Aims: Neuropeptide Y (NPY) is a potent vasoconstrictor released during sympathetic activation that may be involved in myocardial ischaemia. We examined the effect of a Y1 receptor antagonist on haemodynamic and ischaemic responses to exercise in patients with coronary artery disease.
Methods and results: Eighty-two evaluable male patients were included in a randomized, double blind, two-way crossover study with a low dose (6.7 microg/kg/min; n=59)and a high dose (13.3 microg/kg/min; n=23) of the Y1 receptor antagonist AR-H040922 given as infusions for 2h or placebo. Myocardial ischaemia during a symptom-limited exercise test was monitored by conventional ST-segment analysis and heart rate (HR)-adjusted ST changes including the ST/HR slope and ST/HR recovery. Administration of the high dose AR-H040922 attenuated systolic blood pressure by 6-11 mmHg (p<0.05) during and after exercise without affecting HR. None of the two doses of AR-H040922 influenced any of the ischaemic parameters or duration of exercise, however. The maximal increase in NPY was higher during AR-H040922 (p<0.05) compared with placebo.
Conclusions: Selective NPY Y1 receptor blockade attenuates the increase in blood pressure during exercise indicating a role for endogenous NPY in blood pressure regulation. Despite this effect, the Y1 receptor antagonist did not influence exercise-induced ischaemic parameters in patients with coronary artery disease.