Transmyocardial revascularization with a carbon dioxide laser in patients with end-stage coronary artery disease

Refractory angina pectoris: a 20-year (2003-2022) bibliometric analysis

Background

The increasing number of patients with refractory angina pectoris, combined with the aging population and improved survival rates among coronary heart disease patients, presents a significant challenge in contemporary cardiovascular medicine. The treatment of refractory angina has been an ongoing area of exploration, yet a comprehensive analysis of the existing literature on this topic is currently lacking. Therefore, this study aims to provide the first bibliometric analysis of publications related to refractory angina.

Methods

A systematic search was conducted in the Web of Science database to identify articles related to refractory angina published between 2003 and 2022. The inclusion criteria were limited to articles and reviews written in English. CiteSpace software was utilized to conduct a collaborative network analysis of countries/regions, institutions and authors, co-occurrence analysis of keywords, and co-citation analysis of authors and references.

Results

A total of 1,386 publications were identified, with an annual publication volume exhibiting fluctuation over time. American and European countries and institutions demonstrated a leading position in terms of research output. Henry TD emerged as the most prolific researcher in the field, while Mannheimer C received the highest number of citations. The primary research hotspot within this field focused on the treatment of refractory angina, with recent emphasis on emerging treatments such as stem cell therapy and the coronary sinus reducer. A significant number of clinical trials have been conducted, with a continuous focus on patient benefits, quality of life, and survival prognosis.

Conclusion

Significant progress has been made in the field of refractory angina pectoris in recent years. Novel treatment methods, including spinal cord stimulation, enhanced external counterpulsation, stem cell therapy, and the coronary sinus reducer, hold promising therapeutic prospects. However, further high-quality evidence-based research is essential to support these emerging interventions. Additionally, the development of comprehensive evidence-based guidelines for refractory angina treatment is crucial. Such guidelines would provide clinicians with a framework to navigate the complexities of treatment choices and optimize patient care in this challenging condition.

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.

Management of refractory angina: an update

Despite the use of anti-anginal drugs and/or percutaneous coronary interventions (PCI) or coronary artery bypass grafting, the proportion of patients with coronary artery disease who have daily or weekly angina ranges from 2% to 24%. Refractory angina refers to long-lasting symptoms (for >3 months) due to established reversible ischaemia, which cannot be controlled by escalating medical therapy with the use of 2nd- and 3rd-line pharmacological agents, bypass grafting, or stenting. While there is uncertain prognostic benefit, the treatment of refractory angina is important to improve the quality of life of the patients affected. This review focuses on conventional pharmacological approaches to treating refractory angina, including guideline directed drug combination and dosages. The symptomatic and prognostic impact of advanced and novel revascularization strategies such as chronic total occlusion PCI, transmyocardial laser revascularization, coronary sinus occlusion, radiation therapy for recurrent restenosis, and spinal cord stimulation are also covered and recommendations of the 2019 ESC Guidelines on the Diagnosis and Management of Chronic Coronary Syndromes discussed. Finally, the potential clinical use of current angiogenetic and stem cell therapies in reducing ischaemia and/or pain is evaluated.

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.

Improving the Design of Future PCI Trials for Stable Coronary Artery Disease: JACC State-of-the-Art Review

The role of percutaneous coronary interventions in addition to medical therapy for patients with stable coronary artery disease continues to be debated in routine clinical practice, despite more than 2 decades of randomized controlled trials. The residual uncertainty arises from particular challenges facing revascularization trials. Which endpoint do doctors care about, and which do patients care about? Which participants should be enrolled? What background medical therapy should we use? When is placebo control relevant? In this paper, we discuss how these questions can be approached and examine the merits and disadvantages of possible options. Engaging multiple stakeholders, including patients, researchers, regulators, and funders, to ensure the design elements are methodologically valid and clinically meaningful should be an aspirational goal in the development of future trials.

Refractory Angina: the Current State of Mechanical Therapies

PURPOSE OF REVIEW

Refractory angina (RA), which is characterized by tissue ischemia along with neurological, mitochondrial, and psychogenic dysfunction, is becoming a major cause of morbidity in patients with advanced coronary artery disease. In this review, we discuss in detail the invasive mechanical non-cell therapy-based options, the evidence behind these therapies, and future trends.

