Long-term effects of spinal cord stimulation on myocardial ischemia and heart rate variability: results of a 48-hour ambulatory electrocardiographic monitoring. Clinical and cost-effectiveness analysis of an open label, single-centre, randomised trial of spinal cord stimulation (SCS) versus percutaneous myocardial laser revascularisation (PMR) in patients with refractory angina pectoris: The SPiRiT trial Cost-Effectiveness of Spinal Cord Stimulation versus Coronary Artery Bypass Grafting in Patients with Severe Angina Pectoris – Long-Term Results from the ESBY Study Electrical stimulation versus coronary artery bypass surgery in severe angina pectoris: the ESBY study. Thoracic spinal cord stimulation improves functional status and relieves symptoms in patients with refractory angina pectoris: the first placebo-controlled randomised study Clinical follow-up after cessation of chronic electrical neuromodulation in patients with severe coronary artery disease: a prospective randomized controlled study on putative involvement of sympathetic activity. Spinal cord stimulation for the treatment of refractory angina pectoris: A multicenter randomized single-blind study (the SCS-ITA trial) Long-term effects of spinal cord stimulation and coronary artery bypass grafting on quality of life and survival in the ESBY study. Efficacy of spinal cord stimulation as adjuvant therapy for intractable angina pectoris: a prospective, randomized clinical study. Working Group on Neurocardiology. Spinal cord stimulation in chronic intractable angina pectoris: a randomized, controlled efficacy study. Effects of Spinal Cord Stimulation and Coronary Artery Bypass Grafting on Myocardial Ischemia and Heart Rate Variability: Further Results from the ESBY Study Spinal cord stimulation therapy for patients with refractory angina who are not candidates for revascularization.
BACKGROUND Spinal cord stimulation ( SCS ) has analgesic properties and may be used to treat pain in patients with therapeutically refractory angina who are unsuitable for myocardial revascularization . Some studies have also demonstrated an anti-ischemic effect . The aim of this study was to evaluate the long-term persistence of the effects of SCS on myocardial ischemia and on heart rate variability . METHODS Fifteen patients ( 9 males , 6 females , mean age 76 + /- 8 years , range 58 - 90 years ) with severe refractory angina pectoris ( Canadian class III-IV ) , on optimal pharmacological therapy , unsuitable for myocardial revascularization and treated with SCS for a mean follow-up of 39 + /- 27 months ( range 9 - 92 months ) were studied . Eleven patients had had a previous myocardial infa rct ion and 5 a coronary artery bypass graft . The mean ejection fraction was 54 + /- 7 % ( range 36 - 65 % ) . All patients underwent 48-hour ambulatory ECG monitoring and were r and omly assigned to 24 hours without SCS ( off period ) and 24 hours with SCS ( on period ) . The primary endpoints were : number of ischemic episodes , total duration of ischemic episodes ( min ) , and total ischemic burden ( mV*min ) . RESULTS The heart rate was not statistically different during the off and on SCS periods ( median 64 and 67 b/min respectively ) . The number of ischemic episodes decreased from a median of 6 ( range 0 - 29 ) during the off period to 3 ( range 0 - 24 ) during the on period ( p < 0.05 ) . The total duration of ischemic episodes decreased from a median of 29 min ( range 0- 186 min ) during the off period to 16 min ( range 0 - 123 min ) during the on period ( p < 0.05 ) . The total ischemic burden decreased from a median of 2.5 mV*min ( range 0 - 19.5 mV*min ) during the off period to 0.8 mV*min ( range 0 - 13 mV*min ) during the on period ( p = NS ) . The heart rate variability parameters were similar during the on and off periods . CONCLUSIONS SCS exerts long-term anti-ischemic effects Background Patients with refractory angina have significant morbidity . This study aim ed to compare two of the treatment options , Spinal Cord Stimulation ( SCS ) and Percutaneous Myocardial Laser Revascularisation ( PMR ) in terms of clinical outcomes and cost-effectiveness . Methods Eligible patients were r and omised to PMR or SCS  and followed up for exercise tolerance time ( ETT ) , Canadian Cardiovascular Society ( CCS ) classification and the quality of life measures SF-36 , Seattle Angina Question naire and the EuroQoL at 3 , 12 and 24 months . Utilities were calculated using the EQ-5D and these and costs were compared between groups . The incremental cost-effectiveness ratio ( ICER ) per QALY for SCS compared to PMR was also calculated . Results At 24 months post-r and omisation , patients that had SCS and PMR had similar ETT ( mean difference 0.05 , 95 % CI -2.08 , 2.18 , p = 0.96 ) and there was no difference in CCS classification or quality of life outcomes . The difference in overall mean costs when comparing SCS to PMR was GBP5,520 ( 95 % CI GBP1,966 to GBP8,613 ; p < 0.01 ) and the ICER of using SCS was GBP46,000 per QALY . Conclusion Outcomes after SCS did not differ appreciably from those after PMR , with the former procedure being less cost-effective as currently applied . Larger studies could clarify which patients would most benefit from SCS , potentially increasing cost-effectiveness . Trial registration Current Controlled Trials IS RCT The present study is a 2-year follow-up of the 104 patients participating in the ESBY study ( Electrical Stimulation versus Coronary Artery Bypass Surgery in Severe Angina Pectoris ) , a r and omised prospect i ve study including patients with increased surgical risk and no prognostic benefit from revascularisation .  