The impact of aspirin resistance on the long-term cardiovascular mortality in patients with non-ST segment elevation acute coronary syndromes.
BACKGROUND
Aspirin resistance has been associated with an adverse long-term outcome in patients with atherosclerotic coronary artery disease, but more studies are needed.


OBJECTIVE
The aim of this study was to investigate the impact of aspirin resistance, assessed by the Platelet Function Analyzer-100 (PFA-100) (Dade Behring Inc., Deerfield, Ill., USA) on the long-term prognosis in patients with non-ST segment elevation acute coronary syndromes (NSTE-ACS).


METHODS
A total of 496 consecutive patients were studied. The 1-y incidence of cardiovascular death was the prespecified study endpoint. The patients were divided, according to the values of PFA-100 collagen epinephrine closure time (CEPI-CT) upon presentation, into aspirin sensitives (those with a PFA-100 CEPI-CT>193 sec) and aspirin resistants (those with a PFA-100 CEPI-CT<or=193 sec).


RESULTS
Aspirin resistants were younger (p-value = 0.04), and less frequently hypertensives (p-value=0.05) or diabetics (p-value=0.04) than aspirin sensitives. By 1 y, the incidence of cardiovascular deaths in the entire cohort was 12.9% (64/496), and aspirin resistants were at significantly higher risk of cardiovascular death (23.1% versus 9.6%; hazard ratio [HR]=2.6; 95% confidence interval [CI]=1.6-4.3; p-value<0.001), than aspirin sensitives. By multivariate Cox regression analysis, aspirin resistance (a PFA-100 CEPI-CT<or=193 sec) was among the most potent predictors of the 1-y incidence of cardiovascular death (HR=2.8; 95% CI=1.7-4.6; p-value<0.001).


CONCLUSIONS
According to the present data, aspirin resistance, assessed by the PFA-100, is an independent predictor of long-term cardiovascular mortality in patients with NSTE-ACS.
Foussas
Stefanos G
SG
Department of Cardiology, Tzanio Hospital, Piraeus, Greece.
Zairis
Michael N
MN
Tsirimpis
Vasilios G
VG
Makrygiannis
Stamatis S
SS
Patsourakos
Nikolaos G
NG
Adamopoulou
Evdokia N
EN
Mytas
Demetrios Z
DZ
Prekates
Athanasios A
AA
Perdiou
Anna J
AJ
Tsoukanas
Vasilios K
VK
Argyrakis
Spyros K
SK
D054058:Acute Coronary Syndrome / Q000401:mortality*; D000368:Aged; D001241:Aspirin / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D004351:Drug Resistance; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D010979:Platelet Function Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012307:Risk Factors; D018709:Statistics, Nonparametric
D010975:Platelet Aggregation Inhibitors; D001241:Aspirin