Which are the exact guidelines for more rationale intervention concerning beta-blockers administration in coronary patients preoperatively?

This interesting study [1] confirms a well-established knowledge: the over-stimulation of the sympathetic system has unfavorable consequences on early and late results in a coronary patient [2,3]. Especially, the combination of decreased parasympathetic and increased sympathetic system activity reduces further the threshold of ischemia, ventricular tachycardia or fibrillation and sudden cardiac death in post-CABG patients [3]. The above mechanism involving the catecholamine elevated levels derived from the corresponding increased stimulation of sympathetic system favors the induction of endothelial injury and the further activation of platelets [2]. However, both the methodology and evaluation of your results raise several questions: