Regional impairment of left ventricular longitudinal strain in aortic regurgitation: have we found the missing piece?
Authors: Ferreira J , Marta L , Presume J , Freitas P , Guerreiro S , Abecasis J , Reis C , Horta E , Ribeiras R , Mendes M , Andrade M J 
Published: June 2023

Abstract

Funding Acknowledgements
Type of funding sources: None.

Background
Aortic regurgitation (AR) has been shown to have an impact on myocardial mechanics and recent studies have proved the value of global longitudinal strain (GLS) as an additional parameter in the assessment of disease severity and prognosis. However, a direct and localized influence of the regurgitant jet (RJ) on regional deformation has not yet been demonstrated.

Purpose
To assess if there is a regional pattern of longitudinal strain (LS) impairment in AR connected to the direction of the RJ, as well as its potential reversibility and prognostic impact.

Methods
We studied patients (pts) with chronic moderate and severe isolated AR referred for echocardiographic evaluation. For each patient, we established the direction of the RJ according to the myocardial segments impacted by its turbulent portion. Pts were considered to have a jet-related LS reduction (JRSR) when the wall segments impacted by the jet had a relative reduction in LS of at least 30% compared to non-affected segments. Parameters of AR severity and left ventricular size and function were assessed. For those who underwent surgical correction of AR, the postop TTE was also compared with the preop.

Results
Of the 203 AR pts screened, 80 met inclusion criteria (median age 57 years, 83% male). Mean GLS and ejection fraction (EF) were -16% and 54%, respectively.
In 34 of the 80 pts, there was a regional reduction of 10 percentage points in the absolute value of LS in the segments impacted by the jet, compared to non-affected segments (median −8% vs −18%, p&lt;0.001), corresponding to a 56% relative decrease.
The predominant jet directions were towards the basal septum (44%), mid posterior/mid lateral segments (24%), and basal inferior segment (12%).
Demographics, severity of AR and parameters of systolic and diastolic function did not significantly differ between those who had JRSR or not.
Of the 34 pts with JRSR, 20 underwent corrective surgery. In an early postop TTE, the difference in LS between the segments impacted by the jet and the non-affected segments attenuated (4.7% absolute difference vs 10% in the preop TTE, p = 0.001).
Pts with JRSR in the preop echo had lower rates of improvement of GLS (11 vs 46% of pts improved at least 2.5%, p = 0.043) and a tendency towards lower rates of recovery of EF after surgery (17% vs 46% recovered at least 5% in EF, p = 0.07).

Conclusion
This study identifies an association between the parietal impact of the RJ in AR and regional LS impairment. It suggests that external factors such as blood flow dynamics affect myocardial deformation. Additionally, the longstanding impact of the jet might damage the myocardium to the point of limiting recovery of systolic function after corrective surgery.
This is, to our knowledge, the first reported case series showing the negative effect of the jet’s impact on LV longitudinal function and, most importantly, on postop outcomes. Longer follow-up is needed to confirm its prognostic role.