Topical Anti-ulcerogenic Effect of the Beta-adrenergic Blockers on Diabetic Foot Ulcers: Recent Advances and Future Prospectives.

BACKGROUND: Patients with diabetes suffer from major complications like Diabetic Retinopathy, Diabetic Coronary Artery Disease, and Diabetic Foot ulcers (DFUs). Diabetes complications are a group of ailments whose recovery time is especially delayed, irrespective of the underlying reason. The longer duration of wound healing enhances the probability of problems like sepsis and amputation. The delayed healing makes it more critical for research focus. By understanding the molecular pathogenesis of diabetic wounds, it is quite easy to target the molecules involved in the healing of wounds. Recent research on beta-adrenergic blocking drugs has revealed that these classes of drugs possess therapeutic potential in the healing of DFUs. However, because the order of events in defective healing is adequately defined, it is possible to recognize moieties that are currently in the market that are recognized to aim at one or several identified molecular processes. OBJECTIVE: The aim of this study was to explore some molecules with different therapeutic categories that have demonstrated favorable effects in improving diabetic wound healing, also called the repurposing of drugs. METHOD: Various databases like PubMed/Medline, Google Scholar and Web of Science (WoS) of all English language articles were searched, and relevant information was collected regarding the role of beta-adrenergic blockers in diabetic wounds or diabetic foot ulcers (DFUs) using the relevant keywords for the literature review. RESULT: The potential beta-blocking agents and their mechanism of action in diabetic foot ulcers were studied, and it was found that these drugs have a profound effect on diabetic foot ulcer healing as per reported literatures. CONCLUSION: There is a need to move forward from preclinical studies to clinical studies to analyze clinical findings to determine the effectiveness and safety of some beta-antagonists in diabetic foot ulcer treatment.

An Interesting Case of Treatment-Resistant Ventricular Tachycardia Secondary to Pheochromocytoma and Left Ventricular Non-compaction.

A 51-year-old patient was admitted with chest pain and broad complex ventricular tachycardia. He received three consecutive direct cardioversion (DC) shocks and was commenced on amiodarone infusion via a central venous catheter or central line (CVC). He responded to treatment and normal sinus rhythm (NSR) was achieved. He had elevated troponin I and underwent coronary angiogram which initially was thought to be responsible for his ventricular tachycardia. Coronary angiogram (CAG) showed unobstructed coronary arteries. He was recently diagnosed with pheochromocytoma and was commenced on Phenoxybenzamine 10 mg two months back. He developed ventricular tachycardia (VT) again the next day that did not respond to four consecutive direct cardioversion shocks (DC) and antiarrhythmic medications. He was intubated and ventilated to terminate his VT and was transferred to the intensive care unit (ICU). He remained intubated for 48 hours and he remained in NSR, after which he was extubated. He was commenced on bisoprolol and was later stepped down to the coronary care unit (CCU). Cardiac magnetic resonance imaging (CMR) showed left ventricular non-compaction (LVNC) or possibly myocarditis in view of patient's known history of pheochromocytoma. He was discussed with surgical team at another hospital for surgical resection of the adrenal tumor and had a few further runs of VT while he was waiting to be transferred. The patient finally underwent surgical resection of the tumor and was booked for implantable cardioverter defibrillator (ICD) in view of his VT. This was an interesting case of treatment-resistant VT driven by pheochromocytoma and LVNC, and it is important to be familiar with the fact that conventional therapies may fail in these patients and may require intubation and ventilation to terminate VT storms.

Cardiovascular Medication Use and Risk of Acute Exacerbation in Patients With Asthma-COPD Overlap (CVACO Study).

