Long-term effects of spinal cord stimulation on angina symptoms and quality of life in patients with refractory angina pectoris--results from the European Angina Registry Link Study (EARL)

A Bibliometric Analysis of Top-Cited Journal Articles Related to Neuromodulation for Chronic Pain

OBJECTIVES

Since its foundation in the 1960s, neuromodulation has become an increasingly used treatment option for chronic pain. This bibliometric analysis examines the most cited research in this field with the aim of uncovering existing trends and future directions.

MATERIALS AND METHODS

Clarivate's Web of Science data base was searched for the top 25 most cited studies focusing on neuromodulation for chronic pain. Various bibliometric parameters were then extracted and analyzed. Randomized controlled trials (RCTs) were compared with non-RCTs.

RESULTS

The top 25 articles had a mean of 347 citations and 22.2 citations per year, with more recent articles having a higher citation rate. Most were published in the last two decades and predominantly originated from the United States. There were 13 RCTs, which were significantly more recent (p = 0.004) and more cited per year (p = 0.001) than the 12 non-RCTs. Sources included 15 journals with a mean impact factor of 13.896. The most studied modality was spinal cord stimulation with 20 articles (76.9%), followed by intrathecal drug delivery (15.4%), dorsal root ganglion stimulation (3.8%), and peripheral nerve stimulation (3.8%).

CONCLUSIONS

Analysis of the most cited articles on neuromodulation reveals a focal shift from historical reports to innovative RCTs that have increasingly guided pain practice in the recent years. As novel techniques and technologies continue to develop, high-quality evidence coupled with broadening indications will likely direct further expansion of this field.

Feasibility of Spinal Cord Stimulation in Patients With Refractory Angina Pectoris and a Cardiac Implanted Electronic Device

OBJECTIVES

Five to 10% of patients with stable coronary artery disease have refractory angina pectoris (RAP). These patients are restricted in performing daily activities due to angina pectoris. Spinal cord stimulation is a last resort treatment option. A number of this patient population also has an indication for a cardiac implanted electronic device (CIED) (pacemaker or implantable cardiac defibrillator). Manufacturers of spinal cord stimulators have stated a warning that interference can occur between the spinal cord stimulator and the CIED. Consequently, only a limited number of patients with RAP and a CIED have received a spinal cord stimulator. The aim of this retrospective cohort study is to determine whether spinal cord stimulation can be safely used in patients with RAP and a CIED.

MATERIALS AND METHODS

All patients with RAP referred to our center were screened and included if 1) the patient received a spinal cord stimulator as treatment for RAP and if 2) the patient received a CIED either prior to or after spinal cord stimulator implantation. A transcutaneous electrical nerve stimulation (TENS) treadmill test was used as a screening tool to determine whether the patient was eligible for implantation of a spinal cord stimulator. Interference between the spinal cord stimulator and CIED was checked 1) after TENS treadmill test, 2) during implantation of spinal cord stimulator or CIED, 3) during mode switches of the SCS, and 4) during regular out patient follow-up.

RESULTS

In total, 22 patients had both a spinal cord stimulator and a CIED with an average follow-up duration of 44.5 months. No interference between the spinal cord stimulator and CIED was found.

CONCLUSION

Spinal cord stimulation can be safely applied in patients with a CIED provided that the CIED is checked for interference during implantation, if mode switches of the SCS occurred and once yearly after implantation according to routine follow-up.

Long-term efficacy and safety of spinal cord stimulation in patients with refractory angina pectoris

Background

The number of patients with refractory angina pectoris (RAP), associated with poor quality of life, has been steadily increasing. Spinal cord stimulation (SCS) is a last resort treatment option leading to significant improvement in quality of life over a one year follow-up. The aim of this prospective, single-centre, observational cohort study is to determine the long-term efficacy and safety of SCS in patients with RAP.

Methods

All patients with RAP who received a spinal cord stimulator from the period July 2010 up to November 2019 were included. In May 2022 all patients were screened for long-term follow-up. If the patient was alive the Seattle Angina (SAQ) and RAND-36 questionnaire were completed and if the patient had passed away cause of death was determined. The primary endpoint is the change in SAQ summary score at long-term follow-up compared to baseline.

Results

From July 2010 up to November 2019 132 patients received a spinal cord stimulator due to RAP. The mean follow-up period was 65.2 ± 32.8 months. Seventy-one patients completed the SAQ at baseline and long-term follow-up. The SAQ SS showed an improvement of 24.32U (95% confidence interval [CI]: 18.71 – 29.93; p < 0.001).

Conclusions

The main findings of the study show that long-term SCS in patients with RAP leads to significant improvement in quality of life, significant reduction in angina frequency, significantly less use of short-acting nitrates and a low risk of spinal cord stimulator related complications over a mean follow-up period of 65.2 ± 32.8 months.

