Clas Mannheimer

Electrical Stimulation Versus Coronary Artery Bypass Surgery in Severe Angina Pectoris The ESBY Study

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 randomized (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.

The effects of transcutaneous electrical nerve stimulation in patients with severe angina pectoris.

The pain-relieving effects of transcutaneous electrical nerve stimulation (TENS) were investigated in patients with severe angina pectoris first with respect to systemic and coronary hemodynamics and myocardial metabolism during pacing-induced angina and second in a controlled long-term study. Two series of patients with severe angina pectoris (NYHA class III to IV) were studied (13 patients in the pacing study and 23 in the long-term study). In the pacing-induced angina study there was increased tolerance to pacing (142 +/- 23 compared with 124 +/- 20 beats/min tolerated, p less than .001), improved lactate metabolism (2 +/- 36% compared with -18 +/- 43%, p less than .01), and less pronounced ST segment depression (2.3 +/- 1.1 compared with 2.9 +/- 2.6 mm, p less than 0.05) with TENS. In the long study the effects of TENS were measured by means of repeated bicycle ergometer test, frequency of anginal attacks, and consumption of short-acting nitroglycerin. TENS was used regularly for 1 hr three times per day. The TENS treatment group had increased work capacity (637 +/- 308 vs 555 +/- 277 W . min, p greater than .001), decreased ST segment depression (2.3 +/- 1.1 vs 3.6 +/- 1.6 mm, p less than .001), reduced frequency of anginal attacks (p less than .05), and reduced consumption of short-acting nitroglycerin per week (p less than .05) compared with the control group. The observed effects were mainly due to decreased afterload resulting from systemic vascular dilatation.

Spinal cord stimulation in severe angina pectoris — presentation of current studies, indications and clinical experience

Spinal cord stimulation has been used in clinical practice for several years in the treatment of chronic pain, mainly of neurogenic origin (31). Since 1976 several reports have been published on the favorable effects of spinal cord stimulation in advanced peripheral arterial vascular disease in the lower extremities. The treatment appears to produce increased local peripheral perfusion which leads in turn to improved healing of arterial leg ulcers (1, 5, 17).

Effect of spinal cord stimulation on regional myocardial perfusion assessed by positron emission tomography

Spinal cord stimulation (SCS) can relieve symptoms in patients with severe angina pectoris refractory to conventional medical or surgical therapy. This symptomatic improvement may result from decreased myocardial ischemia. To test this hypothesis, positron emission tomography (PET) and potassium-38 as a flow tracer were used in 8 patients for the quantitative evaluation of regional myocardial perfusion at rest and after exercise, before and during SCS. Potassium uptake was evaluated as myocardial clearance (flow times net extraction) in ml/min/100 g. Tomographic segments were categorized as nonaffected and affected on the basis of the absence or presence of arterial stenosis on coronary angiography and on the basis of thallium scintigraphic data. In nonaffected segments, before SCS, regional myocardial clearance significantly increased from rest (28 +/- 4) to exercise (47 +/- 13 clearance units; p less than 0.004). A similar increase occurred after SCS. In affected segments, before SCS, regional myocardial clearance barely increased (p = 0.065) from rest (26 +/- 6) to exercise (33 less than or equal to 12). In comparison, after SCS, the resting regional myocardial clearance was slightly elevated (29 +/- 8) reflecting an increased double product, but did not increase (p = 0.192) with exercise (34 +/- 12). However, the magnitude and duration of ST-segment depression decreased during treatment with SCS. Anginal pain occurred in all patients during control exercise, but was attenuated in all but one with SCS. These results indicate that SCS improves exercise-induced angina and electrocardiographic signs of ischemia but this influence does not appear to be mediated by changes in regional myocardial perfusion.

Gabapentin in traumatic nerve injury pain: A randomized, double-blind, placebo-controlled, cross-over, multi-center study

&NA; A double‐blind, randomized, placebo‐controlled cross‐over multi‐center study was conducted to evaluate the efficacy and safety of gabapentin in the treatment of neuropathic pain caused by traumatic or postsurgical peripheral nerve injury, using doses up to 2400 mg/day. The study comprised a run‐in period of two weeks, two treatment periods of five weeks separated by a three weeks’ washout period. The primary efficacy variable was the change in the mean pain intensity score from baseline to the last week of treatment. Other variables included pain relief, health related quality of life (SF‐36), interference of sleep by pain, Clinician and Patient Global Impression of Change, and adverse effects. Nine centers randomized a total of 120 patients, 22 of whom withdrew. There was no statistically significant difference between the treatments for the primary outcome efficacy variable. However, gabapentin provided significantly better pain relief (p = 0.015) compared with placebo. More patients had at least a 30% pain reduction with gabapentin compared with placebo (p = 0.040) and pain interfered significantly less with sleep during gabapentin treatment compared with placebo (p = 0.0016). Both the Patient (p = 0.023) and Clinician (p = 0.037) Global Impression of Change indicated a better response with gabapentin compared with placebo. Gabapentin was well tolerated. The most common adverse effects were dizziness and tiredness.

