October 4th, 2012
Beta-Blockers May Not Work as Well as We Thought: So What Does “Optimal Medical Therapy” Really Mean?
In this week’s issue of JAMA, Bangalore and colleagues report outcomes from the REACH registry stratified by the use of beta-blocker therapy. Enrolling patients with either 3 or more traditional risk factors or established cardiac, peripheral vascular, or cerebrovascular disease, REACH was a large, multinational observational study that examined long-term outcomes in patients at risk for atherothrombotic events. In the present analysis, the outcomes of patients taking beta-blockers were not statistically different from the outcomes of patients not taking these agents. These findings were confirmed in separate cohorts of post-MI patients, patients with known CAD without MI, and patients with risk factors for CAD alone.
Although these data draw attention to the need for more current studies examining the clinical efficacy of established agents such as beta-blockers, particularly in an era of “modern reperfusion,” they should be even more sobering for proponents of optimal medical therapy (OMT) used for the treatment of stable ischemic heart disease (SIHD). Proponents of OMT have repeatedly held to the tenet that the benefits of coronary revascularization for SIHD were demonstrated in outdated studies conducted prior to the institution of contemporary OMT, which on its own could reduce hard cardiovascular outcomes. So in the wake of this REACH analysis, what really is so beneficial about contemporary OMT: aspirin and statins alone? If the data for beta-blockers are scant, the data for nitrates (in terms of a reduction in hard events) are even worse. Calcium channel blockers and ranolazine are additionally unproven classes of agents when it comes to reductions in hard clinical outcomes in SIHD patients.
Frankly, it is probably fair to say that we have as little evidence about the “hard” benefits of OMT (beyond aspirin and statins) as we do about the benefits of coronary revascularization in the present era. Despite its limitations as an observational study, this contribution by Bangalore and colleagues helps to illustrate the potential weaknesses of the evidence base for what many physicians consider one of the mainstays of OMT.
[EDITOR’S NOTE: Comments on this post are closed; we invite readers to engage in a wide-ranging dialog over at Bangalore’s post on this study here]