Archief Roodbont

Beta-blocker induced heart rate reduction ‘harmful in hypertension’

24 October 2008

MedWire News: Slower heart rates are associated with an increased risk for cardiovascular (CV) events and death in patients with hypertension being treated with beta blockers, a meta-analysis of randomized controlled trials (RCTs) has shown.

The finding was unexpected and contrasts with the effect of beta blockers in patients with myocardial infarction (MI) or heart failure, in whom pharmacological heart-rate reduction is known to be beneficial.

The study, by Frank Messerli’s group at St Luke’s Roosevelt Hospital and Columbia University, New York, USA, aimed to evaluate the role of heart-rate reduction with beta blockers on the risk for CV events in patients with hypertension.
“Given that resting heart rate is a risk factor, slowing it should have beneficial effects,” the authors remark.

They searched the literature for RCTs that evaluated beta blockers as first-line therapy for hypertension and featured 1-year follow-up plus data on heart rate. Nine trials were eligible; they included 34,096 patients randomized to beta-blockers (mainly atenolol), 30,139 taking other antihypertensive drugs, and 3,987 taking placebo.

Unexpectedly, Messerli et al found that after 1 year of beta-blocker therapy heart rates inversely correlated with all-cause mortality (p<0.0001), cardiovascular mortality (p<0.0001), MI (p<0.0001), stroke (p=0.06), and heart failure (p<0.0001).

The authors say the most likely explanation for their findings is that pharmacologically induced bradycardia leads to dyssynchrony between outgoing and reflected pulse wave, thereby increasing central aortic pressure and the hemodynamic burden to the target organs.

They conclude: “In contrast to patients with MI and heart failure, beta-blocker– associated reduction in heart rate increased the risk for cardiovascular events and death for hypertensive patients.”

In an accompanying editorial Norman Kaplan (University of Texas Southwestern Medical Center, Dallas, TX) says the new data add weight to the argument that beta blockers are not appropriate therapy for primary uncomplicated hypertension.

“With this addition to the evidence, beta blockers will surely remain indicated for heart failure, for after MI, and for tachyarrhythmias, but no longer for hypertension in the absence of these compelling indications,” he observes.

J Am Coll Cardiol 2008; 52: 1482–1489