To the Editor.
—The article by Soumerai and colleagues1 provides valuable evidence to support existing guidelines to prescribe β-blockers for secondary prevention of AMI. While the authors mention that barriers to prescribing β-blockers include "exaggerated concerns regarding adverse effects on quality of life," they do not consider the implications of this on their findings.As the authors acknowledge, β-blocker use is not recommended in patients with a history of depression.2 Furthermore, depression has recently been linked to coronary heart disease morbidity and mortality.3,4 As depressed people may be more likely to receive calcium channel blockers than β-blockers and also are more likely to have future cardiac events, confounding by depression could explain the reported association. While the authors may not be able to evaluate this adequately as the cross-linked data sets they are using may not have reliable information on depression, perhaps they could control for antidepressant use as a
Lapane KL, Hume AL. Adverse Outcomes of Underuse of β-Blockers in Elderly Patients. JAMA. 1997;277(18):1435. doi:10.1001/jama.1997.03540420031018