Neuroprotection in glaucoma

Neuroprotective therapies in glaucoma may play a role in preventing ischemia and oxidative damage that results in apoptosis of retinal ganglion cells and optic nerve damage. Although intraocular pressure (IOP) is the only known modifiable risk factor for glaucoma, disease progression commonly occurs despite IOP control, suggesting that factors other than IOP play a role in its pathogenesis and can potentially act as targets for neuroprotection. Factors including mediators of apoptosis, ischemic changes, poor ocular blood flow and neurotoxins have been hypothesized to play a role in glaucoma progression. Neuroprotective targets include glutamate-induced neurotoxicity, nitric oxidase synthetase, neurotropins, calcium channel receptors, free radicals, vascular insufficiency, the rho-kinase pathway, and more. Drugs related to these factors are being evaluated for their role in neuroprotection, although this area of investigation faces several challenges including limited evidence for these agents’ efficacy in clinical studies. Additionally, while IOP-lowering therapies are considered neuroprotective as they generally slow the progress of glaucoma progression, they are limited by the extent of their effect beyond IOP control. The aim of this article is to review the current treatment options available for neuroprotection and to explore the drugs in the pipeline.     

☆Comparison of transcutaneous laryngeal ultrasound with video laryngoscope for assessing the vocal cord mobility in patients undergoing thyroid surgery

ObjectiveWe evaluated the accuracy and feasibility of transcutaneous laryngeal ultrasonography as an alternative to videolaryngoscopy for assessing vocal cord mobility to rule out recurrent laryngeal nerve injury following thyroidectomy.MethodsForty-five adult patients scheduled to undergo elective thyroidectomy under general anesthesia were included. Preoperatively, indirect laryngoscopy and transcutaneous laryngeal ultrasonography was done for assessing vocal cord mobility. Intraoperatively, following induction, patients were intubated using videolaryngoscope. On completion of the surgical procedure, one anesthetist performed videolaryngoscopy so as to record vocal cord mobility while the patients were being extubated in deep plane of anesthesia. Simultaneously another anesthesiologist performed transcutaneous laryngeal ultrasonography.Vocal cord mobility, changes in hemodynamics and total time duration for the two procedures was recorded. Indirect laryngoscopic assessment and flexible fiberoptic laryngoscopy was done on postoperative day 1 and 7 respectively.ResultsPostoperative videolaryngoscopy picked up bilaterally mobile vocal cords in 88.8% cases. Transcutaneous laryngeal ultrasonography could correctly identify 39(86.6%) of these patients, with 1(2.5%) patient being misdiagnosed as having bilaterally immobile vocal cords. Further, videolaryngoscopy identified 5 patients of vocal cord palsy, of which transcutaneous laryngeal ultrasonography correctly identified 3 (60%) patients. Hence, in comparison to videolaryngoscopy, the sensitivity, specificity, positive predictive value, and negative predictive value of transcutaneous laryngeal ultrasonography for assessment of vocal cords was 75%, 95.1%, 60%, and 97.5% respectively.ConclusionIn patients undergoing thyroidectomy, transcutaneous laryngeal ultrasonography can serve as a non-invasive, bedside screening tool for assessing vocal cord palsy postoperatively.     

Role of Serum High-Sensitivity C-Reactive Protein as a Predictor of Therapeutic Response to Tadalafil in Patients With Erectile Dysfunction: A Prospective Observational Study

