Cardiovascular Adverse Events After Aortic Valve Replacement in Mixed Aortic Valve Disease: Beyond Ejection Fraction

Clinical impact of aortic valve replacement in patients with moderate mixed aortic valve disease

Background

Information is scarce regarding the clinical implications of aortic valve replacement (AVR) for patients suffering from moderate mixed aortic valve disease (MAVD), characterized by a combination of moderate aortic stenosis (AS) and regurgitation (AR). The objective of this retrospective study was to explore the clinical effects of AVR in individuals with moderate MAVD.

Methods

We examined the clinical data from patients with moderate MAVD and preserved left ventricular ejection fraction, who had undergone echocardiography in the period spanning from 2010 to 2018. Moderate AS was defined as aortic valve area index of 0.60-0.85 cm2/m2 and peak velocity of 3.0-4.0 m/s. Moderate AR was defined as a vena contracta width of 3.0-6.0 mm. The primary endpoint was a composite of all-cause death and heart failure hospitalization.

Results

Among 88 patients (mean age, 74.4 ± 6.8 years; 48.9%, men), 44 (50.0%) required AVR during a median follow-up period of 3.3 years (interquartile range, 0.5-4.9). Mean values of specific aortic valve variables are as follows: aortic valve area index, 0.64 ± 0.04 cm2/m2; peak velocity, 3.40 ± 0.30 m/s; and vena contracta width, 4.1 ± 0.7 mm. The primary endpoint occurred in 32 (36.4%) patients during a median follow-up duration of 5.3 years (interquartile range, 3.2-8.0). Multivariable analysis revealed that AVR was significantly associated with the endpoint (hazard ratio, 0.248; 95% confidence interval, 0.107-0.579; p = 0.001) after adjusting for age, B-type natriuretic peptide, and the Charlson comorbidity index. Patients who underwent AVR during follow-up had significantly lower incidence rates of the endpoint than those managed with medical treatment (10.2% vs. 44.1% at 5 years; p < 0.001).

Conclusions

Approximately half of the patients diagnosed with moderate MAVD eventually necessitated AVR throughout the period of observation, leading to positive clinical results. Vigilant tracking of these patients and watchful monitoring for signs requiring AVR during this time frame are essential.

Left ventricular adaptation to aortic regurgitation in adults with repaired coarctation of aorta

BACKGROUND

Aortic regurgitation (AR) can develop in adults with repaired coarctation of aorta (COA), but there are limited data about left ventricular (LV) remodeling and clinical outcomes in this population. The purpose of the study was to compare LV remodeling (LV mass index [LVMI], LV ejection fraction [LVEF], and septal E/e') and onset of symptoms before aortic valve replacement, and LV reverse remodeling (%-change in LVMI, LVEF and E/e') after aortic valve replacement in patients with versus without repaired COA presenting with AR.

METHODS

Asymptomatic adults with repaired COA presenting with moderate/severe AR (AR-COA group) were matched 1:2 to asymptomatic adults without COA and similar severity of AR (control group).

RESULTS

Although both groups (AR-COA n = 52, and control n = 104) had similar age, sex, body mass index, aortic valve gradient, and AR severity, the AR-COA group had higher LVMI (124 ± 28 versus 102 ± 25 g/m², p < 0.001) and E/e' (12.3 ± 2.3 versus 9.5 ± 2.1, p = 0.02) but similar LVEF (63 ± 9% versus 67 ± 10%, p = 0.4). COA diagnosis (adjusted HR 1.95, 95%CI 1.49-2.37, p < 0.001), older age, E/e', and LV hypertrophy were associated with onset of symptoms. Of 89 patients (AR-COA n = 41, and control n = 48) with echocardiographic data at 1-year post- aortic valve replacement, the AR-COA group had less regression of LVMI (-8% [95%CI -5 to -11] versus -17% [95%CI -15 to -21], p < 0.001) and E/e' (-5% [95% CI -3 to -7] versus -16% [95% CI -13 to -19], p < 0.001).

CONCLUSIONS

Patients with COA and AR had a more aggressive clinical course, and perhaps may require a different threshold for surgical intervention.

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.

Cardiac Remodeling and Disease Progression in Patients With Repaired Coarctation of Aorta and Aortic Stenosis

BACKGROUND

Valvulo-arterial impedance (Zva) is used for assessment of left ventricular (LV) global pressure load in patients with aortic stenosis (AS) and impaired arterial compliance. Because patients with repaired coarctation of aorta (COA) have impaired arterial compliance, we hypothesized that COA patients with greater than or equal to moderate AS (AS-COA group) will have higher Zva, symptomatic progression, and cardiovascular events, as compared to non-COA patients with similar AS severity (AS group).

METHODS

Propensity matching (1:1) of 71 AS-COA and 71 AS patients based on age, sex, body mass index, and aortic valve mean gradient (cohort 1). Of 172 patients, 117 patients (AS-COA [n=62]; AS [n=55]) underwent aortic valve replacement, cohort 2. Cohort 1 was used to assess the relationship between preoperative Zva, cardiac remodeling, and symptomatic progression, while cohort 2 was used to assess the relationship between postoperative Zva, LV mass index regression (reduction in LV mass index after aortic valve replacement), and cardiovascular events.

