Prognostic Impact of Peak Aortic Jet Velocity in Conservatively Managed Patients With Severe Aortic Stenosis: An Observation From the CURRENT AS Registry

Increased left ventricular remodelling index in paradoxical low-flow severe aortic stenosis with preserved left ventricular ejection fraction compared to normal-flow severe aortic stenosis

INTRODUCTION

Patients with paradoxical low-flow (LF) severe aortic stenosis (AS) despite preserved left ventricular ejection fraction (LVEF) appear distinct from normal-flow (NF) patients, showing worse prognosis, more concentric hypertrophy and smaller left ventricular (LV) cavities. The left ventricular remodelling index (LVRI) has been demonstrated to reliably discriminate between physiologically adapted athlete's heart and pathological LV remodelling.

METHODS

We studied patients with index echocardiographic diagnosis of severe AS (aortic valve area <1 cm2) with preserved LVEF (>50%). The LVRI was determined by the ratio of the LV mass to the end-diastolic volume, as previously reported, and was compared between patients with LF and NF AS. Patients were prospectively followed up for at least 3 years, and clinical outcomes were examined in association with LVRI.

RESULTS

Of the 450 patients studied, 112 (24.9%) had LF AS. While there were no significant differences in baseline clinical profile between LF and NF patients, LVRI was significantly higher in the LF group. Patients with high LVRI (>1.56 g/mL) had increased all-cause mortality (log-rank 9.18, P = 0.002) and were more likely to be admitted for cardiac failure (log-rank 7.61, P = 0.006) or undergo aortic valve replacement (log-rank 18.4, P < 0.001). After adjusting for the effect of age, hypertension, aortic valve area and mean pressure gradient on multivariate Cox regression, high LVRI remained independently associated with poor clinical outcomes (hazard ratio 1.64, 95% confidence interval 1.19-2.25, P = 0.002).

CONCLUSION

Pathological LV remodelling (increased LVRI) was more common in patients with LF AS, and increased LVRI independently predicts worse clinical outcomes.

Improving accuracy in diagnosing aortic stenosis severity: An in-depth analysis of echocardiographic measurement error through literature review and simulation study

AIMS

The present guidelines advise replacing the aortic valve for individuals with severe aortic stenosis (AS) based on various echocardiographic parameters. Accurate measurements are essential to avoid misclassification and unnecessary interventions. The objective of this study was to evaluate the influence of measurement error on the echocardiographic evaluation of the severity of AS.

METHODS AND RESULTS

A systematic review was performed to examine whether measurement errors are reported in studies focusing on the prognostic value of peak aortic jet velocity (Vmax ), mean pressure gradient (MPG), and effective orifice area (EOA) in asymptomatic patients with AS. Out of the 37 studies reviewed, 17 (46%) acknowledged the existence of measurement errors, but none of them utilized methods to address them. Secondly, the magnitude of potential errors was collected from available literature for use in clinical simulations. Interobserver variability ranged between 0.9% and 8.3% for Vmax and MPG but was higher for EOA (range 7.7%-12.7%), indicating lower reliability. Assuming a circular left ventricular outflow tract area led to a median underestimation of EOA by 23% compared to planimetry by other modalities. A clinical simulation resulted in the reclassification of 42% of patients, shifting them from a diagnosis of severe AS to moderate AS.

CONCLUSIONS

Measurement errors are underreported in studies on echocardiographic assessment of AS severity. These errors can lead to misclassification and misdiagnosis. Clinicians and scientists should be aware of the implications for accurate clinical decision-making and assuring research validity.

Echocardiographic Evaluation of Aortic Stenosis: A Comprehensive Review

Echocardiography represents the most important diagnostic tool in the evaluation of aortic stenosis. The echocardiographic assessment of its severity should always be performed through a standardized and stepwise approach in order to achieve a comprehensive evaluation. The latest technical innovations in the field of echocardiography have improved diagnostic accuracy, guaranteeing a better and more detailed evaluation of aortic valve anatomy. An early diagnosis is of utmost importance since it shortens treatment delays and improves patient outcomes. Echocardiography plays a key role also in the evaluation of all the structural changes related to aortic stenosis. Detailed evaluation of subtle and subclinical changes in left ventricle function has a prognostic significance: scientific efforts have been addressed to identify the most accurate global longitudinal strain cut-off value able to predict adverse outcomes. Moreover, in recent years the role of artificial intelligence is increasingly emerging as a promising tool able to assist cardiologists in aortic stenosis screening and diagnosis, especially by reducing the rate of aortic stenosis misdiagnosis.

