NEW YORK – Perioperative beta-blocker use in patients with hypertension is associated with increased cardiovascular complications and mortality after noncardiac surgery, researchers from Denmark report.
“The consistency of the findings of increased risks associated with beta-blockers across numerous subgroups was an important finding,” Dr. Mads Emil Jorgensen from Gentofte Hospital in Hellerup said by email. “It supports our concern that in a low-risk population, beta-blocker-associated risks may outweigh the advantages of the treatment, in a wide range of low-risk patients.”
Several studies have shown that perioperative beta-blocker use may benefit patients at high cardiac risk, but may increase mortality in others. Guidelines from the United States and Europe support continuing beta-blocker use perioperatively in patients already using being treated with them, but literature support for these recommendations is sparse.
Dr. Jorgensen’s team used data from Statistics Denmark to investigate whether perioperative beta-blocker use is associated with an increased risk of major adverse cardiovascular events (MACEs) and all-cause mortality in the 30 days after noncardiac surgery in hypertensive patients free of cardiac, renal, and liver disease.
Among 14,644 patients treated with beta-blockers and 40,676 patients treated with other antihypertensives, the incidence of 30-day MACEs was significantly higher among those taking beta-blockers than among those taking other antihypertensives (1.32% vs. 0.84%, p<0.001).
Thirty-day all-cause mortality was also significantly higher in the beta-blocker group than in the other antihypertensives group (1.93% vs. 1.32%, p<0.001), the researchers report in JAMA Internal Medicine, online Oct. 5.
With the exception of combinations that included beta-blockers and two other antihypertensive drugs, all regimens that included a beta-blocker were associated with significantly increased risks of MACE and all-cause mortality, compared with regimens of renin-angiotensin system inhibitors and thiazides.
Results were comparable in subgroup analyses of diabetics versus nondiabetics and patients with low risk versus elevated risk.
The elevated risks were especially notable among patients at least 70 years old (number needed to harm, NNH, 140), men (NNH, 142), and patients undergoing acute surgery (NNH, 97).
“This study, among others, presents the case that the beneficial effects of beta-blockers might be subgroup dependent and that beta-blockers may not be the safe haven that previous perioperative guidelines have suggested,” Dr. Jorgensen concluded. “More studies are needed to further the understanding of patient subgroups at risk, preferably in the setting of a randomized trial.”
“The use of beta-blockers in 1 out of 4 patients with uncomplicated hypertension was higher than expected, as beta-blockers are no longer first-line drugs for treating hypertension,” Dr. Jorgensen noted. “The high prevalence of beta-blocker use in this patient group underlines the clinical importance of these findings.”
“Although we cannot conclude on whether the therapy should be changed prior to surgery, clinicians might want to pay special attention to these otherwise low-risk patients in the perioperative setting,” he said.
“It is important to keep in mind that our population consisted of hypertensive patients without cardiac, renal or liver disease; thus not all patients with hypertension receiving a beta-blocker are expected to be at increased risk,” Dr. Jorgensen cautioned. “Several conditions may necessitate and fully justify the use of beta-blockers, such as congestive heart failure or recent myocardial infarction, as demonstrated in a previous study from our research group.”
Dr. Mark L. Friedell from the University of Missouri Kansas City School of Medicine in Kansas City coauthored one of the earlier reports that called into question the safety of perioperative beta-blocker use in low-risk patients. He said by email, “I was surprised at the higher mortality of patients with no cardiac risk factors. But, when taking the POISE trial into consideration, it makes sense that patients with no risk factors might be the ones most harmed by hypotension/stroke since there was no counter balance of cardiac protection such as that given to the patients with 3-4 cardiac risk factors.”
His conclusion: “Patients with no or 1-2 cardiac risk factors do not need to be started on a beta-blocker perioperatively to try to mitigate cardiac risk.”