RECENT FINDINGS

There is extensive ongoing research in the areas of spinal-cord stimulation, transmyocardial laser revascularization, sympathectomy, angiogenesis, and other non-cell-based therapies to explore the best therapy for refractory angina. There is conflicting data in the literature suggesting subjective improvement in angina, but very few studies boast improvement in core objective parameters such as myocardial blood flow, survival, or rehospitalizations. Patients with refractory angina are a complex group of patients that need novel approaches to help alleviate their symptoms and reduce mortality. A carefully selected sequence of therapies may provide the best results in this patient population.

Transmyocardial revascularization (TMR): current status and future directions

Purpose

Cardiac surgeons are increasingly faced with a more complex patient who has developed a pattern of diffuse coronary artery disease (CAD), which is refractory to medical, percutaneous, and surgical interventions. This paper will review the clinical science surrounding transmyocardial revascularization (TMR) with an emphasis on the results from randomized controlled trials.

Methods

Randomized controlled trials which evaluated TMR used as sole therapy and when combined with coronary artery bypass grafting were reviewed. Pertinent basic science papers exploring TMR's possible mechanism of action along with future directions, including the synergism between TMR and cell-based therapies were reviewed.

Results

Two laser-based systems have been approved by the United States Food and Drug Administration (FDA) to deliver laser therapy to targeted areas of the left ventricle (LV) that cannot be revascularized using conventional methods: the holmium:yttrium-aluminum-garnet (Ho:YAG) laser system (CryoLife, Inc., Kennesaw, GA) and the carbon dioxide (CO₂) Heart Laser System (Novadaq Technologies Inc., (Mississauga, Canada). TMR can be performed either as a stand-alone procedure (sole therapy) or in conjunction with coronary artery bypass graft (CABG) surgery in patients who would be incompletely revascularized by CABG alone. Societal practice guidelines have been established and are supportive of using TMR in the difficult population of patients with diffuse CAD.

Conclusions

Patients with diffuse CAD have increased operative and long-term cardiac risks predicted by incomplete revascularization. The documented operative and long-term benefits associated with sole therapy and adjunctive TMR in randomized trials supports TMR's increased use in this difficult patient population.

Safety and efficacy of percutaneous intramyocardial bone marrow cell injection for chronic myocardial ischemia: Long-term results

BACKGROUND

Intramyocardial injection of bone marrow cells (BMC) in refractory angina patients with chronic myocardial ischemia has shown to be safe and improve clinical status during short-term follow-up. However, scarce data are available on long-term (>12 months) safety and efficacy. Therefore, the occurrence of clinical events and the long-term clinical effects of intramyocardial BMC injection were evaluated in patients with chronic myocardial ischemia up to 10 years after treatment.

METHODS AND RESULTS

Patients (n = 100, age 64 ± 9 years, male 88%) with chronic myocardial ischemia who underwent intramyocardial BMC injection between 2004 and 2010 were evaluated. During yearly outpatient clinic visits, the occurrence of clinical events was documented. In addition, clinical status was assessed according to the Canadian Cardiovascular Society (CCS) score and quality of life was measured using the Seattle Angina Questionnaire. These parameters were evaluated at baseline and during the first year, followed by cross-sectional long-term follow-up which was performed in 2011 and 2014. No adverse events considered related to the procedure occurred during 10 years of follow-up. Observed annual mortality rate and annual myocardial infarction rate were 3.8% and 1.9% per year, respectively. When compared to baseline, CCS class and quality of life remained significantly better during 5-year follow-up after BMC treatment (both P < 0.05).

CONCLUSIONS

The present long-term follow-up study shows that intramyocardial BMC injection in patients with chronic myocardial ischemia is safe and improves both angina complaints and quality of life up to 5 years after BMC treatment.

Clinical outcomes meta-analysis: measuring subendocardial perfusion and efficacy of transmyocardial laser revascularization with nuclear imaging

INTRODUCTION

Randomized and nonrandomized clinical trials have tried to assess whether or not TMR patients experience an increase in myocardial perfusion. However there have been inconsistencies reported in the literature due to the use of different nuclear imaging modalities to test this metric. The primary purpose of this meta-analysis was to determine whether SPECT, MUGA and PET scans demonstrate changes in myocardial perfusion between lased and non-lased subjects and whether laser type affects myocardial perfusion. The secondary purpose was to examine the overall effect of laser therapy on clinical outcomes including survival, hospital re-admission and angina reduction.

