Multimodality imaging to assess severity and outcome in asymptomatic patients with aortic stenosis: a medium-long term follow-up study

Multimodality imaging approach is becoming more and more common in evaluating the severity and outcome of aortic stenosis (AS).

To assess the outcome of asymptomatic AS and the usefulness of aortic calcium score (CS) by computed tomography (CT) for solving the dilemma of low flow, low gradients (LFLG) severe AS.

70 (81.4±8.4 years) prospective asymptomatic patients with AS were followed for 2.77±2.01 years with a trans-thoracic echo (TTE) every 6 months. End-points were all cause mortality, aortic valve replacement (AVR or TAVR), aortic velocity and gradients progression and symptoms occurrence. Prevalence of LFLG-AS was investigated and these patients underwent CT for CS calculation at the end of follow-up (FU), Figure 1.

Baseline TTE results from the 70 pts were: peak velocity 3.1±0.8m/sec; peak gradient 44±21mmHg; mean gradient 26±14 mmHg; AVA 1±0.3 cm²; DVI 0.31±0.1; Svi 33.8±18 ml/m²; EF: 55±9% with an AS being mild in 32.9%, moderate in 28.4%, severe in 27.1%; 36.8% of severe AS were LFLG. During FU, 23 (32.8%) pts died (5.7% LFLG) and 13 (18.5%) underwent AVR/TAVR. Predictors of mortality were aortic gradients (p=0.03), AVA (p=0.008), DVI (p<0.001), pulse pressure (p=0.005) and dilated ascending aorta (p<0001). Predictors of AVR/TAVR were: gradients (p=0.003), peak aortic velocity (p=0.02) and dilated ascendent aorta (p=0.01). The best cut-off to predict survival was AVA = 1 cm² (100% sensitivity and 80% specificity). In 34 pts ending FU we found an overall progression of AS severity (peak velocity 3.6±0.9m/sec; peak gradient 50±24 mmHg; mean gradient 33±15 mmHg; AVA 0.7±0.3 cm²; DVI 0.25±0.08; Svi 36±10 ml/m²; EF 54±10%; p<0.05 for all vs baseline) with 24 (70.5%) pts with severe AS and 10 (29.5%) with not severe AS. 18 (75%) of progressive severe AS were LFLG, 12 asymptomatic and 6 symptomatic and all underwent CS revealing that AS was not severe in 6 (1233±1123 AU; 622±55 AU/m²) and true severe in 12 (3388±1188 AU; 1858±795 AU/m²; p=0.005 and p=0.002, respectively). Symptomatic severe LFLG AS were all true severe according to CS (Figure 1). Table 1 shows the main CS correlations.

Asymptomatic AS in elderly people is associated with high mortality risk and rapid progression. AVA remains the best predictor of outcome. In severe LFLG AS, calcium score correlates with symptoms occurrence, progression of valve disease, LV hypertrophy and function and also with RV function.

Type of funding sources: None.