Clinical outcome of patients treated with spinal cord stimulation for therapeutically refractory angina pectoris

Objective-To determine morbidity and mortality characteristics in patients treated with electrical neuromodulation for refractory angina pectoris. Design-A retrospective multicentre study of patients treated with spinal co rd stimulation between 1987 and 1397; 21 centres were contacted and 14 resp onded. Setting-Specialist centres worldwide. Patients-Questionnaires were returned on 517 patients, of whom 71% were mal e. One was lost to follow up. Mean (SD) age was 63.9 (10.1) years, Duration of angina pectoris was 8.1 (6.3) years. Results-Before spinal cord stimulation, 66% of the patients had experienced myocardial infarction, 68% had three vessel disease, and in 24% the left v entricular ejection fraction (LVEF) was less than or equal to 40%. Percutan eous transluminal coronary angioplasty and bypass surgery were performed in 17% and 58% of the subjects, respectively. During a median follow up of 23 months (range 0 to 128), 103 patients died (52 from a cardiac cause, 25 fr om a non-cardiac cause, and 26 from an unknown cause), Annual all cause mor tality was 7-8%; annual cardiovascular fatality was 3.5-5%. Mortality was u nivariately related to sex, number of diseased vessels, number of revascula risation procedures, previous myocardial infarction, LVEF, insulin dependen t diabetes, beta blocking agents, and angiotensin converting enzyme inhibit ors. Multiple variate analysis showed that LVEF,sex, beta blockers, and age greater than or equal to 71 years were independent predictors of mortality . During spinal cord stimulation, New York Heart Association functional cla ss improved from 3.5 to 2.1 (p < 0.01); 25 of the deceased patients (24%) a nd 32 survivors (8%) experienced myocardial infarction; hospital admissions were significantly(p < 0.001) more common in the deceased group (66% upsil on 37%). Conclusions-The clinical outcome of patients with intractable angina is not : adversely affected by the chronic use of neurostimulation.