Clinical Impact of Chronic Aortic Regurgitation in Asymptomatic Patients with Native Aortic Valve Stenosis

Clinical journey for patients with aortic regurgitation: A retrospective observational study from a multicenter database

BACKGROUND

Data using real-world assessments of aortic regurgitation (AR) severity to identify rates of Heart Valve Team evaluation and aortic valve replacement (AVR), as well as mortality among untreated patients, are lacking. The present study assessed these trends in care and outcomes for real-world patients with documented AR.

METHODS

Using a deidentified data set (January 2018-March 2023) representing 1,002,853 patients >18 years of age from 25 US institutions participating in the egnite Database (egnite, Inc.) with appropriate permissions, patients were classified by AR severity in echocardiographic reports. Rates of evaluation by the Heart Valve Team, AVR, and all-cause mortality without AVR were examined using Kaplan-Meier estimates and compared using the log-rank test.

RESULTS

Within the data set, 845,113 patients had AR severity documented. For moderate-to-severe or severe AR, respectively, 2-year rates (95% confidence interval) of evaluation by the Heart Valve Team (43.5% [41.7%-45.3%] and 65.4% [63.3%-67.4%]) and AVR (19.4% [17.6%-21.1%] and 46.5% [44.2%-48.8%]) were low. Mortality at 2 years without AVR increased with greater AR severity, up to 20.7% for severe AR (p < 0.001). In exploratory analyses, 2-year mortality for untreated patients with left ventricular end-systolic dimension index > 25 mm/m2 was similar for moderate (34.3% [29.2%-39.1%]) and severe (37.2% [24.9%-47.5%]) AR.

CONCLUSIONS

Moderate or greater AR is associated with poor clinical outcomes among untreated patients at 2 years. Rates of Heart Valve Team evaluation and AVR were low for those with moderate or greater AR, suggesting that earlier referral to the Heart Valve Team could be beneficial.

Impact of Aortic Valve Regurgitation on Doppler Echocardiographic Parameters in Patients with Severe Aortic Valve Stenosis

BACKGROUND

Diagnosing severe aortic stenosis (AS) depends on flow and pressure conditions. It is suspected that concomitant aortic regurgitation (AR) has an impact on the assessment of AS severity. The aim of this study was to analyze the impact of concomitant AR on Doppler-derived guideline criteria. We hypothesized that both transvalvular flow velocity (maxVAV) and the mean pressure gradient (mPGAV) will be affected by AR, whereas the effective orifice area (EOA) and the ratio between maximum velocity of the left ventricular outflow tract and transvalvular flow velocity (maxVLVOT/maxVAV) will not. Furthermore, we hypothesized that EOA (by continuity equation), and the geometric orifice area (GOA) (by planimetry using 3D transesophageal echocardiography, TEE), will not be affected by AR.

METHODS AND RESULTS

In this retrospective study, 335 patients (mean age 75.9 ± 9.8 years, 44% male) with severe AS (defined by EOA < 1.0 cm2) who underwent a transthoracic and transesophageal echocardiography were analyzed. Patients with a reduced left ventricular ejection fraction (LVEF < 53%) were excluded (n = 97). The remaining 238 patients were divided into four subgroups depending on AR severity, and they were assessed using pressure half time (PHT) method: no, trace, mild (PHT 500-750 ms), and moderate AR (PHT 250-500 ms). maxVAV, mPGAV and maxVLVOT/maxVAV were assessed in all subgroups. Among the four subgroups (no (n = 101), trace (n = 49), mild (n = 61) and moderate AR (n = 27)), no differences were obtained for EOA (no AR: 0.75 cm2 ± 0.15; trace AR: 0.74 cm2 ± 0.14; mild AR: 0.75 cm2 ± 0.14; moderate AR: 0.75 cm2 ± 0.15, p = 0.998) and GOA (no AR: 0.78 cm2 ± 0.20; trace AR: 0.79 cm2 ± 0.15; mild AR: 0.82 cm2 ± 0.19; moderate AR: 0.83 cm2 ± 0.14, p = 0.424). In severe AS with moderate AR, compared with patients without AR, maxVAV (p = 0.005) and mPGAV (p = 0.022) were higher, whereas EOA (p = 0.998) and maxVLVOT/maxVAV (p = 0.243) did not differ. The EOA was smaller than the GOA in AS patients with trace (0.74 cm2 ± 0.14 vs. 0.79 cm2 ± 0.15, p = 0.024), mild (0.75 cm2 ± 0.14 vs. 0.82 cm2 ± 0.19, p = 0.021), and moderate AR (0.75 cm2 ± 0.15 vs. 0.83 cm2 ± 0.14, p = 0.024). In 40 (17%) patients with severe AS, according to an EOA < 1.0 cm2, the GOA was ≥ 1.0 cm2.

