Myocardial laser revascularization for the treatment of end-stage coronary artery disease

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.

Internal barriers to efficiency: why disinvestments are so difficult. Identifying and addressing internal barriers to disinvestment of health technologies

Although efficiency is a core concept in health economics, its impact on health care practice still is modest. Despite an increased pressure on resource allocation, a widespread use of low-value care is identified. Nonetheless, disinvestments are rare. Why is this so? This is the key question of this paper: why are disinvestments not more prevalent and improving the efficiency of the health care system, given their sound foundation in health economics, their morally important rationale, the significant evidence for a long list of low-value care and available alternatives? Although several external barriers to disinvestments have been identified, this paper looks inside us for mental mechanisms that hamper rational assessment, implementation, use and disinvestment of health technologies. Critically identifying and assessing internal inclinations, such as cognitive biases, affective biases and imperatives, is the first step toward a more rational handling of health technologies. In order to provide accountable and efficient care we must engage in the quest against the figments of our minds; to disinvest in low-value care in order to provide high-value health care.

Biases distorting priority setting

Modern health care faces an ever widening gap between technological possibilities and available resources. To handle this challenge we have constructed elaborate systems for health policy making and priority setting. Despite such systems many health care systems provide a wide range of documented low-value care while being unable to afford emerging high-value care. Accordingly, this article sets out asking why priority setting in health care has so poor outcomes while relevant systems are well developed and readily available. It starts to identify some rational and structural explanations for the discrepancy between theoretical efforts and practical outcomes in priority setting. However, even if these issues are addressed, practical priority setting may still not obtain its goals. This is because a wide range of irrational effects is hampering priority setting: biases. By using examples from the literature the article identifies and analyses a wide range of biases indicating how they can distort priority setting processes. Overuse, underuse, and overinvestment, as well as hampered disinvestment and undermined priority setting principles are but some of the identified implications. Moreover, while some biases are operating mainly on one level, many are active on the micro, meso and on the macro level. Identifying and analyzing biases affecting priority setting is the first, but crucial, step towards improving health policy making and priority setting in health care.

Can enhanced external counter pulsation as a non-invasive modality be useful in patients with ischemic cardiomyopathy after coronary artery bypass grafting?

Background

Angina symptom in patients with ischemic cardiomyopathy (ICM) after coronary artery bypass grafting (CABG) surgery is a major challenging problem in practice. The choice among different treatment modalities available can be judged by different parameters especially measuring the risk/cost ratio to achieve the benefit. Enhanced external counter pulsation (EECP) is one of safest noninvasive modality for treatment of angina as well as it has an anti-failure effect.

Patients and method

42 patients with ICM after CABG were suffering from stable angina and were treated at Al-Hayat Cardiology Centre in Tanta City (ACC). 20 patients of them (group A) received 35 sessions of EECP plus their anti-ischemic and anti-failure treatment, while the other 22 patients (group B) received only medical treatment and were followed up for 3 months regarding their angina class, functional class, frequency of angina attack, frequency of sublingual nitrate and rate of rehospitalization when needed during follow up period.

Results

Despite both groups had nearly similar severity of symptoms regarding the CCS class and NYHA class, yet patients in group A experienced significant improvement in comparison to patients in group B (p-value = .005, p-value = .002 respectively), and this was reflected on frequency of angina and need for sublingual nitrates per week which showed significant decrease in group A (p-value = .001).

Conclusion

As a non-invasive treatment modality EECP is very effective in improving the symptoms of angina and heart failure when combined with medical treatment in patients with ICM after CABG.

Treatment of Inoperable Coronary Disease and Refractory Angina: Spinal Stimulators, Epidurals, Gene Therapy, Transmyocardial Laser, and Counterpulsation

