Computed Simulation of Transcatheter Edge-to-Edge Mitral Valve Repair - A Proof of Concept Study

AIMS

As transcatheter mitral valve (MV) interventions are expanding and more device types and sizes become available, a tool supporting operators in preprocedural planning and the clinical decision-making process is highly desirable. We sought to develop a finite element (FE) computational simulation model to predict results of transcatheter edge-to-edge (TEER) interventions.

METHODS AND RESULTS

We prospectively enrolled patients with secondary mitral regurgitation (MR) referred for a clinically indicated TEER. Three-dimensional (3D) transesophageal echocardiograms performed at the beginning of the procedure were used to perform the simulation. On the 3D dynamic model of the MV that was first obtained, we simulated the clip implantation using the same clip(s) type, size, number, and implantation location that was used during the intervention. The 3D model of the MV obtained after simulation of the clip implantation was compared to the clinical results obtained at the end of the intervention. We analyzed the degree and location of residual MR and the shape and area of the diastolic mitral valve area. We performed computational simulation on 5 patients. Overall, the simulated models predicted well the degree and location of the residual regurgitant orifice(s) but tended to underestimate the diastolic mitral orifice area.

CONCLUSIONS

In this proof-of-concept study, we present preliminary results on our algorithm simulating clip implantation in 5 patients with functional MR. We show promising results regarding the feasibility and accuracy in terms of predicting residual MR and the need to improve the estimation of the diastolic mitral valve area.

Cost-effectiveness of population screening for aortic stenosis

BACKGROUND AND AIMS

Aortic stenosis (AS) is a progressive disease predominantly affecting elderly patients that carries significant morbidity and mortality without aortic valve replacement, the only proven treatment. Our objective was to determine the cost-effectiveness of AS screening using transthoracic echocardiography (TTE) in a geriatric population from the perspective of the publicly funded healthcare system in Canada.

METHODS

Markov models estimating the cost-effectiveness ratio (ICER) for AS screening with a one-time TTE were developed. The model included diagnosed and undiagnosed AS health states, hospitalizations, TAVR and post-TAVR health states. Primary analysis included screening at 70 and 80 years of age with intervention at symptom onset, with scenario analysis included for early intervention at the time of severe asymptomatic AS diagnosis. Monte Carlo simulation of 5000 replications was completed with a lifetime horizon and 1.5% discount for costs and outcomes.

RESULTS

Screening for AS at the age of 70 years was associated with an ICER of $156,722 and screening at 80 years of age was associated with an ICER of $28,005, suggesting that screening at 80 years of age is cost-effective when willingness-to-pay per QALY is $50,000. Scenario analysis with early intervention was not cost-effective with an ICER of $142,157 at 70 years, and $124,651 at 80 years.

CONCLUSION

Screening for AS at 80 years of age with a one-time TTE, in a Canadian population, improves quality of life and is cost-effective in a publicly funded healthcare system providing TAVR is reserved for symptomatic patients.

Aortic valve replacement for aortic stenosis: Influence of centre volume on TAVR adoption rates and outcomes in France

BACKGROUND

Transcatheter (TAVR) has supplanted surgical (SAVR) aortic valve replacement (AVR).

AIM

To evaluate whether adoption of this technology has varied according to centre volume at the nationwide level.

METHODS

From an administrative hospital-discharge database, we collected data on all AVRs performed in France between 2007 and 2019. Centres were divided into terciles based on the annual number of SAVRs performed in 2007-2009 ("before TAVR era").

