Device-based Therapies Research Articles

The future of lasers in onychomycosis

Introduction: Laser therapy is one of the most promising device-based therapies for onychomycosis. To date, reported clinical efficacies, as well as anecdotal clinical results, have varied greatly, and the specific mechanism of action has not been well-elucidated. Methods: Here, we provide an overview of the mechanisms of action and detailed analysis of the technical parameters involved in creating a laser that will be successfully fungicidal in onychomycosis. Results: This review provides important insight into why the efficacies of laser studies reported to date vary so greatly and what is critical in order to obtain high efficacy in the clinical treatment of onychomycosis. Conclusions: There is substantial opportunity to improve the targeting and anti-targeting properties of lasers to address the specific considerations required to treat onychomycosis and, more generally, other dermal pathogens.

Reducing asthma attacks in patients with severe asthma: The role of bronchial thermoplasty.

Asthma remains one of the most common diseases worldwide and results in significant societal health care costs and in morbidity and mortality to those afflicted. Despite currently available medications, 5-10% of patients with asthma have severe disease with debilitating symptoms and/or life-threatening exacerbations. Bronchial thermoplasty is a device-based therapy with proven efficacy in this subgroup of patients. Thus far, bronchial thermoplasty has been shown to reduce exacerbations and to improve important measures of asthma control. The purpose of this article is to review the pathophysiology of severe asthma, including the role of airway smooth muscle cells and the procedural aspects of bronchial thermoplasty, and to review the evidence behind this important therapy.

Transcatheter Structural Heart Interventions for the Treatment of Chronic Heart Failure.

Heart failure (HF) is a major cause of mortality and morbidity in developed countries.1 In the past 2 decades, improvements in drug therapy and the widespread use of implantable cardioverter-defibrillators and cardiac resynchronization therapy devices has improved the prognosis of HF patients.2 However, morbidity and mortality rates remain high, with an estimated 5-year mortality rate exceeding 50% coupled with significant rehospitalization rates. Several transcatheter implantable devices have recently emerged in an attempt to improve the prognosis and quality of life of such patients. We reviewed the current literature on interventional chronic HF. The review focus on the description of the devices and main procedural characteristics, patient eligibility, procedural results, and clinical outcomes associated with such devices. This article will focus only on mechanical transcatheter structural heart interventions for treating chronic HF. Devices used for percutaneously delivering biological therapies and interventions for acute HF fall beyond the scope of this article. Several surgical and device-based therapies have emerged in an attempt to reverse LV remodeling by restoring normal LV architecture and reducing LV volumes and wall stress. Among these surgical therapies, the most commonly used is the endoventricular circular patch plasty or Dor procedure, which consists of excluding the akinetic septal and apical ventricular regions by performing aneurysm resection with the insertion of a circular pericardial patch. Although this procedure showed promising results in multicenter registries,3 the only randomized trial—Surgical Treatment for Ischemic Heart Failure (STICH)—failed to demonstrate differences in the composite end point of death and rehospitalization for cardiac causes between surgical ventricular restoration+coronary artery bypass graft versus coronary artery bypass graft alone.4 However, some subgroups, experienced significant benefits with surgical ventricular restoration.5,6 In this regard, the parachute device (Cardiokinetix, Inc, Menlo Park, CA) emerged as a percutaneous device with the purpose of …

Autonomic Regulation Therapy in Heart Failure.

Autonomic regulation therapy (ART) is a rapidly emerging therapy in the management of congestive heart failure secondary to systolic dysfunction. Modulation of the cardiac neuronal hierarchy can be achieved with bioelectronics modulation of the spinal cord, cervical vagus, baroreceptor, or renal nerve ablation. This review will discuss relevant preclinical and clinical research in ART for systolic heart failure. Understanding mechanistically what is being stimulated within the autonomic nervous system by such device-based therapy and how the system reacts to such stimuli is essential for optimizing stimulation parameters and for the future development of effective ART.

