2023 Korean Society of Echocardiography position paper for diagnosis and management of valvular heart disease, part I: aortic valve disease

This manuscript represents the official position of the Korean Society of Echocardiography on valvular heart diseases. This position paper focuses on the clinical management of valvular heart diseases with reference to the guidelines recently published by the American College of Cardiology/American Heart Association and the European Society of Cardiology. The committee tried to reflect the recently published results on the topic of valvular heart diseases and Korean data by a systematic literature search based on validity and relevance. In part I of this article, we will review and discuss the current position of aortic valve disease in Korea.

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.

Repair of Aortic Regurgitation in Young Adults: Sooner Rather Than Later

Background Establishing surgical criteria for aortic valve replacement (AVR) in severe aortic regurgitation in young adults is challenging due to the lack of evidence-based recommendations. We studied indications for AVR in young adults with severe aortic regurgitation and their outcomes, as well as the relationship between presurgical echocardiographic parameters and postoperative left ventricular (LV) size, function, clinical events, and valve-related complications. Methods and Results Data were collected retrospectively on 172 consecutive adult patients who underwent AVR or repair for severe aortic regurgitation between 2005 and 2019 in a tertiary cardiac center (age at surgery 29 [22-41] years, 81% male). One-third underwent surgery before meeting guideline indications. Postsurgery, 65% achieved LV size and function normalization. LV ejection fraction showed no significant change from baseline. A higher presurgical LV end-systolic diameter correlated with a lack of LV normalization (odds ratio per 1-cm increase 2.81, P<0.01). The baseline LV end-systolic diameter cut-off for predicting lack of LV normalization was 43 mm. Pre- and postoperative LV dimensions and postoperative LV ejection fraction predicted clinical events during follow-up. Prosthetic valve-related complications occurred in 20.3% during an average 5.6-year follow-up. Freedom from aortic reintervention was 98%, 96.5%, and 85.4% at 1, 5, and 10 years, respectively. Conclusions Young adult patients with increased baseline LV end-systolic diameter or prior cardiac surgery are less likely to achieve LV normalization after AVR. Clinicians should carefully balance the long-term benefits of AVR against procedural risks and future interventions, especially in younger patients. Evidence-based criteria for AVR in severe aortic regurgitation in young adults are crucial to improve outcomes.

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.

Utility of dobutamine stress echocardiography in aortic valve regurgitation and reduced left ventricular function

OBJECTIVE

Predictors for post-operative reverse remodeling in patients with severe aortic regurgitation (AR) and reduced left ventricular ejection fraction (LVEF) are unknown. We performed low-dose dobutamine stress echocardiography (DSE) in patients with severe AR and reduced LVEF to evaluate the relationship between contractile reserve (CR) and reverse remodeling after surgery.

METHODS

In 31 patients with chronic severe AR and reduced LVEF (LVEF < 50%), we performed pre-operative DSE, assessed CR, and examined whether changes in preoperative DSE were associated with improvement of post-operative LVEF after aortic valve surgery.

RESULTS

The pre-operative echocardiographic findings were as follows: left ventricular (LV) end-diastolic dimension: 67 ± 10 mm, LV end-systolic dimension: 52 ± 13 mm, and LVEF: 42 ± 8%. All patients underwent aortic valve surgery. Patients with pre-operative LVEF of ≥45% exhibited a significant increase in LVEF; however, patients with pre-operative LVEF of <45% showed no significant change. When we examined the results of DSE performed in patients with pre-operative LVEF of <45%, ΔLVEF of ≥6% (with CR) during DSE was related to an improvement in post-operative LVEF; ΔLVEF of ≥6% during DSE predicted an improvement in post-operative LVEF, with sensitivity 100%; specificity 78%; and area under curve (AUC) .92.

CONCLUSIONS

DSE might be a helpful tool for predicting post-operative reverse remodeling in patients with severe AR and moderately reduced LVEF.

Left ventricle reverse remodeling in chronic aortic regurgitation patients with dilated ventricle after aortic valve replacement

BACKGROUND

Aortic valve replacement (AVR) for chronic aortic regurgitation (AR) with a severe dilated left ventricle and dysfunction leads to left ventricle remodeling. But there are rarely reports on the left ventricle reverse remodeling (LVRR) after AVR. This study aimed to investigate the LVRR and outcomes in chronic AR patients with severe dilated left ventricle and dysfunction after AVR.

METHODS

We retrospectively analyzed the clinical datum of chronic aortic regurgitation patients who underwent isolated AVR. The LVRR was defined as an increase in left ventricular ejection fraction (LVEF) at least 10 points or a follow-up LVEF ≥ 50%, and a decrease in the indexed left ventricular end-diastolic diameter of at least 10%, or an indexed left ventricular end-diastolic diameter ≤ 33 mm/m². The changes in echocardiographic parameters after AVR, survival analysis, the predictors of major adverse cardiac events (MACE), the association between LVRR and MACE were analyzed.

RESULTS

Sixty-nine patients with severe dilated left ventricle and dysfunction underwent isolated AVR. LV remodeling in 54 patients and no LV remodeling in 15 patients at 6-12 months follow-up. The preoperative left ventricular dimensions and volumes were larger, and the EF was lower in the LV no remodeling group than those in the LV remodeling group (all p < 0.05). The adverse LVRR was the predictor for MACE at follow-up. The mean follow-up period was 47.29 months (range 6 to 173 months). The rate of freedom from MACE was 94.44% at 5 years and 92.59% at 10 years in the remodeling group, 60% at 5 years, and 46.67% at 10 years in the no remodeling group.

