Relationship of plasma erythropoietin to long-term outcome in acute coronary syndrome

The association between red cell distribution width, erythropoietin levels, and coronary artery disease

BACKGROUND

Red cell distribution width (RDW) is a cardiac marker for risk stratification and prognostic evaluation of coronary artery disease (CAD); however, the underlying mechanism remains unclear. Erythropoietin (EPO), a crucial factor affecting erythropoiesis, has been reported to be a protective molecule regulating the process of myocardial ischemia and relevant damage. No study has as yet reported the relationship between RDW and endogenous EPO in CAD patients. This cross-sectional study aimed to establish the association between endogenous EPO levels and increases in RDW in CAD patients.

PATIENTS AND METHODS

Two hundred participants who underwent coronary arteriography were recruited from July 2015 to October 2015. The participants were divided into CAD and non-CAD groups on the basis of angiography diagnosis. Demographic data were obtained through personal interviews and general clinical methods.

RESULTS

RDW and EPO levels in the CAD group were higher than those in the non-CAD group. The correlation between RDW and EPO levels was statistically significant among CAD patients (r=0.411, P<0.001). The increases in EPO and RDW were related to the prevalence of CAD. The levels of RDW were correlated to endogenous EPO levels in CAD patients.

CONCLUSION

Increased EPO and RDW might be risk factors for CAD. Endogenous EPO levels are associated with increases in RDW in CAD patients.

[Endogenous erythropoietin, acute kidney injury, and prognosis in patients with acute coronary syndrome]

AIM

To investigate the prognostic value of serum endogenous erythropoietin (EPO) in patients with acute coronary syndrome (ACS), including that in the development of acute kidney injury (AKI).

SUBJECTS AND METHODS

Eighty-four patients (46 men, 38 women; mean age 63 ± 11 years) with ACS were examined. Twenty-one (25%) patents were diagnosed with ECG ST-segment elevation acute myocardial infarction (STSEAMI), 12 (14%) had ECG non-STSEAMI, and 51 (61%) had unstable angina. Thrombolytic therapy was performed in 10 (48%) patients with STSEAMI. The patients whom had not undergone coronarography were included in the investigation to exclude the nephrotoxic effect of X-ray contrast agents.

RESULTS

AKI was observed in 7 of the patients with acute myocardial infarction and in only 1 of those with unstable angina. Four (5%) patients died during hospitalization. The EPO level of > 10.5 IU/ml predicted the development of AKI in the ACS patients with a sensitivity of 71% and a specificity of 67%. That of > 13.7 IU/ml was associated with hospital death in the ACS patients with a sensitivity of 100% and a specificity of 75% (AUC = 0.93%).

CONCLUSION

High serum EPO levels in an ACS patent during his hospital stay may serve as a biomarker for a high risk for AKI and high death rates.

Inflammatory markers in ST-elevation acute myocardial infarction

After acute myocardial infarction, ventricular remodeling is characterized by changes at the molecular, structural, geometrical and functional level that determine progression to heart failure. Inflammation plays a key role in wound healing and scar formation, affecting ventricular remodeling. Several, rather different, components of the inflammatory response were studied as biomarkers in ST-elevation acute myocardial infarction. Widely available and inexpensive tests, such as leukocyte count at admission, as well as more sophisticated immunoassays provide powerful predictors of adverse outcome in patients with ST-elevation acute myocardial infarction. We review the value of inflammatory markers in ST-elevation acute myocardial infarction and their association with ventricular remodeling, heart failure and sudden death. In conclusion, the use of these biomarkers may identify subjects at greater risk of adverse events and perhaps provide an insight into the mechanisms of disease progression.

Endogenous serum erythropoietin and no-reflow in patients with ST-elevation myocardial infarction

BACKGROUND

In models of acute ischaemia, erythropoietin (EPO) administration has been found to attenuate vascular injury largely through reduced apoptosis, suppressed inflammation and increased nitric oxide availability. We studied the association between circulating endogenous EPO and no-reflow in patients with first ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI).

METHODS

Blood sampling was performed before PPCI. Consecutive patients with (n = 24) or without (n = 24) evidence of angiographic no-reflow after PPCI were enrolled. Angiographic no-reflow was defined as Thrombolysis in Myocardial Infarction (TIMI) flow ≤ 2 or as TIMI flow = 3 but with myocardial blush grade < 2. We also assessed electrocardiographic (ECG) no-reflow as ≤ 50% resolution of maximal ST elevation 60 min after PPCI.

RESULTS

Baseline characteristics did not correlate significantly with EPO concentrations. In contrast, both angiographic and ECG no-reflow correlated with lower EPO levels at univariate analysis [median (interquartile): 4·2 (0·6-9·5) vs. 12·2 (5·2-20·3) mIU mL(-1), P = 0·001, and 4·0 (0·6-7·1) vs. 9·3 (1·0-12·6) mIU mL(-1), P = 0·01, respectively]. At multivariable analysis, decreasing EPO tertiles and left anterior descending as the infarct-related artery were the only factors that predicted both angiographic and ECG no-reflow (P = 0·017 and P = 0·02 for EPO; P < 0·005 and P > 0·05 for left anterior descending artery, respectively).

CONCLUSIONS

We found an independent, graded, inverse relation between endogenous EPO levels and angiographic and ECG no-reflow following PPCI. In animal models of ischaemia, EPO has been found to be protective. In humans, endogenous EPO may contribute to offset the mechanisms responsible for no-reflow.

Erythropoietin and the heart: facts and perspectives

EPO (erythropoietin) has long been identified as a primary regulator of erythropoiesis. Subsequently, EPO has been recognized as playing a role in a broad variety of processes in cardiovascular pathophysiology. In particular, the tight interactions of EPO with the nitric oxide pathway, apoptosis, ischaemia, cell proliferation and platelet activation appear of great interest. Although enhanced EPO synthesis is viewed as an appropriate compensatory mechanism in the cardio-renal syndrome, which features CHF (congestive heart failure) and CRF (chronic renal failure), maladaptative excessive EPO synthesis in the advanced stages of these diseases appears to be predictive of higher mortality. Clinical trials based on the use of EPO in both heart and renal failure have so far produced contradictory results, whereas treatment targeted to restore low Hb levels appears rational and is supported by regulatory authorities. New areas for therapeutic use of EPO, such as acute coronary syndromes, are under investigation, and they are discussed in the present review together with other clinical applications in cardiovascular diseases. The revisited concept of a potential use of endogenous EPO levels as a predictor of CHF severity, as well as in the monitoring of responses to treatment, deserves appropriate investigation, as this may identify EPO as a useful biomarker in the clinical management of cardiovascular diseases.