RESULTS

A total of 192,773 AVRs (134,662 SAVRs and 58,111 TAVRs) were performed in 47 centres. The annual number of AVRs and TAVRs increased significantly and linearly in low-volume (<152 SAVRs/year; median 106, interquartile range [IQR] 75-129), middle-volume (152-219 SAVRs/year; median 197, IQR 172-212) and high-volume (>219 SAVRs/year; median 303, IQR 268-513) terciles, but to a greater degree in the latter (+14, +16 and +24 AVRs/centre/year and +16, +19 and +31 TAVRs/centre/year, respectively; PANCOVA<0.001). Charlson Comorbidity Index and in-hospital death rates declined from 2010 to 2019 in all terciles (all Ptrend<0.05). In 2017-2019, after adjusting for age, sex and Charlson Comorbidity Index, there was a trend toward lower death rates in the high-volume tercile (P=0.06) for SAVR, whereas death rates were similar for TAVR irrespective of tercile (P=0.27). Similar results were obtained when terciles were defined based on number of interventions performed in the last instead of the first 3years. Importantly, even centres in the lowest-volume tercile performed a relatively high number of interventions (150 TAVRs/year/centre).

CONCLUSIONS

In a centralized public healthcare system, the total number of AVRs increased linearly between 2007 and 2019, mostly due to an increase in TAVR, irrespective of centre volume. Progressive declines in patient risk profiles and death rates were observed in all terciles; in 2017-2019 death rates were similar in all terciles, although lower in high-volume centres for SAVR.

Edge-to-edge with partial band mitral valve repair compared to replacement and undersized restrictive annuloplasty for ischemic mitral regurgitation

Objective

Evidence supports replacement over repair for ischemic mitral regurgitation due to improved durability; however, the latter often involves an undersized ring annuloplasty that does not include edge-to-edge approximation. The objective of this study was to evaluate the outcomes of replacement, edge-to-edge leaflet approximation with mild-undersized annuloplasty and undersized ring annuloplasty for ischemic mitral regurgitation.

Methods

This is a single-center retrospective study of patients undergoing mitral surgery for moderate-severe or greater ischemic mitral regurgitation, between 2004 and 2020, with mild-undersized annuloplasty, mitral valve replacement, or undersized restrictive annuloplasty (undersized ring annuloplasty). The primary outcome was all-cause mortality. Secondary outcomes included first recurrence of mitral regurgitation, heart failure hospitalization, and composite of valve-related events (bleeding, thromboembolism, endocarditis, and mitral valve reoperation).

Results

There were 121, 93, and 78 patients in the mitral valve replacement, mild-undersized annuloplasty, and undersized restrictive annuloplasty groups, respectively, with a median follow-up of 3.1, 5.9, and 3.8 years, respectively. Both mitral valve replacement (hazard ratio, 1.87; 95% CI, 1.029-3.415) and undersized restrictive annuloplasty (hazard ratio, 2.73; 95% CI, 1.480-5.061) were associated with worse survival compared with mild-undersized annuloplasty. At 2 years, the rate of mild-moderate mitral regurgitation was greater in the mild-undersized annuloplasty group compared with the mitral valve replacement group (P = .001) but less than in the undersized restrictive annuloplasty group (P = .001). The rate of recurrent moderate or greater mitral regurgitation at 2 years was similar between mild-undersized annuloplasty and mitral valve replacement groups but significantly higher after undersized restrictive annuloplasty (P < .0001). Mitral valve replacement and undersized restrictive annuloplasty were associated with a significant increase in the incidence of first heart failure hospitalization compared with mild-undersized annuloplasty (P < .001 and P = .001, respectively). Mitral valve replacement was associated with an increased incidence of valve-related events compared with mild-undersized annuloplasty (P = .002).

Conclusions

Surgical edge-to-edge approximation in addition to a mild-undersizing annuloplasty offers similar durability compared with replacement, with a lower rate of hospitalization for heart failure, and may confer a survival advantage.

Impact of the coronavirus disease 2019 pandemic on aortic valve replacement and outcomes in France

BACKGROUND

The coronavirus disease of 2019 (COVID-19) pandemic lockdowns limited access to medical care. The impact on surgical (SAVR) and transcatheter (TAVR) aortic valve replacement (AVR) has been poorly described.

AIM

We sought to evaluate the impact of the COVID-19 pandemic on the number and modalities of AVR, patient demographics and in-hospital outcomes at the nationwide level.