PURPOSE: Current clinical guidelines are unclear regarding the association of cardiovascular medication with the risk of acute exacerbation (AE) in patients with asthma-chronic obstructive pulmonary disease (COPD) overlap (ACO). METHODS: We conducted a retrospective cohort study by interrogating the claims database of Taipei Veterans General Hospital. Patients with coexistent fixed airflow limitation and asthma were enrolled as an ACO cohort between 2009 and 2017. Exposure to cardiovascular medications, including angiotensin converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), non-selective beta-blockers, cardioselective beta-blockers, dihydropyridine (DHP) calcium channel blockers (CCBs), and non-DHP CCBs, in 3-month period each served as time-dependent covariates. Patients receiving a cardiovascular medication ≥ 28 cumulative daily doses were defined as respective cardiovascular medication users. Patients were followed up until December 31, 2018. The primary endpoint was severe AE, defined as hospitalization or emergency department visit for either asthma, COPD, or respiratory failure. The secondary outcome was moderate AE. RESULTS: The final study cohort consisted of 582 ACO subjects, with a mean follow-up period of 2.98 years. After adjustment, ARB (hazard ratio [HR], 0.64, 95% confidence interval [CI], 0.44-0.93, P = 0.019), cardioselective beta-blocker (HR, 0.29, 95% CI, 0.11-0.72, P = 0.008) and DHP CCB (HR, 0.66, 95% CI, 0.45-0.97, P = 0.035) therapies were associated with lower risks of severe AE. ARB (HR, 0.42, 95% CI, 0.30-0.62, P < 0.001) and DHP CCB (HR, 0.55, 95% CI, 0.38-0.80, P = 0.002) therapies were associated with lower risks of moderate AE. Cardioselective beta-blockers, ARBs, and DHP CCBs were associated with lower risks of severe AE in frequent exacerbators. ACEI, non-selective beta-blocker, or non-DHP CCB use did not change the risk of severe AE. CONCLUSIONS: ARB, cardioselective beta-blocker, and DHP CCB therapies may lower the risk of AE in patients with ACO.

Rate control with intravenous diltiazem, verapamil, and metoprolol in acute atrial fibrillation with rapid ventricular rate.

INTRODUCTION: Diltiazem is a preferred agent for rate control in atrial fibrillation due to its quick onset, minimal side effects, and low cost. Due to its intermittent national shortage since February 2018, the utilization of intravenous metoprolol and verapamil has increased. This study investigated the effect of intravenous diltiazem, metoprolol, and verapamil on rate control in patients with atrial fibrillation with rapid ventricular rate. METHODS: This study was a retrospective, single-center, cohort study conducted in patients with acute atrial fibrillation receiving intravenous diltiazem, metoprolol, or verapamil for rapid ventricular rate between 1 January 2012 and 31 August 2018. The primary outcome was the incidence of patients who achieved a rate less than 100 bpm within 1 h of treatment. Secondary outcomes included time to achieve rate control, heart rate at 30 min and 1 h after administration, bradycardia and hypotension incidence, the requirement of other rate control agent(s), inpatient admission, length of stay, and mortality. RESULTS: A total of 73 patients were included in the study. At 1 h after receiving the initial rate control drug, there was no statistically significant difference between diltiazem, metoprolol, and verapamil in achieving rate control. Median time to ventricular rate control was 166 min in the diltiazem group, 297 min in the metoprolol group, and 100.5 min in the verapamil group. CONCLUSION: There was no difference in achieving rate control when using intravenous diltiazem, metoprolol, or verapamil. Any of the three rate control agents may be used for rate control. However, further studies are needed to determine which agent is superior for rate control.

Evolution of Knowledge in the Treatment of Long-Standing Atrial Fibrillation in a UK Tennis Champion.

During the last several decades, there have been major advances in the evolution of drug therapies for the rate management of atrial fibrillation (AF). Initially, the drug of choice was digoxin but currently, the drug of choice is beta-adrenergic blockers. Drug therapies for stroke prevention in AF have also evolved. Initially, the drug of choice was aspirin, then became warfarin, and now in the current era, there are newer oral anticoagulants, such as apixaban, which are the preferred drugs. In this case report, we present the details of a 79-year-old athletic man who developed palpitations due to rapid AF at age 31. At the time of his initial presentation, he was treated with digoxin and aspirin and has remained on these drugs to the present. In 1973, 28 years after his initial presentation, he became the United Kingdom (UK) amateur tennis champion in the 55 and over division at age 59.  At present, the clinical applications of advances in the management of AF should include quality of life considerations in the context of patient preferences. This patient is an active and vigorous 79-year-old man who plays competitive tennis and pickleball. He steadfastly adheres to an antediluvian regimen for the management of his AF, but this may be viewed in the context of the famous quotation by Bert Lance, Director of the Office of Management and Budget in the US under President Carter who said "sometimes, if it ain't broke, don't fix it." In addition to the evolution of drug therapies from digoxin to beta-adrenergic blockers for rate control as well as from aspirin to warfarin to apixaban for the prevention of stroke, there have been other recent remarkable advances. For example, recent promising findings from randomized trials include that early rhythm control was more effective than rate control as well as that cryoballoon ablation was superior to drug therapies. These findings require confirmation in additional randomized trials designed a priori to test these promising but unproven hypotheses.

