Underlying cardiovascular risk and major adverse cardiovascular events after acute respiratory infection: a population-based cohort study of over 4.2 million individuals in England, 2008-2018

ABSTRACT Background While acute respiratory infections (ARIs) can lead to cardiovascular complications, the effect of underlying cardiovascular risk profile on ARI incidence and cardiovascular complications in those without established cardiovascular disease (CVD) is unknown. Whether to consider individuals at raised cardiovascular risk a priority group for vaccination against respiratory infections therefore remains unclear. Methods We conducted a cohort study in individuals aged 40-64 years without established CVD or a chronic health condition eligible for influenza vaccination, using Clinical Practice Research Datalink GOLD and Aurum data from 01/09/2008-31/08/2018 linked to Hospital Episode Statistics Admitted Patient Care and Office for National Statistics mortality data from England. We classified cardiovascular risk based on diagnosed hypertension and overall predicted cardiovascular risk estimated using QRISK2 score (≥10% compared with <10%). Using multivariable Poisson regression models, we obtained incidence rate ratios (IRR) for ARI. Among individuals who had an ARI, we then used multivariable Cox regression to obtain hazard ratios (HR) for the risk of major adverse cardiovascular events (MACE) within one year of infection. Findings 4,212,930 individuals were included; 12·5% had hypertension and 14·4% had a QRISK2 score ≥10%. After adjusting for confounders, patients with hypertension (IRR 1·04, 95% CI 1·03-1·05) or QRISK2 score ≥10% (IRR 1·39, 1·37-1·40) had a higher incidence of ARI. Of the 442,408 individuals with an ARI, 4,196 had a MACE within one year of infection. After adjustment, hypertension (HR 1·98, 1·83-2·15) and QRISK2 score ≥10% (HR 3·65, 3·42-3·89) were associated with substantial increased risk of a MACE after infection. Interpretation People without diagnosed CVD but who have raised cardiovascular risk, measured by diagnosed hypertension or, in particular, overall predicted cardiovascular risk, have increased incidence of both ARI and cardiovascular complications following an ARI.