Do prescription stimulants increase the risk of adverse cardiovascular events?: A systematic review

BACKGROUND There is increasing concern that prescription stimulants may be associated with adverse cardiovascular events such as stroke, myocardial infarction, and sudden death. Public health concerns are amplified by increasing use of prescription stimulants among adults. METHODS The objective of this study was to conduct a systematic review of the evidence of an association between prescription stimulant use and adverse cardiovascular outcomes. PUBMED, MEDLINE, EMBASE and Google Scholar searches were conducted using key words related to these topics (MESH): ADHD; Adults; Amphetamine; Amphetamines; Arrhythmias, Cardiac; Cardiovascular Diseases; Cardiovascular System; Central Nervous Stimulants; Cerebrovascular; Cohort Studies; Case-control Studies; Death; Death, Sudden, Cardiac; Dextroamphetamine; Drug Toxicity; Methamphetamine; Methylphenidate; Myocardial Infarction; Stimulant; Stroke; Safety. Eligible studies were population-based studies of children, adolescents, or adults using prescription stimulant use as the independent variable and a hard cardiovascular outcome as the dependent variable. RESULTS Ten population-based observational studies which evaluated prescription stimulant use with cardiovascular outcomes were reviewed. Six out of seven studies in children and adolescents did not show an association between stimulant use and adverse cardiovascular outcomes. In contrast, two out of three studies in adults found an association. CONCLUSIONS Findings of an association between prescription stimulant use and adverse cardiovascular outcomes are mixed. Studies of children and adolescents suggest that statistical power is limited in available study populations, and the absolute risk of an event is low. More suggestive of a safety signal, studies of adults found an increased risk for transient ischemic attack and sudden death/ventricular arrhythmia. Interpretation was limited due to differences in population, cardiovascular outcome selection/ascertainment, and methodology. Accounting for confounding and selection biases in these studies is of particular concern. Future studies should address this and other methodological issues.