METHODS

Using the French nationwide administrative hospital discharge database, we compared projected numbers and proportions of AVR and hospital outcomes, obtained using linear regressions derived from 2015-2019 trends, with those observed in 2020.

RESULTS

In 2020, 21,382 AVRs were performed (13,051 TAVRs, 5706 isolated SAVRs and 2625 SAVRs combined with other cardiac surgery). Compared with the 2020 projected number of AVRs (24,586, 95% confidence interval [CI] 23,525-25,646), TAVRs (14,866, 95% CI 14,164-15,568), isolated SAVRs (6652, 95% CI 6203-7100) and SAVRs combined with other cardiac surgery (3069, 95% CI 2822-3315), there were reductions of 13.0%, 12.2%, 14.2% and 14.5%, respectively. These trends were similar regardless of sex or age. In 2020, the mean age, Charlson Comorbidity Index and hospital admission duration continued to decline, and the proportion of females remained constant, following 2015-2019 trends. Overall, 2020 in-hospital mortality was higher than projected (2.0% observed vs. 1.7% projected; 95% CI 1.5-1.9%), with no increased pacemaker implantation, but more acute kidney injury and cerebrovascular accidents in some surgical subsets.

CONCLUSIONS

During the COVID-19 pandemic, fewer TAVR and SAVR procedures were performed, with increased in-hospital mortality and periprocedural complications. Extended follow-up will be important to establish the long-term effect of the COVID-19 pandemic on patient management and outcomes.

The Prevalence and Characteristics of Arrhythmic Mitral Valve Prolapse in Patients With Unexplained Cardiac Arrest

BACKGROUND

There is growing evidence that mitral valve prolapse (MVP) is associated with otherwise unexplained cardiac arrest (UCA). However, reports are hindered by the absence of a systematic ascertainment of alternative diagnoses.

OBJECTIVES

This study reports the prevalence and characteristics of MVP in a large cohort of patients with UCA.

METHODS

Patients were enrolled following an UCA, defined as cardiac arrest with no coronary artery disease, preserved left ventricular ejection fraction, and no apparent explanation on electrocardiogram. A comprehensive evaluation was performed, and patients were diagnosed with idiopathic ventricular fibrillation (IVF) if no cause was found. Echocardiography reports were reviewed for MVP. Patients with MVP were divided into 2 groups: those with IVF (AMVP) and those with an alternative diagnosis (nonarrhythmic MVP). Patient characteristics were then compared. The long-term outcomes of AMVP were reported.

RESULTS

Among 571 with an initially UCA, 34 patients had MVP (6%). The prevalence of definite MVP was significantly higher in patients with IVF than those with an alternative diagnosis (24 of 366 [6.6%] vs 5 of 205 [2.4%]; P = 0.03). Bileaflet prolapse was significantly associated with AMVP (18 of 23 [78%] vs 1 of 8 [12.5%]; P = 0.001; OR: 25.2). The proportion of patients with AMVP who received appropriate implantable cardioverter-defibrillator therapies over a median follow-up of 42 months was 21.1% (4 of 19).

CONCLUSIONS

MVP is associated with otherwise UCA (IVF), with a prevalence of 6.6%. Bileaflet prolapse appears to be a feature of AMVP, although future studies need to ascertain its independent association. A significant proportion of patients with AMVP received appropriate implantable cardioverter-defibrillator therapies during follow-up.

Association of Age and Sex With Use of Transcatheter Aortic Valve Replacement in France

BACKGROUND

Current guidelines recommend selecting surgical aortic valve replacement (SAVR) or transcatheter aortic valve replacement (TAVR) based on age, comorbidities, and surgical risk. Nevertheless, reports from the United States suggest a rapid expansion of TAVR in young patients.

OBJECTIVES

The authors sought to evaluate the trends in TAVR uptake at a nationwide level in France according to age and sex.