Neuromodulation in patients with refractory angina pectoris: a review

The number of patients with coronary artery disease (CAD) who have persisting angina pectoris despite optimal medical treatment known as refractory angina pectoris (RAP) is growing. Current estimates indicate that 5-10% of patients with stable CAD have RAP. In absolute numbers, there are 50 000-100 000 new cases of RAP each year in the USA and 30 000-50 000 new cases each year in Europe. The term RAP was formulated in 2002. RAP is defined as a chronic disease (more than 3 months) characterized by diffuse CAD in the presence of proven ischaemia which is not amendable to a combination of medical therapy, angioplasty, or coronary bypass surgery. There are currently few treatment options for patients with RAP. One such last-resort treatment option is spinal cord stimulation (SCS) with a Class of recommendation IIB, level of evidence B in the 2019 European Society of Cardiology guidelines for the diagnosis and management of chronic coronary syndromes. The aim of this review is to give an overview of neuromodulation as treatment modality for patients with RAP. A comprehensive overview is given on the history, proposed mechanism of action, safety, efficacy, and current use of SCS.

Single-Center Experience With High-Density Spinal Cord Stimulation in Patients With Refractory Angina Pectoris

OBJECTIVES

Spinal cord stimulation (SCS) is a treatment option for patients with refractory angina pectoris (RAP) which was first used in 1987 and led to a reduction in the number of angina pectoris episodes, less consumption of short-acting nitrates, and an improvement in the quality of life. The conventional mode of stimulation leads to paresthesia felt at the target area. In recent years novel modes of stimulation have been developed that are paresthesia free, such as "burst," "high-density (HD)," or "high-frequency/10 kHz" stimulation. To date, these new modes of stimulation have not been used in patients with RAP and a spinal cord stimulator. This retrospective, single-center, observational study gives a description of the experience of using HD stimulation in selected patients with RAP being treated with SCS.

MATERIALS AND METHODS

All patients with RAP who received a spinal cord stimulator as treatment at our center from September 2009 to February 2021 were screened. Patients were eligible for inclusion into this retrospective, observational study if 1) patients had used HD stimulation, or 2) were currently using HD stimulation.

RESULTS

Fifty-three patients out of a total of 157 patients who had a spinal cord stimulator due to RAP use or have used HD stimulation. In most patients (79.2%), the reason for switching from conventional to HD stimulation was due to progression of symptoms under conventional stimulation. The average duration of conventional stimulation use prior to switching to HD stimulation was 40.3 (± 29.6) months. In total, 26 patients (of 53 patients; 49.1%) were using HD stimulation at the end of the follow-up period or until lost to follow-up, and two patients used both forms of stimulation interchangeably. Five patients (9.4%) had stopped using SCS, and 20 patients (37.7%) switched back to conventional stimulation due to a variety of reasons.

CONCLUSIONS

This retrospective study shows that the use of HD stimulation in patients with RAP being treated with SCS could be an alternative option for conventional stimulation. Due to the nature of this study, additional research is essential to confirm these initial findings.

Pre-Operative Assessment of Patients Undergoing Spinal Cord Stimulation for Refractory Angina Pectoris

Spinal cord stimulation (SCS) is used to treat a variety of chronic pain conditions refractory to more conservative management including refractory angina pectoris. We identified 31 patients who underwent SCS implantation for the indication of refractory angina at a single institution from 2003 through 2018. Sixteen patients were male, and 15 were female. Average age was 53.9 years. Prior to SCS implantation, all patients had at least one coronary angiogram. Ten (32.3%) patients had undergone percutaneous coronary intervention, and four (12.9%) had undergone coronary artery bypass grafting. Thirty patients (96.7%) were currently using anti-angina medications. Twenty-six patients (83.9%) were on antiplatelet or anticoagulant agents at the time of SCS evaluation. Spinal cord stimulation implanters must perform a comprehensive evaluation incorporating appropriate multidisciplinary care particularly in patients with refractory angina given their cardiovascular comorbidities. It is important to have baseline data (e.g., pain scores, nitroglycerin consumption, frequency of angina episodes, and a questionnaire, such as the Seattle Angina Questionnaire) to compare with follow-up data to help define treatment success. We report a single institution's pre-operative experience for patients undergoing SCS for refractory angina to illustrate unique pre-operative SCS considerations in this chronic pain population.

Son of a Lesser God: The Case of Cell Therapy for Refractory Angina

In the last decades, various non-pharmacological solutions have been tested on top of medical therapy for the treatment of patients affected by refractory angina (RA). Among these therapeutics, neuromodulation, external counter-pulsation and coronary sinus constriction have been recently introduced in the guidelines for the management of RA in United States and Europe. Notably and paradoxically, although a consistent body of evidence has proposed cell-based therapies (CT) as safe and salutary for RA outcome, CT has not been conversely incorporated into current international guidelines yet. As a matter of fact, published randomized controlled trials (RCT) and meta-analyses (MTA) cumulatively indicated that CT can effectively increase perfusion, physical function and well-being, thus reducing angina symptoms and drug assumption in RA patients. In this review, we (i) provide an updated overview of novel non-pharmacological therapeutics included in current guidelines for the management of patients with RA, (ii) discuss the Level of Evidence stemmed from available clinical trials for each recommended treatment, and (iii) focus on evidence-based CT application for the management of RA.

