Global Longitudinal Strain: A Robust and Independent Prognostic Indicator in Patients with HFimpEF

Table of Content

Introduction

Patients with reduced ejection fraction (EF) often show improvement in left ventricular EF (LVEF). Patients having LVEF increases by an absolute amount of 10% or ≥40% from a baseline <40% are referred to as having heart failure with improved EF (HFimpEF). Patients with HFimpEF have a variable clinical course. Global longitudinal strain (GLS), a sensitive indicator of LV systolic function, may be a valuable predictor of risk of future events in this patient subgroup.

Aim

To determine whether GLS would independently predict future clinical events in patients with HFimpEF

Patients Profile

  • HF patients with LVEF ≥40% on index echocardiogram, and an LVEF <40% on initial study echocardiogram with an improvement of ≥10% (age above 18 years; n=289)

Methods

Study Design

  • Single-centred retrospective cohort study

Assessment

  • GLS was assessed using 2-dimensional speckle-tracking software on index echocardiography

Outcomes

Primary Outcome

  • Time to first occurrence of cardiovascular (CV) mortality or HF hospitalization or emergency treatment

Secondary Outcome

  • All-cause death, heart transplantation, LV assist device implantation, and episodes of treated ventricular tachycardia (VT) or appropriate implantable cardioverter-defibrillator (ICD) therapy events

Results

  • The median age of the study population was 64 years, 70% were male, 68.5% had nonischemic etiology, and 75.9% had New York Heart Association (NYHA) functional class I or II symptoms.
  • Median time from first HF diagnosis to index echocardiography was 22 months, median absolute values of GLS (aGLS) and LVEF from index echocardiography were 12.7% and 52%, respectively.
  • The incidence of primary outcome, over the period of 53 months following index echocardiography, was less frequent in patients with aGLS above the median than below it (Fig. 1).
Fig. 1: Incidence of Primary outcome during the study

  • Assessment as a continuous variable revealed that each 1% increase in aGLS on index echocardiogram was associated with a lower likelihood of the composite outcome (HR; 0.86, 95% CI; 0.79-0.93, P <0.001). The association persisted after multivariable adjustment as well (HR; 0.90, 95% CI; 0.82-0.97, P=0.01).
  • LVEF reduction >5% to <40% was observed in 88 (38.6%) patients. Lower aGLS was associated with increased likelihood of deteriorating LVEF, thus; deterioration in LVEF was more common in patients with aGLS below the median vs.  those with aGLS above the median (49.6% vs. 25.7%, P <0.001).
  • Patients with LVEF below the median at the index echocardiography had higher rate of VT or appropriate ICD shock (6.4% vs. 1.9%; P=0.047) during subsequent follow-up.

Conclusions

  • Patients with HFimpEF had a better prognosis as compared with patients having persistently low LVEF. Such patients were at a low risk of worsening HF, CV death and future deterioration of cardiac function.
  • GLS was a strong and independent predictor for future HF events and deteriorating cardiac function in patients with HFimpEF.
  • It is therefore important to look for deterioration in patients with impaired GLS, despite having normalized LVEF.

J Am Coll Cardiol HF. 2022 Jan;10(1):27-37.