Insuffisance cardiaque aiguë à fraction d’éjection altérée : signes électrocardiographiques associés à la mortalité à l'institut de cardiologie d'Abidjan

Introduction

Heart failure with impaired ejection fraction (HFIEF) represents the end-stage of most cardiac diseases, and is responsible for a high mortality rate. In order to identify patients at risk, numerous clinical and paraclinical prognostic factors have been proposed. The electrocardiogram (ECG), easy to perform and inexpensive, retains a powerful role in the prognostic evaluation of heart failure patients. The aim was to evaluate ECG signs associated with mortality in a retrospective cohort of patients with ICFEA.

Methodology

The study was observational and analytical based on retrospective data collected from patients benefiting from a primary hospitalization for ICFEA at the Abidjan Heart Institute from January 2018 to July 2020.

Results

Of the 370 patients included, 197 had died by August 1, 2020, representing an overall mortality of 53%. Mortality progressed gradually up to one year, then remained unchanged up to 30 months.

In multivariate Cox regression including ECG variables only, the presence of intra-ventricular conduction disorders (OR: 1.80; 95% CI [1.01–3.25]), microvoltage (OR: 1.82; 95% CI [1.05–16]), and pathological Q waves (OR: 1.70; 95% CI [1.02–2.83]), were significantly associated with overall mortality. When ECG variables and clinical, paraclinical and therapeutic demographic variables were included, only the presence of pathological Q waves (OR:1.74; 95% CI [1.01–3.01]) persisted as a risk factor for mortality. Hypertension and treatment of heart failure, in particular ACEI/ARII, beta-blockers and ARM, were protective factors. The presence of Q waves was associated with a significant reduction in survival, based on curves obtained using the Kaplan-Meier model.

Conclusion

ICFEA is responsible for high mortality, mainly in the year following the 1^st hospitalization for cardiac decompensation. The presence of pathological Q waves is the only electrocardiographic sign that remains statistically associated with a poor prognosis, after adjustment.