The Use of the Seattle Angina Questionnaire in Patients Who Underwent Spinal Cord Stimulation for Refractory Angina Pectoris

BACKGROUND

The Seattle Angina Questionnaire (SAQ) is a self-administered questionnaire used in cardiac patients to quantify angina based on five scales: physical limitation scale, anginal stability scale, anginal frequency scale, treatment satisfaction scale, and the disease perception scale. Here we report the use of the SAQ to assess angina symptoms in 18 patients who underwent spinal cord stimulation (SCS) for refractory angina pectoris (RAP) at the Mayo Clinic.

METHODS

Electronic health records were searched to find patients who underwent SCS for the treatment of RAP at a single institution from 2003 to 2018. Eligible patients were asked to participate in a phone survey that included the SAQ.

RESULTS

Out of 13 patients who still had their implant, six (46%) had minimal physical limitations. Ten patients (76.9%) had favorable anginal frequency scores, defined as minimal or mild. Out of the five patients who had their device removed, one (20%) had minimal physical limitations and three (60%) had favorable anginal frequency scores. There was a high treatment satisfaction score for both those with their implant in place and those with the device removed.

CONCLUSION

The SAQ is useful as a comprehensive measure specific to patients with RAP assessing function, pain, and satisfaction. The utilization of this tool pre- and post-operatively may provide additional information to analyze the effectiveness of SCS for RAP.

Non-pharmacological treatment of refractory angina: The coronary sinus reducer, the new kid on the block

Refractory angina is defined as persistent angina (≥3 months) despite optimal medical and interventional therapies. It is increasing in frequency, due to the success of current medical and interventional therapies in improving the prognosis of coronary artery disease. Long-term mortality is similar to that of patients with asymptomatic stable disease, but it affects patients' quality of life, and has a significant impact on health care resources. Several therapeutic targets have been investigated, most with disappointing results. Many of the techniques have been abandoned because of lack of efficacy, safety issues, or economic and logistic limitations to wider applicability. The primary focus of this review is the coronary sinus Reducer, supporting evidence for which, although scarce, is promising regarding safety and efficacy in improving anginal symptoms and quality of life. It is also accessible to virtually all interventional cardiology departments.

Non-pharmacological treatment of refractory angina: The coronary sinus reducer, the new kid on the block

Refractory angina is defined as persistent angina (≥3 months) despite optimal medical and interventional therapies. It is increasing in frequency, due to the success of current medical and interventional therapies in improving the prognosis of coronary artery disease. Long-term mortality is similar to that of patients with asymptomatic stable disease, but it affects patients' quality of life, and has a significant impact on health care resources. Several therapeutic targets have been investigated, most with disappointing results. Many of the techniques have been abandoned because of lack of efficacy, safety issues, or economic and logistic limitations to wider applicability. The primary focus of this review is the coronary sinus Reducer, supporting evidence for which, although scarce, is promising regarding safety and efficacy in improving anginal symptoms and quality of life. It is also accessible to virtually all interventional cardiology departments.

A Retrospective Review of Lead Migration Rate in Patients Permanently Implanted with Percutaneous Leads and a 10 kHz SCS Device

Background

Spinal cord stimulation (SCS) has been used over decades for pain management, but migration of percutaneous leads has been the most common complication. Better surgical techniques and newer SCS technologies likely reduced the incidence of lead migration requiring surgical revision, although data are sparse. This study aimed to retrospectively evaluate the incidence of clinically significant percutaneous lead migration in patients permanently implanted with a 10 kHz SCS system.

Methods

Consecutive patients with chronic trunk and/or limb pain, permanently implanted between January 2016 and June 2019, were included in the analysis. Data were collected from the hospital's electronic medical records and the manufacturer's database. Clinically significant lead migration, defined as diminished pain relief followed by surgery to correct lead location, was assessed at the 6-month follow-up.

Results

At the 6-month follow-up, there were no cases of clinically significant lead migration, average pain relief was 65.2%, 82% of patients had response (≥50% pain relief), improvement of function was noted in 72% of patients, and decrease of medication was observed in 42% of patients. Therapy efficacy was sustained in patients with >12 months follow-up; the average pain relief was 58.5%, and the response rate was 82%.

Conclusions

The surgical techniques in use today are designed to minimise the risk of percutaneous lead migration and may have reduced its incidence. In addition, new SCS systems may give greater opportunity to mitigate cases of minor lead movement using alternative stimulation programs.

YouTube as a Source of Medical Information About Spinal Cord Stimulation

BACKGROUND

Social media platforms may play an important role in the dissemination of medical information on interventional pain procedures. This cross-sectional study quantitatively assessed the reliability and quality of information from YouTube regarding spinal cord stimulation.

MATERIALS AND METHODS

YouTube was queried on May 20, 2020 using keywords "spinal cord stimulator," "spinal cord stimulation experience," and "spinal cord stimulation risks." The top 50 viewed videos from each search were analyzed. The primary outcome was video quality, which was analyzed using the modified DISCERN (mDISCERN) criteria.

