Microscopic Colitis and Risk of Colon Adenomas: A Multicenter Retrospective Cohort Study.

Microscopic colitis (MC) is a common cause of chronic watery diarrhea, with the highest incidence in women over age 50.1 Cross-sectional studies have suggested that patients with MC have a lower incidence of adenomatous colon polyps compared with those without MC.2-4 The existing literature is limited by cross-sectional design, small sample sizes, lack of longitudinal follow-up, and the use of average-risk patients, rather than those with chronic diarrhea, as controls. We aimed to explore the association between MC and colon adenomas.

Nanoscale coupling of junctophilin-2 and ryanodine receptors regulates vascular smooth muscle cell contractility.

Junctophilin proteins maintain close contacts between the endoplasmic/sarcoplasmic reticulum (ER/SR) and the plasma membrane in many types of cells, as typified by junctophilin-2 (JPH2), which is necessary for the formation of the cardiac dyad. Here, we report that JPH2 is the most abundant junctophilin isotype in native smooth muscle cells (SMCs) isolated from cerebral arteries and that acute knockdown diminishes the area of sites of interaction between the SR and plasma membrane. Superresolution microscopy revealed nanometer-scale colocalization of JPH2 clusters with type 2 ryanodine receptor (RyR2) clusters near the cell surface. Knockdown of JPH2 had no effect on the frequency, amplitude, or kinetics of spontaneous Ca2+ sparks generated by transient release of Ca2+ from the SR through RyR2s, but it did nearly abolish Ca2+ spark-activated, large-conductance, Ca2+-activated K+ (BK) channel currents. We also found that JPH2 knockdown was associated with hypercontractility of intact cerebral arteries. We conclude that JPH2 maintains functional coupling between RyR2s and BK channels and is critically important for cerebral arterial function.

Modifying the Adult Rat Tonotopic Map with Sound Exposure Produces Frequency Discrimination Deficits That Are Recovered with Training.

Frequency discrimination learning is often accompanied by an expansion of the functional region corresponding to the target frequency within the auditory cortex. Although the perceptual significance of this plastic functional reorganization remains debated, greater cortical representation is generally thought to improve perception for a stimulus. Recently, the ability to expand functional representations through passive sound experience has been demonstrated in adult rats, suggesting that it may be possible to design passive sound exposures to enhance specific perceptual abilities in adulthood. To test this hypothesis, we exposed adult female Long-Evans rats to 2 weeks of moderate-intensity broadband white noise followed by 1 week of 7 kHz tone pips, a paradigm that results in the functional over-representation of 7 kHz within the adult tonotopic map. We then tested the ability of exposed rats to identify 7 kHz among distractor tones on an adaptive tone discrimination task. Contrary to our expectations, we found that map expansion impaired frequency discrimination and delayed perceptual learning. Rats exposed to noise followed by 15 kHz tone pips were not impaired at the same task. Exposed rats also exhibited changes in auditory cortical responses consistent with reduced discriminability of the exposure tone. Encouragingly, these deficits were completely recovered with training. Our results provide strong evidence that map expansion alone does not imply improved perception. Rather, plastic changes in frequency representation induced by bottom-up processes can worsen perceptual faculties, but because of the very nature of plasticity these changes are inherently reversible.SIGNIFICANCE STATEMENT The potent ability of our acoustic environment to shape cortical sensory representations throughout life has led to a growing interest in harnessing both passive sound experience and operant perceptual learning to enhance mature cortical function. We use sound exposure to induce targeted expansions in the adult rat tonotopic map and find that these bottom-up changes unexpectedly impair performance on an adaptive tone discrimination task. Encouragingly, however, we also show that training promotes the recovery of electrophysiological measures of reduced neural discriminability following sound exposure. These results provide support for future neuroplasticity-based treatments that take into account both the sensory statistics of our external environment and perceptual training strategies to improve learning and memory in the adult auditory system.

The Modern Physical Exam - A Transatlantic Perspective from the Resident Level.