METHODS

Using a nationwide administrative database, we evaluated age- and sex-related trends in TAVR uptake, patient demographics, and in-hospital outcomes between 2015 and 2020.

RESULTS

A total of 107,397 patients (44.0% female) underwent an isolated aortic valve replacement (AVR) (59.1% TAVR, 40.9% SAVR). In patients <65 years of age, the proportion of TAVR increased by 63.2% (P < 0.001) from 2015 to 2020 but remained uncommon at 11.1% of all AVR by 2020 (12.4% in females, 10.6% in males) while TAVR was the dominant modality in patients ≥65 years of age. In patients undergoing TAVR, the Charlson comorbidity index (CCI) (P = 0.119 for trend) and in-hospital mortality (P = 0.740 for trend) remained unchanged in patients <65 years of age but declined in those ≥65 years of age irrespective of sex (all P < 0.001 for trends). Females were older (P < 0.001), had lower CCI (P < 0.001), were more likely to undergo TAVR (P < 0.001), and experienced higher in-hospital mortality (TAVR, P = 0.015; SAVR, P < 0.001) that persisted despite adjustment for age and CCI.

CONCLUSIONS

In France, the use of TAVR remained uncommon in young patients, predominantly restricted to those at high risk. Important sex differences were observed in patent demographics, selection of AVR modality, and patient outcomes. Additional research evaluating the long-term impact of TAVR use in young patients and prospective data evaluating sex differences in AVR modality selection and outcomes are needed.

Arrhythmic Mitral Valve Prolapse: Risk Assessment and Management

Arrhythmic mitral valve prolapse (MVP) has gained great interest recently because of the increasing recognition of its potential role in unexplained cardiac arrest. Although evidence has accumulated to show the association of arrhythmic MVP (AMVP) with sudden cardiac death (SCD), risk stratification and management remain unclear. Physicians are faced with the challenges of screening for AMVP among MVP patients and the dilemma of when and how to intervene to prevent SCD in these patients. In addition, there is little guidance to help approach MVP patients who present with an otherwise unexplained cardiac arrest to know whether MVP was the primary cause of cardiac arrest or just an innocent bystander. Herein we review the epidemiology and definition of AMVP, the risk and mechanisms of SCD, and summarize the clinical evidence behind risk markers of SCD and therapeutic interventions that could potentially prevent it. We also propose an algorithm that provides guidance as to how to screen for AMVP and what therapeutic interventions to use. Last, we propose a diagnostic algorithm for approaching patients with otherwise unexplained cardiac arrest who are shown to have MVP.

Unmet needs in valvular heart disease

Valvular heart disease (VHD) is the next epidemic in the cardiovascular field, affecting millions of people worldwide and having a major impact on health care systems. With aging of the population, the incidence and prevalence of VHD will continue to increase. However, VHD has not received the attention it deserves from both the public and policymakers. Despite important advances in the pathophysiology, natural history, management, and treatment of VHD including the development of transcatheter therapies, VHD remains underdiagnosed, identified late, and often undertreated with inequality in access to care and treatment options, and there is no medication that can prevent disease progression. The present review article discusses these gaps in the management of VHD and potential actions to undertake to improve the outcome of patients with VHD.

Aortic Stenosis Progression: A Systematic Review and Meta-Analysis

BACKGROUND

Aortic valve stenosis is a progressive disorder with variable progression rates. The factors affecting aortic stenosis (AS) progression remain largely unknown.

OBJECTIVES

This systematic review and meta-analysis sought to determine AS progression rates and to assess the impact of baseline AS severity and sex on disease progression.

METHODS

The authors searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from inception to July 1, 2020, for prospective studies evaluating the progression of AS with the use of echocardiography (mean gradient [MG], peak velocity [PV], peak gradient [PG], or aortic valve area [AVA]) or computed tomography (calcium score [AVC]). Random-effects meta-analysis was performed to evaluate the rate of AS progression for each parameter stratified by baseline severity, and meta-regression was performed to determine the impact of baseline severity and of sex on AS progression rate.