Hospital care costs , morbidity and causes of death after spinal cord stimulation ( SCS ) and coronary artery bypass grafting ( CABG ) were assessed , as well as the complication rate of SCS treatment . SCS proved to be a less expensive symptomatic treatment modality of angina pectoris than CABG ( p < 0.01 ) . The SCS group had fewer hospitalisation days related to the primary intervention ( p < 0.0001 ) and fewer hospitalisation days due to cardiac events ( p < 0.05 ) . The groups did not differ with regard to causes of death . There were no serious complications related to the SCS treatment BACKGROUND Spinal cord stimulation ( SCS ) has been shown to have antianginal and anti-ischemic effects in severe angina pectoris . The present study was performed to investigate whether SCS can be used as an alternative to coronary artery bypass grafting ( CABG ) in selected patient groups , ie , patients with no proven prognostic benefit from CABG and with an increased surgical risk . METHODS AND RESULTS One hundred four patients were r and omized ( SCS , 53 ; CABG , 51 ) . The patients were assessed with respect to symptoms , exercise capacity , ischemic ECG changes during exercise , rate-pressure product , mortality , and cardiovascular morbidity before and 6 months after the operation . Both groups had adequate symptom relief ( P<.0001 ) , and there was no difference between SCS and CABG . The CABG group had an increase in exercise capacity ( P=.02 ) , less ST-segment depression on maximum ( P=.005 ) and comparable ( P=.0009 ) workloads , and an increase in the rate-pressure product both at maximum ( P=.0003 ) and comparable ( P=.03 ) workloads compared with the SCS group . Eight deaths occurred during the follow-up period , 7 in the CABG group and 1 in the SCS group . On an intention-to-treat basis , the mortality rate was lower in the SCS group ( P=.02 ) . Cerebrovascular morbidity was also lower in the SCS group ( P=.03 ) . CONCLUSIONS CABG and SCS appear to be equivalent methods in terms of symptom relief in this group of patients . Effects on ischemia , morbidity , and mortality should be considered in the choice of treatment method . Taking all factors into account , it seems reasonable to conclude that SCS may be a therapeutic alternative for patients with an increased risk of surgical complications Background : Spinal cord stimulation ( SCS ) is an alternative treatment option for refractory angina . Controlled trials demonstrate symptom relief and improvement in functional status . Since patients experience retrosternal prickling during active SCS , there is no option for blinding patients to active treatment or for placebo control . Objective : To examine the therapeutic effects of subthreshold SCS in patients with refractory angina in a placebo-controlled study . Methods : 12 responders to treatment who had already been treated with SCS for refractory angina were enrolled . Patients were r and omised into four consecutive treatment arms , each for 4 weeks , with various stimulation timing and output parameters : 3 × 2 h/day ( phase A ) and 24 h/day with conventional output ( phase B ) ; 3 × 2 h/day with a subthreshold output ( phase C ) ; and 24 h/day with 0.1 V output , which served as control ( phase D ) . Functional status , quality of life , Canadian Cardiovascular Society classification and nitrate usage were assessed at the end of each 4-week period . Results : In phase D , patients showed a significant reduction in walking distance compared with phases A and C. Canadian Cardiovascular Society classification worsened in phase D compared with phases A – C. Frequency of angina attacks and the visual analogue scale were significantly worse in phase D than in phases A – C. In three patients , it was necessary to prematurely terminate phase D owing to intolerable angina attacks . Conclusions : In this first placebo-controlled trial to apply SCS in patients with refractory angina , improvement in functional status and symptoms was revealed in phases with conventional or subthreshold stimulation , in comparison to a low-output ( placebo ) phase The present study assessed the reoccurrence of myocardial ischemia after withholding electrical neurostimulation .  After r and omization , in the study or withdrawal group , spinal cord stimulation ( SCS ) was set active during the first 4 weeks , followed by 4 weeks of withholding stimulation . In the control group , SCS was switched off during 4 weeks before the end of the study . The control group had no crossover period . Measurements were done at baseline , then after 4 and 8 weeks . The first periods at 4 weeks of each sequence of both groups were compared . In addition , a comparison of clinical variables was performed between the study group 4 weeks after withholding stimulation and the control group 4 weeks following r and omization . A total number of 24 patients with refractory angina and an implanted spinal cord stimulator were included in the study ( n = 12 ) and control group .  