Issue: The physical examination has been in decline for many years and poorer skills contribute to medical errors and adverse events. Diagnostic error is also increasing with the complexity of medicine. Comparing the physical examination in Ireland and the United States with a focus on education, assessment, culture, and health systems may provide insight into the decline of the physical exam in the United States, uncover possible strategies to improve clinical skills, and limit diagnostic error. Evidence: The physical exam is a core component of both undergraduate and postgraduate medical education in Ireland. This is reflected by the time and effort invested by medical schools and medical societies in Ireland in teaching and assessing skills. This high standard of skills results in the physical exam being a key component of the diagnostic process and a gatekeeper to expensive investigations essential in a resource-limited health system such as Ireland. Use of the physical exam in the United States is hindered by the high-tech transformation of healthcare and a more litigious society. Known strategies to highlight the role of the physical exam in clinical practice include creating an evidence base to show that better physical exam skills improve outcomes, identifying accurate physical exam maneuvers, stressing the therapeutic alliance the physical exam brings to the patient encounter, and the incorporation of technology into the bedside exam. Implications: Contrasting the education and clinical use of the physical examination in the United States with Ireland allowed us to identify a number of strategies which could be used to promote the physical exam among learners in both countries. Highlighting simple and pragmatic physical exam maneuvers combined with evidence-based physical exam diagnostic data may renew confidence in the physical exam as a core diagnostic tool. Use of the hypothesis-driven approach may streamline a clinician's physical exam during a patient encounter, focusing on the key examination components and avoiding unnecessary and low yield maneuvers. The absence of assessment of physical exam skills using real patients in United States licensing exams communicates to learners that these skills are not important. However, steps to introduce a culture of assessment to drive learning are being introduced. One area Ireland could learn from the United States is incorporating more technology into the bedside exam. Enhanced physical examination skills in both countries could reduce reliance on expensive investigations and improve diagnostic accuracy.

Implantable cardioverter-defibrillators in previously undiagnosed patients with catecholaminergic polymorphic ventricular tachycardia resuscitated from sudden cardiac arrest.

AIMS: In patients with catecholaminergic polymorphic ventricular tachycardia (CPVT), implantable cardioverter-defibrillator (ICD) shocks are sometimes ineffective and may even trigger fatal electrical storms. We assessed the efficacy and complications of ICDs placed in patients with CPVT who presented with a sentinel event of sudden cardiac arrest (SCA) while undiagnosed and therefore untreated. METHODS AND RESULTS: We analysed 136 patients who presented with SCA and in whom CPVT was diagnosed subsequently, leading to the initiation of guideline-directed therapy, including ß-blockers, flecainide, and/or left cardiac sympathetic denervation. An ICD was implanted in 79 patients (58.1%). The primary outcome of the study was sudden cardiac death (SCD). The secondary outcomes were composite outcomes of SCD, SCA, appropriate ICD shocks, and syncope. After a median follow-up of 4.8 years, SCD had occurred in three patients (3.8%) with an ICD and none of the patients without an ICD (P = 0.1). SCD, SCA, or appropriate ICD shocks occurred in 37 patients (46.8%) with an ICD and 9 patients (15.8%) without an ICD (P < 0.0001). Inappropriate ICD shocks occurred in 19 patients (24.7%) and other device-related complications in 22 patients (28.9%). CONCLUSION: In previously undiagnosed patients with CPVT who presented with SCA, an ICD was not associated with improved survival. Instead, the ICD was associated with both a high rate of appropriate ICD shocks and inappropriate ICD shocks along with other device-related complications. Strict adherence to guideline-directed therapy without an ICD may provide adequate protection in these patients without all the potential disadvantages of an ICD.

Incidence and outcomes of high bleeding risk patients with type 1 and type 2 myocardial infarction in a community-based cohort: Application of the Academic Research Consortium High Bleeding Risk Criteria.

