A total of @ male patients who suffered from congestive heart failure were recruited in a double-blind , placebo-controlled trial and randomized to receive an intramuscular ( gluteal ) long-acting androgen injection ( @mL of testosterone enanthate @mg/mL ) once every four weeks for @ weeks or receive intramuscular injections of saline ( @mL of @ % wt/vol NaCl ) with the same protocol .