Survival Benefit of Aortic Valve Replacement in Older Patients With Asymptomatic Chronic Severe Aortic Regurgitation

Economic Benefits of Surgical Aortic Valve Replacement on Patients With Symptomatic Aortic Valve Regurgitation

BACKGROUND

Aortic regurgitation is distinguished by the backflow of blood from the aorta into the left ventricle. American College of Cardiology/American Heart Association guidelines recommend surgical aortic valve replacement (SAVR) for patients with symptomatic aortic regurgitation (sAR). This study estimates the difference in mortality, health care use, and costs between patients with sAR who receive SAVR within 12 months of diagnosis versus those who do not.

METHODS AND RESULTS

We used the Optum United Healthcare database to identify 132 317 patients diagnosed with sAR from 2016 to 2021 who had at least 6 months of enrollment before sAR and 12 months of enrollment after. Criteria were no history of aortic stenosis or transcatheter aortic valve replacement and ≥2 visits for heart failure, angina, dyspnea, or syncope. Outcomes were all-cause mortality, health care use, and annualized cost. Baseline differences in demographics and comorbidities were adjusted with inverse propensity score weighting. We modeled survival and estimated health care use and costs using Cox proportional hazards and general linear models, respectively. Of the 132 317 patients, 400 underwent SAVR within 12 months of diagnosis. They were on average younger, more often men, and with a slightly higher Elixhauser Comorbidity Index score. After inverse propensity score weighting, patients with sAR who had SAVR had lower mortality, fewer inpatient and emergency department visits, fewer hospital days, and lower annualized cost.

CONCLUSIONS

SAVR performed within 12 months of an sAR diagnosis is associated with improved mortality and lower annualized health care use and costs. These clinical and economic benefits should be considered when managing patients with sAR.

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.

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.

Myocardial fibrosis in asymptomatic patients undergoing surgery for mitral and aortic valve regurgitation

BACKGROUND

Chronic heart valve regurgitation induces left ventricular (LV) volume overload, leading to the development of hypertrophy and progressive dilatation of the ventricle to maintain physiological cardiac output. In order to prevent potential irreversible LV structural changes, the identification of the best timing for treatment is pivotal.

OBJECTIVE

To assess the presence and extent of fibrosis in myocardial tissue in asymptomatic patients with valvular heart disease (VHD) and preserved LV dimensions and function undergoing cardiac surgery.

METHODS

Thirty-nine patients were enrolled. Sixteen patients were affected by aortic or mitral regurgitation: they were all asymptomatic, undergoing valve surgery according to VHD European Society of Cardiology guidelines. Twenty-three patients with end-stage nonischemic dilated cardiomyopathy (DCM) and severe LV dysfunction undergoing cardiac surgery for implantation of a durable left ventricular assist device (LVAD) served as controls. During surgery, VHD patients underwent three myocardial biopsies at the level of the septum, the lateral wall and LV apex, while in LVAD patients the coring of the apex of the LV was used. For both groups, the tissue samples were analyzed on one section corresponding to the apical area. All slides were stained with hematoxylin and eosin and Masson's trichrome staining and further digitalized. The degree of fibrosis was then calculated as a percentage of the total area.

RESULTS

Of 39 patients, 23 met the inclusion criteria: 12 had mitral or aortic insufficiency with a preserved ejection fraction and 11 had idiopathic dilated cardiomyopathy. Quantitative analysis of apical sections revealed a myocardial fibrosis amount of 10 ± 6% in VHD patients, while in LVAD patients the mean apical myocardial fibrosis rate was 38 ± 9%. In VHD patients, fibrosis was also present in the lateral wall (9 ± 4%) and in the septum (9 ± 6%).

CONCLUSION

Our case series study highlights the presence of tissue remodeling with fibrosis in asymptomatic patients with VHD and preserved LV function. According to our results, myocardial fibrosis is present at an early stage of the disease, well before developing detectable LV dysfunction and symptoms. Since the relationship between the progressive magnitude of myocardial fibrosis and potential prognostic implications are not yet defined, further studies on this topic are warranted.

