Background

According to current understanding, atherosclerosis is believed to be inflammatory in origin. Haematological parameters, as markers of inflammation, have been shown to be linked to various outcomes among patients with ST segment elevated myocardial infarction (STEMI).

Objectives

To identify the pattern of haematological cellular response in patients with STEMI and to compare the results among patients with different sub-groups of STEMIs.

Methods

A descriptive cross-sectional study was conducted at the Cardiology Unit, Teaching Hospital, Kandy in 2016 and 2017. Full blood counts of all eligible patients who had acute STEMI were obtained on admission. Patients with clinical evidence of inflammatory or infectious conditions preceding STEMI were excluded. Controls were defined as patients who had STEMI six months previously and were treated with medical thrombolysis with no further events of acute coronary syndrome. Haematological parameters of white blood cell (WBC) count, neutrophil/lymphocyte ratio (NLR), mean platelet volume (MPV), platelet distribution width (PDW), and platelet/lymphocyte ratio (PLR) were evaluated. Diabetic sub group was compared with age and sex matched non-diabetic group. Comparison also made among groups with different extensions of the anterior and inferior STEMI.

Results

There were 350 patients with acute STEMI and 250 age and sex matched controls in the study. Of the patients, 259(74.00%) were males. The mean age of the patients was 61.27±11.64 years. There was a significant higher value noted in absolute NLR (7.00±5.86 vs. 5.55±4.32, p=0.00), PDW (16.61±2.32 vs. 14.58±2.51, p=0.00) and PLR (164.42±111.21 vs. 122.79±64.46, p=0.00) in acute STEMI patients compared to controls. Out of the STEMI patients 20.86% (n=73) were diabetics.  There was a significant higher value noted in NLR (9.43±6.66 vs. 6.62±7.14, p=0.00), PDW (17.62±3.31 vs. 13.61±1.52, p=0.00) and PLR (178.32±121.24 vs. 146.50±102.34) among diabetic vs. non-diabetic patients. In relation to territory of the infarct, there was a significantly higher NLR (8.88±6.32 vs. 7.21±6.12, p=0.00) and PLR (176.62±135.62 vs142.58±112.89, p=0.00) in the anterior STEMI group compared to the inferior STEMI patients.

Conclusion

Leucocytes, platelets and their cell distribution characteristics have their own unique patterns of behaviour in patients with acute STEMI. These observations need further elaboration with respect to cell biology and cytochemical aspects, since they may have the potential to predict plaque instability and determine prognosis.