IntroductionHigh-sensitivity C-reactive protein (hs-CRP), a marker of inflammation, is known to be elevated in patients with erectile dysfunction (ED). However, its role in predicting therapeutic response to phosphodiesterase-5 inhibitors is incompletely understood.AimThe aim of this study was to understand the relationship among hs-CRP, mechanism of ED, and therapeutic response of ED to tadalafil, a phosphodiesterase-5 inhibitor.MethodsA total of 282 men (mean age 36.6 ± 12.0 years) with ED were included. All subjects underwent detailed evaluation, including estimation of a 6-item abbreviated version of the International Index of Erectile Function (IIEF-6) score, penile Doppler studies, and measurement of hs-CRP. IIEF-6 scoring and hs-CRP measurement were repeated after 6 weeks of tadalafil therapy (10 mg/day). The patients were categorized into vasculogenic and nonvasculogenic ED groups based on penile Doppler findings.Main Outcome MeasureThe main outcome measure was the therapeutic response to tadalafil, in relation to the mechanism of ED and hs-CRP levels.ResultsVasculogenic ED was much less common (23.8% of the subjects) than non-vasculogenic ED. Subjects with vasculogenic ED were older, had higher prevalence of cardiovascular risk factors, had more severe (mean IIEF-6 score 9.2 ± 4.6 vs 14.8 ± 4.7; P < .001) and longer duration ED, and responded less favorably to therapy (response rate 10.4% vs 75.0%; P < .001). Those showing improvement with tadalafil had lower hs-CRP at baseline (median 1.5 mg/L [interquartile range 0.9?2.3] vs 2.0 mg/L [interquartile range 1.1?3.1; P = .034]) and had proportionately greater reduction in its level. However, on multivariate analysis, only shorter duration of ED (P = .008), non-vasculogenic origin (P = .025), and higher IIEF-6 score at baseline (P = .013) were independent predictors of response to treatment.Clinical ImplicationsSerum hs-CRP is elevated in patients who are less likely to respond to vasodilator therapy but does not have an independent predictive value for this purpose.Strengths & LimitationsThis is the largest study to evaluate the relationship among the mechanism of ED, serum hs-CRP level, and therapeutic response of ED to tadalafil. All patients underwent a penile Doppler study to characterize the type of ED. The limitations were nonrandomized nature of the study and nearly 22% dropout rate.ConclusionSerum hs-CRP level is higher in vasculogenic ED compared with non-vasculogenic ED, and is associated with poorer response to tadalafil therapy. However, this association is not independent of underlying risk factors and mechanism of ED.Jamaluddin, Bansal M, Srivastava GK, et al. Role of Serum High-Sensitivity C-Reactive Protein as a Predictor of Therapeutic Response to Tadalafil in Patients With Erectile Dysfunction: A Prospective Observational Study. J Sex Med 2019;16:1912–1921.     

Using technology to advance type 1 diabetes care among women during the reproductive years and in pregnancy

The prevalence of diabetes is increasing globally. Technology to improve care among individuals with diabetes is constantly being developed. Women living with Type 1 Diabetes Mellitus (T1DM) have unique challenges affecting their glucose control relating to menstrual cycles, pregnancy, and menopause. The purpose of this review is to examine the literature related to the use of technology to help women with T1DM manage their diabetes during the reproductive years, pregnancy, and beyond. Continuous subcutaneous insulin infusion (CSII) therapy can provider equivalent or better glucose control when compared with multiple daily injections (MDI), with less hypoglycemia, diabetic ketoacidosis, and weight gain. The CSII therapy has features that could help improve glucose control over the menstrual cycle, menopause, and pregnancy, although the most studied of these stages is pregnancy. Continuous glucose monitoring (CGM) can be combined with any insulin delivery system (MDI or CSII) to provide data on glucose values every few minutes and show glucose trends over time. CGM introduction can highlight glucose variability for women with T1DM, may be beneficial during pregnancy, and can reduce hypoglycemia. Sensor-augmented pump therapy and hybrid artificial pancreas (closed-loop) systems are promising tools that improve outcomes among individuals with diabetes. The use of modern technology to improve glucose and metabolic control among menopausal women with diabetes has not been well studied. Internet and phone-based technologies are emerging as important tools that may help with diabetes self-care for women living with diabetes.     

Facilitatory I wave interaction in proximal arm and lower limb muscle representations of the human motor cortex

Transcranial magnetic stimulation (TMS) of the human motor cortex elicits direct and indirect (I) waves in the corticospinal tract. Facilitatory I wave interaction has been demonstrated with a suprathreshold first stimulus (S1) followed by a subthreshold to threshold second stimulus (S2). Intracortical inhibition (ICI) and intracortical facilitation (ICF) can be studied by another paired TMS paradigm with a subthreshold conditioning stimulus (CS) followed by a suprathreshold test stimulus. Facilitatory I wave interaction in motor representations other than the hand area and its relationship to ICI and ICF has not been studied. We studied I wave interaction, ICI and ICF in an intrinsic hand muscle (abductor pollicis brevis, APB), in a proximal arm muscle (biceps brachii, BB) and in a lower limb muscle (tibialis anterior, TA) in 11 normal subjects. I wave facilitation was studied by paired TMS at 24 interstimulus intervals (ISIs) from 0.5 to 5.1 ms. For APB and TA, facilitation occurred in three distinct peaks at ISIs of 0.9-1.7, 2. 5-3.5, and 4.1-5.1 ms. For BB, facilitation was significant for the first two peaks. The latencies of the peaks were similar among different muscles, but the magnitude of facilitation was much greater for APB and TA compared with BB. For all three muscles, changing the S2 to transcranial electrical stimulation (TES) resulted in much less facilitation of the first peak. For APB, there was significant I wave facilitation with S2 at 72% motor threshold (MT). The same stimulus used as the CS did not elicit ICF at ISI of 15 ms, suggesting that the threshold for eliciting I wave facilitation is lower than that for ICF. For BB and TA, there was no I wave facilitation with S2 at 90% of APB MT, and the same stimulus used as CS led to ICI. Thus in BB and TA the threshold for eliciting ICI is lower than that for I wave facilitation. We conclude that the circuits that mediate I wave interactions are present in the proximal arm and lower limb representations of the motor cortex. I wave facilitation occurs predominately in the cortex and may be primarily related to the monosynaptic corticomotoneuronal (CM) system. The reduced I wave facilitation for BB compared with APB and TA may be related to less extensive CM projection and involvement of other polysynaptic descending pathways. I wave facilitation, ICI, and ICF appears to be mediated by different neuronal circuits.     