Myocardial Turnover of Endogenous Opioids and Calcitonin-Gene-Related Peptide in the Human Heart and the Effects of Spinal Cord Stimulation on Pacing-Induced Angina Pectoris

Earlier studies have shown that spinal cord stimulation (SCS) has antianginal and anti-ischemic effects in severe coronary artery disease. In the present study, 14 patients were subjected to right-sided atrial catheterization and atrial pacing. The patients were paced to angina during a control session and during spinal cord stimulation. Myocardial extraction of β-endorphin (BE) during control pacing (8 ± 22%) changed to release at the maximum pacing rate during treatment (–21 ± 47%, a negative value representing release). Furthermore, the results indicate local myocardial turnover of leuenkephalin, BE and calcitonin-gene-related peptide. In addition, it is implied that SCS may induce myocardial release of BE which could explain the beneficial effects in myocardial ischemia.

Socio-economic burden of patients with a diagnosis related to chronic pain--register data of 840,000 Swedish patients.

Chronic pain constitutes a substantial socio‐economic challenge but little is known about its actual cost.

Cost-effectiveness of spinal cord stimulation versus Coronary Artery Bypass grafting in patients with severe Angina pectoris-long-term results from the ESBY study

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 randomised prospective 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.

Spinal cord stimulation in angina pectoris with normal coronary arteriograms

BackgroundPatients with angina pectoris with normal coronary arteriograms, also known as Syndrome X (typical exercise-induced angina pectoris, positive exercise testing, and normal coronary arteriograms), are often difficult to treat with conventional forms of medical therapy. Spinal cord stimulation has been used in recent years for the treatment of severe angina pectoris refractory to conventional medical and surgical therapy in coronary artery disease. The aim of this study was to investigate the effects of spinal cord stimulation on angina pectoris with normal coronary arteriograms. MethodsTwelve patients underwent five bicycle exercise tests, three tests without (control), and two tests with spinal cord stimulation treatment. ResultsThe exercise tolerance of the patients increased (108± 22 W versus 96±21W; P< 0.001), the magnitude of ST-segment depression at comparable work load decreased (1.0± 0.6mm versus 1.5± 0.9mm; P< 0.01), time to angina increased (5.4 ± 2.2 min versus 2.7 ± 1.9 min; P< 0.01), and time to the appearance of ST-segment depression increased (3.5± 1.9 min versus 2.4 ± 1.6 min; P< 0.01).The rate-pressure product at maximum work load during treatment increased, compared with the maximum work load during the control session (28 038 ± 6124mmHg x bpm versus 25 222 ± 4519mmHgx bpm; P< 0.05 ) and the comparable work load during treatment (28 038 ± th6124mmHg x bpm versus 24 795 ± 5022mmHg x bpm; P< 0.01). ConclusionsSpinal cord stimulation has beneficial effects in angina pectoris with normal coronary arteriograms in terms of relief of symptoms of angina pectoris and improvement of exercise tolerance. These effects may be associated with a reduction in myocardial ischemia.

Spinal cord stimulation in severe angina pectoris: a systematic review based on the Swedish Council on Technology assessment in health care report on long-standing pain

Abstract Patients who continue to suffer from lasting and severely disabling angina pectoris despite optimum drug treatment and who are not suitable candidates for invasive procedures, suffer from a condition referred to as “chronic refractory angina pectoris”. Based on the available data, spinal cord stimulation, SCS, is considered as the first‐line additional treatment for these patients by the European Society of Cardiology. However, no systematic review of randomised controlled studies has yet been published. A systematic literature research, 1966–2003, as part of the Swedish Board of Health and Welfare (SBU) report on long‐standing pain, and an additional research covering the years 2003–2007, were carried out. Acute studies, case reports and mechanistic reviews were excluded, and the remaining 43 studies were graded for study quality according to a modified Jadad score. The eight medium‐ to high‐score studies formed the basis for conclusions regarding the scientific evidence (strong, moderately strong or limited) for the efficacy of SCS. There is strong evidence that SCS gives rise to symptomatic benefits (decrease in anginal attacks) and improved quality of life in patients with severe angina pectoris. There is also a strong evidence that SCS can improve the functional status of these patients, as illustrated by the improved exercise time on treadmill or longer walking distance without angina. In addition, SCS does not seem to have any negative effects on mortality in these patients (limited scientific evidence). The complication rate was found to be acceptable.