Elevated plasma apelin at admission was independently associated with higher 6-month mortality in patients with ST-elevation heart attacks, adding prognostic value beyond standard biomarkers.
Independent predictor of mortalityApelin at admission predicted 6-month death after heart attack even after adjusting for BNP, troponin, and clinical risk factors
What the researchers found
In 250 consecutive STEMI patients, increased plasma apelin concentrations at admission independently predicted 6-month all-cause mortality after adjusting for age, diabetes, systolic blood pressure, heart rate, glomerular filtration rate, Killip class, left ventricular ejection fraction, BNP, and sensitive troponin I.
Combining apelin with BNP and troponin I further improved predictive accuracy compared to any single biomarker. Notably, apelin levels were associated with markers of ischemic heart failure severity (reflecting the heart's functional decline) but not with markers of ischemic insult severity (reflecting the acute damage) — suggesting apelin reflects the heart failure response rather than the ischemic injury itself.
Why it matters
Quickly identifying which heart attack patients are at highest risk of dying is critical for clinical decision-making. Standard biomarkers like BNP and troponin are already used, but adding apelin to the panel improved prediction. The finding that apelin reflects heart failure severity rather than ischemic damage severity suggests it captures a different aspect of cardiovascular stress — potentially identifying patients who need more aggressive heart failure management after their acute event.
How the study worked
This was a prospective observational study that consecutively enrolled 250 patients with STEMI from January 2012 to January 2013 at a single center. Plasma apelin, BNP, and sensitive troponin I were measured from blood samples collected at hospital admission. Clinical, hemodynamic, and laboratory variables were recorded. The primary outcome was all-cause mortality at 6-month follow-up. Multivariable regression was used to assess apelin's independent prognostic value.
What this study cannot tell us
This is a single-center observational study with a moderate sample size (250 patients). The study cannot determine whether elevated apelin is a cause, consequence, or merely a marker of worse outcomes. Apelin was measured only at admission, so the prognostic value of serial measurements is unknown. The specific cut-off values for clinical use were not established. External validation in larger, multicenter cohorts is needed.
How to read the evidence
This is a prospective observational cohort study from a single center with 250 patients. The study design is appropriate for biomarker discovery, and multivariable adjustment strengthens the findings, but the moderate sample size and single-center design limit generalizability.
When this study was published
Published in 2017, this study remains relevant as apelin biomarker research continues and the apelin/APJ system remains an active area of cardiovascular investigation.
The bigger picture
Apelin and its receptor (APJ) have been extensively studied as regulators of cardiovascular function, with roles in blood pressure control, cardiac contractility, and fluid balance. This study adds to the growing evidence that apelin could serve as a clinical biomarker. The distinction between ischemia markers and heart failure markers is particularly interesting — it suggests that measuring apelin could help clinicians differentiate between patients whose hearts are struggling functionally versus those with extensive tissue damage, guiding different treatment strategies.
Questions still open
- Could apelin-targeted therapies improve outcomes in heart attack patients with elevated apelin levels?
- Does serial apelin monitoring during hospitalization provide better prognostic information than a single admission measurement?
- Why is apelin elevated in heart failure rather than proportional to ischemic damage — what mechanism drives this distinction?
Common questions
What is apelin and what role does it play in the heart?
Why not just use existing biomarkers like troponin and BNP?
Read the original research
Prognostic value of plasma apelin concentrations at admission in patients with ST-segment elevation acute myocardial infarction.
Clinical biochemistry, 50(6), 279-284
Citation
Sans-Roselló, Jordi; Casals, Gregori; Rossello, Xavier; González de la Presa, Bernardino; Vila, Montserrat; Duran-Cambra, Albert; Morales-Ruiz, Manuel; Ferrero-Gregori, Andreu; Jiménez, Wladimiro; Sionis, Alessandro. (2017). Prognostic value of plasma apelin concentrations at admission in patients with ST-segment elevation acute myocardial infarction.. Clinical biochemistry, 50(6), 279-284. https://doi.org/10.1016/j.clinbiochem.2016.11.018