Predicting long-term survival after de novo cardioverter-defibrillator implantation for primary prevention: A population based study.

Background: Implantable cardioverter-defibrillators (ICDs) reduce the risk of sudden cardiac death in patients with left ventricular dysfunction. While short-term mortality benefit of ICD insertion has been established in landmark randomized controlled trials, little is known about the long-term outcomes of patients with ICDs in clinical practice. In this paper, we describe the long-term survival of patients following de novo ICD implantation for primary prevention in clinical practice and determine the factors which help predict survival after ICD implant. Methods: Retrospective population-based study of all patients receiving a de novo ICD for primary prevention in Ontario, Canada from 2007 to 2011 using the Ontario ICD Database housed within ICES. Simple random selection was used to split the population into a derivation and internal validation cohort in a ratio of 2:1. Cox proportional hazards regression was used to determine predictors of interest and predict 10-year survival, model performance was assessed using calibration and validation. Results: In the derivation cohort (n = 3399), mean age was 65.3 years (standard deviation [SD] = 11.0), 664 patients were female (19.5 %) and 2344 patients (69.0 %) had ischemic cardiomyopathy. Ten year survival was 45.7 % (95 % confidence interval [CI] 44.0 %-47.4 %). The final prediction model included age, sex, disease factors (ischemic vs nonischemic cardiomyopathy, left ventricular ejection fraction) and patient factors (symptoms, comorbidities), and biomarkers at the time of ICD assessment. This model had good discrimination and calibration in derivation (0.79, 95 % CI 0.77, 0.81) and validation samples (0.78, 95 % CI 0.76, 0.79). Conclusions: A combination of demographic and clinical factors determined at baseline can be used to predict 10-year survival in patients with implantable cardioverter-defibrillators with good accuracy. Our findings help to identify individuals at risk of long-term mortality and may be useful in targeting future prevention strategies to enhance longevity in this high-risk population.

Women and Alcohol: Limitations in the Cardiovascular Guidelines.

Patients and physicians rely on evidence-based guidelines to guide alcohol consumption recommendations, but significant discrepancies in alcohol consumption limits are found between different international societies. Current American Heart Association (AHA) preventive management guidelines on hypertension, transient ischemic attack, stroke, and stable ischemic heart disease recommend sex-specific daily alcohol consumption limits which are inconsistent from other international society recommendations. In this focused review of current American Heart Association guidelines and their sources, we evaluate the evidence behind sex-specific alcohol consumption cut-offs. We found insufficient experimental and epidemiologic evidence to conclude that women should have a reduced daily alcohol consumption limit as compared to men; further studies are required to determine whether sex-specific differences exist in alcohol metabolism and its related cardiovascular impact.

Disseminated Lyme disease and dilated cardiomyopathy: A systematic review.

Lyme carditis is a well-established manifestation of early disseminated Lyme infection, yet the relationship between late disseminated Lyme disease and the development of dilated cardiomyopathy (DCM) remains unclear. The present systematic review aims to summarize existing literature on the association between late disseminated Lyme disease and DCM. A systematic review was conducted in PubMed, Embase, CENTRAL, and MEDLINE databases, after which a total of 11 observational studies (n = 771) were ultimately included for final data extraction. Although most studies (7/11) identified evidence associating Borrelia-infection with DCM, further research is required to isolate late disseminated Borrelia infection as a causative agent of DCM.

Pacemaker Explantation in Patients With Lyme Carditis.

Early recognition of Lyme carditis is critical to preventing unnecessary pacemaker implantation for conduction abnormalities associated with this tick-born infection. Patients who do receive a pacemaker should be considered for device extraction after the completion of their antibiotic therapy if they recover normal atrioventricular node conduction. (Level of Difficulty: Intermediate.).

Prediction of Sudden Cardiac Arrest in the General Population: Review of Traditional and Emerging Risk Factors.

Sudden cardiac death (SCD) is the most common and devastating outcome of sudden cardiac arrest (SCA), defined as an abrupt and unexpected cessation of cardiovascular function leading to circulatory collapse. The incidence of SCD is relatively infrequent for individuals in the general population, in the range of 0.03%-0.10% per year. Yet, the absolute number of cases around the world is high because of the sheer size of the population at risk, making SCA/SCD a major global health issue. On the basis of conservative estimates, there are at least 2 million cases of SCA occurring worldwide on a yearly basis. As such, identification of risk factors associated with SCA in the general population is an important objective from a clinical and public health standpoint. This review will provide an in-depth discussion of established and emerging factors predictive of SCA/SCD in the general population beyond coronary artery disease and impaired left ventricular ejection fraction. Contemporary studies on the association of age, sex, race, socioeconomic status, and the emerging contribution of diabetes and obesity to SCD risk beyond their role as atherosclerotic risk factors are reviewed. In addition, the role of biomarkers, particularly electrocardiographic ones, on SCA/SCD risk prediction in the general population are discussed. Finally, the use of machine learning as a tool to facilitate SCA/SCD risk prediction is examined.

Long-term Outcomes in Treated Lyme Carditis.