Milestones in Heart Failure: How Far We Have Come and How Far We Have Left to Go.

Heart failure is a clinically complex syndrome that results due to the failure of the ventricles to function as pump and oxygenate end organs. The repercussions of inadequate perfusion are seen in the form of sympathetic overactivation and third spacing, leading to clinical signs of increased blood pressure, dyspnea, fatigue, palpitations, etc. This article provided a brief overview of the clinical syndrome of heart failure; its epidemiology, risk factors, symptoms, and staging; and the mechanisms involved in disease progression. This article also described several landmark trials in heart failure that tested the efficacy of first-line drugs such as beta-blockers, angiotensin receptor blockers, angiotensin-converting enzyme inhibitors, and the latest drugs in the field of heart failure: angiotensin receptor neprilysin inhibitors. Most studies described in this article were guideline-setting trials that revolutionized the practice of medicine and cardiology.

Beta-Adrenergic Blockers as a Potential Treatment for COVID-19 Patients.

More than 15 million people have been affected by coronavirus disease 2019 (COVID-19) and it has caused 640 016 deaths as of July 26, 2020. Currently, no effective treatment option is available for COVID-19 patients. Though many drugs have been proposed, none of them has shown particular efficacy in clinical trials. In this article, the relationship between the Adrenergic system and the renin-angiotensin-aldosterone system (RAAS) is focused in COVID-19 and a vicious circle consisting of the Adrenergic system-RAAS-Angiotensin converting enzyme 2 (ACE2)-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (which is referred to as the "ARAS loop") is proposed. Hyperactivation of the ARAS loop may be the underlying pathophysiological mechanism in COVID-19, and beta-adrenergic blockers are proposed as a potential treatment option. Beta-adrenergic blockers may decrease the SARS-CoV-2 cellular entry by decreasing ACE2 receptors expression and cluster of differentiation 147 (CD147) in various cells in the body. Beta-adrenergic blockers may decrease the morbidity and mortality in COVID-19 patients by preventing or reducing acute respiratory distress syndrome (ARDS) and other complications. Retrospective and prospective clinical trials should be conducted to check the validity of the hypothesis. Also see the video abstract here https://youtu.be/uLoy7do5ROo.

Use of beta-blockers for rosacea-associated facial erythema and flushing: A systematic review and update on proposed mode of action.

BACKGROUND: Flushing and erythema are frequent skin symptoms in rosacea. Because their adequate treatment remains a clinical challenge, new treatment options are explored, such as oral ß-blockers. OBJECTIVES: To evaluate the efficacy of oral ß-blockers for rosacea-associated facial flushing and erythema. METHODS: PubMed, Embase, Web of Science, and Cochrane Library were systematically searched, including studies providing original data on the efficacy of oral ß-blockers in rosacea patients with facial flushing and/or persistent erythema. Risk of bias was assessed using the Cochrane Risk of Bias tool, Newcastle-Ottawa scale, and Quality in Prognosis Studies tool. RESULTS: Nine studies evaluating the use of carvedilol, propranolol, nadolol, and ß-blockers in general were included. Articles studying carvedilol and propranolol showed a large reduction of erythema and flushing during treatment with a rapid onset of symptom control. Bradycardia and hypotension were the most commonly described adverse events. LIMITATIONS: Most studies had a retrospective design with a small sample size, and outcome measurement was often subjective. CONCLUSIONS: Oral ß-blockers could be an effective treatment option for patients with rosacea with facial erythema and flushing that does not respond to conventional therapy. Larger prospective trials with objective outcome assessment are needed to validate the promising results of these studies.

