Immature platelets in patients with acute coronary syndromes.
Platelets newly released from the bone marrow are RNA-containing and more haemostatically active than mature platelets. Immature platelets are reliably quantified by flow cytometry, and the immature platelet fraction (IPF) reflects platelet production and the rate of platelet turnover. It was the objective of this study to evaluate the presence of immature platelets in healthy subjects, patients with stable coronary artery disease (CAD) and patients with acute coronary syndromes. Flow cytometric determination of immature platelets was performed with an automated analyzer (Sysmex XE-2100) using RNA fluorescent dyes. IPF was determined in 420 individuals: 22 healthy subjects, 39 patients with stable CAD, 182 patients with unstable angina/non-ST-segment elevation myocardial infarction (non-STEMI) and 177 patients with acute STEMI. The geometric mean [95% confidence interval] of IPF was 2.51 [2.04-3.10] in healthy subjects, 2.87 [2.45-3.36] in CAD patients, 2.93 [2.72-3.15] in the non-STEMI/unstable angina group and 3.71 [3.45-3.99] in patients with STEMI (ANOVA: p < 0.0001). This difference remained significant after adjusting for baseline characteristics (p = 0.0003). In active smokers, IPF was 18% higher than in non-smoking individuals (p = 0.007), and IPF was 16% higher in diabetics compared with non-diabetics (p = 0.060). In conclusion, the fraction of immature platelets is increased in acute coronary syndromes, especially in the acute phase of STEMI. Immature platelets with an increased haemostatic potential may contribute to coronary thrombus formation.
Grove
Erik Lerkevang
EL
Department of Cardiology, Aarhus University Hospital Skejby, Brendstrupgaardsvej 100, DK-8200 Aarhus N, Denmark. erikgrove@dadlnet.dk
Hvas
Anne-Mette
AM
Kristensen
Steen Dalby
SD
D054058:Acute Coronary Syndrome / Q000097:blood* / Q000150:complications; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000789:Angina, Unstable / Q000097:blood; D001792:Blood Platelets / Q000473:pathology*; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood* / Q000150:complications; D003328:Coronary Thrombosis / Q000097:blood / Q000209:etiology*; D005260:Female; D005434:Flow Cytometry; D006487:Hemostasis; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood; D010976:Platelet Count; D018570:Risk Assessment; D012307:Risk Factors; D034061:Thrombopoiesis