Clinical Management and Prevention of Sudden Cardiac Death

Despite the revolutionary advancements in the past 3 decades in the treatment of ventricular tachyarrhythmias with device-based therapy, sudden cardiac death (SCD) remains an enormous public health burden. Survivors of SCD are generally at high risk for recurrent events. The clinical management of such patients requires a multidisciplinary approach from postresuscitative care to a thorough cardiovascular investigation in an attempt to identify the underlying substrate, with potential to eliminate or modify the triggers through catheter ablation and ultimately an implantable cardioverter-defibrillator (ICD) for prompt treatment of recurrences in those at risk. Early recognition of low left ventricular ejection fraction as a strong predictor of death and association of ventricular arrhythmias with sudden death led to significant investigation with antiarrhythmic drugs. The lack of efficacy and the proarrhythmic effects of drugs catalyzed the development and investigation of the ICD through several major clinical trials that proved the efficacy of ICD as a bedrock tool to detect and promptly treat life-threatening arrhythmias. The ICD therapy is routinely used for primary prevention of SCD in patients with cardiomyopathy and high risk inherited arrhythmic conditions and secondary prevention in survivors of sudden cardiac arrest. This compendium will review the clinical management of those surviving SCD and discuss landmark studies of antiarrhythmic drugs, ICD, and cardiac resynchronization therapy in the primary and secondary prevention of SCD.

Autonomic modulation for the management of patients with chronic heart failure.

Dysregulation of the autonomic nervous system in heart failure (HF) has received considerable attention during the past 3 decades, largely because of the well-recognized association between increased sympathetic activity and the elaboration of biologically active molecules, collectively referred to as neurohormones, that help to maintain cardiovascular homeostasis through increased volume expansion, peripheral arterial vasoconstriction, and increased myocardial contractility. However, high and sustained levels of these biologically active molecules (eg, norepinephrine, angiotensin II, aldosterone) are overtly toxic to the heart and circulation.1 These and other insights have led to the clinical use of neurohormonal antagonists, such as angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, aldosterone antagonists, and β-blockers to treat patients with HF with a reduced left ventricular ejection fraction (LVEF).1 The effectiveness of these pharmacological agents is predominantly because of their ability to directly antagonize the deleterious effects of excessive sympathetic and renin–angiotensin activation. However, the current guideline-directed medical therapy (GDMT) in patients with HF fails to completely restore normal autonomic balance disrupted as a part of HF pathophysiology. During the last decade, a novel approach has generated widespread interest: modulation of the autonomic nervous system as a result of either a one-time intervention (eg, denervation) or of ongoing active therapy (eg, electric stimulation) as a means of further diminishing the sympathovagal imbalance that develops in HF.2,3 Of note, therapeutic neuromodulation with device-based therapies, either with spinal cord stimulation (SCS) or vagal stimulation (VS), has been used safely in patients with chronic pain, epilepsy, and depression, since the 1980s. As noted above, HF with a reduced LVEF is associated with sustained activation of the sympathetic nervous system that is accompanied by a withdrawal of parasympathetic tone. Impaired arterial baroreflexes have been proposed as an important mechanism that contributes to the sympathovagal imbalance present in HF4 …

MicroRNA Therapeutics for Cardiac Regeneration.

It is estimated that a typical myocardial infarction results in the loss of approximately one billion functional cardiomyocytes, which are replaced by a non-contractile fibrous scar, eventually leading to heart failure. The currently available surgical, drug, and device-based therapies cannot reverse the loss of functional myocardium, which is the fundamental cause of the problem. As a result of this lack of an available medical solution, heart failure has evolved into a global epidemic. Therefore, the development of regenerative therapeutic strategies to halt the progression of ischemic heart disease to advanced heart failure has become one of the most urgent medical needs of this century. This review first addresses the extremely limited endogenous regenerative capacity of the mammalian heart, and the benefits and limitations of stem cell-based therapies for cardiac repair. Then it discusses the known roles of microRNAs after cardiac injury and the possibility of employing microRNAs to enhance cardiac regeneration.

