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At least 235 records · Page 13Linked to original sources

PubMed1998

Maximizing the hemodynamic benefit of enhanced external counterpulsation.

BACKGROUND: Enhanced external counterpulsation (EECP) has been demonstrated to be an effective treatment for angina and exertional ischemia in patients with coronary disease. HYPOTHESIS: It is hypothesized that the ability of EECP to enhance the recruitment or development of coronary collaterals in coronary artery disease may be determined by the relative magnitude of diastolic augmentation (DA) and systolic unloading (SU). This study examines the relation between the proposed EECP effectiveness ratio (DA/SU), as assessed by finger plethysmography, and changes in descending aortic flow as assessed by Doppler echocardiography in 15 patients during EECP. METHODS: Varying external cuff pressures (0-275 mmHg) were used to generate a range of DA/SU ratios. The effect on aortic antegrade systolic and retrograde diastolic flow was assessed by Doppler echocardiography to determine whether there was an optimal EECP effectiveness ratio that maximizes the hemodynamic effects of EECP. With increasing DA/SU there was an initial positive linear increase in both systolic and diastolic flow volume. Systolic flow maximized at an effectiveness ratio of 1.5 and diastolic flow at a ratio of 2.0 RESULT: Therefore, effectiveness ratios (DA/SU) in the range of 1.5-2.0 are optimal for maximizing the hemodynamic effects of EECP.

Adult↗

PubMed1999

Enhanced external counterpulsation in the management of patients with cardiovascular disease.

Studies over the past several decades support the hypothesis that enhanced external counterpulsation (EECP) can provide long-term benefits in patients with angina secondary to chronic coronary disease. Numerous non-sham controlled trials have recently been substantiated by a multicenter, randomized trial. Although the mechanism by which this mechanical treatment effects an alteration in cellular processes within the myocardium remains unclear, recent scientific investigations suggest that shear stress induced by chronic exposure to EECP might result in the release of a variety of growth factors and the subsequent stimulation of angiogenesis in the coronary beds. Ongoing clinical trials in patients with significant left ventricular dysfunction, an international registry, and additional clinical trials may help to elucidate further the role of this novel and unique therapy in our clinical armamentarium.

Angina Pectoris↗

PubMed2000

Long-term prognosis of patients with angina treated with enhanced external counterpulsation: five-year follow-up study.

BACKGROUND: Enhanced external counterpulsation (EECP) is a noninvasive treatment for coronary artery disease (CAD) that has been used successfully in patients not responding to medical and/or surgical therapy. HYPOTHESIS: The study was undertaken to evaluate the effect of EECP on long-term prognosis in such patients. METHODS: Major adverse cardiovascular events (MACE) were tracked in 33 patients with CAD treated with EECP. Patients were subgrouped based on whether or not they demonstrated an early improvement in radionuclide stress perfusion imaging (Responders vs. Nonresponders) and followed for MACE over a mean follow-up of 5 years. Patient population characteristics included 73% with multivessel disease; 45% with prior myocardial infarction(s); and 61% who had undergone either coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA), or both. RESULTS: There were 26 of 33 (79%) Responders, and 7 of 33 (21%) Nonresponders. Subsequent MACE over the 5-year follow-up included four deaths and eight patients with cardiovascular events [acute myocardial infarct (4), new CABG or PTCA (6), valve replacement (1), unstable angina (1)]. Nonresponders had significantly (p < 0.01) more MACE (6/7 or 86%) than Responders (6/26 or 23%). Overall, 21 of the 33 (64%) patients remained alive and without MACE and the need for revascularization 5 years post EECP treatment. CONCLUSION: This study suggests that, particularly for the majority of patients demonstrating improvement in radionuclide stress perfusion post treatment, EECP may be an effective long-term therapy.

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PubMed2001

Does higher diastolic augmentation predict clinical benefit from enhanced external counterpulsation?: Data from the International EECP Patient Registry (IEPR).