METHODS

Sixteen studies were included in the primary endpoint analysis after excluding all other non-imaging TMR papers. Standardized mean difference was used as the effect size for all quantitative outcomes and log odds ratio was used as the effect size for all binary outcomes.

RESULTS

Statistically significant improvements in myocardial perfusion were observed between control and treatment groups in myocardial perfusion at 6-month follow up using PET imaging with a porcine model. However non-significant differences were observed in patients at 3 and 12 months using SPECT, PET or MUGA scans. Both CO₂ and Ho:YAG laser systems demonstrated an increase in myocardial perfusion however this effect was not statistically significant. In addition both laser types displayed statistically significant decreases in patient angina at 3, 6 and 12 months but non-significant increases in survival rates and decreases in hospital re-admissions.

CONCLUSION

In order to properly assess myocardial perfusion in TMR subjects, subendocardial perfusion needs to be analyzed via nuclear imaging. PET scans can provide this level of sensitivity and should be utilized in future studies to monitor and detect perfusion changes in lased and non-lased subjects.

Advancements in pharmacotherapy for angina

INTRODUCTION

Angina pectoris is the most prevalent symptomatic manifestation of ischemic heart disease, frequently leads to a poor quality of life, and is a major cause of medical resource consumption. Since the early descriptions of nitrite and nitrate in the 19th century, there has been considerable advancement in the pharmacologic management of angina. Areas covered: Management of chronic angina is often challenging for clinicians. Despite introduction of several pharmacological agents in last few decades, a significant proportion of patients continue to experience symptoms (i.e., refractory angina) with subsequent disability. For the purpose of this review, we searched PubMed and Cochrane databases from inception to August 2016 for the most clinically relevant publications that guide current practice in angina therapy and its development. In this article, we briefly review the pathophysiology of angina and mechanism-based classification of current therapy. This is followed by evidence-based insight into the traditional and novel pharmacotherapeutic agents, highlighting their clinical usefulness. Expert opinion: Considering the wide array of available therapies with different mechanism efficacy and limiting factors, a personalized approach is essential, particularly for patients with refractory angina. Ongoing research with novel pharmacologic modalities is likely to provide new options for management of angina.

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.

Epidemiology and pathogenesis of diffuse obstructive coronary artery disease: the role of arterial stiffness, shear stress, monocyte subsets and circulating microparticles

Despite falling age-adjusted mortality rates coronary artery disease (CAD) remains the leading cause of death worldwide. Advanced diffuse CAD is becoming an important entity of modern cardiology as more patients with historical revascularisation no longer have suitable anatomy for additional procedures. Advances in the treatment of diffuse obstructive CAD are hampered by a poor understanding of its development. Although the likelihood of developing clinically significant (obstructive) CAD is linked to traditional risk factors, the morphology of obstructive CAD among individuals is highly variable - some patients have diffuse stenotic disease, while others have a focal stenosis. This is challenging to explain in mechanistic terms as vascular endothelium is equally exposed to injury stimulants. Patients with diffuse disease are at high risk of adverse outcomes, particularly if unsuitable for revascularisation. We searched multiple electronic databases (MEDLINE, EMBASE and the Cochrane Database) and reviewed the epidemiology, pathogenesis and prognosis relating to advanced diffuse CAD with particular focus on the role of endothelial shear stress, large artery stiffness, monocyte subsets and circulating microparticles. Key messages Although traditional CAD risk factors correlate strongly with disease severity, significant individual variation in disease morphology exists. Advanced, diffuse CAD is difficult to treat effectively and can significantly impair quality of life and increases mortality. The pathophysiology associated with the progression of CAD is the result of complex maladaptive interaction between the endothelium, cells of the immune system and patterns of blood flow.

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.

Transmyocardial Revascularization: Peril and Potential

Transmyocardial laser revascularization is a technique for the treatment of patients with chronic angina pectoris that is refractory to medical therapy and who are not eligible for surgical intervention. Percutaneous myocardial revascularization is a less-invasive catheter-based procedure that has been adapted from transmyocardial laser revascularization. Six prospective randomized clinical trials have been performed with transmyocardial laser revascularization and 5 have been performed using percutaneous myocardial revascularization. All of the transmyocardial laser revascularization and 4 of the percutaneous myocardial revascularization studies showed a significant improvement in angina class; however, results for improved survival, increased exercise tolerance, improved ejection fraction, and improved myocardial perfusion were less definitive. Transmyocardial laser revascularization has significant potential for morbidity and mortality. This article summarizes the results of the randomized trials, explains the current theories for the mechanism of transmyocardial laser revascularization, and discusses its current role in treatment for patients, considering the evidence that currently exists.

