Impact of Moderate Aortic Stenosis in Patients With HFrEF
- In a single-center, retrospective review of echo patients with LVEF <50%, in a propensity score-matched cohort the presence of moderate AS defined by AVA compared to no AS was associated with an increased risk of HF hospitalization and mortality (HR, 1.24; 95% CI, 1.04-1.49; p = 0.01) and fewer days alive outside of the hospital (p < 0.0001).
- Although surgical or transcatheter AVR was uncommon among patients with moderate AS (12.2% of patients), it was associated with improved survival (HR, 0.60; CI, 0.36-0.99; p < 0.05) but was not associated with the primary outcome measure of all-cause mortality and HF hospitalization (HR, 0.9; CI, 0.6-1.4; p = 0.74).
- The study contributes to data that moderate AS is associated with worse clinical outcomes among patients with LV systolic dysfunction, but it does not address how to mitigate that risk.
What are the clinical outcomes of patients with heart failure with reduced ejection fraction (HFrEF) and moderate aortic stenosis (AS) relative to those without AS or with severe AS?
The echocardiographic database at a single large hospital was used to retrospectively identify patients from 2016–2019 with left ventricular ejection fraction (LVEF) <50% (used to define as HFrEF). AS was categorized based on aortic valve area (AVA) (AVA <1.0 cm2, severe AS; AVA 1.0-1.5 cm2, moderate AS). Dobutamine stress echocardiography was not routinely performed, and patients with low-flow low-gradient AS were categorized as having severe AS. The primary endpoint, defined as a composite of all-cause mortality and heart failure (HF) hospitalization, was compared across groups and within a propensity score-matched cohort. Secondary outcomes included death, HF hospitalization, number of HF hospitalizations, and days alive outside the hospital.
There were 9,133 patients with LVEF <50% (HFrEF), including 374 with moderate AS and 362 with severe AS. Over a median follow-up time of 3.1 (interquartile range [IQR] 1.9-4.4) years, the primary outcome occurred in 62.7% of patients with moderate AS versus 45.9% with no AS (p < 0.0001); rates were similar with severe and moderate AS (62.0% vs. 62.7%; p = 0.68). Patients with severe AS compared to moderate AS had a lower incidence of HF hospitalization (36.2% vs. 43.6%; p < 0.05) and were more likely to undergo surgical or transcatheter aortic valve replacement (AVR) within the follow-up period (112 [33.7%] vs. 46 [12.2%]). Within a propensity score-matched cohort, moderate AS compared to no AS was associated with an increased risk of HF hospitalization and mortality (hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.04-1.49; p = 0.01) and fewer days alive outside of the hospital (p < 0.0001). AVR was associated with improved survival (HR, 0.60; CI, 0.36-0.99; p < 0.05) but was not associated with the primary outcome measure (HR, 0.9; CI, 0.6-1.4; p = 0.74).
The authors conclude that, in patients with HFrEF, moderate AS is associated with increased rates of HF hospitalization and mortality, and that further investigation is warranted to determine whether AVR in this population improves clinical outcomes.
Moderate AS is associated with left atrial and LV enlargement, and with adverse remodeling affecting LV systolic and diastolic function. With its implicit effect of increasing LV afterload, it is not surprising that hemodynamically significant albeit only moderate AS would be associated with worse clinical outcomes among patients with coincident LV systolic dysfunction. This single-center, retrospective review found that patients with LVEF <50% and moderate AS compared to those with LVEF <50% and no AS had a higher rate of HF hospitalization, all-cause mortality, burden of HF hospitalizations, and fewer days alive out of hospital; and that mortality was similar among those with moderate AS and severe AS (albeit confounded by a greater percentage of patients with severe AS having undergone AVR, which may have mitigated risk).
Study limitations include its retrospective nature and reliance on administrative claims data for the assessment of comorbid conditions and HF hospitalizations; the exclusive use of echo/Doppler AVA (with its inherent limitations, especially among patient who might have low flow) to assess AS severity; a potentially heterogeneous group of ‘severe’ AS patients that could have included patients with pseudosevere AS; and an unstated definition of ‘no AS,’ with no report of AVA and statistically indistinguishable mean gradients between patients with moderate AS (16, IQR 12-21) and no AS (8, IQR 5-12; p = 0.6). This study contributes to existing data that moderate AS is associated with worse clinical outcomes among patients with LV systolic dysfunction, but it does not address how to mitigate that risk.
Clinical Topics: Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Valvular Heart Disease, Aortic Surgery, Cardiac Surgery and Heart Failure, Cardiac Surgery and VHD, Acute Heart Failure, Interventions and Imaging, Interventions and Structural Heart Disease, Echocardiography/Ultrasound
Keywords: Aortic Valve Stenosis, Cardiac Surgical Procedures, Dobutamine, Echocardiography, Heart Failure, Heart Valve Diseases, Hospitalization, Outcome Assessment, Health Care, Risk, Stroke Volume, Transcatheter Aortic Valve Replacement, Ventricular Function, Left
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