Background/Purpose: Giant cell arteritis (GCA) is the
most common form of vasculitis in the UK, with an incidence of 2.2 cases per 10,000
person-years. Cerebrovascular and cardiovascular disease may be increased in
patients with GCA but risk factors are not confirmed. Social deprivation may be
associated with visual ischaemic complications in
GCA. This study evaluated the risk of cerebrovascular and cardiovascular disease
in patients with GCA compared with matched controls, and identified predictors of
these outcomes.

Methods: A UK General Practice Research Database
(GPRD) from 1991 to 2001 was used for a parallel cohort study of 5,827 patients
with GCA and 37,090 controls, matched on age, gender and location (GP practice).A multivariable
competing risk model (non-cardiovascular related death as the competing risk)
determined the relative risk (subhazard ratio, SHR)
between non-GCA and GCA patients for each of the following outcomes
“cerebrovascular disease”, “cardiovascular disease” or “cardiovascular or
cerebrovascular disease” (three analyses). The model adjusted for smoking
history, history of hypertension, prior use of anti-hypertensives,
history of diabetes or prior use of diabetic medications, history of hyperlipidaemia, prior use of lipid- lowering medications)
and Index of Multiple Deprivation (IMD) quintiles. The model was then run on
each cohort separately to identify predictors of cerebrovascular and cardiovascular
disease (age and gender were now included).

Results: Comparing the GCA cohort with the non-GCA
cohort, the SHR (95% CI) for cerebrovascular disease (1.45 [1.31-1.60]),
cardiovascular disease (1.49 [1.37-1.62]) and for cerebrovascular or
cardiovascular disease (1.47 [1.37-1.57]) were increased. In the GCA cohort only,
predictors of the composite outcome of “cardiovascular or cerebrovascular
disease” included increasing age (1.98 (1.62-2.42), p<0.001 for patients
>80 compared with those <65 years); male gender (1.20 (1.05-1.38),
p<0.001) and those in the most deprived IMD quintile compared with the least
deprived (1.34 (1.01-1.78), p<0.05).  A history of hypertension was predictive of
cardiovascular disease within the GCA cohort (1.53 (1.14-2.05), p<0.01) but
no other significant associations were seen between the other conventional
cardiovascular risk factors and either cardiovascular or cerebrovascular
disease as either separate or composite outcomes.

Conclusion: Patients with GCA are fifty percent more
likely to have cerebrovascular disease or cardiovascular disease than age, gender
and location matched controls. This effect is independent of conventional
cardiovascular risk factors but may be associated with higher levels of social deprivation.

Figure 1. Cumulative incidence of cerebrovascular and cardiovascular
disease by level of social deprivation in patients with and without giant cell
arteritis