RESULTS

Seventy-nine of 103 (77%) videos were classified as useful. Fifteen of 103 (14%) videos were classified as misleading and contained nonfactual information on spinal cord stimulation. Hospitals, group practices, or physicians produced a greater proportion of useful videos compared to misleading videos (63.3% vs. 26.7%, p = 0.008). Nonmedical independent users produced a greater proportion of misleading videos compared to useful videos (73.3% vs. 16.4%, p < 0.001). Useful videos had significantly higher mDISCERN scores compared to misleading videos (2.6 vs. 1.9, p = 0.009). Nonmedical independent users produced a greater proportion of low-quality videos (mDISCERN score < 3) than high-quality videos (mDISCERN score ≥ 3; 50.8% vs. 2.4%, respectively, p < 0.001). Educational videos from professional pain medicine societies were not captured.

CONCLUSION

YouTube is an accessible platform for medical information on spinal cord stimulation, yet a significant amount of nonfactual information is present. As social media platforms continue to gain prominence in health care, future efforts to appraise the quality of medical content delivered to the public are warranted. In addition, reputable sources including professional pain medicine societies should consider collaborating with producers to disseminate high-quality video content that reaches a wider audience.

Refractory Angina-Unsolved Problem

The article discusses pharmacologic and interventional therapeutic options for patients with refractory angina. Refractory angina refers to long-lasting symptoms (≥3 months) due to established reversible ischemia in the presence of obstructive coronary artery disease, which cannot be controlled by escalating medical therapy with second-line and third-line pharmacologic agents, bypass grafting, or stenting. Due to an aging population, increased number of comorbidities, and advances in coronary artery disease treatment, incidence of refractory angina is growing. Although the number of therapeutic options is increasing, there is a lack of randomized clinical trials that could help create recommendations for this group of patients.

Improvement in quality of life and angina pectoris: 1-year follow-up of patients with refractory angina pectoris and spinal cord stimulation

Aims

Spinal cord stimulation (SCS) is a treatment for patients with refractory angina pectoris (RAP) who remain symptomatic despite optimal medical therapy and without revascularisation options. Previous studies have shown that SCS improves the quality of life in this patient group and reduces the severity of the angina pectoris. The aim of this prospective, single-arm observational study is to show this effect in a single-centre cohort using a multidisciplinary team approach to the selection process, with a follow-up period of 1 year.

Methods and results

Between July 2010 and March 2017, 87 patients with RAP referred to our centre received SCS. The Seattle Angina Questionnaire (SAQ) and RAND 36-Item Health Survey (RAND-36) were completed at baseline, prior to implantation, and 1 year post-implantation. After 1 year of follow-up there was a statistically significant decrease in the frequency of angina pectoris attacks from more than 4 times a day to 1–2 times a week (p < 0.001). The SAQ showed statistically significant improvement in four of the five dimensions: physical limitation (p < 0.001), angina frequency (p < 0.001), angina stability (p < 0.001) and quality of life (p < 0.001). The RAND-36 showed statistically significant improvement in all nine dimensions: physical functioning (p = 0.001), role/physical (p < 0.001), social functioning (p = 0.03), role/emotional (p < 0.05), bodily pain (p < 0.001), general health (p < 0.001), vitality (p < 0.001), mental health (p = 0.02) and health change (p < 0.001).

Conclusion

This study showed a significant improvement in quality of life and reduction of angina pectoris severity after 1 year of follow-up in patients treated with SCS for RAP.

Electronic supplementary material

The online version of this article (10.1007/s12471-020-01422-0) contains supplementary material, which is available to authorized users.

The Effects of Spinal Cord Stimulators on End Organ Perfusion: A Literature Review

Spinal cord stimulators (SCS) have been gaining momentum in the last decade as their role in the management of chronic pain has become more apparent. Our intention was to search, analyze and highlight the effects of spinal cord stimulators on end-organ perfusion. We also looked at vascular diseases of atherosclerotic and nonatherosclerotic nature by examining objective evidence of improved circulation, pain control, limb salvage, and quality of life. We paid specific attention to disease processes such as cerebral hypoperfusion, Chronic-Critical Limb Ischemia, Intractable Angina Pectoris (IAP), Raynaud’s syndrome and Thromboangiitis Obliterans.

We performed a Medline database search for medical literature relevant to Spinal cord stimulators encompassing the years 1950 to 2019. Search terms included “Spinal cord stimulator,” plus one of the following search terms: vasculopathy, stroke, cerebral blood flow, angina pectoris, diabetic ulcers, chronic critical leg ischemia, thromboangiitis obliterans and peripheral vascular disease. We included both clinical and experimental human studies that investigated the effect of SCS’s on end-organ perfusion. We also investigated the pathophysiological mechanism of action of SCS’s on the vasculature. We found 497 articles of which 43 more relevant and impactful articles investigating the hemodynamic effects of SCS and its possible mechanism were selected. Animal studies were excluded from the literature review as they provided heterogeneity. In addition to reporting literature supporting the use of stimulators for currently FDA approved uses, we also actively looked for potential future uses. Spinal Cord stimulators showed improvement in cerebral blood flow, increased capillary recruitment, and better quality of life in many studies. Patients also had increased exercise capacity and a significant reduction in the use of narcotic drug use and daily anginal attacks in patients suffering from IAP.

