Natural history observations in moderate aortic stenosis

Echocardiographic and Clinical Outcomes in Symptomatic Patients With Less Than Severe Aortic Stenosis After Supra-Annular Self-Expanding Transcatheter Aortic Valve Replacement

Optimal timing for aortic valve replacement in symptomatic patients with less than severe aortic stenosis (AS) is not well defined. There is limited information on the benefit of valve replacement in these patients. Symptomatic patients with less than severe AS, defined as a mean aortic gradient ≥20 and <40 mm Hg, peak aortic velocity >3 and <4 m/s, and aortic valve area >1.0 and <1.5 cm2, enrolled in the Society for Thoracic Surgery/American College of Cardiology Transcatheter Valve Therapy Registry and who underwent attempted supra-annular, self-expanding transcatheter aortic valve replacement (TAVR) were reviewed. Site-reported valve hemodynamics, clinical events, and quality of life metrics were analyzed at 30 days and 1 year after the procedure. A total of 1,067 patients with attempted TAVR (mean age 78.4 ± 8.4 years; Society for Thoracic Surgery score 4.7 ± 3.4%) were found to have symptoms but less than severe AS. From baseline to postprocedure, mean gradient decreased (29.9 ± 4.9 vs 8.4 ± 4.8 mm Hg, p <0.001), and aortic valve area increased (1.2 ± 0.1 vs 2.2 ± 0.7 cm2, p <0.001). Clinical events included 30-day and 1-year all-cause mortality (1.5% and 9.6%), stroke (2.2% and 3.3%), and new pacemaker implantation (18.1% and 20.9%). There were statistically significant improvements in the New York Heart Association functional class and Kansas City Cardiomyopathy Questionnaire at 30 days and 1 year. In conclusion, patients with symptomatic but less than severe AS who underwent supra-annular, self-expanding TAVR experienced improved valve hemodynamics and quality of life measures 1 year after the procedure. Randomized studies of TAVR versus a control arm in symptomatic patients with less than severe AS are ongoing.

Prognostic Signals From Moderate Valve Disease in Big Data: An Artefact of Digital Imaging and Communications in Medicine Structured Reporting?

BACKGROUND

Recent studies have identified an association between moderate aortic stenosis (AS) and outcome. We assessed whether Digital Imaging and Communications in Medicine (DICOM) structured reporting (SR), which captures and inserts echocardiographic measurements and text data directly into radiological reports, may lead to misclassifying patients with severe AS as moderate.

METHODS

Moderate or severe AS cases were filtered from an echocardiography data set based on aortic valve area (AVA) < 1.5 cm2, indexed AVA (AVAi) ≤ 0.85 cm2/m2, mean pressure gradient ≥ 25 mm Hg, dimensionless severity index (DSI) ≤ 0.5, or peak velocity > 3 m/sec. Data validation was conducted by verification of each parameter. All echocardiographic parameters and definitions of AS were compared pre- and postvalidation by taking differences in measurements. Misclassification rates were assessed by determining the percentage of cases that changed AS severity classification and impact on outcomes. Patients were followed over 4.3 ± 1.5 years.

RESULTS

Of 2,595 validated echocardiograms with AS, up to 36% of the echocardiographic parameters for AS criteria had a >10% difference between DICOM-SR and manual validation, the highest with mean pressure gradient (36%) and the lowest with DSI (6.5%). The validation process changed the reported degree of AS in up to 20.6% of echocardiograms with resultant changes in AS severity and its association with mortality or heart failure-related hospitalizations. In contrast to multiple quantitative metrics in DICOM-SR after manual validation, clinicians' evaluation of AS severity was unable to distinguish composite outcomes over 3 years between moderate and severe AS. The risk of composite outcomes was significantly increased when severe AS was evidenced by at least 1 echocardiographic parameter of severe AS (hazard ratio = 1.24; 95% CI, 1.12-1.37; P < .001). The greatest hazard was based on DSI only (hazard ratio = 1.26; 95% CI, 1.10-1.44; P < .001), which was higher after manual validation compared to DICOM-SR. Averaging of repeated echo measures including invalid values contributed the most to erroneous data.