Angina pectoris complaints , nitroglycerin intake , ischemia , and heart rate variability using 48-hour ambulatory electrocardiographic monitoring were assessed . In addition , neurohormonal status and symptom-limited aerobic capacity were evaluated . There was no increase of anginal complaints or ischemia after withholding stimulation . Neurohormonal levels and aerobic capacity were not altered . We conclude that there is no adverse clinical rebound phenomenon after withholding neurostimulation in patients with refractory angina pectoris & NA ; Spinal cord stimulation ( SCS ) is believed to be effective in treating  refractory angina . The need for SCS‐related chest paresthesia , however , has hitherto made impossible placebo‐controlled trials . Subliminal ( non paresthesic ) SCS , however , might be also effective on anginal pain . In this trial we compared subliminal SCS with paresthesic SCS and with sham SCS .  Twenty‐five refractory angina patients , who had never received SCS before , underwent SCS device implantation and were r and omized to three groups : paresthesic SCS ( group PS ; n = 10 ) , subliminal SCS ( group SS ; n = 7 ) or “ sham ” SCS ( group NS ; n = 8) . After 1 month group NS patients were r and omized to either group PS or SS . After 1 month , changes in angina episodes ( p = 0.016 ) , nitroglycerin use ( p = 0.015 ) , angina class ( p = 0.02 ) , quality of life score ( p = 0.05 ) , and items 2 ( p = 0.008 ) and 3 ( p = 0.009 ) of Seattle angina question naire differed significantly among groups . Group PS showed significant improvement in outcomes compared to group NS , whereas there were no significant differences between groups SS and NS ; furthermore , only nitroglycerin use differed significantly between groups PS and SS . At 3 months , a significant difference between groups PS and SS was observed in angina attacks ( p = 0.002 ) , but not in other variables . Thus , in this study , paresthesic , but not subliminal SCS was superior to sham SCS in improving clinical status in refractory angina patients . The lack of significant differences between PS and SS groups in this small study suggests that a possible role for subliminal SCS in individual patients deserves to be assessed in larger trials with appropriate statistical power AIMS To assess the long-term outcome regarding quality of life and survival in patients who were included in the ESBY study 1992 - 1995 . The ESBY study ( Electrical Stimulation versus Coronary Artery Bypass Surgery in Severe Angina Pectoris ) included 104 patients -with severe angina , increased surgical risk and no prognostic benefits from revascularization-r and omized to coronary artery bypass grafting or spinal cord stimulation .  METHODS AND RESULTS The ESBY patients '  quality of life was analysed using two question naires , and 5-year mortality was assessed . Quality of life improved significantly 6 months after spinal cord stimulation and coronary artery bypass grafting , respectively , compared to run-in ( P<0.001 ) . The results were consistent after 4.8 years . The 5-year mortality was 27.9 % . There were no significant differences between the groups . CONCLUSIONS Spinal cord stimulation as well as coronary artery bypass grafting offered long-lasting improvement in quality of life . Survival up to 5 years was comparable between the groups . Both methods can be considered as effective treatment options for patients with severe angina , increased surgical risks and estimated to have no prognostic benefits from coronary artery bypass grafting OBJECTIVES In a prospect i ve , r and omized study with an 8-week follow-up period , we evaluated the efficacy of spinal cord stimulation on exercise capacity and quality of life in patients with intractable angina . BACKGROUND Despite important achievements in therapy for ischemic heart disease , there remain patients with intractable symptoms of angina . In uncontrolled observations , several investigators have reported beneficial effects of spinal cord stimulation as an additional therapy for patients with angina pectoris . METHODS Seventeen patients were r and omly assigned to the treatment ( implantation within 2 weeks , eight patients ) or control ( implantation after 8 weeks , nine patients ) group . Assessment of exercise capacity was performed by treadmill exercise testing .  