Cardiac sympathectomy and spinal cord stimulation attenuate reflex-mediated norepinephrine release during ischemia preventing ventricular fibrillation

The purpose of this study was to define the mechanism by which cardiac neuraxial decentralization or spinal cord stimulation (SCS) reduces ischemia-induced ventricular fibrillation (VF). Direct measurements of norepinephrine (NE) levels in the left ventricular interstitial fluid (ISF) by microdialysis, in response to transient (15-minute) coronary artery occlusion (CAO), were performed in anesthetized canines. Responses were studied in animals with intact neuraxes and were compared with those in which the intrathoracic component of the cardiac neuraxes (stellate ganglia) or the intrinsic cardiac neuronal (ICN) system was surgically delinked from the central nervous system and those with intact neuraxes with preemptive SCS (T1-T3). With intact neuraxes, animals with exaggerated NE release due to CAO were at increased risk for VF. During CAO, there was a 152% increase in NE when the neuraxes were intact compared with 114% following stellate decentralization and 16% following ICN decentralization. During SCS, CAO NE levels increased by 59%. Risk for CAO-induced VF was 38% in controls, 8% following decentralization, and 11% following SCS. These data indicate that ischemia-related afferent neuronal transmission differentially engages central and intrathoracic sympathetic reflexes and amplifies sympathoexcitation. Differences in regional ventricular NE release are associated with increased risk for VF. Surgical decentralization or SCS reduced NE release and VF.

Palliative care for people living with heart failure: European Association for Palliative Care Task Force expert position statement

Contrary to common perception, modern palliative care (PC) is applicable to all people with an incurable disease, not only cancer. PC is appropriate at every stage of disease progression, when PC needs emerge. These needs can be of physical, emotional, social, or spiritual nature. This document encourages the use of validated assessment tools to recognize such needs and ascertain efficacy of management. PC interventions should be provided alongside cardiologic management. Treating breathlessness is more effective, when cardiologic management is supported by PC interventions. Treating other symptoms like pain or depression requires predominantly PC interventions. Advance Care Planning aims to ensure that the future treatment and care the person receives is concordant with their personal values and goals, even after losing decision-making capacity. It should include also disease specific aspects, such as modification of implantable device activity at the end of life. The Whole Person Care concept describes the inseparability of the physical, emotional, and spiritual dimensions of the human being. Addressing psychological and spiritual needs, together with medical treatment, maintains personal integrity and promotes emotional healing. Most PC concerns can be addressed by the usual care team, supported by a PC specialist if needed. During dying, the persons’ needs may change dynamically and intensive PC is often required. Following the death of a person, bereavement services benefit loved ones. The authors conclude that the inclusion of PC within the regular clinical framework for people with heart failure results in a substantial improvement in quality of life as well as comfort and dignity whilst dying.

Implantable Pulse Generator Site May Be Associated With Spinal Cord Stimulation Revision Surgeries

BACKGROUND

The use of implantable pulse generators (IPG) for spinal cord stimulation (SCS) in patients with chronic pain has been well established. Although IPG-related complications have been reported on, the association between IPG site and SCS complications has not been well studied.

OBJECTIVE

To investigate whether IPG placement site in buttock or flank is associated with SCS complications and, hence, revision surgeries.

METHOD

A retrospective cohort study was performed that included 330 patients (52% female) treated at a single institution who underwent permanent implantation of an SCS system between 2014 and 2018. Patients ranged between 20 and 94 years of age (mean: 57.54 ± 13.25). Statistical analyses were conducted using IBM SPSS Statistics. Tests included independent samples t test, chi-square test, Mann-Whitney U test, Spearman's rank correlation coefficient, and logistic regression.

RESULTS

There was a total of 93 revision surgeries (rate of 28%), where 71 out of 330 patients (rate of 21.5%) had had at least one revision surgery. Univariate tests demonstrated a significant association between IPG site and revision surgeries (p = 0.028 [chi-square test] and p = 0.031 [Mann-Whitney U test]); however, multivariate logistic regression demonstrated that neither IPG site was more likely than the other to require revision surgeries (p = 0.286).

CONCLUSION

Although this study found a significant association between IPG site and revision surgeries, the effect of IPG site was not found to be predictive. The IPG site likely influences whether a patient will require revision surgery, but further investigation is required to establish this association.

Spinal Cord Stimulation

Spinal cord stimulation (SCS) has been well established as a safe and effective treatment of pain derived from a wide variety of etiologies. Careful patient selection including a rigorous trial period and psychological evaluation are essential. When patients proceed to permanent implantation, various considerations should be made, such as the type of lead, type of anesthesia, and waveform patterns for SCS. This article discusses the common indications for SCS, patient selection criteria, and pertinent outcomes from randomized clinical trials related to common indications treated with SCS. Technical considerations, such as type of implant, anesthesia, and programming, are also discussed.