Intractable angina from refractory coronary disease is a severe form of myocardial ischemia for which revascularization provides no prognostic benefit. Inoperable coronary disease is also accompanied by a “vicious cycle” of myocardial dystrophy from a chronic alteration of the cardiac sympathetic tone and sensitization of damaged cardiac tissues. Several adjunctive treatments have demonstrated efficacy when revascularization is either unsuccessful or contraindicated. Spinal cord stimulation modifies the neurologic input and output of the heart by delivering a very low dose of electrical current to the dorsal columns of the high thoracic spinal cord. Neural fibers then release CGRP and other endogenous peptides to the coronary circulation reducing myocardial oxygen demand and enhancing vasodilation of collaterals to improve the myocardial blood flow of the most diseased regions of the heart. Randomized study has shown the survival data at five years is comparable to bypass for high-risk patients. Transmyocardial laser revascularization creates small channels into ischemic myocardium in an effort to enhance flow though studies have shown no improvement in prognosis over medical therapy alone. Enhanced external counterpulsation uses noninvasive pneumatic compression of the legs to improve diastolic filling of the coronary vessels and promote development of collateral flow. The compressor regimen requires thirty-five hours of therapy over a seven-week treatment period. Therapeutic angiogenesis requires injection of cytokines to promote neovascularization and improve myocardial perfusion into the regions affected by chronic ischemia. Phase 3 trials are pending. High thoracic epidural blockade produces a rapid and potent sympatholysis, coronary vasodilation and reduced myocardial oxygen demand in refractory coronary disease. This technique can be used as an adjunct to bypass surgery or medical therapy in chronic or acute unstable angina. Epidurals are easy to perform and often available for outpatient or inpatient use. The rapid anti-ischemic effect may complement therapeutic angiogenesis or other interventions with delayed onset to clinical benefit. A new era for interventional and implant cardiology is beginning to emerge as more clinicians, including cardiologists, gradually learn new procedures to safely provide more therapeutic options for patients suffering refractory angina.

Extracorporeal shockwave myocardial therapy is efficacious in improving symptoms in patients with refractory angina pectoris--a multicenter study

OBJECTIVE

Medically refractory angina remains a significant health concern despite major advances in revascularization techniques and emerging medical therapies. We aimed to determine the safety and efficacy of extracorporeal shockwave myocardial therapy (ESMT) in managing angina pectoris.

METHODS

A single-arm multicenter prospective study was designed aiming to determine the safety and efficacy of ESMT. Patients of functional Canadian Cardiovascular Society class II-IV, despite stable and optimal medical management, with documented myocardial segments with reversible ischemia and/or hibernation on the basis of echocardiography/single-photon emission computerized tomography (SPECT) were enrolled from 2010 to 2012. A total of 111 patients were enrolled, 33 from Indonesia, 21 from Malaysia, and 57 from Philippines. Patients underwent nine cycles of ESMT over 9 weeks. Patients were followed up for 3-6 months after ESMT treatment. During follow-up, patients were subjected to clinical evaluation, the Seattle Angina Questionnaire, assessment of nitrate intake, the 6-min walk test, echocardiography, and SPECT.

RESULTS

The mean age of the population was 62.9±10.9 years. The summed difference score on pharmacologically induced stress SPECT improved from 9.53±17.87 at baseline to 7.77±11.83 at follow-up (P=0.0086). Improvement in the total Seattle Angina Questionnaire score was seen in 83% of patients (P<0.0001). Sublingual nitroglycerin use significantly decreased (1.14±1.01 tablets per week at baseline to 0.52±0.68 tablets per week at follow-up; P=0.0215). There were no changes in left ventricular function on echocardiography (0.33±9.97, P=0.93). The Canadian Cardiovascular Society score improved in 74.1% of patients.

CONCLUSION

This multicenter prospective trial demonstrated that ESMT is both a safe and an efficacious means of managing medically refractory angina.

Noncoronary Collateral Myocardial Blood Flow: The Human Heart's Forgotten Blood Supply

The “noncoronary collateral circulation” (NCCC) or “noncoronary collateral myocardial blood flow” (NCCMBF), reaches the heart through a micro-vascular network arising from the bronchial, esophageal, pericardial, diaphragmatic, and aortic arteries. The left and right internal thoracic arteries (ITAs) along with their collateral branches also serve as a source of NCCMBF-a feature seen in other mammals. Under certain circumstances the ITAs have a high potential for developing collateral branches. In the case of severe Leriche syndrome or with chronic obstruction of the abdominal aorta, the ITAs can serve as the main or even sole source of blood supply to the lower limbs. It is also possible for the ITAs to develop angiographically visible branches that directly connect with the coronary arteries. In ischemic conditions there is a functional, ischemia-reducing extracardiac coronary artery supply via natural ipsilateral ITA anastomosis. To date we know little about NCCMBF and its potential benefits in clinical applications, which makes this a challenging and intriguing field of research. This paper reviews all available data on noncoronary collateral blood supply to the human heart.

