Low dose imipramine improves chest pain but not quality of life in patients with angina and normal coronary angiograms

AIMS: We investigated patients with chest pain and normal coronary angiograms to determine whether low dose imipramine prescribed as add-on therapy to conventional anti-anginals reduced the incidence of chest pain and whether this led to an overall improvement in quality of life. METHODS AND RESULTS: We performed a randomized, double-blind, cross-over trial of imipramine 50 mg daily vs placebo in 18 women (median age 53 years; range 35-72) with chest pain and normal coronary angiograms who were suffering at least two anginal episodes per week despite conventional anti-anginal medication. Each treatment phase lasted 5 weeks and the incidences of chest pain and side effects were carefully recorded. Quality of life was monitored using a validated health profile questionnaire scoring perceived distress in six domains (pain, energy, mobility, sleep, emotional reactions and social isolation). The total number of chest pain episodes was significantly less during active treatment compared to placebo [11 (3-22) vs 21 (16-28)--median (interquartile range); P = 0.01]. However, a high incidence (83%) of side effects was reported during active treatment and three patients had to be withdrawn from the study as a consequence. No significant improvement was detected in any of the six quality of life domains when imipramine was compared to placebo. CONCLUSION: Imipramine reduces the incidence of chest pain in patients with chest pain and normal coronaries who remain symptomatic despite conventional anti-anginal therapy. The failure to demonstrate associated improvements in quality of life may have been due to the high incidence of side effects.