BACKGROUND: Enhanced external counterpulsation (EECP) has been demonstrated to be an effective treatment for stable angina in patients with coronary disease. The hemodynamic effects of EECP are maximized when the ratio of diastolic to systolic pressure area is in the range of 1.5 to 2.0. HYPOTHESIS: It is hypothesized that patients undergoing EECP who are able to achieve higher diastolic augmentation (DA) ratios may derive greater clinical benefit. This study examines the relationship between the DA ratio and clinical outcomes in patients undergoing EECP. METHODS: We analyzed demographic, noninvasive hemodynamic, and clinical outcome data on 1,004 patients enrolled in the International EECP Patient Registry (IEPR) for treatment of chronic angina between January 1998 and August 1999. Blood pressure waveforms were recorded from finger plethysmography. Six-month clinical outcomes were obtained by telephone interview. RESULTS: At the end of EECP treatment, 370 (37%) patients had a higher DA ratio (defined as > or = 1.5) and 634 (63%) had a lower DA ratio (defined as < 1.5). Factors associated with a lower DA ratio included age > or =65 years (p <0.001), female gender (p < 0.001), left ventricular ejection fraction < 35% (p < 0.05), hypertension (p < 0.01), prior coronary bypass surgery (p < 0.01), noncardiac vascular disease (p < 0.001), multivessel disease (p < 0.01), congestive heart failure (p < 0.01), current smoking (p < 0.01), unsuitability for further revascularization (p < 0.001), and higher baseline angina class (p < 0.001). There were no significant differences regarding diabetes mellitus, prior coronary angioplasty, prior myocardial infarction, or antianginal medication use between patients with higher or lower DA ratios. Based on a multiple logistic regression model, independent predictors of a DA ratio < 1.5 at the end of EECP included current smoking (odds ratio 3.3; 95% confidence intervals 2.0-5.4); multivessel disease (1.7; 1.3-2.3); female gender (2.2; 1.7-3.0); no prior EECP (1.9; 1.1-3.3); noncardiac vascular disease (2.3; 1.7-2.9); age > or = 65 years (1.7; 1.4-2.2), and patients not suitable for revascularization (1.6; 1.2-2.0). By the end of therapy, there were no significant differences in myocardial infarction, revascularization rates, or nitroglycerin use with respect to higher DA ratios. At 6-month follow-up, patients with higher DA had a trend toward a greater reduction in angina class compared with those with lower DA (p = 0.069). There was a significantly higher rate of unstable angina and congestive heart failure in the group not achieving higher augmentation (p < 0.05). CONCLUSIONS: Patients who are younger, male, nonsmoking, and without multivessel coronary or noncardiac vascular disease are most likely to have higher DA with EECP. Patients with higher DA tended to have a greater reduction in angina class at 6-month follow-up compared with those with lower DA ratios. There is evidence that higher DA ratios are associated with improved short- or long-term clinical outcomes, suggesting that clinical benefit from EECP is associated with the magnitude of DA.

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PubMed2002

A historical overview of enhanced external counterpulsation.

Angina remains a significant health problem in the United States and the world. Although there are a variety of pharmacologic and interventional therapies to treat angina, many patients are not adequately helped by these treatments. Enhanced external counterpulsation (EECP) is an effective, noninvasive technique designed to decrease the frequency and duration of anginal episodes, as well as increase exercise duration in patients with acute angina. Since the early 1960s, the technology of EECP has been thoroughly refined. In addition, a number of important clinical trials have provided evidence for its effectiveness. Continuing research is needed to determine the best patients for EECP and its appropriate clinical application.

Angina Pectoris↗

PubMed2002

A review of enhanced external counterpulsation clinical trials.

A variety of clinical trials of enhanced external counterpulsation (EECP) have been conducted since the 1960s. The vast majority of these studies have investigated the use of EECP in patients with angina pectoris. Only one of these trials was randomized. These clinical trials have demonstrated the benefits of EECP in terms of reduction in anginal episodes, increased exercise times, and improvement in health-related quality of life scores. The International EECP Patient Registry, through its phase I and II enrollment, is expanding the data set on outcomes after EECP treatment.

Angina Pectoris↗

PubMed2002

Enhanced external counterpulsation: mechanism of action.

The mechanisms accounting forthe salutary benefits of enhanced external counterpulsation (EECP) remain largely unknown. Emerging data now point to three possible hypotheses to explain its efficacy. These possible explanations include enhanced diastolic flow, changes in the neurohumoral milieu, and changes in ventricular function independent of changes in cardiac load. While each of these three hypotheses may help explain the mechanism behind EECP's effects, more clinical studies are required to refine these proposed explanations.

Animals↗

PubMed2002

Current use of enhanced external counterpulsation and patient selection.

Most patients who receive enhanced external counterpulsation (EECP) have symptomatic coronary artery disease. These patients have either responded poorly to pharmacologic therapy or are poor candidates for revascularization procedures. Such patients receive a variety of consistent benefits from EECP treatment. As more is learned about EECP, patients once excluded from early clinical trials are now able to take advantage of EECP. Nevertheless, EECP is not suitable for some patients. It has a favorable adverse event profile for most patients undergoing the treatment. Medicare reimbursement coverage limitations remain an obstacle to having a broad cross-section of patients benefit from EECP.

