Long-term serial changes in platelet activation indices following sirolimus elution and bare metal stent implantation in patients with stable coronary artery disease

BACKGROUND

Platelet activation is crucial in the development of stent thrombosis following percutaneous coronary intervention (PCI). We carried out a long-term assessment of multiple factors implicated in the thrombotic process and monitored markers of platelet activation after the implantation of sirolimus-eluting stents (SES) in patients with stable coronary artery disease (CAD). Additionally, we compared these findings with those after bare-metal stent (BMS) implantation.

METHODS

A cohort of 47 consecutive patients, aged <70 years, with severe stenosis (>70% narrowing of the lumen) of one major epicardial coronary artery and stable CAD underwent successful elective PCI. Patients were randomly allocated to SES (n = 25) or BMS (n = 22). Venous blood was obtained 24 hours before and 24 hours, 48 hours, 1 month, and 6 months after PCI for measurements of plasma levels of sP-selectin, von Willebrand Factor (vWF), fibrinogen, d-dimer, sCD40, factor VIII, b-thromboglobulin (b-TG) and platelet factor 4 (PF-4).

RESULTS

There were no significant differences between the two groups in levels of fibrinogen or d-dimers in peripheral blood. However, we observed a significant kinetic effect (p<0.001) and stent-effect (p<0.015) on vWF levels and a significant kinetic effect (p = 0.012) on factor VIII, sP-selectin (p = 0.04), b-TG (p<0.001), and PF4 (p = 0.016). A trend towards a significant stent effect on sCD40 was also detected (p = 0.06).

CONCLUSIONS

SES and BMS did not show significant differences in relationship to markers of platelet activation and coagulation in patients with stable CAD. Although some markers showed an increase after stent implantation, they returned to the initial levels 6 months later.

TLR2 and TLR4 gene expression in peripheral monocytes in nondiabetic hypertensive patients: the effect of intensive blood pressure-lowering

The activation of innate immune receptors, such as Toll-like receptors (TLRs), participates in the pathogenesis of cardiovascular diseases. The authors evaluated TLR2 and TLR4 gene expression in the peripheral monocytes of nondiabetic hypertensive patients compared with normotensive individuals and investigated the effect of intensive systolic blood pressure (SBP)-lowering. Included were 43 nondiabetic hypertensive patients with essential hypertension who were randomly assigned to an intensive treatment arm, with an SBP target of <130 mm Hg, or a standard arm, with an SBP target of <140 mm Hg. TLR2 and TLR4 messenger RNA (mRNA) levels in monocytes were estimated before and 12 weeks after therapy initiation. Sixteen healthy individuals were included for comparison. Hypertensives revealed significantly higher TLR4 mRNA levels compared with normotensives (985 ± 885 vs 554 ± 234, P=.005). In contrast, no statistically significant difference was found in TLR2. Compared with standard treatment, intensive treatment significantly downregulated TLR2 and TLR4 mRNAs, expressed as fold induction (0.66 ± 0.49 vs 1.38 ± 1.65 and 0.62 ± 0.3 vs 1.9 ± 1.2, respectively; P<.001 for both). In conclusion, TLR4 mRNA levels in peripheral monocytes are significantly elevated in nondiabetic hypertensive patients. Intensive control of SBP results in attenuation of TLR2 and TLR4 gene expression in those patients. Our findings suggest that a strict SBP target in nondiabetic hypertensive patients may offer additional benefits.