Atrial fibrillation in patients with severe aortic stenosis

BACKGROUND

There has been no previous report evaluating the long impact of atrial fibrillation (AF) on the clinical outcomes stratified by the initial management [conservative or aortic valve replacement (AVR)] strategies of severe aortic stenosis (AS).

METHODS

We analyzed 3815 patients with severe AS enrolled in the CURRENT AS registry. Patients with AF were defined as those having a history of AF when severe AS was found on the index echocardiography. The primary outcome measure was a composite of aortic valve-related death or hospitalization for heart failure.

RESULTS

The cumulative 5-year incidence of the primary outcome measure was significantly higher in patients with AF than in those without AF (44.2 % versus 33.2 %, HR 1.54, 95 % CI 1.35-1.76). After adjusting for confounders, the risk of AF relative to no AF remained significant (HR 1.34, 95 % CI 1.16-1.56). The magnitude of excess adjusted risk of AF for the primary outcome measure was greater in the initial AVR stratum (N = 1197, HR 1.95, 95 % CI 1.36-2.78) than in the conservative stratum (N = 2618, HR 1.26, 95 % CI 1.08-1.47) with a significant interaction (p = 0.04). In patients with AF, there was a significant excess adjusted risk of paroxysmal AF (N = 254) relative to chronic AF (N = 528) for the primary outcome measure (HR 1.34, 95 % CI 1.01-1.78).

CONCLUSIONS

In patients with severe AS, concomitant AF was independently associated with worse clinical outcomes regardless of the initial management strategies. In those patients with conservative strategy, paroxysmal AF is stronger risk factor than chronic AF.

A risk prediction model in asymptomatic patients with severe aortic stenosis: CURRENT-AS risk score

AIMS

Early aortic valve replacement (AVR) might be beneficial in selected high-risk asymptomatic patients with severe aortic stenosis (AS), considering their poor prognosis when managed conservatively. This study aimed to develop and validate a clinical scoring system to predict AS-related events within 1 year after diagnosis in asymptomatic severe AS patients.

METHODS AND RESULTS

We analysed 1274 asymptomatic severe AS patients derived from a retrospective multicentre registry enrolling consecutive patients with severe AS in Japan (CURRENT AS registry), who were managed conservatively and completed 1-year follow-up without AVR. From a randomly assigned derivation set (N = 849), we developed CURRENT AS risk score for the AS-related event (a composite of AS-related death and heart failure hospitalization) within 1 year using a multivariable logistic regression model. The risk score comprised independent risk predictors including left ventricular ejection fraction <60%, haemoglobin ≤11.0 g/dL, chronic lung disease (2 points), diabetes mellitus, haemodialysis, and any concomitant valve disease (1 point). The predictive accuracy of the model was good with the area under the curve of 0.79 and 0.77 in the derivation and validation sets (N = 425). In the validation set, the 1-year incidence of AS-related events was much higher in patients with score ≥2 than in patients with score ≤1 (Score 0: 2.2%, Score 1: 1.9%, Score 2: 13.4%, Score 3: 14.3%, and Score ≥4: 22.7%, P < 0.001).

CONCLUSION

The CURRENT-AS risk score integrating clinical and echocardiographic factors well-predicted the risk of AS-related events at 1 year in asymptomatic patients with severe AS and was validated internally.

Contemporary issues in severe aortic stenosis: review of current and future strategies from the Contemporary Outcomes after Surgery and Medical Treatment in Patients with Severe Aortic Stenosis registry