Direct Oral Anticoagulants in Addition to Antiplatelet Therapy for Secondary Prevention after Acute Coronary Syndromes: a Review

PURPOSE OF REVIEW

As the management of acute coronary syndrome (ACS) continues to evolve, many old practices proved to be of a little benefit and other approaches established the new pillars of modern medicine. Treating ACS patients with dual antiplatelet therapy (DAPT) for a year by combining aspirin and a P2Y12 inhibitor (clopidogrel, ticagrelor, or prasugrel) has resulted in better outcomes and is currently the standard of therapy. However, owing to the persistent activation of the coagulation cascade, patients may continue to experience recurrent ischemia and high mortality rates despite compliance with the dual antiplatelet therapy. Research is underway to establish new treatment modalities for secondary prevention post-ACS, including the use of the novel direct oral anticoagulants (DOACs).

RECENT FINDINGS

Multiple trials have been conducted to evaluate the use of DOACs for the secondary prevention after ACS. Recent emerging data showed that the addition of rivaroxaban in a very low dose of 2.5 mg twice daily to the regular DAPT regimen after ACS is beneficial in the reduction of major cardiovascular events, including recurrent myocardial infarction (MI) and strokes. On the other hand, other DOACs, including apixaban, did not show similar efficacy and did not improve the cardiovascular outcomes. Patients who experience an ACS continue to suffer long-term consequences and thromboembolic complications. Many studies have shown that after the initial ACS event, patients remain in a hypercoagulable state and are more prone to recurrent ischemic attacks including stroke, recurrent MI, or unstable angina (UA). With the objective of seeking better outcomes, it is imperative to explore more aggressive anticoagulation strategies in ACS patients. In this article, we discuss the progress that was made and the limitations we face regarding the role of different anticoagulants in this setting.

Long-term quality of life improvement for chronic intractable back and leg pain patients using spinal cord stimulation: 12-month results from the SENZA-RCT

Purpose

Chronic axial low-back pain is a debilitating disorder that impacts all aspects of an afflicted individual’s life. Effective, durable treatments have historically been elusive. Interventional therapies, such as spinal cord stimulation (SCS), have shown limited efficacy at best. Recently, a novel treatment, 10 kHz SCS, has demonstrated superior pain relief compared with traditional SCS in a randomized controlled trial (RCT). In this manuscript, we report on the long-term improvements in quality of life (QoL) outcomes for subjects enrolled in this study.

Methods

A prospective, multicenter, randomized controlled trial (SENZA-RCT) was conducted. Patients with both chronic back and leg pain were enrolled and randomized (1:1) into 10 kHz SCS or traditional SCS treatment groups. A total of 171 subjects received a permanent SCS device implant. QoL and functionality measures were collected up to 12 months. The device remote control utilization, which is an indication of patient interaction with the device for adjustments, was collected at 24-month post-implantation.

Results

At 12 months, a higher proportion of 10 kHz SCS subjects had marked improvement of their disability (Oswestry Disability Index) to a “moderate” or “minimal” impact on their daily function versus the control group. The subjects also reported better improvement in the Global Assessment of Functioning, Clinician Global Impression of Change, Pittsburgh Sleep Quality Index, and short-form McGill Pain Questionnaire, compared to traditional SCS subjects. The 10 kHz SCS subjects also reported far higher rates of both driving and sleeping with their device turned on, as well as reduced reliance on their programmers to adjust therapy settings.

Conclusions

In addition to superior pain relief, 10 kHz SCS provides long-term improvements in quality of life and functionality for subjects with chronic low-back and leg pain. Trial registration: ClinicalTrials.gov (NCT01609972).

Newer Therapies for Management of Stable Ischemic Heart Disease With Focus on Refractory Angina

Ischemic heart disease remains a major public health problem nationally and internationally. Stable ischemic heart disease (SIHD) is one of the clinical manifestations of ischemic heart disease and is generally characterized by episodes of reversible myocardial demand/supply mismatch, related to ischemia or hypoxia, which are usually inducible by exercise, emotion, or other stress and reproducible-but which may also be occurring spontaneously. Improvements in the treatment of acute coronary syndromes along with increasing prevalence of cardiovascular risk factors, including diabetes and obesity, have led to increasing population of patients with SIHD. A significant number of these continue to have severe angina despite medical management and revascularization procedures performed and may progress to refractory angina. This article reviews the newer therapies in the treatment of SIHD with special focus in treating patients with refractory angina.

Advanced Innovations for Pain

Chronic pain represents one of the most important public health problems in terms of both the number of patients afflicted and health care costs. Most patients with chronic pain are treated with medications as the mainstay of therapy, and yet most medically treated patients continue to report ongoing pain. Additionally, adverse effects from pain medications represent a major challenge for clinicians and patients. Spinal cord stimulation and intrathecal drug delivery systems are well-established techniques that have been utilized for over 25 years. Intrathecal drug delivery systems have proven efficacy for a wide variety of intractable pain conditions and fewer adverse effects than systemic medical therapy in patients with refractory cancer-related pain. Spinal cord stimulation is cost-effective and provides improved pain control compared with medical therapy in patients with a variety of refractory pain conditions including complex regional pain syndrome, painful diabetic neuropathy, and chronic radiculopathy. Patients who have intractable pain that has not responded to reasonable attempts at conservative pain care measures should be referred to a qualified interventional pain specialist to determine candidacy for the procedures discussed in this article.