Quality of life was evaluated by daily and social activity scores and recording sublingual glyceryl trinitrate intake and angina pectoris attacks in a diary . After the 8-week study period , the control group also received the spinal cord stimulation device , and all patients were followed up for 12 months . RESULTS The treatment but not the control group demonstrated a significant increase in exercise duration ( p < 0.02 ) , rate-pressure product ( p < 0.03 ) and time to angina ( p < 0.04 ) , with a decrease in ST segment depression ( p < 0.05 ) . This was associated with an increase in daily life ( p < 0.008 ) and social activity ( p < 0.005 ) scores and a reduction in glyceryl trinitrate intake ( p < 0.004 ) and episodes of angina pectoris ( p < 0.003 ) . During the 1-year follow-up , improvement in all quality of life variables was linear for the entire group compared with baseline . The time to angina , exercise duration and ST segment depression showed a second-order trend . CONCLUSIONS Spinal cord stimulation significantly improves exercise capacity and quality of life . On the basis of an increase in exercise capacity and rate-pressure product , the mechanism by which spinal cord stimulation acts may be related to improved oxygen supply to the heart combined with an analgesic effect BACKGROUND Spinal cord stimulation is known to be a successful treatment for chronic intractable angina pectoris . Its effect may be anti-ischemic . It is uncertain if the clinical effect is partly caused by a placebo effect of surgery for implantation of a stimulator . In this study , clinical efficacy is investigated , together with a possible placebo effect . METHODS AND RESULTS Efficacy of spinal cord stimulation as a treatment for chronic intractable angina pectoris was studied for 6 weeks in 13 treated patients and 12 control patients with chronic angina . Assessment s were exercise capacity and ischemia , daily frequency of anginal attacks and nitrate tablet consumption , and quality of life ( perceived quality of life and pain ) . Compared with control , exercise duration ( P = .03 ) and time to angina ( P = .01 ) increased ; anginal attacks and sublingual nitrate consumption ( P = .01 ) and ischemic episodes on 48-hour electrocardiogram ( P = .04 ) decreased . ST-segment depression on the exercise electrocardiogram decreased at comparable workload ( P = .01 ) . Anginal attacks and consumption of sublingual nitrates decreased ( P = .01 ) , perceived quality of life increased ( P = .03 ) , and pain decreased ( P = .01 ) . CONCLUSIONS Spinal cord stimulation is effective in chronic intractable angina pectoris , and its effect is exerted through anti-ischemic action . Efficacy is unlikely to be explained as a placebo effect from surgery In the present study , 24-hour ECG recordings were analyzed from the Electrical Stimulation versus Coronary Artery Bypass Surgery ( ESBY ) Study where spinal cord stimulation was compared to CABG ( coronary artery bypass grafting ) in selected patients with severe angina pectoris . During the monitoring period , the spinal cord stimulation was discontinued to evaluate possible long-term effects of this treatment . The number of ischemic episodes and the duration of ischemia decreased in the CABG group at the follow-up when compared to spinal cord stimulation ( p < 0.05 ) . In spite of this , the number of anginal attacks decreased ( p < 0.0001 ) in both groups . The fact that the anginal symptoms decreased in the spinal cord stimulation group in spite of discontinued stimulation and lack of effects on ischemic ST changes could indicate a long-term primary analgesic effect of this treatment in addition to the well-documented acute anti-ischemic effect OBJECTIVES The aim of this study was to evaluate the safety and efficacy of spinal cord stimulation ( SCS ) for refractory angina . MATERIAL S AND METHODS This multicenter , r and omized , single-blind , controlled trial evaluated SCS in two patient groups :  high stimulation ( HS ) ( treatment ) and low stimulation ( LS ) ( control ) . The HS group controlled SCS with a programmer for a minimum of two hours four times daily . The LS group received SCS therapy above the paresthesia threshold for one min once daily . The primary efficacy endpoint was number of angina attacks recorded by patients at six months . The primary safety endpoint was the major adverse cardiac event ( MACE ) rate at six months . RESULTS Due to slow enrollment , a futility analysis was performed , result ing in early termination of the study . Sixty-eight patients were r and omized after implantation .  Mean change in angina attacks per day from baseline to six months was -1.19 ± 2.13 ( HS ) and -1.29 ± 1.66 ( LS ) . The difference from baseline was significant within each group ( both p < 0.001 ) but not between groups ( p = 0.45 ) . Total exercise time and time to angina onset increased significantly from baseline to six months within each group ( both p = 0.02 and 0.002 ) but not between groups ( p = 0.52 and 0.51 ) . MACE was similar between groups . CONCLUSION Although this study was terminated early , the results obtained at six months suggest that SCS ( HS ) is not more effective than the control ( LS ) in patients with refractory angina
Objective Spinal cord stimulation ( SCS ) is an invasive method used for treating patients with refractory angina .
Although SCS is recommended by the European Society of Cardiology and American Heart Association ( class IIb , level of evidence B and C , respectively ) , the method is used very rarely and data on its eff ectiveness is limited .
The aim of this work was to perform a systematic review of all r and omized controlled trials ( RCTs ) that investigated the eff ectiveness of SCS as a treatment for refractory angina .