RESULTS

The AS-COA group had higher Zva (4.2±0.6 versus 3.5±0.4 mm Hg/mL·m², P<0.001), more advanced cardiac remodeling, and higher 5-year incidence of symptomatic progression (85% versus 51%, P<0.001). Preoperative Zva was independently associated with cardiac remodeling (r=0.66, P<0.001) and symptomatic progression (hazard ratio, 1.06 [1.02-1.10], per mm Hg/mL·m² increase in Zva). The AS-COA group had higher postoperative Zva (3.3±0.5 versus 2.4±0.4 mm Hg/mL·m², P<0.001), less robust LV mass index regression at 1-year post-aortic valve replacement, and higher 5-year incidence of cardiovascular events. Postoperative Zva was independently associated with LV mass index regression (r=-0.46, P<0.001) and cardiovascular events (hazard ratio, 1.06 [1.02-1.10], per mm Hg/mL·m² increase in Zva).

CONCLUSIONS

Adults with AS-COA had higher LV global pressure load, cardiac remodeling, symptomatic progression, and cardiovascular events as compared to non-COA patients with similar severity of AS. Zva can identify patients at risk for adverse outcomes, and perhaps should be used for risk stratification with regards to timing of aortic valve replacement.

Infective Endocarditis After Transcatheter Versus Surgical Aortic Valve Replacement: A Meta-Analysis

We determined the incidence, clinical characteristics, and risk factors of post-transcatheter aortic valve replacement (TAVR)-associated infective endocarditis (IE). We compared the incidence of IE after TAVR versus after surgical aortic valve replacement (SAVR). The incidence rate of IE 1-year post-TAVR was 0.9% (95% confidence interval [CI]: 0.8-1.0). Transcatheter aortic valve replacement was associated with significantly reduced IE incidence (incidence rate ratio: 0.69, 95% CI: 0.52-0.92, P = .011) compared with SAVR. In patients with TAVR IE, the pooled in-hospital mortality was 37.8% (95% CI: 32.4-43.3, I ² = 54.9%). Pooled adjusted hazard ratio (HR) revealed that peri-procedural peripheral artery disease (HR: 4.02, 95% CI: 2.28-7.10, P < .0001), moderate or severe residual aortic regurgitation (HR: 2.34, 95% CI: 1.53-3.59, P < .0001), orotracheal intubation (HR: 2.13, 95% CI: 1.19-3.82, P = .011), and male gender (HR: 1.70, 95% CI: 1.47-1.97, P < .0001) were risk factors for post-TAVR IE. Post-TAVR IE is a life-threatening complication often resulting in in-hospital mortality. The current evidence-based meta-analysis to identify risk factors may lead to the development of effective preventive and therapeutic strategies for post-TAVR IE to ultimately improve patient outcomes.

Moderate Aortic Stenosis and Heart Failure With Reduced Ejection Fraction: Can Imaging Guide Us to Therapy?

Clinical management of patients with only moderate aortic stenosis (AS) but symptoms of heart failure with a reduced left ventricular ejection fraction (HFrEF) is challenging. Current guidelines recommend clinical surveillance with multimodality imaging; aortic valve replacement (AVR) is deferred until the stenosis becomes severe. Given the known benefits of afterload reduction in management of patients with HFrEF, it has been hypothesized that AVR may be beneficial in patients with only moderate AS who present with HFrEF. In this article, we first review the current approach for management of patients with moderate AS and HFrEF based on close clinical and imaging surveillance with AVR delayed until AS is severe. We then discuss the case for transcatheter AVR (TAVR) earlier in the disease course, when AS is moderate, based on stress echocardiographic data. We conclude with a detailed summary of the TAVR UNLOAD (Transcatheter Aortic Valve Replacement to UNload the Left Ventricle in Patients With ADvanced Heart Failure) trial, in which patients with moderate AS and HFrEF are randomized to guideline-directed heart failure therapy alone versus guideline-directed heart failure therapy plus TAVR.

Outcomes of surgical aortic valve replacement for mixed aortic valve disease

Background

Mixed aortic valve disease (MAVD) is associated with a poorer natural history compared with isolated lesions. However, clinical and echocardiographic outcomes for aortic valve replacement (AVR) in mixed disease are less well understood.

Methods

Retrospective review of AVRs (n=1,011) from 2000-2016. Isolated AVR, AVR + coronary bypass, and AVR + limited ascending aortic replacement were included. Predominant aortic stenosis (AS) group was stratified into group 1 (n=660) with concomitant mild or less aortic insufficiency (AI), and group 2 (n=197) with accompanying moderate or greater AI. Predominant AI group was stratified using the same schema for concomitant AS into groups 3 (n=143) and 4 (n=53). Median follow-up was 3.1 and 4.4 years respectively for AS and AI groups.

Results

For the predominant AS group (n=857) preoperatively, group 2 had a larger preoperative left ventricular end diastolic diameter (LVESD) (51.0±8.4 vs. 48.6±7.2, P=0.02) and lower preoperative left ventricular ejection fraction (LVEF) (57.6% vs. 60.2%, P=0.043). No differences in left ventricular (LV) dimensions, LV or right ventricular (RV) function was evident at follow up (P>0.05). After propensity matching for age, operation, and comorbidities, there was no difference in survival (P=0.19). After propensity matching for the predominant AI group (n=196), survival was lower for group 4 compared to 3 (P=0.02). There were no differences in LV dimensions, LV or RV function preoperatively or on follow-up (P>0.05).

Conclusions

Predominant AS associated with higher AI grades had larger LV dimensions and worse LV function preoperatively. These differences resolve after AVR with equivalent survival. However, predominant AI with more severe AS had reduced survival despite AVR.