Hepatitis C treatment reduces the risk of subsequent stroke
or heart attack by between 25 and 35%, a meta-analysis of studies published in
the Journal of Viral Hepatitis shows.
People with hepatitis C have a higher risk of cardiovascular
disease. A
meta-analysis of 22 studies, published in 2016, found that hepatitis C
raised the risk of cardiovascular events by 30% and the risk of stroke by 35%.
However, it has been unclear if curing hepatitis C reduces
that risk, or if people cured of hepatitis C remain at higher risk of heart
attack and stroke due to long-term damage caused by hepatitis C infection.
Several studies have failed to find any effect of treatment on cardiovascular
risk and it is unclear how treating and curing hepatitis C might lead to
improved outcomes.
Chinese researchers at the Beijing Anzhen Hospital at
Capital Medical University carried out a systematic review of studies which
looked at the risk of cardiovascular events in people with hepatitis C, treated
and untreated.
They identified eleven cohort studies carried out in Europe,
North America and Taiwan. Seven of the eleven studies reported on outcomes in
cohorts where some participants received interferon-based treatment. Four
studies reported on outcomes in people treated with direct-acting antivirals.
The meta-analysis compared outcomes in 309,470 people treated for hepatitis C.
Four studies compared cardiovascular outcomes in people
treated for hepatitis C and those who were untreated. Any treatment was
associated with a 36% reduction in the risk of cardiovascular disease (odds
ratio 0.64, 95% CI 0.50-0.83).
Any treatment for hepatitis C reduced the risk of coronary
artery disease by 27% (OR 0.73, (5% CI 0.55-0.96), meta-analysis of five
studies showed.
Five studies looked at the risk of stroke. Any treatment
reduced the risk of stroke by 26% (OR 0.74, 95% CI 0.64-0.86).
Five studies compared cardiovascular outcomes in people
cured of hepatitis C and people who were not cured. Curing hepatitis C reduced
the risk of any cardiovascular outcome by 26% (HR 0.74. 95% CI 0.60-0.72).
The investigators point to several routes by which curing
hepatitis C might limit cardiovascular disease. Hepatitis C is known to cause
endothelial dysfunction, in which the walls of blood vessels lose elasticity,
raising blood pressure and constricting blood supply to the heart. Direct-acting
antivirals improve endothelial function.
Direct-acting antiviral therapy also improves diabetes and
pre-diabetes, and several studies have shown that the impact of direct-acting
antivirals on cardiovascular disease is more pronounced in people with type 2
diabetes.