CONCLUSIONS

Nonpeak data in DICOM-SR led to incorrect categorization of a high proportion of patients based on AS severity definitions. Standardization of data fields and curation to ensure that only peak values are imported from DICOM-SR data are essential.

Natural history and clinical burden of moderate aortic stenosis: a systematic review and explorative meta-analysis

AIMS

The mortality risk of patients with moderate aortic stenosis is not well known, but recent studies suggested that it might negatively affect prognosis. We aimed to assess the natural history and clinical burden of moderate aortic stenosis and to investigate the interaction of patients' baseline characteristics with prognosis.

METHODS

Systematic research was conducted on PubMed. The inclusion criteria were inclusion of patients with moderate aortic stenosis; and report of the survival at 1-year follow-up (minimum). Incidence ratios related to all-cause mortality in patients and controls of each study were estimated and then pooled using a fixed effects model. All patients with mild aortic stenosis or without aortic stenosis were considered controls. Meta-regression analysis was performed to assess the impact of left ventricular ejection fraction and age on the prognosis of patients with moderate aortic stenosis.

RESULTS

Fifteen studies and 11 596 patients with moderate aortic stenosis were included. All-cause mortality was significantly higher among patients with moderate aortic stenosis than in controls in all timeframes analysed (all P  < 0.0001). Left ventricular ejection fraction and sex did not significantly impact on the prognosis of patients with moderate aortic stenosis ( P  = 0.4584 and P  = 0.5792), while increasing age showed a significant interaction with mortality (estimate = 0.0067; 95% confidence interval: 0.0007-0.0127; P  = 0.0323).

CONCLUSION

Moderate aortic stenosis is associated with reduced survival. Further studies are necessary to confirm the prognostic impact of this valvulopathy and the possible benefit of aortic valve replacement.

Is "moderate" aortic stenosis still the right name? A review of the literature

Current guidelines recommend aortic valve replacement for symptomatic or selected asymptomatic high-risk patients with severe aortic stenosis. Conversely, a watchful waiting attitude applies to patients with moderate aortic stenosis, regardless of their risk profile and symptoms, until the echocardiographic thresholds of severe aortic stenosis are reached. This strategy is based on data reporting high mortality in untreated severe symptomatic aortic stenosis, whereas moderate aortic stenosis has always been perceived as a non-threatening condition, with a benefit-risk balance against surgery. Meanwhile, numerous studies have reported a worrying event rate in these patients, surgical techniques and outcomes have improved significantly and the use of transcatheter aortic valve replacement has become more widespread and extended to lower-risk patients, leaving this strategy open to question, especially for patients with moderate aortic stenosis and left ventricular dysfunction. In this review, we summarize the current state of knowledge about moderate aortic stenosis progression and prognosis. We also discuss the particular case of moderate aortic stenosis associated with left ventricular dysfunction, and the ongoing trials that that might change our paradigm for the management of this "moderate" valvular heart disease.

Aortic Valve Disease, Transcatheter Aortic Valve Replacement, and the Heart Failure Patient: A State-of-the-Art Review

Concomitant aortic stenosis (AS) in heart failure (HF) is associated with high rates of mortality and morbidity. Current guidelines recommend aortic valve replacement in patients with severe symptomatic AS and asymptomatic AS with left ventricular ejection fraction <50% and during other cardiac surgeries. Transcatheter aortic valve replacement (TAVR) has now allowed for the treatment of severe AS in previously inoperable or high-surgical-risk patients. Leveraging multimodality imaging techniques is increasingly recognized for reinforcing the rationale for intervening early, thus mitigating the risk of ongoing progression to advanced HF. There are increasing data in favor of TAVR in diverse clinical scenarios, particularly asymptomatic AS and moderate AS. Limited information is, however, available regarding the advantages of HF medical therapy before and after intervention. This review aims to comprehensively examine the phenotypes of AS in the context of HF progression, while exploring the evolving role of TAVR in specific populations.

