A study published this week in the open access journal PLoS Medicine shows
that for elderly people at risk of cardiovascular disease, the presence of
inflammatory markers in the blood can identify that an individual is at a
higher risk of a fatal rather than a non-fatal heart attack or stroke.
Inflammation is an immune response to injury. However, inflammation is
also thought to play a role in cardiovascular disease. Previous studies
have
shown an association between high levels of markers of inflammation in the
circulation with a greater risk of a cardiovascular event, such as a heart
attack or stroke. In this study, Naveed Sattar of the University of
Glasgow and colleagues used data from an existing trial known as PROSPER
(the
Prospective Study of Pravastatin in the Elderly at Risk), which involved
participants aged between 70 and 82 who had or were at risk of
cardiovascular
disease. They examined if three inflammatory markers-interleukin-6 (IL-6),
C-reactive protein (CRP) and fibrinogen-were each more strongly
associated with fatal cardiovascular events than with non-fatal
cardiovascular events in the period of over three years in which the
patients in the
trial were monitored.
Using several statistical models, the researchers found that in this group
of elderly patients increased levels of all three inflammatory markers,
and
in particular IL-6, were more strongly associated with a fatal heart
attack or stroke than with a non-fatal heart attack or stroke. They also
investigated the predictive value of these inflammatory markers-in other
words, whether it was useful to include these markers in tools designed to
distinguish between individuals with a high and a low risk of heart
attacks, strokes and other cardiovascular events. They report that adding
IL-6 to
the established risk factors in predictive tools-including lifestyle
factors such as smoking, high blood pressure and high blood cholesterol,
all of
which greatly increase the risk of cardiovascular disease-could help
better identify those individuals at a risk of a fatal stroke or heart
attack,
but not those at risk of a non-fatal cardiovascular event.
The findings of the study suggest inflammatory markers may be more
strongly associated with fatal heart attacks and strokes than non-fatal
cardiovascular events. The researchers acknowledge that these findings now
need to be confirmed in younger populations and larger studies to
demonstrate an outright association and the design of the current study
cannot show whether the proposed association is a causal one.
Nevertheless,
the findings should stimulate further investigation into whether the
application of inflammatory markers may help better predict the risk of
deaths
from cardiovascular disease, and whether novel treatments which dampen
inflammation might help prolong life.
Competing Interests: SC received research funding and honoraria from Astra
Zeneca, makers of rosuvastatin. JS is a consultant to Astra Zeneca,
GlaxoSmithKline, MSD, and Pfizer, and is on the Speakers Bureau for Astra
Zeneca and Pfizer.
Funding: Funded by Chest, Heart, & Stroke Association, Scotland, and The
Stroke Association, UK. The funding bodies had no role in the study or
writing of the manuscript.
Citation:
"Are Markers of Inflammation More Strongly Associated with Risk for Fatal Than for Nonfatal Vascular Events?"
Sattar N, Murray HM, Welsh P, Blauw GJ, Buckley BM, et al. (2009)
PLoS Med 6(6): e1000099
Source
PLoS Medicine