The traditional classification of aortic stenosis: impact on mortality
Authors: Trifunovic Zamaklar D , Petrovic O , Mladenovic A , Negrojevic S , Vidanovic S , Kerovic A , Jovanovic I , Paunovic I , Vratonjic J , Boricic Kostic M 
Published: November 2023

Abstract

Background
The clinical course of patients with aortic stenosis (AS) depends on the stage of the disease which is defined by the degree of the aortic valve stenosis and left ventricular (LV) function.

Objectives
This study sought to analyze the mortality of different stages of the AS defined by the traditional classification, based on aortic valve area (AVA; cm2), peak velocity across the aortic valve (VP; m/sec), mean pressure gradient across the aortic valve (MGP; mmHg), left ventricular ejection fraction (EF; %) and stroke volume (SV; ml).

Methods
Single-center, retrospective study. Patients were classified into four groups: Group 1 (moderate AS: 1≤AVA &lt;1.5 cm2 and (20&lt;mg&lt;= 3&lt;vp&lt;="4)),"&gt;40), Group 3 (paradoxical low flow, low gradient AS: AVA&lt;1.0 and MPG≤40 and EF ≥50 and SV&lt; 67) and Group 4 (classical low flow, low gradient AS: AVA&lt;1. and MPG≤40 mmHg and EF&lt;50 and SV&lt;67).

Results
2619 patients evaluated for AS between Jan 2014 and Dec 2021 in the central echocardiographic laboratory of the university medical center were initially analyzed. Of them, 1645 patients completed follow-ups and were included in this study. The basic patient characteristics were as follows: mean age 69.6±10.5 yrs, 59% were male, 33% had diabetes mellitus, 15% had atrial fibrillation. The baseline echocardiographic measurements were as follows: VP 4.06±1.4 m/s, PG 67±25 mmHg, MG 40±16 mmHg, AVA 0.83±0.28cm2, LV EDD 5.3±0.73cm, LA diameter 4.4±0.7cm, RV diameter 2.5±0.4cm, RVSP 40.5±12.9 mmHg, EF 60.0±11.8%, SV 70.7±23.7ml. The distribution of patients according to the stages of AS is Group 1: 30%, Group 2: 54%, Group 3: 11%, and Group 4: 5%. During the median 52 months of follow-up, 60% of patients had a surgical aortic valve replacement. In the whole cohort, during the first 5 years, 61.2% of patients died with a significant difference in mortality across the groups: Group 1 vs Group 2 vs Group 3 vs Group 4: 56.5% vs 63.8% vs 54.1% vs 79.4%, p=0.022. The survival analysis (Kaplan Meier) (Picture 1) confirmed significant differences in survival (for overall comparisons: Log Rank (Mantel-Cox) Chi-Square 16.263, p=0.001). The pairwise survival analysis between the groups revealed significant differences between Group 1 vs Group 2 (p=0.018), Group 1 vs Group 4 (p&lt;0.001), Group 2 vs Group 3 (p=0.044), Group 2 vs Group 4 (p=0.021) and Group 3 vs Group 4 (p=0.001).

Conclusion
Patients with aortic stenosis have still significant mortality during long-term follow-up. It depends on the severity/stages (phenotype) of the disease defined by the traditional classification with an increasing mortality rate from moderate AS, towards classical severe AS and classical LF/LG severe AS, whereas patients with paradoxical LF/LG severe AS have similar survival compared to patients with moderate AS. The impact of early intervention in moderate and paradoxical LFF/LG severe AS patients deserves further investigation.