SEQUELAE OF SPINAL-CORD STIMULATION FOR REFRACTORY ANGINA-PECTORIS - RELIABILITY AND SAFETY PROFILE OF LONG-TERM CLINICAL-APPLICATION

Background Spinal cord stimulation (SCS) is effective in the treatment of severe coronary artery disease (CAD) unresponsive to anti-anginal medication or revascularization procedures. However, there is still co ncern about its safety, Objective To investigate the reliability, morb idity, and mortality aspects of SCS in patients with refractory angina pectoris by studying the predictors of outcome, defined by efficacy, adverse events and mortality, in patients with CAD and SCS. Methods Fi fty-seven patients (18 women) treated with SCS, aged 59.8 +/- 7.6 year s (mean +/- SD) were studied retrospectively. They had suffered from m anifest CAD for 9.4 +/- 4.9 years; 46 of them had experienced a myocar dial infarction prior to the implantation; 28 had had a previous percu taneous transluminal coronary angioplasty; and 52 had undergone corona ry artery bypass surgery, The mean left ventricular ejection fraction was 51.8 +/- 13.8%, All of the patients were being treated with two or three anti-anginal drugs. Results During 2042 patient-months follow-u p, nine of the 57 patients died (annual mortality rate 6.5%). The perc entage of adverse events requiring reprogramming or surgical reinterve ntion was reduced from 83% for 18 patients with the Medtronic ITREL(R) lead to 33% for 39 patients with the ITREL II system, The clinical ou tcome was correlated positively with a left ventricular ejection fract ion > 40% (P=0.0005), and negatively with a high cholesterol level (P= 0.0042), more prior revascularizations (P=0.028), and a higher New Yor k Heart Association classification (P=0.04). Conclusions Improvement o f the SCS system reduced the equipment-related complication rate. The predictors of outcome are related to the traditional risk factors for CAD, The mortality rate of patients with refractory angina treated wit h SCS is similar to that of patients with CAD and stable angina pector is.