RESULTS

A total of 24 studies including 5,450 patients (40% female) met inclusion criteria. The pooled annualized progression of MG was +4.10 mm Hg (95% CI: 2.80-5.41 mm Hg), AVA -0.08 cm² (95% CI: 0.06-0.10 cm²), PV +0.19 m/s (95% CI: 0.13-0.24 m/s), PG +7.86 mm Hg (95% CI: 4.98-10.75 mm Hg), and AVC +158.5 AU (95% CI: 55.0-261.9 AU). Increasing baseline severity of AS was predictive of higher rates of progression for MG (P < 0.001), PV (P = 0.001), and AVC (P < 0.001), but not AVA (P = 0.34) or PG (P = 0.21). Only 4 studies reported AS progression stratified by sex, with only PV and AVC having 3 studies to perform a meta-analysis. No difference between sex was observed for PV (P = 0.397) or AVC (P = 0.572), but the level of confidence was low.

CONCLUSIONS

This study provides progression rates for both hemodynamic and anatomic parameters of AS and shows that increasing hemodynamic and anatomic baseline severity is associated with faster AS progression. More studies are needed to determine if sex differences affect AS progression. (Aortic Valve Stenosis Progression Rate: A Systematic Review and Meta-Analysis; CRD42021207726).

Metabolic activity of the left and right atria are differentially altered in patients with atrial fibrillation and LV dysfunction

BACKGROUND

Alterations in atrial metabolism may play a role in the perpetuation of atrial fibrillation (AF). This study sought to compare 18F-fluorodeoxyglucose (FDG) uptake on PET, in patients with LV dysfunction versus those without AF.

METHODS

Seventy-two patients who underwent myocardial viability assessment were evaluated. AF patients (36) had persistent or permanent AF based on history and ECG. Patients without AF (36) were matched to AF patients based on sex, diabetes, age, and LVEF. Maximum and mean FDG Standard Uptake Values (SUV) in the left atrial (LA) wall and right atrial (RA) wall were measured. Tissue-to-blood ratios (TBR) were calculated as atrial wall to blood-pool activity. Atrial volumes were measured by echocardiography.

RESULTS

Maximum and mean FDG SUV and TBRs were significantly increased in the RA (but not the LA) of patients with AF compared to those without (P < 0.01). When accounting for changes in atrial volume, the presence of AF remained a significant predictor of higher RAMAX, but not RAMEAN FDG uptake.

CONCLUSION

In patients with LV dysfunction from ischemic cardiomyopathy, LA and RA glucose metabolism are differentially altered in those with persistent atrial fibrillation. Further investigations should elucidate the temporal relationship between AF and glucose metabolic changes, as a potential target for therapy.

Aortic valve replacement for aortic stenosis in France – influence of centers' volumes on TAVR adoption rate and outcomes

Aims

Over the last decade, transcatheter aortic valve replacement (TAVR) became extensively used, now being the recommended as first line procedure for aortic valve replacement (AVR) in selected patients' populations. It is unknown whether TAVR adoption rate and variability in outcomes is influenced by centers' volume.

Methods

From a French administrative hospital-discharge database, we collected all AVR performed in France between 2007 and 2019. Centers were stratified to terciles based on their annual SAVR per year per center during 2007–2009 (“pre TAVR era”).

