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Type A behavior and mortality from coronary heart disease
1School of Public Health, University of California, Berkeley 94720.
Insights
Type A behavior in coronary heart disease (CHD) patients was unexpectedly linked to lower subsequent CHD mortality compared to Type B. This suggests Type A individuals with CHD may not face increased mortality risk.
Area of Science:
- Cardiology
- Behavioral Medicine
- Epidemiology
Background:
- The relationship between behavioral patterns (Type A vs. Type B) and coronary heart disease (CHD) outcomes remains controversial.
- Previous studies have yielded conflicting results regarding the impact of behavior type on CHD morbidity and mortality.
Purpose of the Study:
- To investigate the association between behavior type (Type A or Type B) and subsequent CHD mortality in male patients.
- To determine if Type A behavior pattern influences long-term survival rates after a CHD event.
Main Methods:
- Analysis of survival data from 257 male CHD patients in the Western Collaborative Group Study.
- Behavior type was assessed via structured interview prior to the CHD event.
- Survival analysis, including proportional-hazards models, controlled for confounding variables.
Main Results:
- Among 231 patients surviving the initial 24 hours post-event, Type A patients exhibited a lower CHD mortality rate (19.1/1000 person-years) than Type B patients (31.7/1000 person-years).
- Survival analysis revealed a significantly lower relative CHD mortality rate for Type A compared to Type B patients (hazard ratio 0.58, P=0.03).
- This protective association for Type A behavior was observed across age subgroups and was more pronounced in symptomatic myocardial infarction cases.
Conclusions:
- Patients with coronary heart disease and a Type A behavior pattern do not appear to be at increased risk for subsequent CHD mortality.
- The findings suggest a potentially protective effect of Type A behavior on long-term survival post-CHD, warranting further investigation.
Abstract:
The relation of behavior (Type A or Type B) to the morbidity and mortality of coronary heart disease (CHD) is still debated. We studied the survival of 257 male patients with CHD from the initial, 8.5-year phase of the Western Collaborative Group Study to see whether behavior type--as assessed by a structured interview before the CHD event--was related to subsequent CHD mortality. Behavior type was not related to mortality in 26 patients who died within 24 hours of the coronary event. However, of the 231 patients who survived for 24 hours, the mortality rate associated with CHD among 160 Type A patients studied during an average 12.7 years was 19.1 per 1000 person-years. This was unexpectedly lower than the corresponding rate of 31.7 among 71 Type B patients who were followed for an average of 11.5 years (P = 0.04). In a proportional-hazards survival analysis, which controlled for variable follow-up time, the type of initial coronary event, and traditional risk variables, the relative CHD-associated mortality rate among Type A as compared with Type B patients was 0.58 (P = 0.03; 95 percent confidence interval, 0.35 to 0.96). The lower mortality among Type A subjects occurred in both younger and older subgroups but was more pronounced in patients whose initial diagnosis was symptomatic myocardial infarction rather than silent myocardial infarction or angina pectoris. This apparent advantage associated with Type A behavior is surprising and needs confirmation, but the results do indicate that patients with CHD and a Type A behavior pattern are not at increased risk for subsequent CHD mortality.