Transmyocardial laser revascularization versus medical therapy for refractory angina

BACKGROUND

This is an update of a review previously published in 2009. Chronic angina and advanced forms of coronary disease are increasingly more frequent. In spite of the improvement in the efficacy of available revascularization treatments, a subgroup of patients continue suffering from refractory angina. Transmyocardial laser revascularization (TMLR) has been proposed to improve the clinical situation of these patients.

OBJECTIVES

To assess the effects (both benefits and harms) of TMLR versus optimal medical treatment in people with refractory angina who are not candidates for percutaneous coronary angioplasty or coronary artery bypass graft, in alleviating angina severity, reducing mortality and improving ejection fraction.

SEARCH METHODS

We searched the following resources up to June 2014: the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, the metaRegister of Controlled Trials database, ClinicalTrials.gov, and the WHO International Clinical Trials Registry. We applied no languages restrictions. We also checked reference lists of relevant papers.

SELECTION CRITERIA

We selected studies if they fulfilled the following criteria: randomized controlled trials (RCTs) of TMLR, by thoracotomy, in patients with Canadian Cardiovascular Society or New York Heart Association angina grade III-IV who were excluded from other revascularization procedures.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data for each trial about the population and interventions compared and assessed the risk of bias of the studies, evaluating randomisation sequence generation, allocation concealment, blinding (of participants, personnel and outcome assessors), incomplete outcome data, selective outcome reporting, and other potential sources of bias.

MAIN RESULTS

From a total of 502 references, we retrieved 47 papers for more detailed evaluation. We selected 20 papers, reporting data from seven studies, which included 1137 participants, of which 559 were randomized to TMLR. Participants and professionals were not blinded, which suggests high risk of performance bias. Overall, 43.8% of participants in the treatment group decreased two angina classes, as compared with 14.8% in the control group: odds ratio (OR) 4.63, 95% confidence interval (CI) 3.43 to 6.25), and heterogeneity was present. Mortality by intention-to-treat analysis was similar in both groups at 30 days (4.0% in the TMLR group and 3.5% in the control group), and one year (12.2% in the TMLR group and 11.9% in the control group). However, the 30-day mortality as-treated was 6.8% in the TMLR group and 0.8% in the control group (pooled OR was 3.76, 95% CI 1.63 to 8.66), mainly due to a higher mortality in participants crossing from standard treatment to TMLR. The assessment of subjective outcomes, such as improvement in angina, was affected by a high risk of bias and this may explain the differences found. Other adverse events such as myocardial infarction, arrhythmias or heart failure, were not considered in this review, as they were not predefined outcomes in trials design and they show a high inconsistency across studies. No new trials on transmyocardial laser revascularization have been published in the last ten years and it is very unlikely that new research will be undertaken in this field.

AUTHORS' CONCLUSIONS

This review shows that risks associated with TMLR outweigh the potential clinical benefits. Subjective outcomes are subject to high risk of bias and no differences were found in survival, but a significant increase in postoperative mortality and other safety outcomes suggests that the procedure may pose unacceptable risks.

Transcatheter treatment for refractory angina with the Coronary Sinus Reducer

AIMS

To evaluate the clinical efficacy of the coronary sinus (CS) Reducer in attenuating angina severity in patients suffering from severe refractory angina.

METHODS AND RESULTS

Patients with refractory angina, objective evidence of myocardial ischaemia and no option for revascularisation were treated with CS Reducer implantation at two medical centres. Six-month follow-up evaluation consisted of clinical assessment of angina severity. Objective assessment of ischaemia at six-month follow-up was performed in one of the two centres. Successful CS Reducer implantation was achieved in 21 of 23 eligible patients, at both centres. No device-related adverse effects were observed during the procedure or the follow-up period. Canadian Cardiovascular Society (CCS) score diminished from a mean of 3.3 at baseline to 2.0 at six months (n=20, p<0.01), exercise duration was prolonged from 3:16 to 5:16 min (min:sec; n=8, p=0.05). Thallium SPECT summed stress score and summed difference score were both reduced (n=9, 21.5±10 vs.13.2±9, p=0.01, and 11.1±6 vs. 4.7±4, p=0.007, respectively). Wall motion score index at peak dobutamine infusion was also significantly improved (n=8, 1.9±0.4 vs. 1.4±0.4, p=0.046).