BACKGROUND AND AIMS: The incidence and outcomes of high bleeding risk (HBR) patients in a community cohort according to the Academic Research Consortium (ARC) criteria is not known. We hypothesized that HBR is common and associated with worse outcomes for all-comers with myocardial infarction. METHODS: We prospectively collected all patients with cardiac troponin T > 99th percentile upper limit of normal (≥0.01 ng/mL) in Olmsted County between 2003 and 2012. Events were retrospectively classified as type 1 myocardial infarction (T1MI), type 2 myocardial infarction (T2MI), or myocardial injury. Patients were further classified as HBR based on the "ARC-HBR definition." Outcomes included all-cause mortality, cardiovascular mortality, recurrent MI, stroke, and major bleeding. RESULTS: 2419 patients were included in the final study; 1365 were classified as T1MI and 1054 as T2MI. Patients were followed for a median of 5.5 years. ARC-HBR was more common in T2MI than T1MI (73% vs 46%, p < 0.001). Among patients with T1MI, HBR was associated with higher all-cause mortality (HR 3.7, 95% CI 3.2-4.5, p < 0.001), cardiovascular mortality (4.7, 3.6-6.3, p < 0.001), recurrent MI (2.1, 1.6-2.7, p < 0.001), stroke (4.9, 2.9-8.4, p < 0.001), and major bleeding (6.5, 3.7-11.4, p < 0.001). For T2MI, HBR was similarly associated with higher all-cause mortality (HR 2.1, 95% CI 1.8-2.5, p < 0.001), cardiovascular mortality (2.7, 1.8-4.0, p < 0.001), recurrent MI (1.7, 1.1-2.6, p = 0.02) and major bleeding (HR 15.6, 3.8-63.8, p < 0.001). CONCLUSION: HBR is common among unselected patients with T1MI and T2MI and is associated with increased overall and cardiovascular mortality, recurrent cardiovascular events, and major bleeding on long-term follow up.

Right ventricular systolic strain in patients with pulmonary hypertension: clinical feasibility, reproducibility, and correlation with ejection fraction.

BACKGROUND: Right ventricular (RV) systolic function is the major determinant of prognosis in patients with pulmonary hypertension (PH) with quantitative assessment by speckle-tracking strain echocardiography emerging as a viable candidate measure. METHOD: We evaluated a prospective cohort of 231 patients with known or suspected PH referred for clinical echocardiography. All underwent measurement of RV free-wall systolic strain by sonographer staff. Digital images were recorded for blinded offline assessment by an expert echocardiographer. Reproducibility was assessed using the analysis methods of Bland-Altman and the Cohen's-Kappa coefficient. RESULTS: RV strain was feasible in 213 (92%). The average RV systolic pressure was 59 ± 22 mmHg. RV systolic strain correlated with functional class, NT-proBNP, and the degree of RV enlargement. The average free-wall systolic strain was - 20 ± 7% (range - 2 to - 37%). The RV strain measures (clinical practice versus blinded expert) had an excellent correlation with a normal distribution (R2 0.87, p < 0.0001). By Bland-Altman analysis, the mean difference in measurement was - 1.7% (95% CI - 1.4 to - 2.1) with a correlation of 0.93, p value of < 0.0001. The reproducibility of RV strain for clinically relevant thresholds was also excellent (Kappa coefficients 0.68-0.83). There was no effect on the variability of strain measures across body mass, pulmonary pressures, or rhythm. RV strain correlated with RV diastolic volumes and ejection fraction with RV free wall strain being the best echo predictor for a reduction in ejection fraction. CONCLUSION: Here RV systolic strain was found to be highly feasible and reproducible in clinical practice with excellent levels of agreement for clinically relevant thresholds.

Improving In-Hospital Patient Rescue: What Are Studies on Early Warning Scores Missing? A Scoping Review.

