Study explores link between specific temperament traits and clinical events after heart attack

This study explores for the first time the potential predictive power of Cloninger's temperament traits on prognosis in patients after an acute coronary syndrome (ACS) admission. Only Novelty Seeking (NS) was, however, significantly associated with a low risk of severe cardiac effects and a low risk of clinical events. When the potential confounding variables, notably including depression and anhedonia, were taken into account, the effects of NS on severe cardiac effects or on clinical events were no longer significant. High-NS subjects may have a better prognosis after an ACS.

A group of French investigators has explored the link between specific temperament traits and clinical events after a heart attack in a study published in the current issue of Psychotherapy and Psychosomatics. Recent studies have reported an association between either Cloninger's temperament traits and atherosclerosis or between these temperaments and coronary heart disease risk factors of the metabolic cardiovascular syndrome (insulin resistance syndrome). However, Cloninger's model contributed to autonomic cardiac control, a potential mediating mechanism between these temperaments and coronary heart disease risk.

Cloninger's model of temperament consists of 3 temperament traits: novelty seeking (NS), harm avoidance (HA) and reward dependence (RD). According to Cloninger's model, NS reflects behavioral activation, HA reflects behavioral inhibition, and RD reflects behavioral maintenance. NS and HA have been previously associated with biological and behavioral risk factors for coronary heart disease (CHD), but the findings have been somewhat mixed. The results concerning RD are also conflicting. Cloninger's temperament traits could be a risk factor for cardiac events and personality traits such as hostility and type D behavior have been previously associated with cardiac events.

The aim of this study was therefore to investigate the effects of Cloninger's temperament traits on prognosis at a 3-year follow-up in patients hospitalized for acute coronary syndrome (ACS). The study subjects were consecutive patients with suspected ACS admitted to the cardiac/coronary intensive care unit of Montereau Fault-Yonne general hospital in France. The patients completed the French version of the Tridimensional Personality Questionnaire (TPQ) 1-4 days after admission.

Two hundred and ninety-six patients (226 males, 70 females) completed the TPQ. Eleven potential covariates were taken into account: 2 demographic variables (age and gender), 7 medical factors: current tobacco use, hypertension, diabetes mellitus, hypercholesterolemia, obesity, previous and family history of ACS and left ventricular hypertrophy diagnosed by echocardiography, and 2 psychometric variables: anhedonia and depression respectively rated by the revised Physical Anhedonia Scale (PAS) and the Depression subscale of the Hospital Anxiety and Depression Scale (HAD-D). The independent variables were the TPQ subscores.

There were 146 clinical events including 45 severe cardiac events. In univariate Cox regression analysis, age, left ventricular hypertrophy, PAS, HAD-D and NS were significantly related to an increased incidence of severe cardiac events (death or myocardial infarction) at the 3-year follow-up. For clinical events, age, left ventricular hypertrophy, PAS, HAD-D, NS and categorical NS  were significant predictors of an increased risk of clinical events.

The present study explores for the first time the potential predictive power of Cloninger's temperament traits on prognosis in patients after an ACS admission. However, among the various Cloninger temperament traits, only NS using nonadjusted analyses was significantly associated with a low risk of severe cardiac effects and a low risk of clinical events. When the potential confounding variables, notably including depression and anhedonia, were taken into account, the effects of NS on severe cardiac effects or on clinical events were no longer significant. High-NS subjects may have a better prognosis after an ACS. This important result must be confirmed.