Management of Refractory Angina Pectoris

With improvements in survival from coronary artery disease (CAD) and an ageing population, refractory angina (RA) is becoming an increasingly common clinical problem facing clinicians in routine clinical practice. These patients experience chronic symptoms in the context of CAD, characterised by angina-type pain, which is uncontrolled despite optimal pharmacological, interventional and surgical therapy. Although mortality rates are no worse in this cohort, patients experience a significantly impaired quality of life with disproportionately high utilisation of healthcare services. It has been increasingly recognised that the needs of RA patients are multifactorial and best provided by specialist multi-disciplinary units. In this review, we consider the variety of therapies available to clinicians in the management of RA and discuss the promise of novel treatments.

The appropriate use of neurostimulation of the spinal cord and peripheral nervous system for the treatment of chronic pain and ischemic diseases: the Neuromodulation Appropriateness Consensus Committee

INTRODUCTION

The Neuromodulation Appropriateness Consensus Committee (NACC) of the International Neuromodulation Society (INS) evaluated evidence regarding the safety and efficacy of neurostimulation to treat chronic pain, chronic critical limb ischemia, and refractory angina and recommended appropriate clinical applications.

METHODS

The NACC used literature reviews, expert opinion, clinical experience, and individual research. Authors consulted the Practice Parameters for the Use of Spinal Cord Stimulation in the Treatment of Neuropathic Pain (2006), systematic reviews (1984 to 2013), and prospective and randomized controlled trials (2005 to 2013) identified through PubMed, EMBASE, and Google Scholar.

RESULTS

Neurostimulation is relatively safe because of its minimally invasive and reversible characteristics. Comparison with medical management is difficult, as patients considered for neurostimulation have failed conservative management. Unlike alternative therapies, neurostimulation is not associated with medication-related side effects and has enduring effect. Device-related complications are not uncommon; however, the incidence is becoming less frequent as technology progresses and surgical skills improve. Randomized controlled studies support the efficacy of spinal cord stimulation in treating failed back surgery syndrome and complex regional pain syndrome. Similar studies of neurostimulation for peripheral neuropathic pain, postamputation pain, postherpetic neuralgia, and other causes of nerve injury are needed. International guidelines recommend spinal cord stimulation to treat refractory angina; other indications, such as congestive heart failure, are being investigated.

CONCLUSIONS

Appropriate neurostimulation is safe and effective in some chronic pain conditions. Technological refinements and clinical evidence will continue to expand its use. The NACC seeks to facilitate the efficacy and safety of neurostimulation.

Interventional treatment of pain in refractory angina. A review

BACKGROUND

Refractory angina is characterized by repeated attacks of chest pain in patients on maximal anti-anginal pharmacotherapy, with a professional conscensus that further surgical or radiological revascularization would be futile. Refractory angina is a serious but relatively uncommon health problem, with a reported incidence of approximately 30 patients per million people/year. In this condition simply treating the associated pain alone is important as this can improve exercise tolerance and quality of life.

METHODS

An extensive literature search using five different medical databases was performed and from this, eighty-three papers were considered appropriate to include within this review.

RESULTS AND CONCLUSION

Available literature highlights several methods of interventional pain treatment, including spinal cord stimulation and video-assisted upper thoracic sympathectomy which can provide good analgesia whilst improving physical activities and quality of life. The positive effect of spinal cord stimulation on the intensity of pain and quality of life has been confirmed in nine randomized controlled trials. Other potential treatment methods include stellate ganglion blocks, insertion of thoracic epidural or spinal catheters and transcutaneous electrical nerve stimulation. These approaches however appear more useful for diagnostic purposes and perhaps as short-term treatment measures.

Role of the autonomic nervous system in modulating cardiac arrhythmias

The autonomic nervous system plays an important role in the modulation of cardiac electrophysiology and arrhythmogenesis. Decades of research has contributed to a better understanding of the anatomy and physiology of cardiac autonomic nervous system and provided evidence supporting the relationship of autonomic tone to clinically significant arrhythmias. The mechanisms by which autonomic activation is arrhythmogenic or antiarrhythmic are complex and different for specific arrhythmias. In atrial fibrillation, simultaneous sympathetic and parasympathetic activations are the most common trigger. In contrast, in ventricular fibrillation in the setting of cardiac ischemia, sympathetic activation is proarrhythmic, whereas parasympathetic activation is antiarrhythmic. In inherited arrhythmia syndromes, sympathetic stimulation precipitates ventricular tachyarrhythmias and sudden cardiac death except in Brugada and J-wave syndromes where it can prevent them. The identification of specific autonomic triggers in different arrhythmias has brought the idea of modulating autonomic activities for both preventing and treating these arrhythmias. This has been achieved by either neural ablation or stimulation. Neural modulation as a treatment for arrhythmias has been well established in certain diseases, such as long QT syndrome. However, in most other arrhythmia diseases, it is still an emerging modality and under investigation. Recent preliminary trials have yielded encouraging results. Further larger-scale clinical studies are necessary before widespread application can be recommended.