Use of beta-blocker types and risk of incident prostate cancer in a multiethnic population.

PURPOSE: Increased adrenergic innervation is observed in prostate cancer (CaP) and is associated with aggressive disease. Emerging evidence suggests that beta-adrenergic blockade inhibits CaP progression. However, the association between type of beta-blocker use and risk of incident CaP on initial prostate biopsy has not been investigated in multiethnic populations. MATERIALS AND METHODS: A retrospective study of racially/ethnically diverse men (64% African-American and Hispanic), who underwent initial prostate biopsy between 2006 and 2016 in a large healthcare system was performed. Oral use of beta-blocker type was assessed by reviewing active prescriptions within the 5-year period preceding initial biopsy. Patient demographics and clinical factors were collected. RESULTS: Of 4,607 men who underwent initial prostate biopsy, 4,516 met criteria and 2,128 had a biopsy positive for CaP; 20% high-risk, 41% intermediate-risk, and 39% low or very-low risk (National Comprehensive Cancer Network classification). Overall, 15% of patients were taking a beta-blocker prior to initial biopsy, with Metoprolol, Atenolol, and Carvedilol accounting for the majority. Of beta-blocker types, Atenolol alone was associated with a 38% reduction in odds of incident CaP (P= 0.01), with a 40% and 54% reduction in risks of National Comprehensive Cancer Network intermediate and high-risk CaP (P = 0.03 and P = 0.03, respectively) compared to men not taking a beta-blocker. Furthermore, longer duration of Atenolol use (3-5 years) was associated with a 54% and 72% reduction in intermediate and high-risk disease, (P = 0.03 and P = 0.03, respectively). CONCLUSIONS: Among beta blocker types, long-term Atenolol use is associated with a significant reduction in incident CaP risk on initial prostate biopsy for clinically-significant intermediate and high-risk disease compared to men not taking a beta-blocker.

Pulmonary and cardiac drugs: clinically relevant interactions.

Chronic heart and lung diseases are very common in the elderly population. The combination of chronic heart failure and chronic obstructive pulmonary disease (COPD) is also common and, according to current guidelines, these patients should be treated for both diseases. In patients with heart failure, beta-blockers are very important drugs because their use is associated with significantly improved morbidity and mortality. These beneficial effects were documented in patients with and without COPD, although theoretically there is a risk for bronchoconstriction, particularly with non-beta1 selective blockers. In COPD patients, long-acting sympathomimetics (LABA) improve lung function, dyspnea, and quality of life and their combination with a beta-blocker makes sense from a pharmacological and a clinical point of view, because any potential arrhythmogenic effects of the LABA will be ameliorated by the beta-blocker. Inhaled tiotropium, a long-acting muscarinic antagonist (LAMA), has been extensively investigated and no safety concerns were reported in terms of cardiac adverse effects. The same applies for the other approved LAMA preparations and LAMA-LABA combinations. Severe COPD causes air-trapping with increasing pressures in the thorax, leading to limitations in blood return into the thorax from the periphery of the body. This causes a decrease in stroke volume and cardiac index and is associated with dyspnea. All these adverse effects can be ameliorated by potent anti-obstructive therapy as recently shown by means of a LABA-LAMA combination.

A randomized controlled study comparing high-dose insulin to vasopressors or combination therapy in a porcine model of refractory propranolol-induced cardiogenic shock.

