Efficacy of Terminalia arjuna in chronic stable angina: A double-blind, placebo-controlled, crossover study comparing Terminalia arjuna with isosorbide mononitrate 

In this 2002 double-blind, placebo-controlled crossover study, 58 males with chronic stable angina were recruited.  Arjuna treatment was associated with significantly decreased angina frequency and the need for isosorbide dinitrate use.  

References:

Bharani A, Ganguli A, Mathur LK, et al. (2002). Efficacy of Terminalia arjuna in chronic stable angina: a double-blind, placebo-controlled, crossover study comparing Terminalia arjuna with isosorbide mononitrate. Indian Heart J. 54(2): 170-5