A comparison of the VASP index between patients with hemodynamically complicated and uncomplicated acute myocardial infarction.
BACKGROUND
Critically-ill patients with ST-segment elevation myocardial infarction (STEMI) often present with insufficient gastroduodenal motility, liver hypoperfusion, and higher levels of circulating catecholamines. All of these factors can lead to reduced efficacy of clopidogrel, which is only available as a p.o. medication. The aim of the study was to compare clopidogrel effectiveness in unstable STEMI patients on mechanical ventilation with stable STEMI patients.


METHODS
Two groups of twenty patients with STEMI were enrolled. One group (unstable) consisted of 20 hemodynamically unstable patients on mechanical ventilation and catecholamine support. The other group (stable) consisted of 20 control patients (all patients with STEMI in Killip I class). All patients were treated by primary Percutaneous coronary intervention. Blood samples were drawn before (baseline), at 4h (4h+), 24h (1d+) and 2 days (2d+) after clopidogrel administration. Clopidogrel efficacy was assessed by measurement of vasodilator-stimulated phosphoprotein phosphorylation index.


RESULTS
The decrease in the vasodilator-stimulated phosphoprotein (VASP) index was substantially less in unstable patients compared with stable ones (ANOVA, P < 0.001). In stable patients, the VASP index decreased significantly by 20% at 4h+ and by 34% at 1d+, and remained significantly decreased by 31% at 2d+. In unstable patients, the VASP decreased nonsignificantly by 8% at 4h+, and no further decrease of VASP was present (-7% at 1d+, -11% at 2d+).


CONCLUSIONS
Laboratory clopidogrel efficacy is lower in patients with MI and severe hemodynamic instability, probably due to splanchnic and liver hypoperfusion and catecholamine use.
Osmancik
Pavel
P
Cardiocenter, Department of Cardiology, 3rd Medical School, Charles University and University Hospital Kralovske Vinohrady, Prague, Czech Republic. pavel.osmancik@gmail.com
Jirmar
Radovan
R
Hulikova
Katarina
K
Peroutka
Zdenek
Z
Pompachova
Alexandra
A
Motovska
Zuzana
Z
Widimsky
Petr
P
D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary / Q000009:adverse effects / Q000401:mortality; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000187:drug effects* / Q000378:metabolism; D016022:Case-Control Studies; D002395:Catecholamines / Q000627:therapeutic use; D015815:Cell Adhesion Molecules / Q000097:blood*; D000077144:Clopidogrel; D015536:Down-Regulation; D016903:Drug Monitoring / Q000379:methods*; D005260:Female; D006439:Hemodynamics; D006801:Humans; D019934:International Normalized Ratio; D008102:Liver Circulation; D008297:Male; D008840:Microfilament Proteins / Q000097:blood*; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000150:complications / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D010750:Phosphoproteins / Q000097:blood*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010979:Platelet Function Tests; D011446:Prospective Studies; D012121:Respiration, Artificial; D012770:Shock, Cardiogenic / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000628:therapy; D013152:Splanchnic Circulation; D013927:Thrombosis / Q000097:blood / Q000209:etiology / Q000401:mortality / Q000517:prevention & control*; D013988:Ticlopidine / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome; D000098662:Vasodilator-Stimulated Phosphoprotein
D015415:Biomarkers; D002395:Catecholamines; D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; D010750:Phosphoproteins; D010975:Platelet Aggregation Inhibitors; D000098662:Vasodilator-Stimulated Phosphoprotein; D000077144:Clopidogrel; D013988:Ticlopidine