Angina Pectoris↗

PubMed2002

Treatment options for angina pectoris and the future role of enhanced external counterpulsation.

Patients with coronary artery disease have a variety of treatment options available to them. These include medications to control anginal episodes and, when appropriate, revascularization interventions in the form of coronary artery bypass graft and angioplasty. Despite advances in the treatment of angina, a substantial number of patients continue to have symptoms that can significantly impair their quality of life. These patients may benefit from enhanced external counterpulsation (EECP). With recent results of the latest clinical trial of EECPjust published, the role of EECP, including its position in the hierarchy of treatment options, needs to be seriously considered.

Angina Pectoris↗

PubMed2002

Ongoing and planned studies of enhanced external counterpulsation.

There is strong, continued interest in enhanced external counterpulsation (EECP) as evidenced by current, ongoing clinical trials. Many of these have been designed to support the current indications of EECP, mainly its application in the treatment of symptomatic coronary artery disease. An exciting area in this regard ishow EECP may help control blood glucose in patients with angina and diabetes mellitus. A variety of planned or ongoing exploratory studies are also helping to explain the mechanism of action behind EECP. Two clinical trials are now investigating a new indication for EECP in patients with congestive heart failure, including the important randomized Prospective Evaluation of EECP in Congestive Heart failure (PEECH) trial.

Clinical Trials as Topic↗

PubMed2003

Practicability and limitations of enhanced external counterpulsation as an additional treatment for angina.

BACKGROUND: An increasing number of clinical studies indicates reduction of angina and myocardial ischemia by enhanced external counterpulsation (EECP) therapy. However, given the wide range of contraindications and the long duration of treatment, eligibility and practicality issues have not been addressed systematically. HYPOTHESIS: Of all candidates for EECP (patients with drug-refractory angina without possibility of revascularization), the majority either have contraindications or have practical problems complying with the time demands that this therapy imposes. In the rest, EECP leads to satisfactory results. METHODS: During 18 months, every consecutive patient with angina despite medical and interventional therapy was evaluated for EECP at one center. Treated patients underwent a bicycle exercise test and perfusion imaging before and after the standard course of 35 h of EECP. In addition, patients were asked about frequency of angina and nitroglycerin usage before and after EECP, and all patients filled out a final questionnaire 1 year after the end of therapy. RESULTS: Overall, 48 patients were considered candidates for EECP. Of these, 24 were excluded for medical reasons: poor ejection fraction (4), peripheral artery disease (4), anticoagulation (4), and atrial fibrillation (3). Eight further patients declined EECP for lack of time or accommodation. Another 3 of the 16 remaining patients dropped out because of side effects. In the 13 patients who finished the treatment course, weekly anginal episodes were reduced by 48% (p < 0.05), on-demand nitroglycerin puffs were reduced by 51% (p < 0.05), work capacity was improved by 22% (p < 0.05), and the number of reversible perfusion defects in perfusion scans decreased nonsignificantly (-28%). However, 4 of 13 treated patients determined 1 year later that the detriment of loss of time exceeded the benefits of EECP. CONCLUSION: Similar to previous reports, our study confirms the reduction of angina and improvement of work capacity after EECP. However, using established contraindications, approximately two-thirds of patients considered to be candidates had to be excluded, and one-third of the treated patients regarded EECP therapy retrospectively as too time consuming.

Angina Pectoris↗

PubMed2005

An update on enhanced external counterpulsation.

The development of advanced revascularization techniques has resulted in the growth of a subset of patients with coronary artery disease who are nonrevascularizable and are considered to have refractory angina. Enhanced external counterpulsation (EECP) has been developed for the management of these patients with chronic, refractory disease. Evidence has shown that through improvement of vascular endothelial function and recruitment of collateral vessels, EECP provides many clinical benefits. These patients experience sustained decreases in angina, improvement in exercise time, improved myocardial perfusion, and enhanced quality of life. Furthermore, EECP appears to be safe and effective in the treatment of angina in patients with impaired systolic function and has similar potential in patients with congestive heart failure.

Angina Pectoris↗

PubMed2000

[Current use and outcomes of intraaortic balloon counterpulsation in routine cardiology].

