Role of Anion Gap as a Prognostic Indicator in Acute Coronary Syndrome (ACS)

Abstract

Background: Cardiovascular diseases are the leading cause of mortality in India and acute coronary
syndrome (ACS) is one of its anomalies, affecting mainly the coronary arterial blood supply and further the
functioning of heart muscle. Its subtypes are Non-ST elevation myocardial infarction (NSTEMI), unstable
angina, and ST-elevation myocardial infarction (STEMI). There are various diagnostic tools available to
detect ACS like; electrocardiography (ECG), Cardiac stress test, Coronary CT angiography, Coronary
angiogram and cardiac biomarkers. Yet, tools for assessment of prognosis are scanty and new prognostic
tools are always welcomed, one such is anion gap, which can be detected by assessment of certain ions
present in the serum, urine or plasma, etc. In this study we will assess the role of anion gap, in the assessment
of prognosis in ACS.
Objective:
1. To estimate anion gap (AG) in cases of acute coronary syndrome (ACS) at the time of diagnosis;
2. To evaluate association of anion gap (AG) with the prognosis of acute coronary syndrome (ACS)
Methodology: The study will be conducted in the Department of Medicine of a Rural Tertiary Care
Hospital. Estimation of anion gap (AG) in cases of acute coronary syndrome (ACS) will be evaluated at the
time of admission and after five days of treatment. Anion gap will be calculated or measured as difference
between measured cations (Na+ + K+) and the measured anions (Cl- + HCO3-) in serum. Any complications
during the management will be noted (Heart failure arrhythmias, Hypotension, Reinfarction, Death) will be
correlated with anion gap (AG). Chi square test will be applied to evaluate statistical difference between
among anion group quartile groups.
Results: The study will play a key role in identifying and assessing various other prognostic tools like anion
gap, in assessing the severity of disease to some extent in patients with acute coronary syndrome.
Conclusion: High value of serum anion gap levels is associated with poorer prognosis of the disease outcome
in patients with acute coronary syndrome.