Necessity of magnetic resonance imaging examinations after permanent pacemaker implantation

Magnetic resonance imaging (MRI) examinations as a powerful diagnostic tool have dramatically increased. More than 370,000 patients received implantable device-based therapy in the USA in 2003 [1]. However, patients receiving permanent pacemaker implantation (PMI) are contraindicated for MRI recommended by the U.S. Food and Drug Administration [1,2] and by device manufacturers [3–5]. There is an estimation that up to 75% of patients with pacemakers develop an indication for MRI over the lifetime of device owing to medical comorbidities [6,7] and an estimated 200,000 patients might have benefited from MRI.

Interventional and device-based autonomic modulation in heart failure.

"Heart failure is an increasingly prevalent disease with high mortality and public health burden. It is associated with autonomic imbalance characterized by sympathetic hyperactivity and parasympathetic hypoactivity. Evolving novel interventional and device-based therapies have sought to restore autonomic balance by neuromodulation. Results of preclinical animal studies and early clinical trials have demonstrated the safety and efficacy of these therapies in heart failure. This article discusses specific neuromodulatory treatment modalities individually-spinal cord stimulation, vagus nerve stimulation, baroreceptor activation therapy, and renal sympathetic nerve denervation."

Effectiveness of device-based therapy for conservative management of low back pain.

[Purpose] Device based therapy for low back pain (LBP) involves quantitative assessment of muscle strength, resistance and lumbar motion and tailoring the rehabilitation protocol based on this objective assessment. The purpose of this study was to determine the effectiveness of device based therapy for LBP. [Subjects and Methods] In this retrospective study, clinical data of 235 patients who underwent device-based physiotherapy for low back pain was reviewed. Pre and post-treatment outcome measures for pain (visual analogue scale or VAS score), disability (Oswestry disability index) and functional ability were compared to determine effectiveness of device-based physiotherapy at the end of 6 weeks of treatment. [Results] All outcome measures including VAS Score and mean Oswestry Disability Score showed significant improvement at the end of 6 weeks of device-based physical therapy. Before treatment, 73% of patients had moderate to severe disability which reduced to 28% after treatment. [Conclusion] Device-based therapy is effective in relieving pain, improving function and reducing disability in patients with low back pain in the short term. Device-based therapy may help to objectively evaluate the function of the spine and paraspinal muscles and help the therapist tailor treatment accordingly.

Continuous Flow Left Ventricular Assist Device Therapy: A Focused Review on Optimal Patient Selection and Long-Term Follow-up Using Echocardiography

Despite widespread awareness and use of scientifically proven life-prolonging medical and device-based therapies over the last two decades, heart failure remains a leading cause of morbidity, mortality, and health care expenditure in the United States. Mechanical circulatory support with a continuous-flow left ventricular assist device (CF-LVAD), either as a bridge to heart transplantation or as destination therapy, is an increasingly used treatment modality for patients with advanced heart failure syndromes that worsen despite their receiving standard therapies. CF-LVAD support creates unique hemodynamic alterations that must be understood to provide appropriate care for these patients before and after implantation. Echocardiography is essential in the evaluation of patients who are being considered for or are mechanically supported by CF-LVADs. Here we provide a focused clinical review on the use of echocardiography in two main aspects of the evaluation of these patients: (a) optimal patient selection for CF-LVAD support and (b) follow-up assessment of optimal pump function.

Heart Failure Issues and Management: A European Perspective

Heart failure poses an increasing problem for global health care systems. The epidemiological data which have been accrued over the last 30 years have predominantly been accumulated from experience within North America and Europe. The European experience in heart failure, although similar to that in North America, has recently demonstrated differences in hospitalization which may underlie the differences between health care system configurations. Despite the predicted increase in the number of patients affected by heart failure, over the last 30 years a clear management algorithm has evolved for the use of pharmacotherapies, device-based therapies, and mechanical therapies, including left ventricular assist devices and cardiac transplantation. Although the treatment of such patients has been clearly delineated in national and international guidelines, the underuse of all available and appropriate therapies remains a significant problem. The purpose of this review is to provide a European perspective on management of heart failure.

Real World Outcomes of Left Atrial Appendage Occlusion.

