Cardiovascular and clotting risk in AAV peaks around diagnosis

Design

nationwide matched cohort study using Swedish national registers, 2005-2020

Population

4,317 adults with GPA or MPA, 21,582 age- and sex-matched controls, 25,568 first-degree siblings

Primary outcome

composite of myocardial infarction, ischaemic or haemorrhagic stroke, deep vein thrombosis, pulmonary embolism and cardiovascular death

Effect

GPA HR 2.04 (95% CI 1.83-2.38), MPA HR 2.45 (2.00-2.99); HR 7.69 (5.93-9.99) within three months of diagnosis

Adults with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) in the Swedish national registers between 2005 and 2020 were matched to five population controls each, and their first-degree siblings were followed too. Across 4,317 patients, 21,582 controls and 25,568 siblings, both diagnoses were associated with about double the rate of a composite of myocardial infarction, ischaemic or haemorrhagic stroke, deep vein thrombosis, pulmonary embolism and cardiovascular death.

Two details matter more than the headline hazard ratio. The risk was not spread evenly over follow-up: it was almost eight times that of controls within three months of diagnosis, which is the window in which patients are most heavily immunosuppressed, most inflamed and often least mobile. And siblings had no excess risk at all, which argues against shared genetic or household explanations and for the vasculitis itself.

This is registry data, so it shows association rather than cause, and treatment exposure was not modelled. It still changes where to look. Induction is the period to think about venous thromboembolism prophylaxis in an immobile inpatient, to record a cardiovascular risk assessment rather than defer it to the stable phase, and to take chest pain or a swollen calf in a newly diagnosed patient seriously rather than attribute it to the disease.

• Assess and document cardiovascular risk at diagnosis, not once remission is achieved
• Ask about calf pain and breathlessness at every induction-phase visit
• Consider thromboprophylaxis in patients admitted with active AAV and reduced mobility
• In GPA, note the sex split: raised myocardial infarction risk in men, raised ischaemic stroke risk in women
• Reassure siblings — no excess vascular risk was seen in first-degree relatives

The statistics, in plain English

Hazard ratios of 2.04 (95% CI 1.83-2.38) for GPA and 2.45 (2.00-2.99) for MPA both sit well clear of 1.0, so the raised risk is unlikely to be chance. The early-period figure of 7.69 (5.93-9.99) is a within-cohort comparison across time, which is more robust to differences between patients and controls than the overall estimate. Sex-specific findings are subgroup results and rest on fewer events, so treat the male myocardial infarction and female stroke split as a signal to watch rather than a settled difference.

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