BACKGROUND: Intraaortic balloon counterpulsation (IABC) is an established technique for temporary support of the left ventricular function. However, less is known about the current use and outcome of IABC in daily clinical practice. PATIENTS AND METHOD: From July 1995 to May 1999 all patients receiving an IABC in the Department of Cardiology of the Heart Center Ludwigshafen were included in a consecutive registry and follow-up data were obtained. RESULTS: Sixty-six patients (mean age 65 years, 64% male) received an IABC during the registration period. In 95% of cases the indication for IABC was the presence of cardiogenic shock. The shock was due to an acute myocardial infarction in 83%, other reasons were less frequent (< or = 5%). Total inhospital mortality was 48%. Patients in shock due to myocardial infarction (53%) showed the highest mortality. During follow-up (median 20 months) another 21% died. Complications occurred in 20% of patients under IABC, including vascular complications in 12%, infections in 5% and major bleedings in 3%. There was no difference between mortality among patients with complications and total mortality. CONCLUSION: Main indication for IABC in daily practice is the presence of cardiogenic shock (95%), dominantly due to myocardial infarction (83%). Despite IABC therapy, half of these patients die during the hospital stay. High mortality of cardiogenic shock in myocardial infarction with pharmacological therapy justifies IABC treatment with regard to a rate of complications of 20%.

Adult↗

PubMed2004

Improvement of oxygen metabolism in ischemic myocardium as a result of enhanced external counterpulsation with heparin pretreatment for patients with stable angina.

Enhanced external counterpulsation (EECP) is noninvasive, safe, and effective for stable angina. We have reported that the development of functional collateral vessels is one of the mechanisms of EECP therapy using ammonia positron emission tomography (PET). The efficacy of heparin treatment on collateral growth is shown in several clinical studies. We evaluated whether EECP combined with intravenous heparin injection is effective for exercise capacity and oxygen metabolism of ischemic myocardium in stable angina. Eleven patients with stable angina were treated with conventional EECP therapy (C group). Seven patients with stable angina were treated with EECP therapy with 5000 IU heparin pretreatment (H group). At baseline and after the completion of treatment H, 7 patients underwent [(11)C] acetate PET to examine the change in regional myocardial oxygen metabolism. Although the total treadmill exercise time was prolonged after treatment in both groups, the extent of the improvements was significantly greater in the H group compared with the C group. Although k mono, the index of regional myocardial oxygen metabolism, in the nonischemic region remained unchanged, k mono in the ischemic region increased significantly ( P << 0.05) from 0.038 +/- 0.004 to 0.053 +/- 0.007. In conclusion, EECP with heparin pretreatment appears to be a new treatment remedy for patients with stable angina.

Angina Pectoris↗

PubMed2001

Changes in ocular blood flow velocities during external counterpulsation in healthy volunteers and patients with atherosclerosis.

BACKGROUND: External counterpulsation (ECP) is a new noninvasive means of augmenting organ perfusion by applying ECG-triggered diastolic pressure to the vascular bed of the lower limbs. In this study, effects of ECP on changes of ocular blood flow velocities were studied. METHOD: Mean, systolic and diastolic flow velocities of the ophthalmic artery were measured by Doppler sonography before and during ECP. Twelve healthy volunteers (age 31.3+/-4.3 years) and 12 patients with severe atherosclerosis (inclusion criteria: two atherosclerotic risk factors, at least one severe coronary stenosis, age 62.1+/-5.3 years) were included in the study. RESULTS: In healthy subjects, ECP changed diastolic flow velocity of the ophthalmic artery nonsignificantly from 21.6+/-7.7 to 23.7+/-10.5 cm/s. Systolic flow velocity decreased significantly from 36.1+/-13.6 to 28.9+/-10.2 cm/s (P<0.01). Mean flow velocity changed nonsignificantly from 28.1+/-9.4 to 26.5+/-9.9 cm/s. In atherosclerotic patients, mean flow velocity increased significantly from 26.3+/-11.4 to 29.3+/-11.2 cm/s (P<0.001), which was caused by significant diastolic flow augmentation from 19.7+/-9.1 to 23.9+/-9.7 cm/s (P<0.001). Systolic flow velocity was not changed significantly (from 34.2+/-12.8 to 32.6+/-11.8 cm/s). CONCLUSION: No significant change of mean blood flow velocity in the ophthalmic artery was found in young healthy subjects. In elderly patients with atherosclerosis, ECP significantly increased blood flow velocity in the ophthalmic artery by 11.4%. This may indicate an ocular perfusion benefit in these patients as a result of ECP and could also explain the increase of perfusion found in patients with retinal ischemia after ECP.

Adult↗

PubMed1992

Efficacy of enhanced external counterpulsation in the treatment of angina pectoris.

