A comparative analysis of conventional echocardiographic findings among different heart failure stages and phenotypes: insights from the national echocardiographic society registry
Authors: Mladenovic Z , Stankovic I , Petrovic O , Dimic S , Apostolovic S , Ciric N , Vranic I , Paunovic I , Pantic T , Milic G , Saroskovic B , Filipovic T , Antonijevic Z , Neskovic A N , Trifunovic Zamaklar D 
Published: October 2024

Abstract

Background
The contemporary conceptualization of heart failure (HF) encompasses four developmental stages (at risk for HF, pre-HF, symptomatic HF, and advanced HF) and three distinct HF phenotypes categorized by left ventricular ejection fraction (LVEF) (HFpEF, HFmrEF, HFrEF). However, there is a need for a more comprehensive understanding of echocardiographic similarities and differences among pre-HF stages and various HF phenotypes.

Material and Methods
Our national echocardiographic society conducted a multicenter HF screening initiative. General practitioners in 13 primary care centers utilized the original mobile phone app to determine referrals for transthoracic echocardiography and N-terminal pro-B-type natriuretic peptide (NT-proBNP) testing in individuals without a prior HF diagnosis. The 2021 ESC guidelines' algorithms were used to diagnose HF phenotypes and 2016 EACVI/ASA recommendation² to assess diastolic function. This study defined "heart stress" (elevated NT-proBNP in asymptomatic individuals with risk factors, regardless of structural heart disease or cardiac dysfunction) and "patients at risk for HF" (normal NTproBNP and at least one HF risk factor). All patients were categorized into six groups: (I) no HF, no risk, (II) at risk for HF, (III) heart stress, (IV) HFpEF, (V) HFmrEF, and (VI) HFrEF. Echocardiographic findings were compared among groups (II) to (VI), using ANOVA, Kruskal-Wallis and Chi-squared test, when needed.

Results
In a cohort of 930 outpatients (mean age 66±11 years, 61% female), 34.2% were diagnosed with HF, 22.3% experienced heart stress, 37.8% were at risk for HF, and 12.8% had neither HF nor risk factors (Figure). While NT pro BNP showed progressive increase, LVEF showed a progressive decline across the groups, reaching its lowest in HFrEF patients (Table). Simultaneously, left ventricular mass index (LVMi), left atrial volume index (LAVi), and maximal velocity of tricuspid regurgitation (TR Vmax) significantly increased in a stepwise manner. Variations in predominant LV geometry were significant across groups (p&lt;0.001): normal LV geometry in those without HF (60.8%), concentric LV remodeling in at-risk patients (38.6%), normal LV geometry in heart stress (49%), concentric LV hypertrophy (LVH) in HFpEF (27.7%), eccentric LVH in HFmrEF (42.3%), and both concentric and eccentric LVH in HFrEF (43.3% each). Diastolic dysfunction increased prevalence across the groups (12.9% vs 24.7% vs 37.6% vs 19.6% vs 51.1%, p&lt;0.001). Remarkably, HFmrEF group had the highest proportion of undetermined diastolic function (14.7% vs 23.1% vs 27.9% vs 50% vs 26.7%, p&lt;0.001).

Conclusions
The mobile phone app used in primary care setting allowed identification of significant number of individuals in the pre-HF stages, warranting further investigation. Distinct echocardiographic differences in pre-HF stages and HF phenotypes provide valuable insights for early detection and tailored treatments.