"As this was an observational study, we want to first caution against assuming any causality inferences," Dr Karina W. Davidson from Columbia University Medical Center, New said. "We do know that hostility identifies those at ischemic heart disease risk. What we do not yet know is if this risk is modifiable, nor all the mechanisms by which hostility confers risk."
The researchers examined the relationship between scores on the observed hostility (OHO) subscale of the Expanded Structured Interview and incident ischemic heart disease events and sought to determine whether any relation is independent of cardiovascular risk factors, self-reported hostility, and other psychosocial risk factors.
The final analysis included 1749 subjects from Nova Scotia who were free of ischemic heart disease at baseline and were observed for ischemic heart disease events during 10 years of follow-up.
The ESI involves a stressful 12-minute interview. Only 177 people scored a rating of 1, for "No Observed Hostility".
The others, who scored from 2 to 5 ("Any Observed Hostility"), were younger, were more likely to be active smokers, had higher levels of self-reported depressive symptoms, and had more destructive anger justification.
Increased cytokine-induced illness
Compared to the risk of ischemic heart disease events in subjects with no observed hostility, the odds were 1.96-fold higher for OHO rating 2, 2.21-fold higher for OHO rating 3, and 2.42-fold higher for OHO ratings 4 and 5.
After adjustment for cardiovascular and psychosocial covariates (including self-reported hostility), people with any observed hostility had a 2.06-fold increased risk of incident ischemic heart disease compared to those with no observed hostility.
"We have to caution physicians to not mistakenly 'blame-the-victim', to assume that these patients' subsequent medical disease burden is their own fault," Dr Davidson said. "Hostility might be a marker of increased cytokine-induced illness that is currently subclinical, not overt. It might be caused by genes or SNP variants that are causal for cardiovascular disease."
"So," she continued, "while it would be easy to make the assumption that hostility might cause later difficulties, we do not know this. Instead, hostile patients deserve our compassion and care, as they are a patient population that is vulnerable to early disease and death, and we do not yet have cures for either their risk marker or their excess disease burden."
Hostility a risk factor?
Dr Davidson's group has recently completed a randomised controlled trial to determine whether cognitive behavioural techniques reduce ambulatory blood pressure levels in hostile hypertensive patients who didn't reach target levels on medication alone, and secondarily to test if these interventions reduce hostility.
"These results will be out soon," she said, "and we would hope that after we have evidence of both the modifiability of hostility and its attendant medical risks, we can offer a short, useful screen to detect hostile patients and direct them to useful resources."
"Given that 90% of study participants had some observed hostility, it is difficult to consider hostility as a risk factor," said Dr Mary A. Whooley from the University of California, San Francisco and Jonathan Wong from the University of California, Irvine in an editorial. "A more valuable message might be that the absence of hostility was protective against coronary heart disease."
(Reuters Health, Will Boggs MD, September 2011)