Administration of fluoroquinolones emerged as the most important risk factor for CDAD in Quebec during an epidemic caused by a hypervirulent strain of C. difficile.

Most patients with a perioperative MI will not experience ischemic symptoms. Data suggest that routine monitoring of troponin levels in at-risk patients is needed after surgery to detect most MIs, which have an equally poor prognosis regardless of whether they are symptomatic or asymptomatic.

The efficacy of convalescent plasma for coronavirus disease 2019 (COVID-19) is unclear. Although most randomized controlled trials have shown negative results, uncontrolled studies have suggested that the antibody content could influence patient outcomes. We conducted an open-label, randomized controlled trial of convalescent plasma for adults with COVID-19 receiving oxygen within 12 d of respiratory symptom onset (NCT04348656). Patients were allocated 2:1 to 500 ml of convalescent plasma or standard of care. The composite primary outcome was intubation or death by 30 d. Exploratory analyses of the effect of convalescent plasma antibodies on the primary outcome was assessed by logistic regression. The trial was terminated at 78% of planned enrollment after meeting stopping criteria for futility. In total, 940 patients were randomized, and 921 patients were included in the intention-to-treat analysis. Intubation or death occurred in 199/614 (32.4%) patients in the convalescent plasma arm and 86/307 (28.0%) patients in the standard of care arm—relative risk (RR) = 1.16 (95% confidence interval (CI) 0.94–1.43, P = 0.18). Patients in the convalescent plasma arm had more serious adverse events (33.4% versus 26.4%; RR = 1.27, 95% CI 1.02–1.57, P = 0.034). The antibody content significantly modulated the therapeutic effect of convalescent plasma. In multivariate analysis, each standardized log increase in neutralization or antibody-dependent cellular cytotoxicity independently reduced the potential harmful effect of plasma (odds ratio (OR) = 0.74, 95% CI 0.57–0.95 and OR = 0.66, 95% CI 0.50–0.87, respectively), whereas IgG against the full transmembrane spike protein increased it (OR = 1.53, 95% CI 1.14–2.05). Convalescent plasma did not reduce the risk of intubation or death at 30 d in hospitalized patients with COVID-19. Transfusion of convalescent plasma with unfavorable antibody profiles could be associated with worse clinical outcomes compared to standard care.

The present study shows the beneficial influence of generating self-explanations when dealing with less familiar clinical contexts. Generating self-explanations without feedback resulted in better diagnostic performance than in the control group at 1 week after the intervention.

D espite important advances in primary prevention, atherosclerosis remains the leading cause of death in developed societies.1 In addition to risk factors such as hypertension, diabetes mellitus, tobacco use and dyslipidemia, less traditional risk factors have also been sought. Many markers, including C-reactive protein and interleukins, highlight inflammation as a key mediator in both the progression and activation of atherosclerotic lesions.2-4 Some medications that are used to prevent cardiovascular diseases, such as statins, also appear to reduce inflammation. 5 Animal experiments have shown that pneumococcal vaccination reduces the extent of atherosclerotic lesions. 6 We hypothesized that antibodies directed against Streptococcus pneumoniae also recognize oxidized low-density lipoprotein (LDL) and impede the formation of foam cells. Interestingly, a retrospective cohort study involving World War II veterans who had undergone splenectomy documented excess mortality rates from both pneumonia and ischemic heart disease. 7 More recent data have suggested that acute pneumococcal infections, but not vaccinations, increase the risk of vascular events; 8 however, the duration of vaccination exposure considered in that study was limited.Our primary objective was to evaluate the association between pneumococcal vaccination and the risk of myocardial infarction. We also explored whether any effect of vaccination on the risk of infarction waned over time. Methods Design and ethics approvalWe conducted a case-control study of patients who were considered at risk for myocardial infarction and who had been admitted to a tertiary care hospital. We obtained approval for this study from the research ethics board of the Centre hospitalier universitaire de Sherbrooke and Quebec's Commission d'accès à l'information. Data sourcesWe used 2 databases for this study. The first was the research-purpose database 9 of the Centre informatisé de recherche évaluative en services et soins de santé of the Centre hospitalier universitaire de Sherbrooke, a tertiary care teaching hospital in the province of Quebec. Along with demographic data, this database included, for each hospital admission since 1996, detailed information on all primary and secondary diagnoses, coded according to the International Classification of Diseases, 9th revision (ICD-9). This database also contained all biochemical and pharmaceutical data recorded during the admission, including, for each medication prescribed, the name, dosage, formulation, quantity dis- Pneumococcal vaccination and risk of myocardial infarctionFrom the Department of Medicine (Lamontagne, Garant, Carvalho, Lanthier, Pilon), Université de Sherbrooke, Sherbrooke, Que.; and the Department of Clinical Epidemiology and Biostatistics (Lamontagne, Smieja), McMaster University, Hamilton, Ont. CMAJ ResearchBackground: Based on promising results from laboratory studies, we hypothesized that pneumococcal vaccination would protect patients from myocardial infarction. Methods:We conducted a hospital-based ...