Platelet hyperaggregability to platelet activating factor (PAF) in non-ST elevation acute coronary syndromes

Association of platelet-activating factor receptor gene rs5938 (G/T) and rs313152 (T/C) polymorphisms with coronary heart disease and blood stasis syndrome in a Chinese Han population

OBJECTIVE

To explore the association of the platelet-activating factor receptor (PAFR) gene rs5938, rs313152 and rs76744145 polymorphisms with coronary heart disease (CHD) and blood stasis syndrome (BSS) of CHD in Chinese Han population.

METHODS

A total of 570 CHD patients (299 with BSS and 271 with non-BSS) and 317 controls were enrolled. The PAFR gene rs5938, rs313152 and rs76744145 polymorphisms were genotyped using the multiplex SNaPshot technology. The statistical analysis was conducted using a multiple variable logistic regression model.

RESULTS

Significant differences were detected in the genotypes frequency distributions of the rs5938 (P<0.01), but not the rs313152 (P>0.05), between the controls and CHD patients. Individuals with an rs5938 or rs313152 mutated allele had a low risk for CHD [adjusted odds ratio (aOR)=0.35, 95% confidence interval (CI): 0.23 to 0.56, P<0.01; aOR=0.65, 95% CI: 0.46 to 0.91, P<0.05, respectively]. After the CHD patients were stratified as BSS or non-BSS according to their Chinese medicine patterns, the rs5938 polymorphism mutated alleles had a significant association with a low risk for BSS of CHD (aOR=0.32, 95% CI: 0.18 to 0.57, P<0.01) and non-BSS of CHD (aOR=0.31, 95% CI: 0.17 to 0.55, P<0.01). The rs313152 polymorphism was associated with a low risk for BSS (aOR=0.51, 95% CI: 0.33 to 0.79, P<0.01), but not for non-BSS (aOR=1.22, 95% CI: 0.81 to 1.85, P<0.05). Furthermore, the interaction effect of the rs5938 and rs313152 polymorphisms for BSS of CHD was significantly based on an aOR value associated with the combination of the rs5938 GT genotype with the rs313152 TC genotype of 0.27 (95% CI: 0.1 to 0.7, P<0.01).

CONCLUSION

The PAFR gene rs5938 or rs313152 polymorphisms might be a potential biomarker for susceptibility to CHD, especially to BSS of CHD in Chinese Han population.

Preliminary experience with a high bolus dose of tirofiban during percutaneous coronary intervention

BACKGROUND

In the TARGET study, sub-optimal platelet inhibition with tirofiban was held responsible for the higher incidence of periprocedural CK-MB release compared to abciximab. Since then, a new, higher bolus dose of tirofiban has been proposed to increase blood concentrations very soon after the start of treatment.

OBJECTIVE

The aim of this study was to explore the bleeding risk and clinical outcome at 30 days in a series of patients undergoing percutaneous coronary intervention (PCI) with the new dosing regimen of tirofiban (25 microg/kg bolus followed by a 0.15 microg kg(-1) min(-1) infusion for 18 h).

METHODS

A total of 133 consecutive patients underwent a PCI and received a high bolus dose of tirofiban. Platelet function inhibition was measured using the Ultegra RPFA (Accumetrics) 10 min and 8 and 24 h after the start of therapy in the first 38 cases.

RESULTS

The procedural success rate was 98.5%. The mean level of platelet inhibition 10 min after the start of therapy was 94.7 +/- 5.9%. No major bleedings, no need for red blood cell transfusion and no episodes of severe thrombocytopoenia were recorded. Groin haematoma was observed in seven patients (5.3%). The cumulative incidence of 30-day major adverse cardiovascular events was 4.6% (five myocardial infarctions and one repeat PTCA for sub-acute stent thrombosis).

CONCLUSIONS

The use of a high bolus dose of tirofiban in patients undergoing PCI seems to be safe and not associated with an increased risk of major bleeding. This high bolus dose may help to further reduce the rate of periprocedural adverse events.