Coronary heart disease (CHD) is a leading cause of morbidity and mortality in the industrialised world, and places a heavy burden on society in terms of personal disability and health care costs. The first signs of CHD often present acutely as a myocardial infarction (AMI), commonly known as a heart attack. Survivors of a heart attack remain vulnerable to poor health-related quality of life (HRQOL), further cardiac events, and increased morbidity due to a progression of CHD. Thus, the implementation of interventions to reduce these risks is an important public health strategy. To date, secondary prevention and rehabilitation efforts post-AMI focus primarily on the patient. However, it is argued that recovery from AMI occurs within a social context, and that risk reduction strategies are likely to be enhanced if interventions take into account the impact of the event on the quality of life of patients and their partners. Evidence from a review of couple relationship literature indicates that a significant proportion of couples experiences poor HRQOL (i.e., physical and emotional wellbeing) when coping with stressful life events, and that interactive aspects of a couple relationship (i.e., dyadic functioning and behaviour) are associated with individual well-being at such a time. Information from studies of couples dealing with recovery from heart attack is sparse, but tends to reflect the findings from the broader literature. Further research is required with post-AMI couples, though, as there are a number of shortcomings associated with the existing evidence. For instance, it is derived from studies conducted with, mostly small, samples of convenience; many different instruments are used to collect the data; and no studies specifically measure HRQOL. Analytically, most evidence is obtained with univariate and bivariate statistics, and data are analysed as groups of patients or partners, as opposed to dyads. Where multivariable analyses are undertaken a number of bivariate relationships are no longer significant after accounting for covariates such as age and gender; and few researchers investigate predictive associations between dyadic functioning/behaviour and HRQOL outcomes. Finally, there is a paucity of information from comparative analyses. Thus, it is not known whether the well-being of post-AMI couples over time is better than, similar to, or worse than, for example, that in the general population. The research program underpinning this thesis, the QUT-AMI Project, comprised two studies designed to address these methodological issues. The first was an observational, cross-sectional, pilot study conducted in 1998 with 26 post-AMI couples. The main investigation was a prospective cohort study of 93 post-AMI couples undertaken in 1999-2000. In both studies the samples comprised a consecutive series of adult males younger than 75 years who had experienced a first AMI, and their female partners. The average couple in both studies was middle-aged, had been married for many years, and both members of the dyad were working at the time of the heart attack. Prospective participants were identified in major clinical centres that admit cardiac patients, and couples were recruited to the project soon after the patient's heart attack. Clinical data were collected in hospital. Further data were collected with self-administered questionnaires during a home visit at 1 month (pilot and main study), and by mailed questionnaire or during a home visit at 6 months(main study) after the heart attack. The pilot study was undertaken to test recruitment and data collection procedures in preparation for the second (main) study, measure couples' HRQOL at 1 month after the event using the SF-36, and qualitatively investigate life issues for couples coping with recovery from AMI. In the main study couples' HRQOL outcomes were measured at 1 and 6 months post-AMI using the SF-36, and examined for changes over that time. The outcomes were also compared with those from matched population norms to estimate the impact of a heart attack on couples' HRQOL during the early and later recovery period. Additionally, the following relationships were investigated to determine the extent to which:* patients' dyadic functioning (e.g. happiness/satisfaction with relationship, measured with the Marital Adjustment Scale) and use of dyadic behaviour (e.g., hiding concerns and negative feelings from the other member of the dyad, measured with the Protective Buffering Scale) at 1 month predicted patients' emotional well-being at 6 months post-AMI;* partners' dyadic functioning and behaviour at 1 month predicted partners' emotional well-being at 6 months post-AMI;* patients' and partners' dyadic functioning at 1 month predicted patients' or partners' emotional well-being at 6 months post-AMI; and* patients' and partners' dyadic behaviour at 1 month predicted patients' or partners' emotional well-being at 6 months post-AMI. Exploratory analyses were also undertaken to determine the effect of dyadic discrepancies in functioning and behaviour, at 1 month after the heart attack, on patients' and partners' emotional well-being at 6 months after the event. Important findings were as follows:* At 1 month after an AMI the HRQOL of couples is impaired. The major impact is on physical well-being for patients, and emotional well-being for their partners.* In general, couples' HRQOL improves between 1 and 6 months after an AMI.* At 6 months after an AMI, the HRQOL of average couples is similar to that of their peers in the normal population.* There are subgroup variations in the quality of life of post-AMI couples, and these are associated with age, clinically poor physical health, and depression.* The combination of patients' and partners' use of dyadic behaviour at 1 month after an AMI explains 7% of the variation in patients' emotional well-being at 6months after the event, after adjustment for patients' concurrent physical wellbeing and prior levels of emotional well-being, as well as duration of couple relationships.* The combination of partners' perceptions of dyadic functioning and use of dyadic behaviour at 1 month after an AMI explains 5% of the variation in partners' emotional well-being at 6 months after the event, after adjustment for partners' concurrent physical well-being and prior levels of emotional well-being, as well as duration of couples' relationships.* Patients have poorer emotional well-being at 6 months after an AMI if partners use dyadic behaviour infrequently at 1 month after the event.* Partners have poorer emotional well-being at 6 months after an AMI if they are not satisfied/unhappy with the functioning of their relationships at 1 month after the event. Adjusted exploratory analyses, undertaken to determine the extent to which dyadic discrepancies in perceptions of functioning or use of protective buffering behaviour, predict emotional well-being, show that patients who are less satisfied/unhappier with functioning than their partners at 1 month after an AMI have poor emotional wellbeing at 6 months after the event; patients who use the behaviour more frequently than their partners at 1 month after an AMI have poor emotional well-being at 6months after the event; and partners who are less satisfied/unhappier with functioning than their patients at 1 month after an AMI have poor emotional well-being at 6months after the event. The evidence from the QUT-AMI Project supports the proposition that the interaction that occurs within a couple relationship, combined with individual characteristics of members of a dyad, influences the extent to which a heart attack impacts on couples' HRQOL. It is argued that it is not enough to merely focus on implementing secondary prevention strategies with post-AMI patients. Given that poor emotional well-being is known to predict adverse cardiac events, and premature mortality due to cardiac disease, it is recommended that a couple-focused intervention designed to meet specific needs should be implemented with at-risk couples as a public health strategy to improve not only the patients' quality of life but also that of his partner. Further research is recommended to determine the extent to which such an intervention improves post-AMI couples' quality of life.