CONCLUSIONS

CS Reducer implantation was safe and resulted in significant improvement of angina class. The results of the ongoing randomised sham-control trial will address the concern regarding the possible placebo effect, and hopefully further support our encouraging observations.

[Long-term results of catheter ablation of atrial fibrillation: cure or just palliation?]

Knowing the pitfalls when evaluating the long-term results after catheter ablation of atrial fibrillation enables a critical analysis of the outcome presented in numerous studies on this topic. Nevertheless, catheter ablation is a long-term successful and safe therapeutic procedure for symptomatic atrial fibrillation, especially for patients with paroxysmal atrial fibrillation. In patients with persistent symptomatic atrial fibrillation, the decision for ablation has to be made with caution due to a higher recurrence rate and higher likelihood for multiple procedures.

Safety and efficacy of extracorporeal shock wave myocardial revascularization therapy for refractory angina pectoris

OBJECTIVE

To assess the safety and efficacy of extracorporeal shockwave myocardial revascularization (ESMR) therapy in treating patients with refractory angina pectoris.

PATIENTS AND METHODS

A single-arm multicenter prospective trial to assess safety and efficacy of the ESMR therapy in patients with refractory angina (class III/IV angina) was performed. Screening exercise treadmill tests and pharmacological single-photon emission computed tomography (SPECT) were performed for all patients to assess exercise capacity and ischemic burden. Patients were treated with 9 sessions of ESMR to ischemic areas over 9 weeks. Efficacy end points were exercise capacity by using treadmill test as well as ischemic burden on pharmacological SPECT at 4 months after the last ESMR treatment. Safety measures included electrocardiography, echocardiography, troponin, creatine kinase, and brain natriuretic peptide testing, and pain questionnaires.

RESULTS

Fifteen patients with medically refractory angina and no revascularization options were enrolled. There was a statistically significant mean increase of 122.3±156.9 seconds (38% increase compared with baseline; P=.01) in exercise treadmill time from baseline (319.8±157.2 seconds) to last follow-up after the ESMR treatment (422.1±183.3 seconds). There was no improvement in the summed stress perfusion scores after pharmacologically induced stress SPECT at 4 months after the last ESMR treatment in comparison to that at screening; however, SPECT summed stress score revealed that untreated areas had greater progression in ischemic burden vs treated areas (3.69±6.2 vs 0.31±4.5; P=.03). There was no significant change in the mean summed echo score from baseline to posttreatment (0.4±5.1; P=.70). The ESMR therapy was performed safely without any adverse events in electrocardiography, echocardiography, troponins, creatine kinase, or brain natriuretic peptide. Pain during the ESMR treatment was minimal (a score of 0.5±1.2 to 1.1±1.2 out of 10).

CONCLUSION

In this multicenter feasibility study, ESMR seems to be a safe and efficacious treatment for patients with refractory angina pectoris. However, larger sham-controlled trials will be required to confirm these findings.

Long-term success and follow-up after atrial fibrillation ablation

Atrial fibrillation (AF) is the most prevalent sustained arrhythmia in clinical practice. It is associated with significant morbidity and mortality and has been identified as an independent risk factor for ischemic stroke and thromboembolic events. Catheter ablation has become an established rhythm control therapy in patients with highly symptomatic drug-refractory AF. The definition of ablation success remains controversial since current symptom-based or intermittent electrocardiogram monitoring strategies fail to sufficiently disclose rhythm outcome. This failure is mainly related to the high incidence of asymptomatic AF recurrences, the unpredictable nature of arrhythmia relapses, and the poor correlation of symptoms and AF episodes. There is a clear correlation between the intensity of the monitoring strategy and the sensitivity for it to detect arrhythmia recurrences. Furthermore, several clinical studies assessing the long-term efficacy of catheter ablation procedures have reported late AF recurrences in patients who were initially considered responders to catheter ablation. In certain subsets of patients, precise long-term monitoring may help to guide therapy, e.g. patients in whom withdrawal of antithrombotic therapy may be considered if they are free of arrhythmia recurrences. Recently, sub-cutaneous implantable cardiac monitors (ICM) have been introduced for prolonged and continuous rhythm monitoring. The performance of a leadless ICM equipped with a dedicated AF detection algorithm has recently been assessed in a clinical trial demonstrating a high sensitivity and overall accuracy for identifying patients with AF. The clinical impact of ICM-based follow-up strategies, however, has to be evaluated in prospective clinical trials.

