Effect of spinal cord stimulation in patients with refractory angina: evidence from observational studies

To review the evidence in observational studies of the effect of spinal cord stimulation (SCS) in patients with refractory angina pectoris (RAP) due to obstructive coronary artery disease. The effect of SCS in patients with refractory microvascular angina (MVA) also was assessed.

We reviewed the observational studies, published from 1987 to 2010, which investigated the effects of SCS on RAP. The number of angina attacks and that of taken nitrate tablets, as well as the class of angina, were considered as main outcome variables. The occurrence of adverse events related to the treatment also was assessed.

The results showed a consistent reduction of the number of angina attacks (by 45-84%) and of consumption of short-acting nitrate tablets (by -75% to -94%), whereas the New York Heart Association and Canadian Cardiovascular Society class of angina were significantly improved in some studies. No case fatalities related to the therapy were reported. Significant clinical benefits were observed in some studies in patients with refractory MVA. Device-related infections and catheter dislodgment were the most significant and frequent side-effects, respectively.

In observational studies, SCS showed to be an effective form of treatment for RAP, including refractory MVA. The treatment appears to be safe both at short- and long-term follow-up.