CONCLUSIONS

The left ventricle remodeling after AVR was the important predictor for MACE. LV no remodeling may not be associated with benefits from AVR for chronic aortic regurgitation patients with severe dilated LV and dysfunction.

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.

Presence of fragmented QRS is associated with left ventricular systolic dysfunction after surgery in patients with severe aortic regurgitation

BACKGROUND AND AIM OF THE STUDY

Chronic severe aortic regurgitation (AR) is associated with progressive accumulation of interstitial fibrosis and disruption of myocardial structure. After aortic valve replacement (AVR), the negative remodeling process reverses, and left ventricular ejection fraction (LVEF) improves but not in all patients. In this study, we aimed to investigate the association of fragmented QRS (F-QRS), which is a possible marker of myocardial fibrosis, with postoperative left ventricular (LV) systolic dysfunction.

METHODS

A total of 147 consecutive patients with AVR were included in this study. F-QRS was identified by the presence of various RSR' patterns (QRS duration <120 ms) such as additional R wave (R prime)or notching of the R or S wave in at least two consecutive leads. Patients were compared in two groups based on the presence or absence of F-QRS. A logistic regression model was used to determine independent predictors of postoperative LV systolic dysfunction (LVEF <50%).

RESULTS

Patients with F-QRS were associated with poor recovery of LV systolic function after AVR compared to the patients without F-QRS, regardless of preoperative LVEF (p = .008). F-QRS was found to be an independent predictor of postoperative LV systolic dysfunction (LVEF <50%). Lower preoperative LVEF and increased LV end diastolic diameter index were also found as independent risk factors for postoperative LV systolic dysfunction.

CONCLUSIONS

As a possible marker of myocardial fibrosis, F-QRS was associated with postoperative LV systolic dysfunction. Therefore, as a simple and convenient clinical parameter, F-QRS may be used to predict poor recovery of LVEF after AVR.

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.

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.

Left ventricular reverse remodeling after aortic valve surgery for acute versus chronic aortic regurgitation

AIMS

Extent of left ventricular (LV) reverse remodeling after aortic valve repair or replacement (AVR) may differ between patients operated for acute aortic regurgitation (AR) and chronic AR. The aim of this study was to compare changes in LV volumes and function between patients with acute and chronic AR who underwent AVR.

METHODS AND RESULTS

A total of 98 patients (54±15 years, 61% men) with acute (n=21) or chronic AR (n=77) were included in the present retrospective evaluation. LV volumes, LV ejection fraction, and global longitudinal strain indexed for LV end-diastolic volume (GLSi) were assessed preoperatively and after a median follow-up of 28 months (interquartile range: 17-66 months). Patients with acute AR tended to have smaller preoperative LV end-diastolic volume compared with chronic AR (156±15 vs 183±6 mL; P=.070). Both in patients with acute and chronic AR, significant LV reverse remodeling with sustained reduction in LV volumes occurred during follow-up with a significant smaller LV end-diastolic volume in acute AR compared with chronic AR (106±8 vs 128±5 mL; P=.032). Preoperative and postoperative LV ejection fractions were not significantly different between groups. In contrast, GLSi was better in patients with acute AR compared with chronic AR before AVR (-1.34±0.20 vs -0.96±0.07%/10 mL; P=.042) and during follow-up (-1.65±0.16 vs -1.29±0.07%/10 mL; P=.017).

CONCLUSIONS

After AVR, LV reverse remodeling occurs both in patients with acute and chronic AR. However, LV end-diastolic volume was more reduced and GLSi was more preserved during follow-up in acute AR than in chronic AR.

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.

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).

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.

[Surgery of aortic regurgitation with reduced left ventricular function]

BACKGROUND

Aortic valve replacement improves clinical symptoms and left ventricular systolic function in patients with chronic aortic regurgitation despite a higher surgical risk. The objective of this study is to determine if left ventricular function will be normalized after surgery.

PATIENTS AND METHOD

This retrospective study included 40 patients (nine females and 31 males) with chronic aortic regurgitation and left ventricular systolic dysfunction who were evaluated by echocardiography Doppler. Were included patients with left ventricular ejection fraction less or equal to 45%. Ages ranged from 18 to 77 years (mean = 46.4 ± 12.6 years). Preoperatively, six patients (15%) were asymptomatic, ten (25%) were in NYHA II, half (50%) in NYHA III and four (10%) in NYHA IV. The mean preoperative ejection fraction (EF) was 36.2 ± 2%. The mean end systolic and diastolic dimensions were 61.7 ± 8.5 mm and 78.9 ± 9.7 mm respectively. Aortic regurgitation was quantified grade III in sixteen patients (40%) and grade IV in twenty-four (60%).

RESULTS

Thirty-seven patients underwent aortic valve replacement and three Bentall operations. Hospital mortality was 7.5% (3/40). The mean follow-up period was 69.7 months. All survivor patients were investigated. Out of these, five were lost and 32 were controlled. Symptomatic improvement was noted in most of the survivors. Sixty percent (24/40) were severely symptomatic before and only 6.25% (2/32) during follow-up. The ejection fraction increased significantly after surgery (36.2 ± 2% in preoperative period vs. 55.2 ± 10% in postoperative period, P < 0.02). Left ventricular diameters decreased significantly also. Survival rates were 3-year 94%, 5-year 91% and 7-year 89%.

CONCLUSION

Despite reduced left ventricular systolic function, aortic valve replacement in chronic aortic regurgitation was associated with acceptable operative risk. Surgery improves functional status, symptoms and ejection fraction in most patients.

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.