Wang, Yang

Objective To determine the harms of ezetimibe in people who need lipid-lowering treatment. Design Systematic review and meta-analysis. Data sources Randomised controlled trials and cohort studies. Eligibility criteria for selecting studies Studies comparing ezetimibe with placebo, standard care, or other lipid-lowering agents in people who need lipid-lowering treatment with a follow-up duration of at least six months (or 24 weeks). The relative effects for potential harms of ezetimibe were pooled by use of random effect pairwise meta-analyses for randomised controlled trials and the evidence from observational studies was narratively summarised. The certainty of evidence was assessed using the Grading of Recommendation Assessment, Development, and Evaluation. Results 48 randomised controlled trials with 28 444 participants (median follow-up 34 weeks, range 24-312 weeks) and four observational studies with 1667 participants (median follow-up 282 weeks, range 72-400 weeks) were included. The meta-analyses of randomised trials showed moderate to high certainty that ezetimibe was not associated with cancer (relative risk 1.01; 95% confidence interval 0.92 to 1.11), fractures (0.90; 0.74 to 1.10), discontinuation due to any adverse event (0.87; 0.74 to 1.03), gastrointestinal adverse events leading to discontinuation (1.34; 0.58 to 3.08), myalgia or muscular pain leading to discontinuation (0.82; 0.51 to 1.33), neurocognitive events (1.48; 0.58 to 3.81), or new-onset diabetes (0.88; 0.61 to 1.28). The narrative analysis of observational studies provided consistent findings. No credible subgroup effects were identified for the harm outcomes, including shorter versus longer follow-up duration of trials. Conclusions Ezetimibe results in little to no difference in adverse events or other undesirable effects compared with placebo, usual care or other lipid-lowering agents. Review registration PROSPERO CRD42020187437.

Measurements of stroke volume were made in dogs during graded exercise on a horizontal treadmill up to the maximal exercise which they could maintain for 2 to 3 minutes. Eleven series of experiments were performed on 7 dogs. The cardiac output was measured by the indicator-dilution technic and the heart rate was measured from the aortic pressure tracing. At all grades of exercise, there was little or no change in stroke volume. Even with severe exercise, when the cardiac output had increased from 1.5 to 3.5 (average, 2.4) times the values obtained with the dog standing at rest, the stroke volume showed less than 5 per cent change over resting values in 5 experiments on 4 dogs, while in the remainder the increases were 8, 11, 11, 14, 15, and 19 per cent. Thus, the increase in cardiac output in the untrained exercising dog is almost directly proportional to the increase in heart rate. This is in contrast to other situations, such as the combination of exercise with infusion of catecholamines, where an increase in stroke volume may make an important contribution to the increase in cardiac output.