Predictive Value of CHA2DS2VASC Score for Contrast-induced Nephropathy After Primary Percutaneous Coronary Intervention in ST-segment Elevation Myocardial Infarction Patients

Contrast induced acute kidney injury has commonly been referred to as contrast induced nephropathy (CIN) defined as an increase in serum creatinine ≥25% or ≥0.5 mg/dl from baseline within 48-72 hours with peak incidence 2-5 days after contrast exposure.1. CIN, Which can potentially lead to acute kidney failure or mortality, is still common among hospitalized patients. In addition, contrast medium exposure may lead to long-term outcomes such as dialysis-requiring renal failure or death.2. The incidence of CIN ranges from 7% to 25% in different population subgroups based on the risk status. Hence, risk stratification has an important bearing in order to provide the appropriate preventive therapies to those high-risk individuals before and after contrast media exposure.3.

In the past, several risk prediction models have been proposed to envisage the CIN incidence. Mehran proposed a scoring system comprising eight variables which correlated well with the CIN risk. Despite having a fair degree of accuracy; complexity was one of the major limitations of such models.4 .Most predictive models for contrast induced nephropathy in clinical use have modest ability, and are only applied to patients receiving contrast for coronary angiography. Further research is needed to develop models that can better inform patient centered decision making, as well as improve the use of preventive strategies for contrast induced nephropathy.5.

ST-elevation myocardial infarction (STEMI) is a clinical syndrome defined by characteristic symptoms of myocardial ischemia in association with persistent electrocardiographic ST elevation (STE) and subsequent release of biomarkers of myocardial necrosis.1 STE is the single best immediately available surrogate marker for detecting acute complete coronary artery occlusion, denoting a significant region of injured myocardium at imminent risk of irreversible infarction, requiring immediate reperfusion therapy.6.

Primary percutaneous coronary intervention(PCI) if performed in a timely fashion is the recommended modality of reperfusion in STEMI cases as per guidelines [ACC-ESC-STEMI & revascularization]. Frequently, baseline kidney functions are unknown, nevertheless, to maximize salvaging myocardial tissue for STEMI patients; immediate reperfusion is prioritized over awaiting tests results. Considering the systemic inflammatory response associated with STEMI and that commonly due to severe pain and agony, those patients are not properly hydrated, added to higher prevalence of MI-related myocardial dysfunction and heart failure than in elective cases, primary PCI for STEMI cases might have higher risk than usual of CIN.7,8.

The CHA2DS2-VASC score is traditionally used for embolic risk stratification in atrial fibrillation (AF) patients and includes the following variables: congestive heart failure (CHF), hypertension, age ≥75 years, diabetes mellitus (DM), previous stroke, vascular disease, age 65 to 74 years and sex.9.

The CHA2DS2-VASC score has been reported recently to have a prognostic utility to predict adverse clinical outcomes in patients with acute coronary syndrome (ACS), regardless of having AF.10.

The CHA2DS2VASC score is practical and easy to memorize and apply in STEMI cases, however, strong evidence to validate its prognostic value in predicting CIN in the setting acute STEMI is lacking.