Results

There was 218,489 AVRs (153,747 SAVR and 74,732 TAVR) performed in 46 centers between 2007–2019. Number of total AVR and even more so number of number of TAVR significantly and linearly increased from 2007 to 2019 in all terciles but faster in the high volume tercile (+17, +17 and +31 AVR/center/year in the low, middle and high terciles respectively, P [ANCOVA]&lt;0.001; +11, + 19 and +33 TAVR/center/year in the low, medium and high tercile respectively, P [ANCOVA] &lt;0.00, Figure 1). The age of patients underwent TAVR remained grossly unchanged in all three terciles, however, the Charlson index declined from 2010 to 2019 (from 1.35±1.42 to 0.65±1.04, from 1.21±1.40 to 0.65±1.05 and from 1.53±1.58 to 0.81±1.21, in the low, middle and high terciles, P for trend &lt;0.001, 0.021, and &lt;0.001, respectively). Charlson score in the years 2017–2019, was higher in the high than middle and low terciles (0.87±1.22, 0.76±1.11 and 0.65±1.04, respectively, P&lt;0.0001). The in-hospital mortality rate for TAVR significantly declined from 2010 to 2019 for TAVR in all terciles (from 8.3% to 2.1%, from 7.5% to 2.5% and from 8.2% to 2.1% for low, middle and high TAVR terciles, respectively; p for trend = 0.002, 0.001 and &lt;0.001, respectively, Figure 2). Average mortality in 2017–2019 was similar in all terciles (2.3%, 2.5% and 2.2% for low, middle and high terciles, respectively, P=0.47). After adjusting for age, sex and Charlson score, mortality was higher in the low tercile compared with middle and high terciles (OR 1.15, P&lt;0.001, confidence interval [CI] 1.0–1.2, and OR 1.18, P&lt;0.001, CI 1.1–1.2, respectively).

Conclusions

From 2007 to 2019 total AVR linearly increased, mostly due to increase in TAVR, irrespective of centers' volume, but increase rate was higher in high volume centers. A constant decline in patients risk profile, with a striking decrease in mortality rate, was observed in all volume terciles. High-volume centers patients' have higher risk profile, with adjusted mortality slightly lower than medium and low volume centers.

Funding Acknowledgement

Type of funding sources: None.

Natural History of Mitral Annulus Calcification and Calcific Mitral Valve Disease

BACKGROUND

The natural history of mitral annular calcification (MAC) and risk for developing calcific mitral valve disease (CMVD) has been poorly defined. We sought to evaluate the progression rate of MAC and of the development of CMVD.

METHODS

Patients with MAC and paired echocardiograms at least one year apart between 2005 and 2019 were included. Progression rates from mild/moderate to severe MAC and to CMVD (defined as severe MAC and significant mitral stenosis and/or regurgitation) were assessed, along with potential association with sex.

RESULTS

A total of 11,605 patients (73±10years, 51%male) with MAC (78% mild, 17% moderate, 5% severe) were included and had a follow up echocardiogram at 4.2±2.7years. In patients with mild/moderate MAC, 33% presented with severe MAC at 10 years. The rate of severe MAC was higher in females than in males (41% vs. 24%, P<0.001, HR=1.3, P<0.001) and in patients with moderate vs. mild MAC (71% vs. 22%, P<0.001, HR=6.1, P<0.001). At 10 years 10% presented with CMVD (4%, 23% and 60% in patients with mild, moderate, and severe MAC respectively) and was predicted by female sex (15% vs. 5%, P<0.0001), even after adjustment for MAC severity (HR=1.9, P<0.001).

CONCLUSION

In this large cohort of patients with MAC, progression to severe MAC was common and frequently results in CMVD. Female sex was associated with higher progression rates. MAC and CMVD are expected to dramatically increase as the population ages highlighting the importance of a better understanding of the pathophysiology of MAC in order to develop effective preventive medical therapies.

Increased myocardial oxygen consumption rates are associated with maladaptive right ventricular remodeling and decreased event-free survival in heart failure patients

BACKGROUND

Reduced left ventricular (LV) function is associated with increased myocardial oxygen consumption rate (MVO2) and altered sympathetic activity, the role of which is not well described in right ventricular (RV) dysfunction.