Therapeutic goals in patients with refractory chronic angina

Refractory angina presents a major clinical challenge for everyday medical practice. Despite the widespread use of statins and improvements in revascularization techniques, a substantial proportion of patients with preserved left ventricular function and no life-threatening arrhythmias remain symptomatic, with severe debilitating angina. Because the rate of major cardiac events in this population is relatively low, the major aim of therapy should be not only to prolong survival but also to improve quality of life. The cornerstone of therapy for all these patients should be the aggressive modification of risk factors using evidence-based treatment, with the aim of stabilizing the disease process and improving overall survival. No opportunity for revascularization should be overlooked. Complementary approaches should be implemented to raise the angina threshold by either reducing oxygen demand or improving hemodynamics to increase myocardial oxygen supply. This review provides an update on therapeutic techniques and goals, and reinforces the need for a multidisciplinary approach to the management of patients with refractory angina.

Chronic coronary artery disease: diagnosis and management

Coronary artery disease (CAD) is the single most common cause of death in the developed world, responsible for about 1 in every 5 deaths. The morbidity, mortality, and socioeconomic importance of this disease make timely accurate diagnosis and cost-effective management of CAD of the utmost importance. This comprehensive review of the literature highlights key elements in the diagnosis, risk stratification, and management strategies of patients with chronic CAD. Relevant articles were identified by searching the PubMed database for the following terms: chronic coronary artery disease or stable angina. Novel imaging modalities, pharmacological treatment, and invasive (percutaneous and surgical) interventions have revolutionized the current treatment of patients with chronic CAD. Medical treatment remains the cornerstone of management, but revascularization continues to play an important role. In the current economic climate and with health care reform very much on the horizon, the issue of appropriate use of revascularization is important, and the indications for revascularization, in addition to the relative benefits and risks of a percutaneous vs a surgical approach, are discussed.

Transmyocardial laser revascularization versus medical therapy for refractory angina

BACKGROUND

Chronic angina and advanced forms of coronary disease are increasingly more frequent. Although the improved efficacy of available revascularization treatments, a subgroup of patients present with refractory angina. Transmyocardial laser revascularization (TMLR) has been proposed to improve the clinical situation of these patients.

OBJECTIVES

To assess the efficacy and safety of TMLR versus optimal medical treatment in patients with refractory angina in alleviating the severity of angina and improving survivorship and heart function.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials on The Cochrane Library (Issue 2 2007), MEDLINE (January 2006 to June 2007), EMBASE ( 2004 to June 2007) and ongoing studies were sought using the metaRegister of Controlled Trials database (mRCT) and ClinicalTrials.gov databases. No languages restrictions were applied. Reference lists of relevant papers were also checked.

SELECTION CRITERIA

Studies were selected if they fulfilled the following criteria: randomized controlled trials of TMLR, by thoracotomy, in patients with angina grade III-IV who were excluded from other revascularization procedures. From a total of 181 references, 20 papers were selected, reporting data from seven studies.

DATA COLLECTION AND ANALYSIS

Two reviewers abstracted data from selected papers; . The reviewers performed independently both quality assessment and data extraction. Selected studies present methodological weaknesses. None of them fulfilled all the quality criteria.

MAIN RESULTS

Seven studies (1137 participants of which 559 randomized to TMLR) were included. Overall, 43.8 % of patients in the treatment group decreased two angina classes as compared with 14.8 % in the control group, odds ratio (OR) of 4.63 (95% confidence interval (CI) 3.43 to 6.25), and heterogeneity was statistically significant. Mortality by intention-to-treat analysis at both 30 days (4.0 % in the TMLR group and 3.5 % in the control group) and 1 year (12.2 % in the TMLR group and 11.9 % in the control group) was similar in both groups. The 30-days mortality as treated was 6.8% in TMLR group and 0.8% in the control group, showing a statistically significant difference. The pooled OR was 3.76 (95% CI 1.63 to 8.66), because of the higher mortality in patients crossing from standard treatment to TMLR.

AUTHORS' CONCLUSIONS

There is insufficient evidence to conclude that the clinical benefits of TMLR outweigh the potential risks. The procedure is associated with a significant early mortality.