Context: Although cerebral perfusion (CP) is preserved across a wide range of mean arterial pressures (MAP) through cerebral-vascular autoregulation, the relationship between MAP and CP in refractory poison-induced cardiogenic shock (PICS) has never been studied. We compared the effects of therapies used in PICS: high-dose insulin (HDI), HDI plus norepinephrine (NE), and vasopressors alone (NE plus epinephrine (Epi)) on cerebral tissue oxygenation (PtO2). Methods: Fifteen swine were randomized to either HDI, HDI + NE, or NE + Epi. All animals received a propranolol infusion using an established model of toxicity. At primary toxicity (P1), defined as a 25% reduction in heart rate (HR) multiplied by MAP, the HDI and HDI + NE groups received HDI and the NE + Epi group received NE. Once a sustained MAP < 55 mmHg was reached (P2), the HDI group received saline (NS), the HDI + NE group received NE and the NE + Epi group received Epi until death or censoring. PtO2 and hemodynamic parameters including MAP, cardiac output (CO) and central venous pressure (CVP) were measured every 10 minutes. Glucose and potassium were measured at predetermined intervals. Results: Animals treated with HDI + NE maintained PtO2 over time more than the HDI-alone group. Due to rapid hemodynamic collapse, we were unable to analyze PtO2 data in the vasopressor only animals. Mean survival time was 1.9, 2.9 and 0.1 hours for the HDI, HDI + NE and NE + Epi groups, respectively. Survival time from P2 (sustained MAP <55 mmHg) to death or censoring was not different between HDI and HDI + NE groups. Conclusions: HDI + NE treatment was superior to HDI-alone at preserving PtO2 when MAP < 55 mmHg. We were unable to compare the PtO2 between the NE + Epi to the HDI or HDI + NE due to rapid decline in CO and death. If MAP is sustained at < 55 mmHg after maximizing HDI, adjunctive treatment with NE should be considered to preserve PtO2.

Inferential characterization of the dose-response relationships of neurohormonal antagonists in chronic heart failure: A novel approach based on large-scale trials with active comparators.

BACKGROUND: Current guidelines for the treatment of heart failure strongly recommend the use of inhibitors of the renin-angiotensin system and sympathetic nervous system in all patients with a reduced ejection fraction who can tolerate these drugs. Yet, there is no consensus about the efficacy of low doses of these drugs or the likely shape of the dose-response relationship for these agents. METHODS: Inferences were made by examining the effects of drugs in placebo-controlled trials before the protocol-specified opportunity for uptitration and by reassessing the results of large-scale trials with active comparators that inadvertently produced different intensities of neurohormonal blockade. RESULTS: In the case of inhibitors of the renin-angiotensin system, low starting doses appear to be effective in many patients, and 3-5 fold increases in dose do not have a mortality advantage over low doses. By contrast, in the case of beta-adrenergic blockers, although low starting doses appear effective in improving outcomes, achievement of target doses may yield substantial incremental mortality benefits, even such doses are accompanied by only small additional decreases in heart rate. CONCLUSION: When treating patients with heart failure to reduce mortality, the totality of evidence supports a relatively flat dose-response relationship for inhibitors of the renin-angiotensin system but a steep dose-response relationship for beta-adrenergic receptor blockers.

Preventing recurrent events in survivors of acute coronary syndromes in Australia: consensus recommendations using the Delphi process.

OBJECTIVE: There remain substantial gaps in implementation of evidence-based care in patients with acute coronary syndromes (ACS) in Australia, which contribute to high recurrent event rates. Improved translation of evidence into effective action is a key health-care priority. We engaged cardiovascular experts from across Australia to develop straightforward, easily actionable recommendations on key medications to use following ACS. METHODS: An eight-person steering committee (SC) reviewed the published evidence and developed an initial set of statements to be developed into consensus recommendations using a modified Delphi technique. A panel of 21 expert cardiologists in the ACS field (including the SC) voted on their level of agreement with the statements using a 6 point Likert scale. Statements that did not reach consensus (≥80% agreement) were reviewed by the SC, modified as appropriate based on input from the panel and circulated for re-voting. RESULTS: Twenty-eight statements were developed by the SC across six classes of medication: low-density lipoprotein (LDL) cholesterol lowering agents, aspirin, dual antiplatelet therapy, renin-angiotensin-aldosterone system inhibitors, beta blockers and "other". Twenty-six recommendations were endorsed by the voting panel; two statements did not reach consensus. CONCLUSIONS: Despite the extensive evidence base and detailed guidelines outlining best practice post ACS, there remain considerable gaps in translating these into everyday care. We used an internationally recognized technique to develop practical consensus recommendations on medical treatment following ACS. These simple, up-to-date recommendations aim to improve evidence-based medication use and thereby reduce the risk of future cardiovascular events for Australian patients with ACS.

Continuous-Infusion Labetalol vs Nicardipine for Hypertension Management in Stroke Patients.