OBJECTIVES: Administrative and clinical efforts to improve hospital mortality and intensive care utilization commonly focus on patient rescue, where deteriorating patients are systematically identified and intervened upon. Patient rescue is known to depend on hospital context inclusive of technologic environment, structural features, and hospital organizational behavioral features. With widespread adoption of electronic medical records, early warning score (EWS) systems, which assign points to clinical data elements, are increasingly promoted as a tool for timely patient rescue by referencing their prediction of patient deterioration. We describe the extent to which EWS intervention studies describe the hospital environment of the intervention-details that would be critical for hospital leaders attempting to determine the real-world utility of EWSs in their own hospitals. DATA SOURCES: We searched CINAHL, PubMed, and Scopus databases for English language EWS implementation research published between 2009 and 2021 in adult medical-surgical inpatients. STUDY SELECTION: Studies including pediatric, obstetric, psychiatric, prehospital, outpatient, step-down, or ICU patients were excluded. DATA EXTRACTION: Two investigators independently reviewed titles/abstracts for eligibility based on prespecified exclusion criteria. DATA SYNTHESIS: We identified 1,434 studies for title/abstract screening. In all, 352 studies underwent full-text review and 21 studies were summarized. The 21 studies (18 before-and-after, three randomized trials) detailed 1,107,883 patients across 54 hospitals. Twelve reported the staff composition of an EWS response team. Ten reported the proportion of surgical patients. One reported nursing ratios; none reported intensive care staffing with in-house critical-care physicians. None measured changes in bed utilization or availability. While 16 qualitatively described resources for education/technologic implementation, none estimated costs. None described workforce composition such as team stability or culture of safety in the hospitals. CONCLUSIONS: Despite hundreds of EWS-related publications, most do not report details of hospital context that would inform decisions about real-world EWS adoption. To make informed decisions about whether EWS implementation improves hospital quality, decision-makers may require alternatives such as peer networks and implementation pilots nested within local health systems.

Medication use and microscopic colitis: a multicentre retrospective cohort study.

BACKGROUND: Medication use has been implicated in the development of microscopic colitis (MC). However, studies have demonstrated inconsistent findings and there exist variations in design. AIM: To measure the association between medication use and MC. METHODS: Patients who underwent a colonoscopy over a 10-year period at two academic medical centres (Columbia University Medical Centre and Mayo Clinic) were identified. Cases were patients with biopsy-proven MC and controls were patients who underwent colonoscopy for evaluation of diarrhoea with biopsies negative for MC. Cases were matched by age, gender and calendar period with up to two controls. Demographics, medication use, smoking history and coeliac disease status were collected. Conditional logistic regression was used with and without adjustment for smoking. RESULTS: A total of 344 patients with MC were matched to 668 controls. After adjusting for smoking, there was an inverse association between MC and use of proton pump inhibitors (PPIs) (OR 0.64; 95% CI 0.47-0.87), H2 blockers (OR 0.46; 95% CI 0.24-0.88) and oral diabetes medications (OR 0.47; 95% CI 0.27-0.81). There was a positive association with nonsteroidal anti-inflammatory drug (NSAID) use and MC (OR 1.63; 95% CI 1.12-2.38). CONCLUSIONS: NSAID use was associated with MC, while use of PPIs, H2 blockers and oral diabetes medications were inversely related to MC. Our use of a control group with diarrhoea, as opposed to healthy controls, may have contributed to these inverse associations. Future studies of drug-induced microscopic colitis should include control groups with diarrhoea, and not only healthy controls.

TRPML1 channels initiate Ca2+ sparks in vascular smooth muscle cells.

TRPML1 (transient receptor potential mucolipin 1) is a Ca2+-permeable, nonselective cation channel localized to the membranes of endosomes and lysosomes and is not present or functional on the plasma membrane. Ca2+ released from endosomes and lysosomes into the cytosol through TRPML1 channels is vital for trafficking, acidification, and other basic functions of these organelles. Here, we investigated the function of TRPML1 channels in fully differentiated contractile vascular smooth muscle cells (SMCs). In live-cell confocal imaging studies, we found that most endosomes and lysosomes in freshly isolated SMCs from cerebral arteries were essentially immobile. Using nanoscale super-resolution microscopy, we found that TRPML1 channels present in late endosomes and lysosomes formed stable complexes with type 2 ryanodine receptors (RyR2) on the sarcoplasmic reticulum (SR). Spontaneous Ca2+ signals resulting from the release of SR Ca2+ through RyR2s ("Ca2+ sparks") and corresponding Ca2+-activated K+ channel activity are critically important for balancing vasoconstriction. We found that these signals were essentially absent in SMCs from TRPML1-knockout (Mcoln1-/- ) mice. Using ex vivo pressure myography, we found that loss of this critical signaling cascade exaggerated the vasoconstrictor responses of cerebral and mesenteric resistance arteries. In vivo radiotelemetry studies showed that Mcoln1-/- mice were spontaneously hypertensive. We conclude that TRPML1 is crucial for the initiation of Ca2+ sparks in SMCs and the regulation of vascular contractility and blood pressure.