METHODS AND RESULTS

33 patients with left heart failure were assessed for RV function/size using echocardiography. Positron emission tomography (PET) was used to measure 11C-acetate clearance rate (kmono), 11C-hydroxyephedrine (11C-HED) standardized uptake value (SUV), and retention rate. RV MVO2 was estimated from kmono. 11C-HED SUV and retention indicated sympathetic neuronal function. A composite clinical endpoint was defined as unplanned cardiac hospitalization within 5 years. Patients with (n = 10) or without (n = 23) RV dysfunction were comparable in terms of sex (male: 70.0 vs 69.5%), LV ejection fraction (39.6 ± 9.0 vs 38.6 ± 9.4%), and systemic hypertension (70.0 vs 78.3%). RV dysfunction patients were older (70.9 ± 13.5 vs 59.4 ± 11.5 years; P = .03) and had a higher prevalence of pulmonary hypertension (60.0% vs 13.0%; P = .01). RV dysfunction was associated with increased RV MVO2 (.106 ± .042 vs .068 ± .031 mL/min/g; P = .02) and decreased 11C-HED SUV and retention (6.05 ± .53 vs 7.40 ± 1.39 g/mL (P < .001) and .08 ± .02 vs .11 ± .03 mL/min/g (P < .001), respectively). Patients with an RV MVO2 above the median had a shorter event-free survival (hazard ratio = 5.47; P = .01). Patients who died within the 5-year follow-up period showed a trend (not statistically significant) for higher RV MVO2 (.120 ± .026 vs .074 ± .038 mL/min/g; P = .05).

CONCLUSIONS

RV dysfunction is associated with increased oxygen consumption (also characterized by a higher risk for cardiac events) and impaired RV sympathetic function.

Trends in aortic valve replacement for aortic stenosis: a French nationwide study

AIMS

Transcatheter aortic valve replacement (TAVR) as an alternative to surgical aortic valve replacement (SAVR) has profoundly changed the management of patients with aortic valve stenosis (AS). Large unbiased nationwide data regarding TAVR implementation, impact on SAVR and their respective outcomes are scarce.

METHODS AND RESULTS

Based on a French administrative hospital-discharge database, we collected data on all consecutive aortic valve replacements (AVRs) performed in France for AS between 2007 and 2019 [106 253 isolated SAVR (49%), 46 514 combined SAVR (21%), and 65 651 TAVR (30%)]. The number of AVR linearly increased between 2007 and 2019 (from 10 892 to 23 109, P for trend < 0.0001) due to a marked increase in TAVR (from 253 to 13 030, P for trend < 0.0001), while SAVR increased up to 2013 and then declined (10 892 in 2007, 12 699 in 2013, and 10 079 in 2019). The Charlson index decreased linearly for TAVR, but in two steps for SAVR (2011 and 2017). In-hospital mortality rates of both SAVR and TAVR declined (both P for trend < 0.0001) and were similar or lower for TAVR than for isolated SAVR in patients 75 years or above in the last 3 years (2017-19). Complication rates of TAVR also declined but permanent pacemaker rates remained high and length of stay substantial (16.7% and median 6 days, respectively, in 2017-19).

CONCLUSION

The number of AVR has doubled in a decade and TAVR has become the dominant form of AVR in 2018. The improvement in patient profiles seems to have anticipated the demonstrated benefit of TAVR in intermediate and low-risk patients. In patients 75 years or older, TAVR should be considered as the first option. We also highlight two important areas for improvement, the high permanent pacemaker rates, and the long length of stay even in the contemporary era. Our results may have major implications for clinical practice and policymakers.

Clinical Value of Stress Transaortic Flow Rate During Dobutamine Echocardiography in Reduced Left Ventricular Ejection Fraction, Low-Gradient Aortic Stenosis: A Multicenter Study

BACKGROUND

Low rest transaortic flow rate (FR) has been shown previously to predict mortality in low-gradient aortic stenosis. However limited prognostic data exists on stress FR during low-dose dobutamine stress echocardiography. We aimed to assess the value of stress FR for the detection of aortic valve stenosis (AS) severity and the prediction of mortality.

