Spinal Cord Stimulation (SCS) in Refractory Angina

The study aims at assessing safety and efficacy of Spinal Cord Stimulation (SCS) for the treatment of refractory angina pectoris in a single blind, prospective, multicenter study. Sixty patients with refractory angina with new SCS device implantation will be randomized to one of three treatment groups: paresthesic SCS; subliminal SCS; low (non effective) stimulation (control). Clinical follow-up will be done at 1 and 3 months. Control group patients will then be randomized to paresthesic SCS or subliminal SCS for another 3 months and the 2 groups will be reassessed at 6 months.

Aim of the study is to assess safety and efficacy of Spinal Cord Stimulation (SCS) for the treatment of refractory angina pectoris in a single blind, prospective, multicenter study. The study also assesses whether subliminal SCS may be as effective as paresthesic SCS in these patients. Sixty consecutive patients with refractory angina with a new SCS device implantation will be randomized to one of three treatment groups: paresthesic SCS (group 1); subliminal SCS (75-80% of paresthesic threshold; group 2); low stimulation, consisting of an hour of SCS a day at 0.05 mV intensity, which does not have any significant stimulator effect (sham stimulation, group 3). Study Procedure Medical history, clinical data, drug therapy, Angina Canadian Cardiovascular Society (CCS) classification, Seattle Angina Questionnaire (SAQ), quality of life estimation by EuroQoL scale, detailed evaluation of angina attacks (frequency, intensity, duration of episodes; nitrates assumption) according to a structured diary, number of hospitalizations, emergency room (ER) admissions and cardiological visits in the previous 6 months and treadmill exercise stress test results will be obtained at the baseline visit. Patients fulfilling inclusion criteria will undergo SCS implant. During the implant, stimulation tests will be performed to check paresthesic coverage of angina pain chest area. Patients with adequate paresthesias will be randomized to one of the 3 groups. Follow-up visits will be performed at 1, 3, 6, and 12 months after the SCS implant. Drug therapy will not be changed at least during the first 3 months. Patients assigned to group 2 (subliminal SCS) and those assigned to group 3 (sham SCS) will be blinded about the assigned treatment. After the 3 months group 3, patients will be randomized to group 1 or group 2 and reassessed at 6-month follow-up (comparison between paresthesic versus subliminal SCS). The controlled study will end at the 6-month follow-up, when each investigator will decide for the best stimulation for individual patients. Every patient will then be followed until 12 months from SCS implant. Clinical assessment will be done at each follow-up visit. Exercise stress test results will be repeated at 3-, 6- and 12-month follow-up visits.

low stimulation, consisting of an hour of SCS a day at 0.05 mV intensity, which does not have any significant stimulator effect (sham stimulation)

Under sterile conditions and local anesthesia, the epidural space is punctured at the level of T5-T6 and a quadripolar electrode catheter is introduced and advanced under X-ray control into the epidural space. A suitable position for the electrode catheter is sought for, corresponding to the site where a prickling sensation (paresthesia) is felt and covers the area of radiation of angina pain under neurostimulation. The electrode catheter is connected to an internal pulse generator placed in a subcutaneous abdominal or gluteal pocket through an extension lead connected to the electrode by subcutaneous tunneling.

Inclusion Criteria: Stable angina pectoris refractory to optimal medical therapy, with at least 10 angina episodes in the three weeks previous SCS implant; Documentation of coronary artery disease and reversible myocardial ischaemia; Patient is not a candidate for or refuses surgical or percutaneous coronary revascularization; Availability for follow-up visits; Written informed consent. Exclusion Criteria: Severe spinal cord diseases that prevent the catheter positioning in the epidural space; No paresthesic coverage of angina pain area during SCS; Unstable angina pectoris; Female patients in fertile age; Enrolment in other studies; Need for anticoagulant therapy; Patients needing diathermy treatment; Life expectancy <12 months.