Myocardial Fibrosis as a Predictor of Sudden Death in Patients With Coronary Artery Disease

BackgroundThe “gray zone” of myocardial fibrosis (GZF) on cardiovascular magnetic resonance may be a substrate for ventricular arrhythmias (VAs).ObjectivesThe purpose of this study was to determine whether GZF predicts sudden cardiac death (SCD) and VAs (ventricular fibrillation or sustained ventricular tachycardia) in patients with coronary artery disease (CAD) and a wide range of left ventricular ejection fractions (LVEFs).MethodsIn this retrospective study of CAD patients, the presence of myocardial fibrosis on visual assessment (MF_VA) and GZF mass in patients with MF_VA were assessed in relation to SCD and the composite, arrhythmic endpoint of SCD or VAs.ResultsAmong 979 patients (mean age [± SD]: 65.8 ± 12.3 years), 29 (2.96%) experienced SCD and 80 (8.17%) met the arrhythmic endpoint over median 5.82 years (interquartile range: 4.1 to 7.3 years). In the whole cohort, MF_VA was strongly associated with SCD (hazard ratio: 10.1; 95% confidence interval [CI]: 1.42 to 1,278.9) and the arrhythmic endpoint (hazard ratio: 28.0; 95% CI: 4.07 to 3,525.4). In competing risks analyses, associations between LVEF <35% and SCD (subdistribution hazard ratio [sHR]: 2.99; 95% CI: 1.42 to 6.31) and the arrhythmic endpoint (sHR: 4.71; 95% CI: 2.97 to 7.47) were weaker. In competing risk analyses of the MF_VA subcohort (n = 832), GZF using the 3SD method (GZF_3SD) >5.0 g was strongly associated with SCD (sHR: 10.8; 95% CI: 3.74 to 30.9) and the arrhythmic endpoint (sHR: 7.40; 95% CI: 4.29 to 12.8). Associations between LVEF <35% and SCD (sHR: 2.62; 95% CI: 1.24 to 5.52) and the arrhythmic endpoint (sHR: 4.14; 95% CI: 2.61 to 6.57) were weaker.ConclusionsIn CAD patients, MF_VA plus quantified GZF_3SD mass was more strongly associated with SCD and VAs than LVEF. In selecting patients for implantable cardioverter-defibrillators, assessment of MF_VA followed by quantification of GZF_3SD mass may be preferable to LVEF.     

Premature Ticagrelor Discontinuation in Secondary Prevention of Atherosclerotic CVD: JACC Review Topic of the Week

Ticagrelor is a cornerstone of modern antithrombotic therapy alongside aspirin in patients with acute coronary syndrome and after percutaneous coronary intervention. Adverse effects such as bleeding and dyspnea have been associated with premature ticagrelor discontinuation, which may limit any potential advantage of ticagrelor over clopidogrel. The randomized trials of ticagrelor captured adverse events, offering the opportunity to more precisely quantify these effects across studies. Therefore, a meta-analysis of 4 randomized clinical trials of ticagrelor conducted between January 2007 and June 2017 was performed to quantify the incidence and causes of premature ticagrelor discontinuation. Among 66,870 patients followed for a median 18 months, premature ticagrelor discontinuation was seen in 25%; bleeding was the most common cause of discontinuation followed by dyspnea. Versus the comparators, the relative risk of dyspnea-related discontinuation during follow-up was 6.4-fold higher, the relative risk of bleeding was 3.2-fold higher, and the relative risk of discontinuation due to any adverse event was 59% higher for patients receiving ticagrelor. Understanding these potential barriers to adherence to ticagrelor is crucial for informed patient-physician decision making and can inform future efforts to improve ticagrelor adherence. This review discusses the incidence, causes, and biological mechanisms of ticagrelor-related adverse effects and offers strategies to improve adherence to ticagrelor.