Effect of angina under-recognition on treatment in outpatients with stable ischaemic heart disease

AIMS

Almost a third of outpatients with chronic coronary artery disease (CAD) report having angina in the prior month, which is frequently under-recognized by their cardiologists. Whether under-recognition is associated with less treatment escalation to control angina, and potential underuse of treatment, is unknown.

METHODS AND RESULTS

Patients with CAD from 25 US cardiology outpatient practices completed the Seattle Angina Questionnaire (SAQ) prior to their clinic visit, and angina was categorized as daily, weekly, monthly and no angina. Cardiologists (n=155) independently quantified patients' angina, blinded to patients' SAQ scores. Under-recognition was defined as the physician reporting a lower category of angina frequency than the patient. Among 1257 patients with CAD, 411 reported angina in the past month, of whom 178 (43.3%) patients were under-recognized. Treatment escalation-defined as intensification (up-titration or addition) of antianginal medications, referral for diagnostic testing or revascularization, or hospital admission-occurred in 106 (25.8%) patients with angina. Patients with under-recognized angina were less likely to get treatment escalation than patients whose angina was appropriately recognized (8.4% vs 39.1%, P<0.001). In a hierarchical multivariable logistic regression model adjusting for demographic and clinical characteristics, as well as the burden of angina, under-recognition remained strongly associated with a lack of treatment escalation (adjusted OR 0.10, 95% CI 0.04-0.21, P<0.001).

CONCLUSIONS

Under-recognition of angina in cardiology outpatient practices is associated with less aggressive treatment escalation and may lead to poorer angina control. Standardizing clinical recognition of angina using validated tools could reduce under-recognition of angina, facilitate treatment, and potentially improve outcomes.

Robotically assisted, completely endoscopic transmyocardial revascularization is feasible

OBJECTIVE

The purpose of this study was to assess the feasibility of an endoscopic, optical-fiber-based, laser delivery system (LDS) developed to perform sole-therapy transmyocardial revascularization (TMR) in a totally endoscopic, robotically assisted operation.

METHODS

Forty-two patients were enrolled in a multicenter, prospective, single-arm clinical trial conducted at four US centers between 2005 and 2007. Transmyocardial revascularization was performed completely endoscopically with robotic assistance, introducing the Holmium:Yttrium aluminum garnet (YAG) LDS via a 5-mm port. Completion of the operation endoscopically defined procedural success. Clinical data were recorded before, during, and at least 30 days after the procedure.

RESULTS

All patients had Canadian Cardiovascular Score angina class IV at baseline. The mean ejection fraction was 49% (range [R], 28-71), the mean age was 59.1 years (R, 36-80), 71% (30/42) were men, 86% (36/42) underwent previous coronary artery bypass grafting surgery, and 76% (32/42) underwent prior coronary stenting. Procedural success was accomplished in 93% (39/42). For the procedural successes, the mean number of TMR channels was 32 (R, 16-50), the median operative time was 88 minutes (R, 48-250 minutes), and the median length of stay postoperatively was 2.5 days (R, 1-10). There was no operative or 30-day mortality, and no patient received any transfusion. At 30 days, freedom from major adverse cardiac events was 95% (two patients had transient congestive heart failure). At the median 6-month follow-up (single-center data, n = 12), the mean (SD) Canadian Cardiovascular Score angina score was 1.3 (0.05) (P < 0.001 vs baseline).

CONCLUSIONS

Robotically assisted TMR can be performed using an endoscopic, optical-fiber-based LDS, with high procedural success, avoidance of early adverse clinical events, and potential for successful angina relief.

Alternative therapy for medically refractory angina: enhanced external counterpulsation and transmyocardial laser revascularization

Medically refractory angina pectoris (RAP) is defined by presence of severe angina with objective evidence of ischemia and failure to relieve symptoms with coronary revascularization. Medication and invasive revascularization are the most common approaches for treating coronary artery disease (CAD). Although symptoms are eliminated or alleviated by these invasive approaches, the disease and its causes are present after treatment. New treatment approaches are needed to prevent the disease from progressing and symptoms from recurring. External enhanced counterpulsation therapy provides a treatment modality in the management of CAD and can complement invasive revascularization procedures. Data support that it should be considered a first-line treatment of RAP.