Perceval valve intermediate outcomes: a systematic review and meta-analysis at 5-year follow-up

OBJECTIVES

New technologies for the treatment of Aortic Stenosis are evolving to minimize risk and treat an increasingly comorbid population. The Sutureless Perceval Valve is one such alternative. Whilst short-term data is promising, limited mid-term outcomes exist, until now. This is the first systematic review and meta-analysis to evaluate mid-term outcomes in the Perceval Valve in isolation.

METHODS

A systematic literature review of 5 databases was performed. Articles included evaluated echocardiographic and mortality outcomes beyond 5 years in patients who had undergone Perceval Valve AVR. Two reviewers extracted and reviewed the articles. Weighted estimates were performed for all post-operative and mid-term data. Aggregated Kaplan Meier curves were reconstructed from digitised images to evaluate long-term survival.

RESULTS

Seven observational studies were identified, with a total number of 3196 patients analysed. 30-day mortality was 2.5%. Aggregated survival at 1, 2, 3, 4 and 5 years was 93.4%, 89.4%, 84.9%, 82% and 79.5% respectively. Permanent pacemaker implantation (7.9%), severe paravalvular leak (1.6%), structural valve deterioration (1.5%), stroke (4.4%), endocarditis (1.6%) and valve explant (2.3%) were acceptable at up to mid-term follow up. Haemodynamics were also acceptable at up mid-term with mean-valve gradient (range 9-13.6 mmHg), peak-valve gradient (17.8-22.3 mmHg) and effective orifice area (1.5-1.8 cm²) across all valve sizes. Cardiopulmonary bypass (78 min) and Aortic cross clamp times (52 min) were also favourable.

CONCLUSION

To our knowledge, this represents the first meta-analysis to date evaluating mid-term outcomes in the Perceval Valve in isolation and demonstrates good 5-year mortality, haemodynamic and morbidity outcomes.

KEY QUESTION

What are the mid-term outcomes at up to 5 years follow up in Perceval Valve Aortic Valve Replacement?

KEY FINDINGS

Perceval Valve AVR achieves 80% freedom from mortality at 5 years with low valve gradients and minimal morbidity.

KEY OUTCOMES

Perceval Valve Aortic Valve Replacement has acceptable mid-term mortality, durability and haemodynamic outcomes.

Natural history of moderate aortic stenosis and predictors for mortality: Systematic review and Meta-analysis

Although the current guidelines advocate imaging surveillance for moderate aortic stenosis (AS), recent studies suggest a worse prognosis associated with moderate AS than previously reported. Considering the recent paradigm shift in AS management, the risk/benefit profile of aortic valve replacement (AVR) for moderate AS needs to be re-evaluated. Herein, we conducted meta-analyses of natural history and risk predictors in patients with moderate AS. PubMed and EMBASE were searched through May 2022 to identify studies that investigated the natural history of patients with moderate AS. Meta-analyses with random effects model were conducted. Our analysis included 20 observational studies which enrolled a total of 11,114 patients with moderate AS. The rate of all-cause death was 11.0 [95 % confidence interval (CI), 7.6-14.4] per 100 patients per year. Surgical or transcatheter AVR occurred at a rate of 8.5 (95 % CI, 6.2-10.8; I², 98.9 %) per 100 patients per year. Occurrence of AVR during follow-up [hazard ratio (HR) (95 % CI) =0.56 (0.42-0.75), p < 0.001] and early AVR for moderate AS [HR (95 % CI) = 0.47 (0.25-0.90), p = 0.02] were associated with significantly lower all-cause mortality, while left ventricular ejection fraction <50 % [HR (95 % CI) =1.84 (1.33-2.57), p = 0.0003] and symptomatic status [HR (95 % CI) = 1.52 (1.32-1.75), p < 0.0001] were associated with increased all-cause mortality. Sex difference was not related to all-cause mortality. Our meta-analysis suggested that moderate AS was associated with high mortality, especially in low left ventricular systolic function or symptomatic patients. In addition, significant portion of the patients underwent AVR during follow-up.

Aortic valve replacement reduces mortality in moderate aortic stenosis: a systematic review and meta-analysis

BACKGROUND

With the introduction of transcatheter aortic valve replacement and an evolving understanding of the natural progression and history of aortic stenosis, the potential for earlier intervention in appropriate patients is promising; however, the benefit of aortic valve replacement in moderate aortic stenosis remains unclear.