METHODS

This is a multicenter cohort study of patients with reduced left ventricular ejection fraction and low-gradient aortic stenosis (aortic valve area <1 cm² and mean gradient <40 mm Hg) who underwent low-dose dobutamine stress echocardiography to identify the AS severity and presence of flow reserve. The outcome assessed was all-cause mortality.

RESULTS

Of the 287 patients (mean age, 75±10 years; males, 71%; left ventricular ejection fraction, 31±10%) over a mean follow-up of 24±30 months there were 127 (44.3%) deaths and 147 (51.2%) patients underwent aortic valve intervention. Higher stress FR was independently associated with reduced risk of mortality (hazard ratio, 0.97 [95% CI, 0.94-0.99]; P=0.01) after adjusting for age, chronic kidney disease, heart failure symptoms, aortic valve intervention, and rest left ventricular ejection fraction. The minimum cutoff for prediction of mortality was stress FR 210 mL/s. Following adjustment to the same important clinical and echocardiographic parameters, among the three criteria of AS severity during stress, ie, the guideline definition of aortic valve area <1cm² and aortic valve mean gradient ≥40 mm Hg, or aortic valve mean gradient ≥40 mm Hg, or the novel definition of aortic valve area <1 cm² at stress FR ≥210 mL/s, only the latter was independently associated with mortality (hazard ratio, 1.72 [95% CI, 1.05-2.82]; P=0.03). Furthermore aortic valve area <1cm² at stress FR ≥210 mL/s was the only severe aortic stenosis criterion that was associated with improved outcome following aortic valve intervention (P<0.001). Guideline-defined stroke volume flow reserve did not predict mortality.

CONCLUSIONS

Stress FR during low-dose dobutamine stress echocardiography was useful for the detection of both AS severity and flow reserve and was associated with improved prediction of outcome following aortic valve intervention.

Size-adjusted aortic valve area: refining the definition of severe aortic stenosis

AIMS

Severe aortic valve stenosis (AS) is defined by an aortic valve area (AVA) <1 cm2 or an AVA indexed to body surface area (BSA) <0.6 cm/m2, despite little evidence supporting the latter approach and important intrinsic limitations of BSA indexation. We hypothesized that AVA indexed to height (H) might be more applicable to a wide range of populations and body morphologies and might provide a better predictive accuracy.

METHODS AND RESULTS

In 1298 patients with degenerative AS and preserved ejection fraction from three different countries and continents (derivation cohort), we aimed to establish an AVA/H threshold that would be equivalent to 1.0 cm2 for defining severe AS. In a distinct prospective validation cohort of 395 patients, we compared the predictive accuracy of AVA/BSA and AVA/H. Correlations between AVA and AVA/BSA or AVA/H were excellent (all R2 > 0.79) but greater with AVA/H. Regressions lines were markedly different in obese and non-obese patients with AVA/BSA (P < 0.0001) but almost identical with AVA/H (P = 0.16). AVA/BSA values that corresponded to an AVA of 1.0 cm2 were markedly different in obese and non-obese patients (0.48 and 0.59 cm2/m2) but not with AVA/H (0.61 cm2/m for both). Agreement for the diagnosis of severe AS (AVA < 1 cm2) was significantly higher with AVA/H than with AVA/BSA (P < 0.05). Similar results were observed across the three countries. An AVA/H cut-off value of 0.6 cm2/m [HR = 8.2(5.6-12.1)] provided the best predictive value for the occurrence of AS-related events [absolute AVA of 1 cm2: HR = 7.3(5.0-10.7); AVA/BSA of 0.6 cm2/m2 HR = 6.7(4.4-10.0)].

CONCLUSION

In a large multinational/multiracial cohort, AVA/H was better correlated with AVA than AVA/BSA and a cut-off value of 0.6 cm2/m provided a better diagnostic and prognostic value than 0.6 cm2/m2. Our results suggest that severe AS should be defined as an AVA < 1 cm2 or an AVA/H < 0.6 cm2/m rather than a BSA-indexed value of 0.6 cm2/m2.