CONCLUSION

In severe AS with moderate AR, the maxVAV and mPGAV are significantly affected by AR, whereas the EOA and maxVLVOT/maxVAV are not. These results highlight the potential risk of overestimating AS severity in combined aortic valve disease by only assessing transvalvular flow velocity and the mean pressure gradient. Furthermore, in cases of borderline EOA, of approximately 1.0 cm2, AS severity should be verified by determining the GOA.

Mixed aortic stenosis and regurgitation: a clinical conundrum

Mixed aortic stenosis (AS) and aortic regurgitation (AR) is the most frequent concomitant valve disease worldwide and represents a heterogeneous population ranging from mild AS with severe AR to mild AR with severe AS. About 6.8% of patients with at least moderate AS will also have moderate or greater AR, and 17.9% of patients with at least moderate AR will suffer from moderate or greater AS. Interest in mixed AS/AR has increased, with studies demonstrating that patients with moderate mixed AS/AR have similar outcomes to those with isolated severe AS. The diagnosis and quantification of mixed AS/AR severity are predominantly echocardiography-based, but the combined lesions lead to significant limitations in the assessment. Aortic valve peak velocity is the best parameter to evaluate the combined haemodynamic impact of both lesions, with a peak velocity greater than 4.0 m/s suggesting severe mixed AS/AR. Moreover, symptoms, increased left ventricular wall thickness and filling pressures, and abnormal left ventricular global longitudinal strain likely identify high-risk patients who may benefit from closer follow-up. Although guidelines recommend interventions based on the predominant lesion, some patients could potentially benefit from earlier intervention. Once a patient is deemed to require intervention, for patients receiving transcatheter valves, the presence of mixed AS/AR could confer benefit to those at high risk of paravalvular leak. Overall, the current approach of managing patients based on the dominant lesion might be too reductionist and a more holistic approach including biomarkers and multimodality imaging cardiac remodelling and inflammation data might be more appropriate.

Transcatheter aortic valve replacement in mixed aortic valve disease: a systematic review and meta-analysis

BACKGROUND

Utilization of transcatheter aortic valve replacement (TAVR) has expanded from high-risk patients to intermediate- and select low-risk candidates with severe aortic stenosis (AS). TAVR is currently not indicated for patients with aortic insufficiency, and its outcomes in mixed aortic valve disease (MAVD) are unclear.

METHODS

A systematic search of PubMed, Medline, CINHAL, and Cochrane databases was performed to identify studies comparing TAVR outcomes in patients with AS vs. MAVD. Primary outcomes included 30-day and late all-cause mortality, and paravalvular regurgitation (PVR). Secondary outcomes were major bleeding, vascular complications, device implantation success, permanent pacemaker, and stroke. Pooled odds ratios (OR) and 95% confidence intervals (CIs) were calculated using Der Simonian-Laird random-effects model.

RESULTS

Six observational studies with 58 879 patients were included in the analysis. There was no significant difference in 30-day all-cause mortality [OR 1.03 (95% CI 0.92-1.15); P = 0.63], however, MAVD group had higher odds of moderate-to-severe PVR [1.81 (1.41-2.31); P < 0.01]. MAVD patients had lower odds of device implantation success [0.60 (0.40-0.91); P = 0.02] while other secondary outcomes were similar in the two groups.

CONCLUSIONS

TAVR in MAVD is associated with increased odds of paravalvular regurgitation and lower odds of device implantation success when compared to severe aortic stenosis.

Early Valve Replacement for Severe Aortic Valve Disease: Effect on Mortality and Clinical Ramifications

Timing of aortic valve intervention for chronic aortic regurgitation (AR) and/or aortic stenosis (AS) potentially affects long-term survival. The 2014 American Heart Association/American College of Cardiology (AHA/ACC) guidelines provide recommendations for the timing of intervention. Subsequent to the guidelines' release, several studies have been published that suggest a survival benefit from earlier timing of surgery for severe AR and/or AS. The aim of this review was to determine whether patients who have chronic aortic regurgitation (AR) and/or aortic stenosis (AS) have a survival benefit from earlier timing of aortic valve surgery. Medical databases were systematically searched from January 2015 to April 2020 for randomized controlled trials (RCTs) and observational studies that examined the timing of aortic valve replacement surgery for chronic AR and/or AS. For chronic AR, four observational studies and no RCTs were identified. For chronic AS, five observational studies, one RCT and one meta-analysis were identified. One observational study examining mixed aortic valve disease (MAVD) was identified. All of these studies, for AR, AS, and MAVD, found long-term survival benefit from timing of aortic valve surgery earlier than the current guidelines. Larger prospective RCTs are required to evaluate the benefit of earlier surgical intervention.