METHODS

Pubmed, Embase, and the Cochrane Library databases were searched up until 30^th of December 2021 using keywords including moderate aortic stenosis and aortic valve replacement. Studies reporting all-cause mortality and outcomes in early aortic valve replacement (AVR) compared to conservative management in patients with moderate aortic stenosis were included. Hazard ratios were generated using random-effects meta-analysis to determine effect estimates.

RESULTS

3470 publications were screened with title and abstract review, which left 169 articles for full-text review. Of these studies, 7 met inclusion criteria and were included, totalling 4,827 patients. All studies treated AVR as a time-dependent co-variable in cox-regression multivariate analysis of all-cause mortality. Intervention with surgical or transcatheter AVR was associated with a 45% decreased risk of all-cause mortality (HR = 0.55 [0.42-0.68], I ² = 51.5%, P < 0.001). All studies were representative of the overall cohort with appropriate sample sizes, with no evidence of publication, detection, or information biases in any of the studies.

CONCLUSION

In this systematic review and meta-analysis, we report a 45% reduction in all-cause mortality in patients with moderate aortic stenosis who were treated with early aortic valve replacement compared to a strategy of conservative management. Randomised control trials are awaited to determine the utility of AVR in moderate aortic stenosis.

Impact of Moderate Aortic Stenosis on Long-Term Clinical Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

The clinical course of patients with moderate aortic stenosis (AS) remains incompletely defined.

OBJECTIVES

This study sought to analyze the clinical course of moderate AS and compare it with other stages of the disease.

METHODS

Multiple electronic databases were searched to identify studies on adult moderate AS. Random-effects models were used to derive pooled estimates. The primary endpoint was all-cause death. The secondary endpoints were cardiac death, heart failure, sudden death, and aortic valve replacement.

RESULTS

Among a total of 25 studies (12,143 moderate AS patients, 3.7 years of follow-up), pooled rates per 100 person-years were 9.0 (95% CI: 6.9 to 11.7) for all-cause death, 4.9 (95% CI: 3.1 to 7.5) for cardiac death, 3.9 (95% CI: 1.9 to 8.2) for heart failure, 1.1 (95% CI: 0.8 to 1.5) for sudden death, and 7.2 (95% CI: 4.3 to 12.2) for aortic valve replacement. Meta-regression analyses detected that diabetes (P = 0.019), coronary artery disease (P = 0.017), presence of symptoms (P < 0.001), and left ventricle (LV) dysfunction (P = 0.009) were associated with a significant impact on the overall estimate of all-cause death. All-cause mortality was higher in patients with reduced LV ejection fraction (<50%) than with normal LV ejection fraction: 16.5 (95% CI: 5.2 to 52.3) and 4.2 (95% CI: 1.4 to 12.8) per 100 person-years, respectively. Compared with moderate AS, the incidence rate difference of all-cause mortality was -3.9 (95% CI: -6.7 to -1.1) for no or mild AS and +2.2 (95% CI: +0.8 to +3.5) for severe AS patients.

CONCLUSIONS

Moderate AS appears to be associated with a mortality risk higher than no or mild AS but lower than severe AS, which increases in specific population subsets. The impact of early intervention in moderate AS patients having high-risk features deserves further investigation.

Implementation of a CT-derived correction factor to refine the measurement of aortic valve area and stroke volume using Doppler echocardiography improves grading of severity and prediction of prognosis in patients with severe aortic stenosis

AIMS

To assess rates of reclassification of severity and associated 5-year survival in patients with severe aortic stenosis (AS) and preserved left ventricular ejection fraction (LVEF) after application of a CT-derived correction factor (CF) to refine the measurement of aortic valve area (AVA) and stroke volume index (SVi) using Doppler echocardiography.