OUP accepted manuscript

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: In patients with asymptomatic severe aortic regurgitation with preserved ejection fraction, is early surgery superior to watchful waiting in terms of long-term survival? Altogether, 648 papers were found using the reported search, 3 of which represented the best evidence to answer the clinical question (all level III evidence). The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The 3 included studies comprised 469 patients. All 3 studies attempted to correct for potential baseline differences by different matching methods. As a result, a predominantly beneficial effect of early surgery on long-term survival in patients with severe asymptomatic AR and preserved LV function was observed, whereas none of the studies demonstrated a disadvantageous effect. Still, because many of the initially conservatively treated patients eventually proceed to surgery, longer term follow-up is warranted. Of note, older patients especially seem to adapt more poorly to chronic volume overload due to aortic regurgitation, making them potential candidates for a more aggressive approach. However, when a justified watchful waiting strategy is applied, close, extensive monitoring seems to be imperative, because the development of class I and II triggers seems to lead to improved survival.

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.

Blunted beta-adrenoceptor-mediated inotropy in valvular cardiomyopathy: another piece of the puzzle in human aortic valve disease

OBJECTIVES

Heart failure induced by valvular cardiomyopathy occurs in a substantial proportion of patients undergoing heart valve surgery. We aimed (i) to quantify beta-adrenoceptor (beta-AR) function by measuring the inotropic effect of isoprenaline in left ventricular (LV) tissue and (ii) to correlate beta-AR-mediated inotropy with clinical markers of heart failure.

METHODS

A total of 179 LV myocardial samples were obtained from 104 consecutive patients who underwent aortic valve (AV) surgery between 2017 and 2019. Beta-ARs were stimulated by increasing the concentrations of isoprenaline, followed by a single high concentration of forskolin and calcium. Beta-AR sensitivity was estimated as the concentration to achieve half maximum effects (EC50). Maximum effect size was calculated as the relative beta-AR-mediated inotropic response compared to the force in the presence of high calcium [FISO/Ca (%)]. In vitro data were correlated with the clinical indicators of LV disease.

RESULTS

FISO/Ca was independent of age and sex and amounted to 79.6 ± 20.5%. In a multivariate regression model, we found a significant inverse association between FISO/Ca and preoperative left ventricular end-diastolic diameter increase per 10 mm (OR -9.24, 95% CI -16.66 to -1.82; P = 0.015). Furthermore, patients with end-stage heart failure showed a strong tendency towards more severe reduction of max beta-AR response, as indicated by reduced FISO/Ca in a multivariate model (OR -29.60, 95% CI -61.92 to 2.72; P = 0.055).

CONCLUSIONS

Our study indicates that in vitro myocardial contractility testing can quantify beta-AR dysfunction in patients with AV disease. We found a significant association between reduced beta-AR sensitivity and increased LV diameter, which may indicate a role of beta-AR dysfunction in the development of heart failure in patients with AV disease.

Optimizing Timing of Valve Intervention in Patients With Asymptomatic Severe Valvular Heart Disease

The management of valvular heart disease has changed dramatically over the past decade with advances in cardiac imaging, the use of novel biomarkers, and the development of transcatheter valve repair and replacement technology. International society guidelines have kept pace to provide recommendations for diagnosis, follow-up, and timing of intervention. The most challenging patient cohort for clinicians are patients with asymptomatic severe disease in whom the optimal timing of intervention can be ill-defined. It is a fine balance between the risks of early intervention on asymptomatic patients and improving patient outcomes by preventing long-term cardiac complications. The key in optimal patient management is gathering the necessary information on patient risk and combining that with the risk, efficacy, and durability of valve interventions to arrive at the appropriate timing for intervention. This group of patients will be the focus of this review as we delve into the natural history, recommended follow-up, and indications for intervention in patients with degenerative aortic and mitral valve disease.

Frequency of early remodeling of left ventricle and its comparison between patients with stroke volume ≥97 Ml versus patients with stroke volume <97 Ml after aortic valve replacement for severe aortic regurgitation

Objectives:

To evaluate the frequency of early remodeling in patients of severe aortic regurgitation after aortic valve replacement and to see the incidence of early remodeling in patients with stroke volume >97 ml versus < 97 ml before aortic valve replacement.