Ventral cardiac denervation increased right coronary arterial blood flow

BACKGROUND

Cardiac denervation accompanied with coronary artery bypass surgery has been widely performed for the treatment of vasospastic angina associated with atherosclerotic coronary artery disease. However, the effect of cardiac denervation on phasic coronary blood flow patterns of the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX) and right coronary artery (RCA) remains unknown. This study aimed to investigate the effect of cardiac denervation on phasic coronary blood flow patterns of the LAD, LCX and RCA.

METHODS

Phasic coronary blood flow patterns were analyzed using three flow probes placed around the LAD, LCX and RCA with and without LAD stenosis. Ventral cardiac denervation (VCD) was performed in 8 pigs, and 16 pigs were used as control subjects. Autonomic activities before and after the VCD were quantified by wavelet analysis of heart rate variability.

RESULTS

The mean LAD flow (34.4+/-9.4 to 32.6+/-7.1 ml/min, p=0.638) and mean LCX flow (26.3+/-10.2 to 27.2+/-6.0 ml/min, p=0.825) showed no significant change after VCD, while the mean RCA flow (31.3+/-9.0 to 38.2+/-11.2 ml/min, p=0.003) significantly increased. The hemodynamic variables in the VCD group were well maintained after creation of LAD stenosis, while they deteriorated in the control group. The low-frequency components, high-frequency components and their ratio did not change after VCD.

CONCLUSIONS

VCD prevented the deterioration of cardiac function after creation of an LAD stenosis and resulted in an increase of the mean RCA flow. VCD did not affect autonomic nervous system activity.

Enhanced external counterpulsation for the treatment of angina pectoris

The treatment of refractory chronic angina pectoris presents an increasing problem for all physicians caring for patients with coronary artery disease because of the large number of individuals who have either failed multiple revascularization procedures or are not appropriate candidates for such procedures. The aim of this study was to review the safety, efficacy, and clinical applicability of a noninvasive technique (external counterpulsation) for the treatment of angina pectoris. A MEDLINE search for all English language abstracts, meeting presentations, journal articles, and reviews from 1960 through December 2005 was conducted. Of the 194 citations in the literature, 60 appeared before 1983 when the enhanced version of the technique (the one that is presently used) was first reported. Criteria for further evaluation of the 134 post-1983 citations were either (1) randomized trial, (2) observational study of at least 10 patients, or (3) investigations into possible mechanisms. Of the 134 citations, 45 were used for data extraction. Observational studies from the United States, Asia, and Europe have demonstrated improvement in symptoms, reduction in anginal episodes, better quality of life, and improved exercise performance in over 5000 patients. The only randomized study (Multicenter Study of Enhanced External Counterpulsation) confirmed these findings as well as the continuation of clinical benefits at least 1 year posttreatment. Although the mechanisms by which diastolic augmentation achieves these beneficial results are still under investigation, this is a promising noninvasive therapy in a group of patients with limited treatment options.

Method for inducing the growth of new arteries in the myocardium

OBJECTIVE

The creation of new coronary arteries has long been an objective of cardiac research. I describe a method for creating new blood vessels in the myocardium of the left ventricular wall in animals.

METHODS

The myocardium was pierced by a fistula. Then a biodegradable hydrogel fiber with antithrombogenic and nonadhesive properties was inserted into the fistula with a venous catheter. Nine dogs were used. Three fibers were inserted in each heart, and two additional punctures were made and left empty as controls.

RESULTS

During absorption of the fiber, the luminal surface of the fistula became lined with endothelial cells and developed many openings to capillary blood vessels of the myocardium naturally. Three straight fibers were inserted so they intersected in the myocardium. They created a new branched vessel. The fistulas had connections to original coronary arteries and worked as new arteries to supply blood to the area where they were created.

CONCLUSIONS

It was possible to create new blood vessels in the myocardium in animals.

A Blinded, Randomized, Placebo-Controlled Trial of Percutaneous Laser Myocardial Revascularization to Improve Angina Symptoms in Patients With Severe Coronary Disease

OBJECTIVES

This study was a randomized, patient- and evaluator-blinded, placebo-controlled trial in patients treated using percutaneous myocardial laser revascularization.

BACKGROUND

Previous studies using similar therapies have been confounded by placebo bias.

METHODS

A total of 298 patients with severe angina were randomly assigned to receive low-dose or high-dose myocardial laser channels or no laser channels, blinded as a sham procedure. The primary end point was the change in exercise duration from baseline examination to six months.

