Staging Cardiac Damage in Patients With Asymptomatic Aortic Valve Stenosis

Abstract

Background: The optimal timing of intervention in patients with asymptomatic severe aortic stenosis (AS) remains controversial.

Objectives: This multicenter study sought to test and validate the prognostic value of the staging of cardiac damage in patients with asymptomatic moderate to severe AS.

Methods: This study retrospectively analyzed the clinical, Doppler echocardiographic, and outcome data that were prospectively collected in 735 asymptomatic patients (71 ± 14 years of age; 60% men) with at least moderate AS (aortic valve area <1.5 cm²) and preserved left ventricular ejection fraction (≥50%) followed in the heart valve clinics of 4 high-volume centers. Patients were classified according to the following staging classification: no cardiac damage associated with the valve stenosis (Stage 0), left ventricular damage (Stage 1), left atrial or mitral valve damage (Stage 2), pulmonary vasculature or tricuspid valve damage (Stage 3), or right ventricular damage or subclinical heart failure (Stage 4). The primary endpoint was all-cause mortality.

Results: At baseline, 89 (12%) patients were classified in Stage 0, 200 (27%) in Stage 1, 341 (46%) in Stage 2, and 105 (14%) in Stage 3 or 4. Median follow-up was 2.6 years (interquartile range: 1.1 to 5.2 years). There was a stepwise increase in mortality rates according to staging: 13% in Stage 0, 25% in Stage 1, 44% in Stage 2, and 58% in Stages 3 to 4 (p < 0.0001). The staging was significantly associated with excess mortality in multivariable analysis adjusted for aortic valve replacement as a time-dependent variable (hazard ratio: 1.31 per each increase in stage; 95% CI: 1.06 to 1.61; p = 0.01), and showed incremental value to several clinical variables (net reclassification index = 0.34; p = 0.003).

Conclusions: The new staging system characterizing the extra-aortic valve cardiac damage provides incremental prognostic value in patients with asymptomatic moderate to severe AS. This staging classification may be helpful to identify asymptomatic AS patients who may benefit from elective aortic valve replacement.

Keywords: aortic valve replacement; aortic valve stenosis; asymptomatic; disease staging; echocardiography.