Poor Long-Term Survival in Moderate Aortic Stenosis Patients
Is there mortality risk associated with less-than-severe aortic stenosis (AS)?
The National Echocardiographic Database of Australia (NEDA) is a very large, observational registry that captures individual echocardiographic and basic demographic data on a retrospective and prospective basis from participating centers throughout Australia; at the time of the study, 12 centers had contributed >500,000 investigations from >350,000 individuals undergoing echocardiography. AS severity was characterized among 122,809 men (61 ± 17 years) and 118,494 women (62 ± 19 years), with measured mean gradient, peak velocity, and/or aortic valve area (AVA). Patients with previous aortic valve intervention were excluded. The relationship between AS severity and survival was examined during a median 1,198 (interquartile range, 591-2,166) days of follow-up.
Mild, moderate, and severe AS was present in 16,129 (6.7%), 3,315 (1.4%), and 6,383 (2.6%) cases, respectively. On an adjusted basis (versus no AS; 5-year mortality 19%), patients with any AS had an increasing risk of long-term mortality (adjusted hazard ratio, 1.44-2.09; p < 0.001 for all comparisons). Five-year mortality was 43% among those with moderate AS (mean gradient 20.0-39.0 mm Hg, peak velocity 3.0-3.9 m/s) and 53% among those with severe AS (≥40.0 mm Hg and ≥4.0 m/s; or AVA <1.0 cm2 in low-flow, low-gradient severe AS). A markedly increased risk of death from all-causes (5-year mortality >50%) and from cardiovascular disease was evident from a mean AV gradient >20.0 mm Hg (moderate AS) after adjusting for age, sex, left ventricular systolic, diastolic dysfunction, and aortic regurgitation.
These data suggest that untreated severe AS is associated with poor long-term survival; and that reduced survival also is observed among patients with moderate AS.
This observational study from a large clinical database suggests that any AS is associated with an adverse prognosis, and that mortality is substantially increased among patients with at least moderate AS. As with any retrospective analysis, the causative role of AS is not established; and data are not provided regarding symptoms, additional testing to address patient risk, and timing or rationale for intervention. Possible explanations for high mortality among patients with moderate AS include underestimation of AS severity at the time of the echocardiogram (not all patients may have had AVA and stroke volume index quantified), AS as a marker of comorbid disease(s), or progression to more severe AS during the monitored study period. Although the study is thought-provoking, additional investigation of risks associated with less-than-severe AS is required, and consideration for intervention for less-than-severe AS would have to be supported by data suggesting risk modification.
Keywords: Aortic Valve Insufficiency, Aortic Valve Stenosis, Diagnostic Imaging, Diastole, Echocardiography, Heart Valve Diseases, Stroke Volume, Systole, Survival, ESC Congress, ESC 19
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