Preserved or slightly depressed ejection fraction and outcomes after myocardial infarction

Area of Science:

• Cardiology
• Medical Imaging
• Clinical Research

Background:

• Left ventricular ejection fraction (EF) is a crucial prognostic marker in patients post-myocardial infarction (MI).
• Existing methods for EF assessment, including transthoracic echocardiography (TTE), contrast ventriculography (CNV), and radionuclide angiography (RNA), show high correlation but modest agreement.
• The impact of the chosen EF measurement modality on patient outcomes, particularly in those with preserved or mildly reduced EF, requires further investigation.

Purpose of the Study:

• To determine if the method used to assess left ventricular ejection fraction (EF) influences the prognostication of post-myocardial infarction (MI) patients with normal or mildly reduced EF.
• To analyze the predictive value of EF for mortality across different measurement modalities within the Prevention of Events with Angiotensin Converting Enzyme Inhibition (PEACE) Trial cohort.

Main Methods:

• Utilized data from the National Heart, Lung, and Blood Institute (NHLBI) limited access dataset of the PEACE Trial (n=8290).
• Cohort was stratified into groups based on EF assessment modality: TTE (n=2582), RNA (n=816), and CNV (n=1155).
• Multivariate analysis was performed to assess EF as a predictor of cardiovascular and all-cause mortality, comparing outcomes across different EF measurement groups.

Main Results:

• Left ventricular ejection fraction (EF) was a significant predictor of both cardiovascular mortality (HR 0.97) and all-cause mortality (HR 0.98) in the study population.
• Despite significant differences in baseline characteristics between TTE, RNA, and CNV groups, no significant differences in all-cause mortality were observed when comparing RNA (HR 1.13) or CNV (HR 1.13) to TTE.
• Similarly, cardiovascular mortality did not differ significantly between the RNA (HR 1.23) or CNV (HR 1.14) groups compared to the TTE group.

Conclusions:

• Left ventricular ejection fraction (EF) remains a significant predictor of mortality in post-myocardial infarction (MI) patients with preserved or mildly depressed EF.
• The modality used for EF measurement (TTE, RNA, or CNV) is interchangeable and does not significantly alter the prognostic value of EF in this patient population.
• These findings support the consistent use of EF as a prognostic indicator regardless of the specific measurement technique employed in post-MI care.