Method:

This was a prospective comparative study conducted from August 2013 to December 2014 in a tertiary care hospital. Fifty seven (57) patients of isolated chronic aortic regurgitation were included in this study. SPSS v23 was used for data analysis. Independent sample t-test was used for analysis of continuous variables and chi-square test for qualitative variables.

Results:

Out of fifty seven patients, early remodeling occurred in 34 (59.64%) patients after surgery. The mean pre-operative stroke volume of patient in whom remodeling occurred was 110.3+9.66 ml while mean pre-operative stroke volume of patients who did not undergo remodeling was 86.65+7.63 ml. There were 28 (82.4%) patients with stroke volume >97 ml in whom Remodeling occurred where as in patients with stroke volume <97 ml remodeling occurred only in 6 (17.6%) patients (p value 0.004). There was no in-hospital mortality.

Conclusion:

There is an association between stroke volume and early LV remodeling after Aortic valve replacement. Stroke volume >97 ml is a good predictor of early LV remodeling.

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).

Prognostic value of cardiac magnetic resonance imaging in patients with aortic regurgitation

Guidelines on valve replacement recommend aortic valve replacement for patients with severe aortic regurgitation (AR) with symptoms or left ventricular (LV) dysfunction. However, the optimal timing of surgery for asymptomatic AR patients without LV dilation or dysfunction is not known. There are data to suggest that excess volume load imposed by AR may not only produce subclinical LV dysfunction, but produce neurohormonal activation similar to the heart failure syndrome resulting in reduced survival. The study by Myerson et al. is the first to investigate the predictive ability of cardiac MRI (CMR) for the outcome of asymptomatic patients with AR. They studied 113 asymptomatic patients with moderate-to-severe AR on echocardiography in four centers. A total of 39 (35%) patients developed symptoms or an indication for surgery over a mean follow-up period of 2.6 years. AR volume, AR regurgitant fraction, LV end-diastolic and end-systolic volumes had high discriminatory powers (area under curve of 0.96, 0.93, 0.88 and 0.78, respectively) to predict these events. Higher association with the outcome was observed when LV end-diastolic volume and regurgitant fraction were combined. A significantly higher number of patients with regurgitant fraction >33% were likely to progress to surgery compared with patients with a regurgitant fraction of <33% (85 vs 8%; p < 0.001). These results demonstrate a potential role for CMR for risk stratification of patients with asymptomatic moderate or severe AR, given the ability of CMR to accurately quantify AR and LV volumes. Based on the data presented, it is possible that we may be waiting too long to offer surgery in patients with severe AR.

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.

Tissue-type plasminogen activator gene targets thrombolysis in atriums

Our previous investigations showed that retroviral gene transfer of tissue-type plasminogen activator (tPA) effectively targeted thrombolysis in vitro and in the model of inferior caval veins of rabbits. This study is to identify the target thrombolysis of retroviral vector recombinant pLEGFP-N1-tPA transferred into the tissue around the Dacron patch (the same materials making of the ring of mechanical valve) in left atriums of rabbits. 70 Dacron patches were transplanted into the left atriums of 70 New Zealand white rabbits. The rabbits were randomly divided into three groups according to the different handling methods, including local pLEGFP-N1-tPA transferred group (gene therapy group, 30 animals), pLEGFP-N1 transferred group (control group, 20 animals), medium DMEM + 10% neonate calf serum (NCS) injected group (blank control group, 20 animals). Samples of blood, Dacron pieces and left atriums (auricles) wall from half of above in each group were harvested on second day and another half were harvested on 75th day after surgery. The EGFP expression of harvested left atriums (auricles) wall were observed under the confocal. The thrombi on the surface of Dacron patches were detected by stereoscope and electron microscope. The tPA expression in left atriums (auricles) wall and in blood from left atriums were detected by Western blot and their thrombolysis and activities were observed and calculated in plasma plates. ELISA were used to identify the contents of tPA. No thrombus was seen on the surface of Dacron patches that were transplanted in left atriums by tPA locally transferring around them. Activity and content of tPA were high in local tissue of left atrium and in blood of left atrium. It demonstrated effectively thrombolysis by tPA rapidly, efficiently and long expressing. This puts the foundation of mechanical valve replacement model for tPA gene valve, next.