Holding the home beta-blocker on admission may not be the safe option

Design

retrospective cohort study using target trial emulation with inverse probability of treatment weighting and Cox regression

Population

4,635 adults on chronic beta-blockers admitted from a single US academic emergency department with suspected infection; shock, heart rate under 40 or over 120, and need for IV rate control excluded

Primary outcome

90-day all-cause mortality, continuation versus non-continuation of oral beta-blocker within 48 hours

Effect

continuation in 25.3%; 90-day mortality HR 0.77 (95% CI 0.61-0.98, p=0.03); in-hospital mortality OR 0.60 (0.30-1.20)

Beta-blockers are routinely stopped when a patient is admitted with suspected infection, on the reasoning that blunting the heart rate response is dangerous. This study used the target trial emulation framework in a single large US academic emergency department, comparing continuation of chronic oral beta-blockers within 48 hours against no continuation in 4,635 adults admitted with suspected infection, defined by blood cultures plus broad-spectrum antibiotics. Patients in shock, with a heart rate under 40 or over 120, or needing intravenous rate control were excluded.

Only 1,172 (25.3%) had their beta-blocker continued. Continuation was associated with lower 90-day all-cause mortality (hazard ratio 0.77, 95% CI 0.61-0.98, p=0.03) and shorter hospital stay. In-hospital mortality did not differ significantly (odds ratio 0.60, 0.30-1.20).

The design deserves respect and scepticism in equal measure. Target trial emulation with inverse probability weighting is the right approach for this question and adjusts for severity, comorbidity and resuscitation status — but the clinician's decision to continue a beta-blocker is itself a judgement that the patient is not too sick, and no weighting fully removes that. The practical reading is not 'continue beta-blockers to reduce mortality'. It is that the reflex to hold them in a patient who is haemodynamically stable, not in shock and not tachycardic beyond 120 lacks evidence behind it, and stopping abruptly carries its own rebound risk in someone with ischaemic heart disease.

• In a stable patient with suspected infection, make holding the beta-blocker a decision rather than a default
• The exclusions define who this does not apply to: shock, heart rate under 40 or over 120, need for IV rate control
• Remember rebound: abrupt withdrawal in ischaemic heart disease carries its own risk
• Document the reason if you do hold it, and set a point at which it will be restarted
• This is observational; it justifies not stopping reflexively, not a policy of continuing

The statistics, in plain English

A hazard ratio of 0.77 with an interval from 0.61 to 0.98 only just excludes 1.0, so the mortality result is fragile and would not survive much additional uncertainty. The in-hospital mortality estimate (0.60, 0.30-1.20) points the same way but crosses 1.0, which is what you expect when fewer events are available. The incidence rate ratio of 0.39 for hospital stay is implausibly large for a drug effect and is far more likely to reflect that clinicians continued beta-blockers in patients who were already destined for a short admission — a clear illustration of confounding by indication that weighting has not removed.

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