METHODS AND RESULTS

We enrolled 1450 patients with severe AS and preserved LVEF from a French registry. Multiplication of echocardiographic LV outflow tract diameter by a CT-derived CF of 1.13 to calculate the AVA and SVi using the continuity equation resulted in reclassification of 39% of patients from severe to moderate AS (AVA > 1 cm²) and 77% from low flow (LF, SVi < 35 ml/m²) to normal flow (NF, SVi ≥ 35 ml/m²). After application of the CF, 5-year survival with conservative management was 50 ± 4% for severe AS compared to 62 ± 4% for moderate AS (p < 0.001). A strategy of medical management followed by intervention for severe AS was associated with higher risk of mortality over 5-year follow-up after adjustment for covariates and application of the CF (HR 1.35 [1.10-1.55], p = 0.015). Five-year survival was also poorer in patients remaining in the LF group after application of the CF, even after valve intervention (72%, 66% and 47% for NF to NF, LF to NF and LF to LF, respectively). After adjustment for covariates (including intervention), risk of mortality was higher in LF to LF patients compared to NF to NF (HR 1.78 [1.25-2.56]), but similar for NF to NF and LF to NF (HR 1.20 [0.90-1.60]).

CONCLUSION

Refined accuracy of echocardiographic LV outflow tract diameter measurement using a CF of 1.13 before derivation of AVA and SVi in patients with severe AS and preserved LVEF allows improved grading of severity, and prediction of prognosis. We recommend implementation of the CF during routine echocardiography when using the continuity equation for Doppler haemodynamic measurements.

Evaluating Medical Therapy for Calcific Aortic Stenosis: JACC State-of-the-Art Review

Despite numerous promising therapeutic targets, there are no proven medical treatments for calcific aortic stenosis (AS). Multiple stakeholders need to come together and several scientific, operational, and trial design challenges must be addressed to capitalize on the recent and emerging mechanistic insights into this prevalent heart valve disease. This review briefly discusses the pathobiology and most promising pharmacologic targets, screening, diagnosis and progression of AS, identification of subgroups that should be targeted in clinical trials, and the need to elicit the patient voice earlier rather than later in clinical trial design and implementation. Potential trial end points and tools for assessment and approaches to implementation and design of clinical trials are reviewed. The efficiencies and advantages offered by a clinical trial network and platform trial approach are highlighted. The objective is to provide practical guidance that will facilitate a series of trials to identify effective medical therapies for AS resulting in expansion of therapeutic options to complement mechanical solutions for late-stage disease.

Discordant severity criteria in patients with moderate aortic stenosis: prognostic implications

Background

The criteria to define the grade of aortic stenosis (AS)—aortic valve area (AVA) and mean gradient (MG) or peak jet velocity—do not always coincide into one grade. Although in severe AS, this discrepancy is well characterised, in moderate AS, the phenomenon of discordant grading has not been investigated and its prognostic implications are unknown.

Objectives

To investigate the occurrence of discordant grading in patients with moderate AS (defined by an AVA between 1.0 cm² and 1.5 cm² but with an MG <20 mm Hg) and how these patients compare with those with concordant grading moderate AS (AVA between 1.0 cm² and 1.5 cm² and MG ≥20 mm Hg) in terms of clinical outcomes.

Methods

From an ongoing registry of patients with AS, patients with moderate AS based on AVA were selected and classified into discordant or concordant grading (MG <20 mm Hg or ≥20 mm Hg, respectively). The clinical endpoint was all-cause mortality.

Results

Of 790 patients with moderate AS, 150 (19.0%) had discordant grading, moderate AS. Patients with discordant grading were older, had higher prevalence of previous myocardial infarction and left ventricular (LV) hypertrophy, larger LV end-diastolic and end-systolic volume index, higher LV filling pressure and lower LV ejection fraction and stroke volume index as compared with their counterparts. After a median follow-up of 4.9 years (IQR 3.0–8.2), patients with discordant grading had lower aortic valve replacement rates (26.7% vs 44.1%, p<0.001) and higher mortality rates (60.0% vs 43.1%, p<0.001) as compared with patients with concordant grading. Discordant grading moderate AS, combined with low LV ejection fraction, presented the higher risk of mortality (HR 2.78 (2.00–3.87), p<0.001).

Conclusion

Discordant-grading moderate AS is not uncommon and, when combined with low LV ejection fraction, is associated with high risk of mortality.