Prediction of Reperfusion Outcome using Platelet Indices in Primary Percutaneous Coronary Intervention- A Prospective Cohort Study

Abstract

Introduction: Platelets play a vital role in systemic inflammation and thrombus formation in ST Elevation Myocardial Infarction (STEMI). Understanding its role has diagnostic and prognostic implications in developing therapeutic strategies. Aim: To estimate the prognostic accuracy of platelet indicesMean Platelet Volume (MPV), Platelet Distribution Width (PDW) and MPV/Platelet Count (PC) Ratio (MPV/PC ratio) on reperfusion outcome in STEMI patients. Materials and Methods: This prospective cohort study enrolled 262 subjects, who presented with acute chest pain within a window period of 12 hours, and an Electrocardiogram (ECG) suggestive of STEMI. Blood samples collected on admission were measured for MPV and PDW. The major endpoints studied were angiographic thrombus burden and in-hospital Major Adverse Cardiovascular Events (MACE). Data was summarised by Mean and SD for continuous variables, frequency and percentage for categorical variables. Results: This study demonstrated that Acute Coronary Syndrome- STEMI (ACS-STEMI) patients with larger PDW had Larger Thrombus Burden (LTB). PDW of more than 13 fL was the best cut off for predicting LTB with a sensitivity of 67.01% and a specificity of 53.23%. There was no significant difference between the means of MPV in LTB and small thrombus burden. The total in-hospital MACE at the end of one week was 20.99% (n=55/262 patients). The maximum MACE was contributed by acute heart failure (12.6%), followed by cardiac death (6.1%) and stent thrombosis (1.5%). There was a significant association between increased PDW and in-hospital MACE, mortality and acute heart failure (p-value=0.024, p-value=0.03, p-value=0.02, respectively). The best cut-off PDW value for prediction of the composite MACE endpoint was 14.7 fL with sensitivity of 75.6% and specificity of 51.4% and the area under the Receiver Operating Characteristic (ROC) curve was 0.63 (95% CI, 0.57 to 0.69). Conclusion: The study emphasises the use of platelet indices, especially PDW, as a predictor of poorer reperfusion outcomes in primary Percutaneous Coronary Intervention (PCI) as evidenced by higher MACE rates in patients with higher PDW. Hence, PDW can help in predicting the thrombus burden even before doing the angiogram and such high-risk patients could benefit from early initiation of stronger antiplatelets, Gp IIb/IIIa (Glycoprotein) antagonist drugs and thrombus aspiration techniques.