RESUMO
We investigated the effect of ß- and α-adrenergic blockers on fractional flow reserve (FFR) and index of microvascular resistance (IMR). In 43 patients (pts) with intermediate stenoses, we measured FFR and IMR before and after nonselective ß-blocker propranolol (30 µg/kg, n = 20) and selective ß1-blocker metoprolol (40 µg/kg, n = 23) IC; (b) In additional 21 pts after percutaneous coronary intervention (PCI), FFR and IMR were measured before and after α-blocker phentolamine (3 mg) IC. Neither propranolol nor metoprolol changed values of FFR and IMR. Phentolamine slightly decreased FFR (from 0.88 ± 0.05 to 0.87 ± 0.06, p = 0.025) but did not change IMR. FFR decreased from >0.80 to ≤0.80 in 3 pts (14%), but in none, the value decreased to <0.75. ß-blockers do not affect FFR and IMR in intermediate stenoses. After PCI, a mild decrease in FFR occurs after α-blockers, though of limited clinical impact.
Assuntos
Antagonistas Adrenérgicos alfa/farmacologia , Antagonistas Adrenérgicos beta/farmacologia , Reserva Fracionada de Fluxo Miocárdico/efeitos dos fármacos , Resistência Vascular/efeitos dos fármacos , Idoso , Cateterismo Cardíaco/métodos , Feminino , Humanos , Masculino , Metoprolol/farmacologia , Fentolamina/farmacologia , Propranolol/farmacologiaRESUMO
ALX-0081 is a novel nano-antibody inhibiting von Willebrand factor (vWF). We evaluated whether direct inhibition of vWF by ALX-0081 improves endothelial function. Stable patients (pts, n = 55) with single vessel disease undergoing percutaneous coronary intervention (PCI) were randomized to ALX-0081 (n = 38) or placebo (n = 17). vWF inhibition was assessed by vWF antigen level (vWF:Ag) and activity by ristocetin test (vWF:RiCo). Endothelial function was assessed before (BL), 6 h and 24 h after PCI by: (a) endothelial peripheral arterial tonometry (Endoscore); (b) endothelial microparticles (EMPs) by flow cytometry. vWF:Ag and vWF:RiCo decreased within 1 h from ALX-0081. In the placebo group, no significant Endoscore changes occurred from BL to 24 h. In ALX-0081 group, Endoscore increased from BL to 24 h (p = 0.014). A decrease in EMPs was observed after ALX-0081 (p < 0.01), while no changes occurred in placebo pts. An inhibition of vWF with ALX-0081 significantly improves peripheral endothelial function.