Spinal Cord Stimulation for Vasospastic Angina Pectoris - a prospective study

According to the 2020 Dutch guideline on chest pain (AP) without obstructive
coronary artery disease, 70% of female and 30% of male patients undergoing a
coronary angiogram, have no obstructive coronary artery disease. In the
majority of patients the complaints are based on vascular dysfunction,
including epicardial vascular spasms (EVS). For patients who are refractory to
drug treatment, spinal cord stimulation (SCS) can be a treatment option. SCS is
used for the treatment of refractory neuropathic and ischaemic pain. In recent
studies the use of SCS is proven for refractory angina pectoris, but the group
with refractory vasospastic angina pectoris (rVSA) predominantly seen in women
with invalidating impairment of quality of life, is overlooked, as no evidence
of obstruction is found at CAG. With this study we hypothesis that SCS is
effective in reducing the number and intensity of angina attacks, reducing
nitrate use, reducing inhospital treatment and ER presentations, thereby
reducing medical costs, and above all, increasing quality of life.

The main objective of this study is to evaluate the clinical effects of SCS on
the number and intensity of VSA attacks. Secondary objective is to objectivate
the effects of SCS on coronary spasms during the provocative acetylcholine
test, and assess medical costs, patient satisfaction and quality of life.

Prospective study in two phases. Phase 1: evaluation of clinical effectiveness.
Phase 2: evaluation of SCS on vascular spasms during acetylcholine provocation
test.

Implantation with a SCS defice with one or two lead(s) in the epidural space of
T1 to T4, active elctrodes depending on mapping of the painfull area, under
local anesthesia and sedation. Acetylcholine test during CAG at 4 to 6 months.

SCS is proven to be safe for neuropathic and ischaemic pain and is widely used
in clinical practice. With the positive results of an ongoing clinical trial
for refractory coronary angina, we estimate the efficacy of SCS to be around
80-90% in reducing VSA attacks with 50% after 3 months and therefore very
effective in otherwise refractory drug treatment regiments. Furthermore,
baseline study parameters will be extracted from the routine questionnaires and
during visits to the outpatient clinic.
Only in patients who specifically consent to it, an additional acetylcholine
test 4 to 6 months after SCS implantation during coranary angiography (CAG) is
performed. This is an additional CAG procedure under local anesthesia which
potentially provokes VSA. Done by experienced personal this is a safe test with
a complication risk of 0-0.7% for severe cardiac complications, comparable to
coronary angiogram with FFR measurement.
A potential benefit for the participants is that SCS results in reduction of
VSA attacks, reduction of nitrate use, less presentation at an ER, an improved
quality of life, and acceptation as standard treatment and therefore insured
treatment for the overall patientgroup.