RESULTS

The incidence of 30-day death, stroke, myocardial infarction, coronary revascularization, or left ventricular perforation occurred in two patients in the placebo, eight patients in the low-dose, and four patients in the high-dose groups (p = 0.12); 30-day myocardial infarction incidence was higher in patients receiving either low-dose or high-dose laser (nine patients) compared with placebo (no patients, p = 0.03). At six months, there were no differences in the change in exercise duration between those receiving a sham (28.0 s, n = 100), low-dose laser (33.2 s, n = 98), or high-dose laser (28.0 s, n = 98, p = 0.94) procedure. There were also no differences in the proportion of patients improving to better than Canadian Cardiovascular Society class III angina symptoms at six months. The follow-up visual summed stress single-photon-emission computed tomography scores were not significantly different from baseline in any group and were no different between groups. The modest improvement in angina symptoms assessed by the Seattle Angina Questionnaire also was not statistically different among the arms.

CONCLUSIONS

Treatment with percutaneous myocardial laser revascularization provides no benefit beyond that of a similar sham procedure in patients blinded to their treatment status.

The prospective clinical and scintigraphic assessment of patients with preserved left ventricular systolic function after transmyocardial laser revascularisation

AIM

To analyse the clinical outcome and myocardial perfusion and function after transmyocardial revascularisation (TMR) in patients with normal left ventricular function and multivessel coronary artery disease non-amenable for standard revascularisation.

METHOD AND RESULTS

Twenty three severely symptomatic patients (CCS score median 4) with normal left ventricular systolic function but coronaries non-amenable for either PTCA or CABG were subjected to TMR. The angina score, left ventricular systolic and diastolic function in radionuclide ventriculography at rest, exercise tolerance and myocardial perfusion--Thallium-201 SPECT (adenosine stress 74 and 37 MBq under nitrate cover) were evaluated before and 3, 6, 12 months post-operatively. After an average of 40 +/- 12 (range 14-56) TMR channels angina score decreased significantly (p< 0.0001) and the exercise tolerance increased (from 6.0 +/- 4.5 to 9.1 +/- 4.6 after 6 months, p< 0.05) in 21 patients. During the follow up period two patients had a myocardial infarction and one committed suicide after 6 months. Ejection fraction dropped significantly only after 1 year post-TMR from 70 +/- 13 to 63 +/- 0.13%, p < 0.05. The overall perfusion improved initially in 14 patients with subsequent deterioration in time. The changes in segmental perfusion were not associated with the symptomatic improvement.

CONCLUSION

Transmyocardial revascularisation in patients with normal ejection fraction may improve the angina class, exercise tolerance and overall but not segmental perfusion and does not show any immediate effect on left ventricular function.

Totally endoscopic robot-assisted transmyocardial revascularization

OBJECTIVE

Laser transmyocardial revascularization is an emerging therapy for intractable angina stemming from diffuse, small-vessel coronary disease not amenable to percutaneous coronary intervention or coronary bypass grafting. Presently, this therapy is delivered through a median sternotomy or left thoracotomy. In this pilot study, we sought to combine the advantages of a dexterous robotic surgical platform with a flexible fiberoptic laser to develop a minimally invasive approach toward transmyocardial revascularization.

METHODS

A flexible fiberoptic holmium:yttrium-aluminum-garnet laser probe (CardioGenesis Corporation, Foothill Ranch, Calif), deployed with the da Vinci surgical robotic system (Intuitive Surgical, Sunnyvale, Calif), was used to create transmyocardial channels through all left ventricular wall regions in 5 canine subjects. The channels were localized, quantified, and histologically analyzed to assess distribution, dimensions, and transmurality.

RESULTS

Transmyocardial channels were successfully created in all 6 defined left ventricular wall segments by using this minimally invasive approach without port repositioning, instrument exchange, or probe modifications. Gross pathologic and histologic analyses confirmed the uniform distribution of 1.0-mm transmural channels in all left ventricular regions. No direct pressure, topical hemostatic agents, or suture repairs were required for hemostasis. No significant hemodynamic instability or sustained arrhythmias were encountered at any time during the procedures.

CONCLUSIONS

We report the first use of a prototype flexible fiberoptic laser probe deployed by the da Vinci surgical robotic system to successfully perform totally endoscopic off-pump transmyocardial revascularization in a canine model, demonstrating the feasibility, precision, and safety of this approach. Refinement of this minimally invasive technique may reduce the morbidity of open-chest transmyocardial revascularization and facilitate its use as sole therapy or as an adjunct to percutaneous coronary interventions.

