Efficacy of anti-anginal drugs in the treatment of angina pectoris associated with silent myocardial ischemia: Importance of quantitative holter ECG data for patient activity

Methods We evaluated the clinical efficacy of transdermal nitroglycerin (NT G-TTS), a patch application of a nitrate, in the treatment of 27 patients w ith angina pectoris who had asymptomatic myocardial ischemic (SMI) attacks, using a double-blind cross-over method. Evaluation was made using Holter E CG and patient activity data. Results In frequency and duration of continuation of SMI episodes, no signi ficant differences were noted between the observation and placebo treatment periods, while the values of both these parameters were decreased signific antly in the active drug treatment period compared with those in the observ ation and placebo treatment periods. Critical heart rate, the heart rate at the initiation of ST-segment depression, was significantly higher during t he period of active drug treatment than during the placebo treatment and ob servation periods. In SMI frequency index, which was determined by adjustin g the SMI frequency for the number of steps taken, there were no significan t differences between the 3 periods, The SMI time index was significantly l ower in the active drug treatment period than in the observation period. Conclusions These results indicated that the clinical evaluation of the eff icacy of anti-anginal drugs against SMI should take into consideration indi vidual patient activity data.