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.

Predictors of long-term clinical endpoints in patients with refractory angina

Background

Clinical outcomes in patients with refractory angina (RA) are poorly characterized and variably described. Using the Duke Database for Cardiovascular Disease (DDCD), we explored characteristics that drive clinical endpoints in patients with class II to IV angina stabilized on medical therapy.

Methods and Results

We explored clinical endpoints and associated costs of patients who underwent catheterization at Duke University Medical Center from 1997 to 2010 for evaluation of coronary artery disease (CAD) and were found to have advanced CAD ineligible for additional revascularization, and were clinically stable for a minimum of 60 days. Of 77 257 cardiac catheterizations performed, 1908 patients met entry criteria. The 3‐year incidence of death; cardiac rehospitalization; and a composite of death, myocardial infarction, stroke, cardiac rehospitalization, and revascularization were 13.0%, 43.5%, and 52.2%, respectively. Predictors of mortality included age, ejection fraction (EF), low body mass index, multivessel CAD, low heart rate, diabetes, diastolic blood pressure, history of coronary artery bypass graft surgery, cigarette smoking, history of congestive heart failure (CHF), and race. Multivessel CAD, EF<45%, and history of CHF increased risk of mortality; angina class and prior revascularization did not. Total rehospitalization costs over a 3‐year period per patient were $10 185 (95% CI 8458, 11912) in 2012 US dollars.

Conclusions

Clinically stable patients with RA who are medically managed have a modest mortality, but a high incidence of hospitalization and resource use over 3 years. These findings point to the need for novel therapies aimed at symptom mitigation in this population and their potential impact on health care utilization and costs.

Transmyocardial revascularization devices: technology update

Transmyocardial laser revascularization (TMR) emerged as treatment modality for patients with diffuse coronary artery disease not amendable to percutaneous or surgical revascularization. The procedure entails the creation of laser channels within ischemic myocardium in an effort to better perfuse these areas. Currently, two laser devices are approved by the US Food and Drug Administration for TMR – holmium:yttrium–aluminum–garnet and CO₂. The two devices differ in regard to energy outputs, wavelengths, ability to synchronize with the heart cycle, and laser–tissue interactions. These differences have led to studies showing different efficacies between the two laser devices. Over 50,000 procedures have been performed worldwide using TMR. Improvements in angina stages, quality of life, and perfusion of the myocardium have been demonstrated with TMR. Although several mechanisms for these improvements have been suggested, evidence points to new blood vessel formation, or angiogenesis, within the treated myocardium, as the major contributory factor. TMR has been used as sole therapy and in combination with coronary artery bypass grafting. Clinical studies have demonstrated that TMR is both safe and effective in angina relief long term. The objective of this review is to present the two approved laser devices and evidence for the safety and efficacy of TMR, along with future directions with this technology.

Surgical therapy for heart failure

Today's healthcare delivery system is challenged with an escalating number of heart failure patients who have exhausted medical therapy and overwhelmed the limits of organ transplantation. Scientific and technological advances over the last 20 years have now brought new surgical options to this vast patient population, ranging from ventricular restoration surgery to surgical gene therapy and beyond. This article reviews the myriad of surgical options that are available to these patients, their benefits and shortcomings, as well as potential future directions.

Long-term outcomes after transmyocardial revascularization

BACKGROUND

Two independent reports documented substantially higher operative mortality associated with transmyocardial revascularization (TMR) when used in isolation than that reported in the premarket clinical trials. To clarify the state of the art, this article assesses temporal trends in the use of TMR, short-term and long-term outcomes, and outcomes stratified by procedure type (TMR only and TMR + coronary artery bypass graft [CABG]) and by the 2 specific TMR devices.

METHODS

The study population included all patients undergoing TMR in isolation or in combination with CABG at 435 cardiothoracic hospitals in the United States participating in the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) from January 2000 through November 2006 (n = 15,386). Analysis of long-term outcomes was accomplished through linkage to Medicare claims data. Short-term and long-term (7 years) adverse outcomes were assessed and compared between the 2 TMR device types.