Percutaneous left atrial appendage occlusion (LAAO) is a device-based therapy for the prevention of stroke in patients with non-valvular atrial fibrillation (AF). Recently, the Watchman device (Boston Scientific, St Paul, MN, US) was approved in the US by the Food and Drug Administration (FDA) based on the results of two randomised clinical trials that evaluated LAAO in patients eligible for oral anticoagulation (OAC) therapy. However, in real-word clinical practice LAAO is typically offered to patients ineligible for OAC therapy, as they appear to have limited treatment options and consequently worse prognosis. Although LAAO has shown favourable clinical outcomes in OAC-ineligible patients in single or multicentre observational studies, these results need to be confirmed in randomised clinical trials.

Biofield Science and Healing: History, Terminology, and Concepts.

Biofield science is an emerging field of study that aims to provide a scientific foundation for understanding the complex homeodynamic regulation of living systems. By furthering our scientific knowledge of the biofield, we arrive at a better understanding of the foundations of biology as well as the phenomena that have been described as “energy medicine.” Energy medicine, the application of extremely low-level signals to the body, including energy healer interventions and bio-electromagnetic device-based therapies, is incomprehensible from the dominant biomedical paradigm of “life as chemistry.” The biofield or biological field, a complex organizing energy field engaged in the generation, maintenance, and regulation of biological homeodynamics, is a useful concept that provides the rudiments of a scientific foundation for energy medicine and thereby advances the research and practice of it. An overview on the biofield is presented in this paper, with a focus on the history of the concept, related terminology, key scientific concepts, and the value of the biofield perspective for informing future research.

Bronchial thermoplasty: a new therapeutic option for the treatment of severe, uncontrolled asthma in adults

Bronchial thermoplasty is a young yet promising treatment for severe asthma whose benefit for long-term asthma control outweighs the short-term risk of deterioration and hospitalisation in the days following the treatment. It is an innovative treatment whose clinical efficacy and safety are beginning to be better understood. Since this is a device-based therapy, the overall evaluation of risk-benefit is unlike that of pharmaceutical products; safety aspects, regulatory requirements, study design and effect size assessment may be unfamiliar. The mechanisms of action and optimal patient selection need to be addressed in further rigorous clinical and scientific studies. Bronchial thermoplasty fits in perfectly with the movement to expand personalised medicine in the field of chronic airway disorders. This is a device-based complimentary asthma treatment that must be supported and developed in order to meet the unmet needs of modern severe asthma management. The mechanisms of action and the type of patients that benefit from bronchial thermoplasty are the most important challenges for bronchial thermoplasty in the future.

Abstract 12158: Population Thresholds for Systematically Applying Nurse-Led Chronic Heart Failure Management Programs to Reduce Recurrent Hospitalization and Prolong Survival

Background: In many countries, a jurisdictional (regional or health fund membership) approach to applying nurse-led, multidisciplinary management programs for high risk individuals hospitalized with chronic heart failure (CHF) has led to their inconsistent application. A health service perspective was therefore used to determine the overall value of funding services for a whole population. Methods: Data from a contemporary study of the burden of CHF in Australia (population ~ 24 million of whom ~25% live in regional settings) to identify the number of de novo admissions for CHF per annum (n=19,397) were used. From these we estimated the proportion of cases readmitted (63% - all cause), days of related hospitalization (44,500 days from 5,300 admissions) and case-fatality (27%) within 12 months. Health economic data from a recent multicentre trial of CHF management were then applied to estimate the cost impact ($US) of applying gold-standard management to de novo CHF cases. Results: Total health care expenditure (excluding index admission and incremental CHF management) for managing de novo cases of CHF is estimated at ~$300 million/annum. Of this total, $240 million (68%) is attributable to hospital care plus device-based therapies. Applying nurse-led multidisciplinary CHF management to all cases (with up-titration of therapy and increased face-to-face and remote contacts as required) would cost ~ $35 million/annum. In order to achieve a cost-neutral state, this service would need to achieve a minimum reduction of 6,500 days (15% reduction) in recurrent hospital stay (all cause). At proven, evidence-based thresholds of impact, a 20% - 30% reduction in recurrent hospital stay would provide annual savings of $12 - 35 million/annum. A one third reduction in mortality at 12 months would also result in 2,100 lives saved at a minimum cost >$17,000 per annum (neutral impact on recurrent hospital stay). Conclusions: These data provide a compelling case for adopting a whole population/health care system approach to systematically applying CHF management programs to reduce recurrent hospital stay and mortality in de novo cases of CHF.

