C-reactive protein levels increase after exercise testing in patients with increased platelet reactivity

Aspirin has the potential to influence C-reactive protein (CRP) levels, an inflammatory marker, by its anti-inflammatory activity. Persistently increased platelet reactivity, however, can be detected with different laboratory methods despite aspirin therapy in some patients. The aim of this study was to investigate the effects of increased platelet reactivity on CRP levels at rest and after exercise in patients with documented or suspected coronary artery disease. Blood samples were collected from 100 patients (age, 58.1+/-8.5 years; 63.0% men) who were treated with 100 or 300 mg/day enteric-coated aspirin for at least 7 days, before and immediately after treadmill test for CRP analyses. Platelet reactivity was measured by the standardized platelet function analyzer-100, and increased platelet reactivity was defined as a normal collagen/epinephrine closure time (<165 s). Of the 100 patients, 82 had normal platelet reactivity (group A) and 18 had increased platelet reactivity (group B). The CRP levels increase was statistically significant after exercise in patients with increased platelet reactivity [group A: 2.3 (1.4-4.3) to 2.8 (1.6-4.9) mg/l, P=0.09; group B: 3.3 (2.0-4.5) to 4.7 (2.9-8.5) mg/l, P=0.02]. Detecting increased platelet reactivity is associated with an increase in CRP levels. The clinical significance of this finding needs to be further investigated.

Effects of persistent platelet reactivity despite aspirin therapy on cardiac troponin I and creatine kinase-MB levels after elective percutaneous coronary interventions

BACKGROUND

Creatinine kinase-MB (CK-MB) and cardiac troponin I (cTnI) elevations are highly specific for myonecrosis after percutaneous coronary intervention (PCI). Aspirin is used to prevent thrombotic complications. Several studies have shown that some individuals exhibit a reduced or completely missing antiplatelet response to aspirin. The aim of this study is to investigate the effects of platelet reactivity despite aspirin therapy on CK-MB and cTnI levels after elective percutaneous coronary interventions despite 600 mg loading dose of clopidogrel.

METHODS

One hundred fourteen (mean age 61.2+/-9.3 years, 78.1% male) patients receiving 300 mg daily enteric coated aspirin for at least 7 days with documented coronary artery disease were included in the study. Platelet reactivity despite aspirin was measured by platelet function analyzer (PFA)-100 collagen/epinephrine cartridge. Blood samples for CK-MB and cTnI were obtained before and at 6, 24, and 36 h after the PCI. Persistent platelet reactivity was defined when collagen/epinephrine closure time<165 s.

RESULTS

A total of 87 (76.4%) patients were noted to have normal platelet reactivity (Group A), and 27 (23.6%) had persistent platelet reactivity (Group B). The elevations of CK-MB and cTnI levels were statistically significant within the groups (both P<0.001). However, there were no significant differences in the CK-MB and cTnI levels of the groups at baseline and after PCI for all studied hours.

CONCLUSION

Persistent platelet reactivity was not associated with increased risk of CK-MB, cTnI elevations in low-to-intermediate risk PCI patients.

Does pravastatin therapy affect cardiac enzyme levels after percutaneous coronary intervention?

Serum cardiac enzyme elevation after percutaneous coronary intervention (PCI), a relatively common complication, is a prognostic determinant of long-term outcome in patients who undergo these procedures. Statins are postulated to reduce such complications. This study investigated the short-term effects of pravastatin on serum creatine kinase myocardial isoform (CK-MB) and serum cardiac troponin I (cTpI) levels after elective PCI. Of 93 patients studied, 72 (77.4%) were men, and 21 (22.6%) were women (mean age, 58.9+/-11.0 y). Patients were randomly divided into 3 groups before they underwent elective PCI. Preoperatively, group 1 patients (n=30) received pravastatin 10 mg/d, and group 2 patients (n=29) received pravastatin 40 mg/d. Control group patients (n=34) received no lipid-lowering medication. Serum CK-MB and serum cTpI levels were measured preoperatively and then again at 6, 24, and 36 h postoperatively. Demographic features of patients and characteristics of the PCI procedure, including number of vessels/lesions and duration and number of inflations, did not differ among groups (P>.05). Mean serum CK-MB and serum cTpI levels were significantly increased after PCI in all patients (P<.001). When compared with control group patients, those given pravastatin did not experience significantly lowered postprocedural serum CK-MB or serum cTpI levels (P>.05). Preprocedural pravastatin therapy at dosages of 10 mg/d and 40 mg/d seems inadequate for preventing serum cardiac enzyme elevations during short-term follow-up after PCI. Additional research on this topic is recommended.