data for pediatric patients.

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.

Contemporary reviews by surgeon: timing of operation for chronic aortic regurgitation

The timing of operation for severe chronic and asymptomatic aortic regurgitation remains problematic, though the present trend is to prefer early surgery. In this article, we review recent reports, mainly published after 2006, regarding indications for surgical treatment for pure chronic AR.