ARCH Trial Adjudicated Cardiovascular Event Counts

confidence: medium · 2 sources

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Working research — not a recommendation.

This page records what the evidence says a policy does, not what anyone should do about it. It has been synthesized from the cited sources but has not been independently reviewed.

What the evidence says

The evidence on this topic is thin. It comes from one randomized, active-comparator trial (ARCH) of romosozumab followed by alendronate versus alendronate alone, as described in two 2026 secondary sources. Neither source gives event counts, incidence rates, hazard ratios or confidence intervals, so this page cannot state a magnitude.

In the first year, positively adjudicated serious cardiovascular adverse events were numerically more frequent in the romosozumab group than in the alendronate group. One source describes the difference as not reaching statistical significance. The direction is stated, but the size of the gap is not.

A post hoc analysis of ARCH reported a significant increase in the risk of major adverse cardiovascular events (MACE) among patients receiving romosozumab. The source gives no hazard ratio, event count or interval. It also does not say how the post hoc analysis defined or adjudicated MACE. The claims do not establish a mechanism by which romosozumab would increase cardiovascular events.

Where the evidence splits

The claims differ on whether the romosozumab–alendronate difference is statistically significant. The primary ARCH report, as described by Ahn, found a numerically higher incidence of adjudicated serious cardiovascular adverse events within 1 year that did not reach statistical significance. The post hoc analysis, also described by Ahn, reported a significant increase in MACE risk. The sources on this page do not explain the split. The two analyses may use different outcome definitions (serious cardiovascular adverse events versus MACE). They may also differ in pre-specification, since one is post hoc. The claims state neither difference, so this is only a possible explanation.

Thresholds and dose-response

No threshold established in the current sources.

Open empirical questions

Findings

Romosozumab followed by alendronate increases adjudicated serious cardiovascular adverse events in the first year compared with alendronate alone, in numerical terms

confidence — direction: mediumconfidence — magnitude: lowconsensus: thin — both sources point the same way, but neither reports a statistically significant difference for this outcome
mechanism
not established in the current sources
effect
increases, numerically; direction stated, magnitude not given; the difference did not reach statistical significance; no event counts, rates or confidence intervals provided
conditions / moderators
first year of treatment; postmenopausal women with osteoporosis at high risk of fracture; active-comparator design (alendronate); other moderators not established

Romosozumab increases the risk of major adverse cardiovascular events (MACE) compared with alendronate in a post hoc analysis of ARCH

confidence — direction: mediumconfidence — magnitude: lowconsensus: thin — a single secondary-source description of one post hoc analysis
mechanism
not established in the current sources
effect
increases; reported as a significant increase in MACE risk; magnitude not given; no hazard ratio, event counts or confidence intervals provided
conditions / moderators
post hoc analysis, not a pre-specified primary comparison; MACE definition and follow-up window not stated; other moderators not established