Cardiac Autonomic Control and Treatment of Hostility: A Randomized Controlled Trial

Two hundred years ago, the British surgeon Sir John Hunter complained, “My life is at the mercy of any scoundrel who chooses to annoy me,” not long before he died of a heart attack provoked by a violent argument (1). Since that time, the contribution of hostility and anger to the development of CAD has become relatively well established although evidence linking hostility and anger to poor outcomes in patients with existing disease is less firm. In a prospective study of 409 male and 321 female initially healthy residents of Glostrup, Denmark, Barefoot et al. showed that an abbreviated version of the Cook-Medley hostility scale predicted acute myocardial infarction and total mortality, even after control of standard risk factors (2). Data from the Kuopio Ischemic Heart Disease Risk Factor Study demonstrated that men with high levels of hostility were at greater than twice the risk of all-cause mortality, cardiovascular mortality, and myocardial infarction relative to men with lower levels. Adjustment for biological and socioeconomic risk factors did not reduce this risk although adjustment for behavioral risk factors did (3). Data from the Multiple Risk Factor Intervention Trial revealed that high hostile men were more likely than their low hostile counterparts to die of cardiovascular disease (4) Among patients, cynical hostility was associated with progression of carotid artery atherosclerosis even after adjustment for conventional risk factors (5). In a case-control study among post-menopausal women, hostile affect from the Cook-Medley scale was linearly associated with risk for MI (6). Potential for hostility, measured by the Type A structured interview, predicted restenosis after angioplasty (7). In a systematic analysis, Suls and Bunde (8) concluded that the evidenced linking hostility and anger to heart disease in initially healthy subjects was reasonably solid, a conclusion consistent with the findings from two older meta-analyses (9, 10). In contrast, the evidence for an effect in patients with existing disease was weaker. Another recent meta-analysis concluded that hostility and anger were associated with heart disease in both healthy and patient populations (11). The mechanisms linking hostility and anger to elevated risk of heart disease are unclear but one candidate is dysregulation of the autonomic nervous system. Abundant evidence demonstrates that reduced autonomic regulation of the heart, measured as RR interval variability (RRV), predicts the development of heart disease in initially healthy subjects in community studies (12, 13) as well as poorer survival in patients with myocardial infarction (14–16) or heart failure (17). Evidence also links hostility and anger to autonomic dysfunction. HF RRV during the daytime was inversely related to hostility in younger subjects (18). In the laboratory, hostility was inversely related to HF RRV at rest (19) and in response to cognitive challenge (20) and carotid-cardiac vagal baroreflex testing (21). Among hostile type A men, administration of isoproterenol was associated with reduced parasympathetic antagonism compared to the response in less hostile type B men (22). In response to cold forehead stimulation, a vagomimetic stimulus, HR deceleration was smaller in high hostile compared to low hostile subjects (23) and in type A compared to type B subjects (24). These data suggest an inverse association between hostility and cardiac vagal modulation. Thus, considerable evidence supports associations among hostility and anger, heart disease, and autonomic nervous system dysfunction. Moreover, behavioral interventions that target hostility as part of more comprehensive stress management protocols have been shown to reduce risk factors and even disease endpoints (cf. Rozanski et al (25) for a review). Nonetheless, no randomized trials have examined whether reduction of hostility enhances cardiac autonomic regulation. The capacity of cognitive behavior therapy to successfully reduce hostility, on the other hand, is well established as several meta-analyses have determined (26, 27). In this paper, we report the results of a randomized controlled trial testing the hypothesis that a cognitively oriented hostility reduction program would improve autonomic regulation of the heart.