RESULTS

The use of TMR in conjunction with CABG surgery is increasing. This study showed modest differences in short-term morbidity and mortality between the 2 devices. In combination with CABG, after risk adjustment, patients treated with the holmium:YAG laser (experienced a higher rate of operative mortality (3.5% vs 2.5%; adjusted hazard ratio 1.39, 95% confidence level 1.03 to 1.87) but no difference in the composite short-term rate of major morbidity or mortality, compared with the Heart Laser CO2 transmyocardial revascularization system (PLC Medical Systems, Inc, Milford, MA). However, there were no clinically meaningful differences in long-term results.

CONCLUSIONS

Modest differences in short-term morbidity and mortality between the 2 devices suggest the usefulness of further research.

Therapeutic angiogenesis for myocardial ischemia revisited: basic biological concepts and focus on latest clinical trials

Therapeutic angiogenesis is based on the premise that the development of new blood vessels can be augmented by exogenous administration of the appropriate growth factors. Over the last years, successful preclinical studies and promising results of early clinical trials have created great excitement about the potential of therapeutic angiogenesis for patients with advanced ischemic heart disease. The authors provide an overview of the biology of angiogenesis, the basic characteristics of angiogenic factors, and the different routes of their delivery. They discuss experimental studies in animal models of myocardial ischemia and outline available clinical studies on therapeutic angiogenesis for myocardial ischemia. Related safety issues are also addressed followed by a critical perspective about the future of proangiogenic therapies for ischemic cardiovascular disorders. Despite the established proof of concept and reasonable safety, however, results of the latest trials on therapeutic angiogenesis for myocardial ischemia have provided inconsistent results and the definite means of inducing clinically useful therapeutic angiogenesis remain elusive. More studies are required to gain further insights into the biology of angiogenesis and address pharmacological limitations of current approaches of angiogenic therapy. The authors hope and envisage that in the not-too-distant future, these investigative efforts will lead to important new strategies for treatment of myocardial ischemic syndromes. Means of non-invasive individualized pharmacological therapeutic neovascularization may be the next major advance in the treatment of ischaemic heart disease.

Refractory post-infarction myocardial ischemia: treatment potential

The treatment of recurrent, refractory post-infarction myocardial ischemia remains an unresolved clinical problem. Aggressive pharmaceutical therapy has limited effectiveness, while percutaneous coronary intervention or coronary artery bypass graft surgery are not possible in these patients, due to various reasons. Currently, alternative methods for refractory angina treatment are being developed for patients with chronic stable angina. The potential of these methods in patients with acute coronary syndrome should be investigated in the future studies.

Does laser type impact myocardial function following transmyocardial laser revascularization?

BACKGROUND

Transmyocardial laser revascularization (TMR) is currently clinically performed with either a CO(2) or Ho:YAG laser for the treatment of severe angina. While both lasers provide symptomatic relief, there are significant differences in the laser-tissue interactions specific to each device that may impact their ability to enhance the perfusion of myocardium and thereby improve contractile function of the ischemic heart.

METHODS

A porcine model of chronic myocardial ischemia was employed. After collecting baseline functional data with cine magnetic resonance imaging (MRI) and dobutamine stress echo (DSE), 14 animals underwent TMR with either a CO(2) or Ho:YAG laser. Transmural channels were created with each laser in a distribution of 1/cm(2) in the ischemic zone. Six weeks post-treatment repeat MRI as well as DSE were obtained after which the animals were sacrificed. Histology was preformed to characterize the laser-tissue interaction.

RESULTS

CO(2) TMR led to improvement in wall thickening in the ischemic area as seen with cine MRI (40.3% vs. baseline, P < 0.05) and DSE (20.2% increase vs. baseline, P < 0.05). Ho:YAG treated animals had no improvement in wall thickening by MRI (-11.6% vs. baseline, P = .67) and DSE (-16.7% vs. baseline, P = 0.08). Correlative semi-quantitative histology revealed a significantly higher fibrosis index in Ho:YAG treated myocardium versus CO(2) (1.81 vs. 0.083, P < 0.05).

CONCLUSIONS

In a side-by-side comparison CO(2) TMR resulted in improved function of ischemic myocardium as assessed by MRI and echocardiography. Ho:YAG TMR led to no improvement in regional function likely due to concomitant increase in fibrosis in the lasered area.