Contemporary Outcomes after Surgery and Medical Treatment in Patients with Severe Aortic Stenosis (CURRENT AS) registry was a large Japanese multicentre retrospective registry of consecutive patients with severe aortic stenosis (AS) before introduction of transcatheter aortic valve implantation. We sought to overview the data from the CURRENT AS registry to discuss the three major contemporary issues related to clinical practice in patients with severe AS: (1) under-referral/underuse of surgical aortic valve replacement (SAVR) in symptomatic patients with severe AS, (2) management of asymptomatic patients with severe AS and (3) management of patients with low-gradient severe aortic stenosis (LG-AS). First, despite the dismal prognosis of symptomatic patients with severe AS, SAVR, including those performed during follow-up, was reported to be underused. In the CURRENT AS registry, overall 53% of symptomatic patients underwent aortic valve replacement (AVR) during follow-up. Second, we reported that compared with conservative strategy, initial AVR strategy was associated with lower risk of all-cause death and heart failure hospitalisation in asymptomatic patients with severe AS. Although current recommendations for AVR are mainly dependent on the patient symptoms, some patients may not complain of any symptom because of their sedentary lifestyle. We also reported several important objective factors associated with worse clinical outcomes in asymptomatic patients with severe AS for risk stratification. Finally, initial AVR strategy was associated with better long-term clinical outcomes than conservative strategy in both patients with high-gradient AS and patients with LG-AS. The favourable effect of initial AVR strategy was also seen in patients with LG-AS with left ventricular ejection fraction of ≥50%.

Prognostic Impact of Aortic Valve Area in Conservatively Managed Patients With Asymptomatic Severe Aortic Stenosis With Preserved Ejection Fraction

Background

Data are scarce on the role of aortic valve area (AVA) to identify those patients with asymptomatic severe aortic stenosis (AS) who are at high risk of adverse events. We sought to explore the prognostic impact of AVA in asymptomatic patients with severe AS in a large observational database.

Methods and Results

Among 3815 consecutive patients with severe AS enrolled in the CURRENT AS (Contemporary Outcomes After Surgery and Medical Treatment in Patients With Severe Aortic Stenosis) registry, the present study included 1309 conservatively managed asymptomatic patients with left ventricular ejection fraction ≥50%. The study patients were subdivided into 3 groups based on AVA (group 1: AVA >0.80 cm², N=645; group 2: 0.8 cm² ≥AVA >0.6 cm², N=465; and group 3: AVA ≤0.6 cm², N=199). The prevalence of very severe AS patients (peak aortic jet velocity ≥5 m/s or mean aortic pressure gradient ≥60 mm Hg) was 2.0%, 5.8%, and 26.1% in groups 1, 2, and 3, respectively. The cumulative 5‐year incidence of AVR was not different across the 3 groups (39.7%, 43.7%, and 39.9%; P=0.43). The cumulative 5‐year incidence of the primary outcome measure (a composite of aortic valve–related death or heart failure hospitalization) was incrementally higher with decreasing AVA (24.1%, 29.1%, and 48.1%; P<0.001). After adjusting for confounders, the excess risk of group 3 and group 2 relative to group 1 for the primary outcome measure remained significant (hazard ratio, 2.21, 95% CI, 1.56–3.11, P<0.001; and hazard ratio, 1.34, 95% CI, 1.01–1.78, P=0.04, respectively).

Conclusions

AVA ≤0.6 cm² would be a useful marker to identify those high‐risk patients with asymptomatic severe AS, who might benefit from early AVR.

Clinical Trial Registration

URL: www.umin.ac.jp. Unique identifier: UMIN000012140.

See Editorial by Tribouilloy et al

Asymptomatic versus Symptomatic Patients with Severe Aortic Stenosis

It is unknown how much different are the clinical outcomes between asymptomatic and symptomatic patients with severe aortic stenosis (AS). In the CURRENT AS registry enrolling 3,815 consecutive patients with severe AS, we compared the long-term outcomes between 1808 asymptomatic and 1215 symptomatic patients (exertional dyspnea: N = 813, syncope: N = 136, and angina: N = 266) without heart failure (HF) hospitalization. Symptomatic patients had greater AS severity, and more depressed left ventricular function than asymptomatic patients without much difference in other baseline characteristics. During a median follow-up of 3.2 years, aortic valve replacement (AVR) was performed in 62% of symptomatic patients, and 38% of asymptomatic patients. The cumulative 5-year incidences for the primary outcome measure (a composite of aortic valve-related death or HF hospitalization) was higher in symptomatic patients than in asymptomatic patients (32.3% versus 27.6%, P < 0.001). After adjusting for AVR and other variables, the greater risk of symptomatic relative to asymptomatic patients for the primary outcome measure was significant (hazard ratio 1.64, 95% confidence interval 1.41-1.96, P < 0.001). In conclusions, the excess risk of symptomatic relative to asymptomatic patients with severe AS for the aortic valve-related event was significant. However, the prevalence of AVR in symptomatic patients was not optimal.