Recent advances in select interventional approaches to cancer-related pain

SUMMARY Interventional approaches for cancer-related pain have demonstrated utility and safety as a component of multimodal pain management. A number of techniques have been developed and implemented to manage the variety of cancer pain conditions and syndromes that exist as a result of the underlying malignant process and its associated oncologic treatment. These procedural pain modalities continue to evolve with advances in experience, understanding and technology in the field. Neurostimulation, vertebral augmentation with stabilization and intrathecal drug delivery, are prime examples of innovative approaches in interventional pain medicine for cancer pain with continued improvement in design to better achieve adequate analgesia and reduce risk. The intent of this article is to describe the aforementioned interventions and recent developments pertaining to them.

Cost-effectiveness of spinal cord stimulation therapy in management of chronic pain

OBJECTIVE

To evaluate the cost-effectiveness of spinal cord stimulation (SCS) and conventional medical management (CMM) compared with CMM alone for patients with failed back surgery syndrome (FBSS), complex regional pain syndrome (CRPS), peripheral arterial disease (PAD), and refractory angina pectoris (RAP).

DESIGN

Markov models were developed to evaluate the cost-effectiveness of SCS vs CMM alone from the perspective of a Canadian provincial Ministry of Health. Each model followed costs and outcomes in 6-month cycles. Health effects were expressed as quality-adjusted life years (QALYs). Costs were gathered from public sources and expressed in 2012 Canadian dollars (CAN$). Costs and effects were calculated over a 20-year time horizon and discounted at 3.5% annually, as suggested by the National Institute of Clinical Excellence. Cost-effectiveness was identified by deterministic and probabilistic sensitivity analysis (50,000 Monte-Carlo iterations). Outcome measures were: cost, QALY, incremental net monetary benefit (INMB), incremental cost-effectiveness ratio (ICER), expected value of perfect information (EVPI), and strategy selection frequency.

RESULTS

The ICER for SCS was: CAN$ 9,293 (FBSS), CAN$ 11,216 (CRPS), CAN$ 9,319 (PAD), CAN$ 9,984 (RAP) per QALY gained, respectively. SCS provided the optimal economic path. The probability of SCS being cost-effective compared with CMM was 75-95% depending on pathology. SCS generates a positive INMB for treatment of pain syndromes. Sensitivity analyses demonstrated that results were robust to plausible variations in model costs and effectiveness inputs. Per-patient EVPI was low, indicating that gathering additional information for model parameters would not significantly impact results.

CONCLUSION

SCS with CMM is cost-effective compared with CMM alone in the management of FBSS, CRPS, PAD, and RAP.

Hospital utilization and costs for spinal cord stimulation compared with enhanced external counterpulsation for refractory angina pectoris

RATIONALE, AIMS AND OBJECTIVES

The aim of this study was to compare acute hospital utilization and costs for patients with refractory angina pectoris undergoing spinal cord stimulation (SCS) versus enhanced external counterpulsation (EECP).

METHOD

Seventy-three persons were included in this register study. The acute hospital utilization and costs for SCS and EECP were followed over a period from 12 months before treatment to 24 months after treatment using Patient Administrative Support in Skåne for publicly organized care.

RESULTS

SCS was significantly more expensive than EECP (P < 0.001). Both SCS and EECP entailed fewer days of hospitalization for coronary artery disease in the 12-month follow-up compared with the 12 months preceding treatment. Patients treated with EECP showed an association between reduced hospital admissions and an improved Canadian Cardiovascular Society classification class compared with 1 year before treatment. A significant reduction in cost was seen in both the SCS group (P = 0.018 and P = 0.001, respectively) and the EECP group (P = 0.002 and P = 0.045, respectively) during 12 and 24 months of follow-up compared with before treatment. There were no significant differences between the groups for hospitalization days or admissions, including costs, at the different follow-ups.

CONCLUSIONS

Cost-effective treatment modalities such as SCS and EECP are valuable additions to medical and revascularization therapy in patients with refractory angina pectoris. Pre-existing conditions and the patient's preferences should be taken in consideration when clinicians choose between treatments for this group of patients.

Electrical neuromodulation for patients with cardiac diseases

In this review we discuss the position of electrical neuromodulation as a safe and reversible adjuvant therapy for treatment of patients with chronic cardiac diseases who have become refractory to conventional strategies. In patients with chronic refractory angina, electrical neuromodulation, independent of the applied modality, has shown to reduce complaints of angina, to enhance exercise capacity, to improve quality of life and to employ anti-ischaemic effects. To date, electrical neuromodulation seems to be one of the best adjuvant therapies for these patients. In addition, neuromodulation in the treatment of heart failure and resistant arrhythmias is the subject of several ongoing studies.

Spinal cord stimulation in pain management: a review

Spinal cord stimulation has become a widely used and efficient alternative for the management of refractory chronic pain that is unresponsive to conservative therapies. Technological improvements have been considerable and the current neuromodulation devices are both extremely sophisticated and reliable in obtaining good results for various clinical situations of chronic pain, such as failed back surgery syndrome, complex regional pain syndrome, ischemic and coronary artery disease. This technique is likely to possess a savings in costs compared with alternative therapy strategies despite its high initial cost. Spinal cord stimulation continues to be a valuable tool in the treatment of chronic disabling pain.