Stroke Induces Prolonged Changes in Lipid Metabolism, the Liver and Body Composition in Mice.

During recovery, stroke patients are at risk of developing long-term complications that impact quality of life, including changes in body weight and composition, depression and anxiety, as well as an increased risk of subsequent vascular events. The aetiologies and time-course of these post-stroke complications have not been extensively studied and are poorly understood. Therefore, we assessed long-term changes in body composition, metabolic markers and behaviour after middle cerebral artery occlusion in mice. These outcomes were also studied in the context of obesity, a common stroke co-morbidity proposed to protect against post-stroke weight loss in patients. We found that stroke induced long-term changes in body composition, characterised by a sustained loss of fat mass with a recovery of lean weight loss. These global changes in response to stroke were accompanied by an altered lipid profile (increased plasma free fatty acids and triglycerides) and increased adipokine release at 60 days. After stroke, the liver also showed histological changes indicative of liver damage and a decrease in plasma alanine aminotransferase (ALT) was observed. Stroke induced depression and anxiety-like behaviours in mice, illustrated by deficits in exploration, nest building and burrowing behaviours. When initial infarct volumes were matched between mice with and without comorbid obesity, these outcomes were not drastically altered. Overall, we found that stroke induced long-term changes in depressive/anxiety-like behaviours, and changes in plasma lipids, adipokines and the liver that may impact negatively on future vascular health.

Heart Rate Recovery After Exercise Is Associated With Arrhythmic Events in Patients With Catecholaminergic Polymorphic Ventricular Tachycardia.

BACKGROUND: Risk stratification in catecholaminergic polymorphic ventricular tachycardia remains ill defined. Heart rate recovery (HRR) immediately after exercise is regulated by autonomic reflexes, particularly vagal tone, and may be associated with symptoms and ventricular arrhythmias in patients with catecholaminergic polymorphic ventricular tachycardia. Our objective was to evaluate whether HRR after maximal exercise on the exercise stress test (EST) is associated with symptoms and ventricular arrhythmias. METHODS: In this retrospective observational study, we included patients ≤65 years of age with an EST without antiarrhythmic drugs who attained at least 80% of their age- and sex-predicted maximal HR. HRR in the recovery phase was calculated as the difference in heart rate (HR) at maximal exercise and at 1 minute in the recovery phase (ΔHRR1'). RESULTS: We included 187 patients (median age, 36 years; 68 [36%] symptomatic before diagnosis). Pre-EST HR and maximal HR were equal among symptomatic and asymptomatic patients. Patients who were symptomatic before diagnosis had a greater ΔHRR1' after maximal exercise (43 [interquartile range, 25-58] versus 25 [interquartile range, 19-34] beats/min; P<0.001). Corrected for age, sex, and relatedness, patients in the upper tertile for ΔHRR1' had an odds ratio of 3.4 (95% CI, 1.6-7.4) of being symptomatic before diagnosis (P<0.001). In addition, ΔHRR1' was higher in patients with complex ventricular arrhythmias at EST off antiarrhythmic drugs (33 [interquartile range, 22-48] versus 27 [interquartile range, 20-36] beats/min; P=0.01). After diagnosis, patients with a ΔHRR1' in the upper tertile of its distribution had significantly more arrhythmic events as compared with patients in the other tertiles (P=0.045). CONCLUSIONS: Catecholaminergic polymorphic ventricular tachycardia patients with a larger HRR following exercise are more likely to be symptomatic and have complex ventricular arrhythmias during the first EST off antiarrhythmic drug.