Eighteen patients with chronic angina despite surgical and medical therapy were treated with an improved system of enhanced external counterpulsation (EECP) (1 hour daily for a total of 36 hours). Patients underwent a baseline treadmill thallium-201 stress test. After EECP treatment, a thallium stress test was repeated for the same exercise duration. One week after treatment, patients also underwent a maximal stress test. All patients improved in anginal symptoms and generally decreased antianginal medications, with 16 obtaining complete relief from angina. Pre- and post-thallium stress testing performed for the same duration showed complete resolution of ischemic defects in 12 patients (67%), reduction in the area of ischemia in 2 (11%), and no change in 4 (22%). Thus, a decrease in myocardial ischemia was observed in 14 patients (78%; p less than 0.01). The exercise duration of maximal stress testing after EECP significantly improved from 8.14 +/- 0.71 to 9.72 +/- 0.77 minutes (p less than 0.005), although the double product did not change significantly. Analysis of these 2 tests in the subgroup of 14 patients with improvement in thallium studies showed significant increases in both exercise duration (8.58 +/- 0.66 to 10.44 +/- 0.59 minutes; p less than 0.001) and double product (21,827 +/- 2,044 to 24,842 +/- 1,707 mm Hg.beats/min; p less than 0.01). The improvement in reperfusion defects and increase in exercise duration are reflections of improved perfusion to ischemic regions of the myocardium. EECP uses additional thigh balloons and sequenced balloon inflation, effecting a significant increase in diastolic augmentation over previously available methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗

PubMed1991

Biochemical and structural adaptation of autologous skeletal muscle used for counterpulsation.

We have studied in a normal animal model (sheep), the biochemical and morphological adaptation of electrically stimulated skeletal muscle used for extra aortic counterpulsation. Immunocytochemical analysis of latissimus dorsi, using monoclonal antibodies to slow and fast myosin heavy chains, indicated an increase in the population of mixed fibres after stimulation for one week. By one month, up to 70% of fibres expressed both slow and fast myosin heavy chains in addition to the 15% of fibres expressing only slow myosin heavy chains. After 4 months, the population of mixed fibres was further transformed towards purely slow fibres to give values of 40 and 67% of fibres expressing only slow myosin heavy chain at 4 and 6 months, respectively. Increased staining, both in intensity and area, for NADH tetrazolium reductase activity (an enzyme of the oxidative metabolic pathway) was detected by 28 days. An increase in mitochondrial number was observed also by 28 days, further indicating a shift towards an oxidative metabolism. The molecular adaptation of latissimus dorsi was achieved by stimulation every fourth cardiac cycle at 35 Hz, 3 V, initiated 48 hours after the operation; this being a marked reduction in the delay from operation prior to stimulation. Evaluation of other regimes indicated that more frequent modes, or an increase in voltage or frequency, caused damage to the muscle during the early phase of molecular adaptation. A thorough understanding of the time sequence of the different adaptive processes is required to determine the ideal regime of stimulation initiated promptly after mobilisation of the muscle; aimed at harvesting the maximum amount of energy from the autologous muscle.

Adaptation, Physiological↗

PubMed1995

Role of intraaortic balloon pump counterpulsation in high risk coronary rotational atherectomy.

OBJECTIVES: This study sought to evaluate the role of intraaortic balloon pump counterpulsation in preventing hemodynamic instability and promoting a successful outcome during percutaneous transluminal coronary rotational atherectomy in high risk patients. BACKGROUND: The application of rotational atherectomy has widened to include patients with complex lesions and left ventricular dysfunction. Although intraaortic balloon pumping has been successfully used to provide hemodynamic support during balloon angioplasty, its role in high risk rotational atherectomy has not yet been defined. METHODS: In a retrospective review of 159 consecutive high risk patients who underwent rotational atherectomy, 28 had an intraaortic balloon pump placed electively before the procedure (Group 1) whereas 131 did not (Group 2). RESULTS: Group 1 was older and more likely to have multivessel disease and left ventricular dysfunction. Augmented diastolic pressure was maintained > 90 mm Hg in all Group 1 patients, and significant procedure-related hypotension was encountered in nine Group 2 patients, requiring an emergency intraaortic balloon pump in five. Procedural success was achieved in all 28 patients in Group 1 and in 118 in Group 2 (p = 0.07). Slow flow occurred in 18% and 17% of Group 1 and 2 patients, respectively. Among patients with slow flow, non-Q wave myocardial infarction occurred only in Group 2 (0% vs. 27%). On multivariate analysis, elective intraaortic balloon pump placement was the only variable to correlate with a successful procedure uncomplicated by hypotension (p < 0.05). Hospital stay and vascular complications were similar in both groups. CONCLUSIONS: Elective placement of an intraaortic balloon pump before coronary rotational atherectomy in selected high risk patients promotes both procedural hemodynamic stability and a successful outcome.

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