Bilateral or unilateral stimulation for baroreflex activation therapy.

Previous trials have shown that in patients with resistant hypertension device-based baroreflex activation therapy (BAT) can substantially reduce blood pressure. However, the fact that electrodes had to be implanted bilaterally may be a drawback for further development of the technique. In this study, we explored whether unilateral stimulation would produce comparable results as bilateral stimulation. In the Pivotal trial, treatment-resistant hypertensive patients were randomized to receive either immediate BAT or deferred BAT, that is, 6 months after implantation. We adjusted stimulation parameters individually so as to provide optimal baroreflex activation. Unilateral stimulation was applied unless bilateral stimulation resulted in a greater blood pressure reduction. When we pooled the 6-month data for the group with immediate BAT and the 12-month data for the group with deferred BAT, a total of 215 patients had been stimulated on one side only (127 at the right side and 88 at the left side), whereas 80 patients had been stimulated bilaterally. Although blood pressure and heart rate did not differ between the 2 groups at baseline, all these variables were significantly lower in the unilateral than in the bilateral group after the 6-month period. When we compared the effect of right-sided stimulation with those of either left-sided or bilateral stimulation, we found right-sided stimulation to be the most effective. We conclude that unilateral and in particular right-sided BAT has a more profound effect on blood pressure than bilateral or left-sided BAT. http://www.clinicaltrials.gov. Unique identifier: NCT00442286.

Critical review of bronchial thermoplasty: where should it fit into asthma therapy?

Bronchial thermoplasty is a device-based therapy for treatment of severe refractory asthma that uses radiofrequency energy to reduce airway smooth muscle and decrease bronchoconstriction. BT improves quality of life and decreases the rate of severe exacerbations with no known major long-term complications. The effectiveness of bronchial thermoplasty persists at least 5years after the treatment is completed. Further investigation is needed to better define the specific subpopulation of patients with severe asthma who would best benefit from this treatment.

Sympathetic activation in resistant hypertension: theory and therapy.

Resistant hypertension defined as requiring 3 or more complementary antihypertensive drugs at maximally tolerated doses accounts for approximately 3% to 4% of all cases of hypertension. Its increased incidence over the past decade is related to the increase in obesity in the Western world. There are a number of dietary factors that affect sympathetic tone including sodium intake apart from increased body mass. This article discusses the mechanisms of sympathetic stimulation and activation in the context of animal models and human studies. In addition, there is a review of clinical trials with and without device therapy that summarizes the clinical findings. Effective management should be based on pathophysiologic principles and a focus on blood pressure reduction to levels well below 150/90 mm Hg because outcome trial evidence and Food and Drug Administration guidance supports this construct. The key to success of device-based therapy depends on identifying the cohort with true resistant hypertension that can benefit from therapies that are adjuncts to pharmacotherapy. Physicians need to concentrate on educating the patient on lifestyle modifications and themselves on use of proper combinations of antihypertensive medications. If this approach fails to result in a safe level of blood pressure then the patient should be referred to a board-certified clinical hypertension specialist.

Use of cardiac implantable electronic devices in older adults with cognitive impairment.

Older adults with mild cognitive impairment (MCI) and dementia have cardiac comorbidities, making them eligible for device-based therapy for cardiac rhythm abnormalities.1-3 The risks and benefits of device implantation should be weighed carefully by pa tients with cognitive impairment, family members, and clinicians given the potential of these devices to have an impact on the quantity and quality of life. This study describes the epidemiology of cardiac implantable electronic devices among a population-based sample of older adults with and without cognitive impairment.