Standardized TENS treadmill test
angina, HD, paresthesia, myocardial ischemia, angina pectoris
PARESTHESIA, MYOCARDIAL ISCHEMIA, APPENDIX, POSITIVE
Eligible patients will be invited to the outpatient clinic to perform a standardized transcutaneous electrical nerve stimulation (TENS) treadmill test. The standardized TENS treadmill test is used as a screening tool, as advised by Mannheimer et al in the ESC report, to determine if the patient is eligible for an implanted spinal cord stimulator.Before the standardized TENS treadmill test the patient will fill out the TENS questionnaire (Appendix Positive: equal to or more than 50% reduction in the time from onset of angina pectoris until resolution of angina pectoris after TENS initiation, compared to the “normal” time it takes for angina pectoris to resolve.Dubious: less than 50% reduction in the time from onset of angina pectoris until resolution of angina pectoris after TENS initiation, compared to the ‘normal’ time it takes for angina pectoris to resolve.Negative: no reduction or increase in the time from onset of angina pectoris until resolution of angina pectoris after TENS initiation, compared to the “normal” time it takes for angina pectoris to resolve.Patients with a positive standardized TENS treadmill test are eligible for participation in the study and a myocardial perfusion PET scan is performed to determine the amount of myocardial ischemia present. Patients with a negative standardized TENS treadmill test are excluded from the study. Patients with a dubious standardized TENS treadmill test will receive TENS treatment in an ambulatory setting for a duration of 2 weeks. After this period the effect of TENS will be re‐evaluated by the same team to determine whether the effect was positive or negative (a dubious test result is not possible). If the effect is positive the patient is eligible and a myocardial perfusion PET scan will be performed 1 month after termination of TENS treatment (washout period to prevent possible lingering effects of the TENS treatment) (Figure Flowchart of the screening process for inclusion into the SCRAP trial; patients eligible for participation in the SCRAP trial. A standardized TENS treadmill test is performed. Patients with a dubious standardized TENS treadmill test will be included if they have a positive result after 2 weeks of ambulatory TENS. Patients with a positive standardized TENS treadmill test will undergo a cardiac PET. CCS, canadian cardiovascular society; FFR, fractional flow reserve; MIBI‐SPECT, methoxyisobutylisonitrile single photon emission computed tomography; MRI,  magnetic resonance imaging; NRS, numeric rating scale; PET, positron emission tomography; RAND‐36, RAND 36‐item Health Survey; SAQ, seattle angina questionnaire; TENS, transcutaneous electrical nerve stimulation.If myocardial ischemia is proven, with myocardial perfusion PET scanning, the patient is included. All participating patients will receive an implanted spinal cord stimulator. The total duration of the study is 12 months during which patients will receive 6 months of HD SCS, a paresthesia free form of SCS, and 6 months of no stimulation using a cross‐over design. To determine the order of the treatment options randomization using the online program Research Manager will be performed (Figure Flowchart of randomization process and study design; after informed consent is given a SCS is implanted. Patients are randomized into arm A or B with 6 months of spinal cord stimulation and 6 months of no stimulation or vice versa. At 6 and 12 months measurements (including PET, 6‐MWT, SAQ, NRS, CCS, and RAND‐36) are performed. The study period is 12 months. 6‐MWT, 6 min walking test; NRS, numeric rat; PET, positron emission tomography, RAND‐36, RAND 36‐item Health Survey; SCS, spinal cord stimulator.