Lyme disease is the most reported tick-borne illness in North America. Lyme carditis (LC) is an early-disseminated manifestation of Lyme disease, most commonly presenting as symptomatic high-degree atrioventricular block (AVB) which resolves with appropriate antibiotic therapy. However, long-term outcomes of treated LC have not previously been described. We present a series of 7 patients (median 28 years, 6 male) with serologically confirmed LC treated with a standard protocol developed at our center including antibiotics and pre-discharge stress test to assess AV node stability. At a mean follow-up of 20.8 months, all patients were asymptomatic, had resumed normal activities, and were free of conduction abnormalities. None required permanent pacing. Our study supports avoidance of permanent pacing for LC if conduction is stable at discharge.

Does It work in Clinical Practice? A Comparison of Colonoscopy Cleansing Effectiveness in Clinical Practice Versus Efficacy from Selected Prospective Trials.

BACKGROUND: Adequate bowel preparation is essential for a high-quality colonoscopy. Many randomized controlled trials (RCTs) have investigated bowel preparation protocols, including split-dose and low-volume regimens. However, RCTs are conducted in an ideal, controlled setting, and translation of trial results to clinical practice is challenging. In this study, we compared the quality of bowel preparations of real-world patients from clinical practice with those enrolled in several prospective trials. METHODS: Bowel preparation quality, defined by the Ottawa Bowel Preparation Scale (OBPS), from four RCTs and one prospective trial were compared with two observational diary studies. Bowel preparations were polyethylene glycol preparation (PEG) or sodium picosulfate plus magnesium citrate (P/MC) taken via traditional or split-dose timing regimen. Age, sex, average number of bowel movements per day, comorbidities, colonoscopy indication and colonoscopy completion rates were also collected. RESULTS: Patients enrolled in prospective trials had a better OBPS by one point when compared with those in observational clinical practice studies (P<0.049), after controlling for age, sex, colonoscopy indication and type of bowel preparation used. We also found that each 10-year increase in age was associated with a 0.2 point increase in OBPS (P=0.008), and men were associated with a 0.5 increase in OBPS when compared with women P=0.014). CONCLUSION: Patients from clinical practice have higher OBPS than prospective trial patients. Increased age and male sex were also associated with increased OBPS. We believe increased patient motivation and education around bowel preparation regimen plays an important role in the success of bowel preparations.

Safe Delivery of Endoscopic Brachytherapy in a Patient with a Dual Chamber Pacemaker.

In patients with advanced esophageal cancer, management of dysphagia is a challenge with significant implications on patient quality of life. Brachytherapy has been shown to be an effective and safe treatment option for symptoms related to dysphagia. The effect of endoscopic brachytherapy on patients with a cardiac implantable electronic device has not previously been described in literature. We present an 89-year-old female with a dual chamber permanent pacemaker who elected to undergo palliative brachytherapy delivered via endoscopy for treatment of dysphagia secondary to locally advanced esophageal adenocarcinoma.

Second-degree interatrial block: A case series.

Advanced interatrial block (IAB) (P-wave ≥120 ms and biphasic P-wave in leads II, III and aVF) is a prevalent ECG pattern frequently associated with supraventricular arrhythmias and stroke, especially in patients with structural heart disease. Intermittent IAB is a much more poorly defined electrocardiographic entity with uncertain clinical significance. In this case series, we review and analyze eight cases of second degree intermittent IAB. In six cases, there is normalization of advanced IAB after a premature supraventricular or ventricular contraction, suggesting a functional block that temporarily recovers post extra-systolic pause. Recognition of intermittent IAB (second degree) may help further characterize the prognostic and clinical implications of this ECG pattern.

Objective assessment of colonoscope manipulation skills in colonoscopy training.

OBJECTIVE: Manipulation of the colonoscope is a technical challenge for novice clinicians which is best learned in a simulated environment. It involves the coordination of scope tip steering with scope insertion, using a rotated image as reference. The purpose of this work is to develop and validate a system which objectively assesses colonoscopy technical skills proficiency in an arbitrary training environment, allowing novices to assess their technical proficiency prior to real patient encounters. METHODS: We implemented a motion tracking setup to objectively analyze and assess the way operators perform colonoscopies, including an analysis of wrist and elbow joint motions. Subsequently, we conducted a validation study to verify whether our motion analysis could discriminate novice colonoscopists from experts. Participants navigated a wooden bench-top model using a standard colonoscope while their motions were tracked. RESULTS: The developed motion tracking setup allowed colonoscopists of varying levels of proficiency to have their colonoscope manipulation assessed, and was able to be operated by a trained non-technical operator. Novice operators had significantly greater median times (101.5 vs. 31.5 s) and number of hand movements (62.0 vs. 21.5) than experts. Experts, however, spent a significantly greater proportion of time in extreme ranges of wrist and elbow joint motion than novices. CONCLUSION: We have developed and implemented a hand and joint motion analysis system that is able to discriminate novices from experts based on objective measures of motion. These metrics could, thus, serve as proxies for technical proficiency during training.