BACKGROUND: Labetalol and nicardipine are antihypertensives commonly used in the management of elevated blood pressure (BP) following an acute stroke, but there is limited evidence to suggest which agent as a continuous infusion should be used preferentially in this setting. OBJECTIVE: This study aimed to compare the safety, efficacy, and ease of administration of continuous-infusion labetalol with continuous-infusion nicardipine following an acute stroke. METHODS: This retrospective cohort study of patients with acute ischemic stroke or intracerebral hemorrhage included patients if they received either study agent within 24 hours of admission. The primary outcome was percent time spent at goal BP. Secondary outcomes included time to goal BP, the number of dose adjustments, and use of rescue antihypertensives. RESULTS: The analysis included 99 patients who received labetalol- (n = 34) or nicardipine- (n = 65) continuous infusions. Intracerebral hemorrhage was the most common stroke subset (n = 81) followed by acute ischemic stroke (n = 18). There was no statistical difference in time at goal BP (labetalol 68.0%, nicardipine 67.0%; P = .885), rescue antihypertensive use (labetalol 14.7%, nicardipine 24.6%; P = .2570), time spent 10% above or below mean systolic BP (labetalol 35.5%, nicardipine 33.5%; P = .885), time to goal BP (labetalol 81.4 minutes, nicardipine 56.3 minutes; P = .162), and mean number of dose adjustments (labetalol 5.9, nicardipine 6.9; P = .262). CONCLUSIONS: Labetalol- and nicardipine-continuous infusions were comparable in the studied safety and efficacy outcomes including time at goal and BP variability. Further prospective studies are needed to validate these safety and efficacy findings and to assess clinical outcomes.

Calcium/Calmodulin-Dependent Protein Kinase II Activity Persists During Chronic ß-Adrenoceptor Blockade in Experimental and Human Heart Failure.

BACKGROUND: Considerable evidence suggests that calcium/calmodulin-dependent protein kinase II (CaMKII) overactivity plays a crucial role in the pathophysiology of heart failure (HF), a condition characterized by excessive ß-adrenoceptor (ß-AR) stimulation. Recent studies indicate a significant cross talk between ß-AR signaling and CaMKII activation presenting CaMKII as a possible downstream mediator of detrimental ß-AR signaling in HF. In this study, we investigated the effect of chronic ß-AR blocker treatment on CaMKII activity in human and experimental HF. METHODS AND RESULTS: Immunoblot analysis of myocardium from end-stage HF patients (n=12) and non-HF subjects undergoing cardiac surgery (n=12) treated with ß-AR blockers revealed no difference in CaMKII activity when compared with non-ß-AR blocker-treated patients. CaMKII activity was judged by analysis of CaMKII expression, autophosphorylation, and oxidation and by investigating the phosphorylation status of CaMKII downstream targets. To further evaluate these findings, CaMKIIδC transgenic mice were treated with the ß1-AR blocker metoprolol (270 mg/kg*d). Metoprolol significantly reduced transgene-associated mortality (n≥29; P<0.001), attenuated the development of cardiac hypertrophy (-14±6% heart weight/tibia length; P<0.05), and strongly reduced ventricular arrhythmias (-70±22% premature ventricular contractions; P<0.05). On a molecular level, metoprolol expectedly decreased protein kinase A-dependent phospholamban and ryanodine receptor 2 phosphorylation (-42±9% for P-phospholamban-S16 and -22±7% for P-ryanodine receptor 2-S2808; P<0.05). However, this was paralled neither by a reduction in CaMKII autophosphorylation, oxidation, and substrate binding nor a change in the phosphorylation of CaMKII downstream target proteins (n≥11). The lack of CaMKII modulation by ß-AR blocker treatment was confirmed in healthy wild-type mice receiving metoprolol. CONCLUSIONS: Chronic ß-AR blocker therapy in patients and in a mouse model of CaMKII-induced HF is not associated with a change in CaMKII activity. Thus, our data suggest that the molecular effects of ß-AR blockers are not based on a modulation of CaMKII. Directly targeting CaMKII may, therefore, further improve HF therapy in addition to ß-AR blockade.