Meta-analysis of survival and relief of angina pectoris after transmyocardial revascularization

A meta-analysis of 7 randomized trials involving 1,053 patients was performed to evaluate the effect of transmyocardial laser revascularization as the sole procedural intervention on survival and angina relief. At 1 year, transmyocardial laser revascularization produced a significant improvement in angina class (p <0.0001) but no improvement in survival (p = 0.75).

Thermal microdebridement does not affect the time zero biomechanical properties of human patellar tendons

BACKGROUND

Thermal microdebridement for the treatment of chronic tendinopathy has recently been introduced. The effect of thermal microdebridement on the biomechanical properties of human tendons, however, remains unknown.

HYPOTHESIS

Thermal microdebridement does not affect the biomechanical properties of human patellar tendons in a cadaveric model at the time of initial treatment.

STUDY DESIGN

Controlled laboratory study.

METHODS

The central 15 mm of 12 matched, human (mean age, 71 years; 8 male, 4 female), fresh-frozen patellar tendons was divided into 3 equal 5-mm specimens. The treatment group (n = 12) underwent thermal microdebridement with a radiofrequency probe. A sham treatment group (n = 12) underwent insertion of a deactivated probe. The control group (n = 12) underwent no treatment. After treatment, each specimen was tested to failure in a servo-hydraulic materials testing machine at an elongation rate of 3 mm/s. One-way repeated measures analysis of variance was used to determine differences between groups.

RESULTS

No significant difference in ultimate stress at failure, elastic modulus, strain energy density, or strain at maximum load was found between the groups. The ultimate stress at failure for the treatment, sham, and control groups was 61.0, 66.7, and 63.0 MPa, respectively (P = .653), and the strain at maximum load was 0.12, 0.11, and 0.09, respectively (P = .279).

CONCLUSIONS

Thermal microdebridement does not affect the biomechanical properties of cadaveric human patellar tendons at the time of initial treatment.

CLINICAL RELEVANCE

It may be safe to proceed with aggressive rehabilitation after thermal microdebridement of the patellar tendon. However, the results in this cadaveric model should be interpreted with caution. Additional studies using an in vivo model will be required to completely assess the effects of thermal microdebridement on the biomechanical properties of human patellar tendons.

Improved myocardial function after transmyocardial laser revascularization according to cine magnetic resonance in a porcine model

OBJECTIVE

This study was undertaken to demonstrate that transmyocardial laser revascularization of hypoperfused myocardium improves regional and global myocardial function.

METHODS

Cine magnetic resonance imaging was used to monitor regional wall thickening (in millimeters) and cardiac output (in milliliters per kilogram per minute). Cine magnetic resonance imaging was performed before and 8 weeks after transmyocardial laser revascularization was applied to the hypoperfused lateral wall of the left ventricle (target area) in a porcine model (n = 9, transmyocardial laser revascularization group). A second group of animals was left untreated (n = 8, control group).

RESULTS

Regional wall thickening in the target area improved after transmyocardial laser revascularization (0.7 +/- 0.3 mm to 3.7 +/- 1.9 mm, P <.02) and was significantly higher (P <.01) after transmyocardial laser revascularization than in the control group, in which it did not improve (0.5 +/- 0.6 mm to 0.5 +/- 1.2 mm). Accordingly, cardiac output and microsphere-derived myocardial blood flows were significantly higher than in the control group (P <.01), and the amount of triphenyltetrazolium chloride-stained myocardium was lower (P <.01).

CONCLUSION

Cine magnetic resonance imaging demonstrates improved global and regional myocardial function after transmyocardial laser revascularization in a porcine model.

Ablation for atrial fibrillation: are cures really achieved?

During the past 10 years numerous studies on the treatment of paroxysmal atrial fibrillation (AF) by right and left atrial ablation procedures have been published. The results of studies based on follow-up periods of a few months have been repeatedly interpreted as providing evidence for curative therapy. However, insufficient focus on the variability of the natural history of paroxysmal AF, the inadequate detection of silent arrhythmic events, the eclectic post-interventional use of antiarrhythmic drugs, and the lack of appropriate control groups make the reports unconvincing. Randomized controlled trials are needed to confirm postulated long-term cure rates for AF.