Beyond the length and look of repolarization: Defining the non-QTc electrocardiographic profiles of patients with congenital long QT syndrome.

BACKGROUND: Little is known about the spectrum and prevalence of ECG features beyond the length and morphology of repolarization in patients with congenital long QT syndrome (LQTS). OBJECTIVE: The purpose of this study was to characterize the full ECG phenotype of LQTS patients and evaluate differences by age and LQTS genotype. METHODS: Retrospective review of 943 patients with LQTS (57% female; median age 25 years; interquartile range 9-34 years) was performed. Comprehensive analysis of their initial evaluation ECG was performed using definitions outlined in professional guidelines. RESULTS: Bradycardia was common (n = 320 [34%]), regardless of beta-blocker use. Left-axis deviation (n = 33 [3.5%]) and bundle branch block (n = 5 [0.5%]) were uncommon. T-wave inversion (TWI) involving leads V1 and V3 was more common in LQTS type 2 compared to LQTS type 1 or type 3 (odds ratio [OR] for V1: 2.67, 95% confidence interval [CI] 1.8-3.9; OR for V3: 1.76, 95% CI 1.2-2.6), whereas TWI in leads III and aVF was most common in LQTS type 3 (OR for III: 2.38, 95% CI 1.4-4.2; OR for aVF: 3.14, 95% CI 1.6-6.4). Notched T waves were most apparent at younger ages (48% in patients age 4-10 compared to 12% in patients age >40: P <.0001). CONCLUSION: Beyond the QT interval and bradycardia, ECG abnormalities are uncommon in LQTS patients, and patients almost never have concomitant bundle branch block. Notably, 19% of LQTS patients overall and 27% of LQTS type 2 patients exhibit anterior TWI that would satisfy a diagnostic criterion for arrhythmogenic right ventricular cardiomyopathy, thus creating the potential for diagnostic miscues.

Long QT syndrome type 5-Lite: Defining the clinical phenotype associated with the potentially proarrhythmic p.Asp85Asn-KCNE1 common genetic variant.

BACKGROUND: Long QT syndrome (LQTS) genetic test reports commonly exclude potentially proarrhythmic common variants such as p.Asp85Asn-KCNE1. OBJECTIVE: The purpose of this study was to determine whether a discernible phenotype is associated with p.Asp85Asn-KCNE1 and whether relatively common KCNE1 variants underlie transient QT prolongation pedigrees with negative commercial LQTS genetic tests. METHODS: Retrospective review was used to compare demographics, symptomatology, and QT parameters of individuals with p.Asp85Asn-KCNE1 in the absence of other rare/ultra-rare variants in LQTS-susceptibility genes and those who underwent comprehensive LQTS genetic testing. RESULTS: Compared to the Genome Aggregation Database, p.Asp85Asn-KCNE1 was more prevalent in individuals undergoing LQTS genetic testing (33/1248 [2.6%] vs 1552/126,652 [1.2%]; P = .0001). In 19 of 33 patients (58%), only p.Asp85Asn-KCNE1 was observed. These patients were predominantly female (90% vs 62%; P = .01) and were less likely to experience syncope (0% vs 34%; P = .0007), receive ß-blockers (53% vs 85%; P = .001), or require an implantable cardioverter-defibrillator (5.3% vs 33%; P = .01). However, they exhibited a similar degree of QT prolongation (QTc 460 ms vs 467 ms; P = NS). Whole exome sequencing of 2 commercially genotype-negative pedigrees revealed that p.Asp85Asn-KCNE1 and p.Arg36His-KCNE1 traced with a transient QT prolongation phenotype. Functional characterization of p.Arg36His-KCNE1 demonstrated loss of function, with a 47% reduction in peak IKs current density in the heterozygous state. CONCLUSION: We provide further evidence that relatively common variants in KCNE1 may result in a mild QT phenotype designated as "LQT5-Lite" to distinguish such potentially proarrhythmic common variants (ie, functional risk alleles) from rare pathogenic variants that truly confer monogenic disease susceptibility, albeit with incomplete penetrance.