High values of CAR, whether using hs-CRP or CRP, were identified as an independent predictor for in-hospital MACEs (P value < 0.001 and 0.002 respectively), in agreement of Cagdas et al who demonstrated also that CAR is associated with CAD severity in patients with acute coronary syndrome (ACS) [14].
Similarly Wei Wang et al stated that CAR was an independent predictor for in-hospital MACEs and may therefore be used for risk stratification in patients with ACS [15].
CAR can be considered as a good precise inflammatory marker that denote higher sensitivity and even specificity helped in prediction of prognosis in different conditions including cardiac events compared when relying on each marker (CRP, Albumin) alone [14–18].
It was described by Fairclough et al. and proposed to predict poor prognosis in patients with acute medical conditions [16]. Similar evidences showed its association with poor prognosis in patients with tumors or sepsis [17,19−23 ]. Previous reports, Karabağ et al, has revealed that CAR can predict no-reflow in patients with ST-elevation myocardial infarction [24] and Zhang et al concluded that the higher the CAR, the higher the risk of death in patients with ACS [25].
Acet et al found that CAR was independently associated with the risk of MACE in STEMI patients undergoing primary percutaneous coronary intervention (pPCI) and adding CAR to the GRACE risk score system could increase the predictive value of GRACE score in the estimation of prognosis in STEMI patients undergoing PCI [26] ,and Kalyoncuoglu et al concluded that CAR can be used as a reliable marker in prediction of CAD severity in patients with NSTEMI and it may be a part of cardiovascular assessment to identify those NSTEMI patients ,who are at high risk for advanced CAD and may necessitate a more aggressive therapeutic approach and closer clinical follow-up [27].
Furthermore, Wada et al. showed that CAR is a stronger predictor than either marker alone in patients treated with percutaneous coronary intervention [28].
In this study, a remarkably worse short-term prognosis was observed in patients with serum hs-CRP levels > 4 mg/l, CRP > 5.25 mg/l. These results of the present study are compatible with previous findings [29, 30]. It is most likely that CRP has a role in all phases of atherosclerosis by directly influencing processes such as endothelial damage, complement activation, apoptosis, vascular cell activation, and thrombosis [31]
It is suggested that decreased albumin plasma concentrations may be attributed development and progression of atherosclerosis [32, 33].
According to the findings of the present study, albumin level can’t be considered as an independent prognosticator for short term MACEs in patients with ACs, in contrast to other literatures, in which low S.albumin was founded to be an independent predictor for in-hospital MACEs in patients with ACS [14, 15].
In the present study, heart failure development, arrhythmia and cardiogenic shock were the most important causes of MACE. This may be due to increased myocardial damage and decreased myocardial reserve, in agreement with Acet et al [26] .
An interesting finding regarding medical outcomes in this study considered a cut off value of CAR (using hs-CRP and CRP) to be, 3.18 mg/l, 9.13mg/l respectively, statistically significant in context of discrimination between medically treated ACS patients and death outcome in term of high CAR (p value < 0.001 for both) which couldn’t be assessed by other authors up to our knowledge.
Similarly, a predictive cut off value of CAR (using hs-CRP and CRP) had concluded to help in making management mode decision between conservative medical treatment from those indicated for immediate intervention PCI considering cut value of 1.4 mg/l and 0.78 mg/L respectively (p = 0.046 for both).
Another interesting finding in which there is a significant linear relationship between CAR (using hs-CRP) and duration of hospital stay (p = 0.036,r = 0.210 ) which may contributed to the development of complications and the need for further hospitalization. Moreover, there is significant linear relationship between CAR (using CRP) and age of the patients (P = 0.008, r = 459).
Therefore; it can be stated that CAR is a more valuable marker than each of CRP and albumin alone in the prediction of in hospital MACEs which is compatible with Cagdas et al [14] Wei Wang et al [15] reports, with good implication concerning the decision of early referral for interventional management rather than keeping with conservative medical management.
In conclusion, High CAR levels are associated with poor outcomes, as independent predictor for in-hospital MACEs, concerning ACS patient at presentation, as well as, it can be used as guide that help in ascertain the need of immediate interventional PCI rather than continuing conventional conservative medical treatment.