A moderator-mediator analysis of coronary heart disease mortality

Explaining heterogeneity in the predictive value of Type D personality for cardiac events and mortality

BACKGROUND

Type D personality has been associated with adverse outcomes in patients with coronary artery disease (CAD). However, large heterogeneity exists between Type D studies, including some studies reporting null-findings.

OBJECTIVES

The aim of this study was to examine i) choice of endpoint and ii) age as two study characteristics that may partly explain this large heterogeneity in the Type D associated prognostic effect.

METHODS

We used four existing data cohorts of 1503 CAD patients (89% male, mean age=57.2±9.1) with baseline measures of Type D and endpoints >5years follow-up: major adverse cardiac events (MACE), cardiac death/MI, and non-cardiac death. Patients were classified in 4 age categories: <50y, 50-59y, 60-69y and ≥70y. Multiple logistic regression models included age, sex, and clinical covariates.

RESULTS

At follow-up, there were 295 events, including 116 cardiac death/MI, and 37 non-cardiac deaths. Both continuous and categorical measures of Type D predicted adverse events. Type D was independently associated with MACE (OR=1.82; 95%CI 1.33-2.50) and cardiac death/MI (OR=2.49; 95%CI 1.55-3.99). However, Type D was not associated with non-cardiac death (OR=1.23; 95%CI 0.57-2.69). Regarding age, Type D consistently predicted MACE in the lower age groups (all ORs≥2.20, all ps≤.004), but not in patients aged ≥70y (OR=1.43, p=.57).

CONCLUSIONS

Choice of endpoint and age modulated the risk conferred by Type D personality. Type D was associated with an increased risk of cardiac events, but not with non-cardiac death, or with events in patients aged ≥70y. Research on psychosocial risk in CAD should account for different sources of heterogeneity in study characteristics.

Does poorer self-rated health mediate the effect of Roma ethnicity on mortality in patients with coronary artery disease after coronaro-angiography?

OBJECTIVES

The aim of this prospective cohort study was to assess the effect of Roma ethnicity and self-rated health (SRH) on 9-year all-cause mortality in patients with coronary artery disease (CAD) after coronaro-angiography (CAG), and whether SRH mediates the effect of ethnicity.

METHODS

623 patients (103 Roma) were included. We obtained data from medical records and patients interviews. A Cox regression model adjusted for age, gender and education was used to analyze the effect of Roma ethnicity on mortality, as well as potential mediation by SRH.

RESULTS

Roma ethnicity and poor SRH were predictors of increased mortality in patients with CAD, with hazard rates (95 % confidence intervals) 2.34 (1.24; 4.42) and 1.81 (1.02; 3.21). Adding education decreased the size of ethnic differences in mortality. The mediating effect of SRH on the association of ethnicity with mortality was not statistically significant; neither modified ethnicity the effect of SRH.

CONCLUSIONS

Poor SRH does not mediate the higher mortality among Roma patients after CAG even though it indicates an increased risk of mortality. Roma patients with CAD have to be referred for special cardiological care earlier.

Effects of emotional response on adherence to antihypertensive medication and blood pressure improvement

Background. Developing interventions to improve medication adherence may depend upon discovery of novel behavioral risk factors for nonadherence. Objective. Explore the effects of emotional response (ER) on adherence to antihypertensive medication and on systolic blood pressure (SBP) improvement. Design. We studied 101 adults with diabetes and hypertension. The primary outcome, 90-day “percentage of days covered” adherence score, was determined from pharmacy refill records. The secondary outcome was change in SBP over 90 days. ER was classified as positive, negative, or neutral. Results. Average adherence was 71.6% (SD 31.4%), and negative and positive ER were endorsed by 25% and 9% of subjects, respectively. Gender moderated the effect of positive or negative versus neutral ER on adherence (interaction P = 0.003); regardless of gender, negative and positive ER were associated with similarly high and low adherence, respectively, but males endorsing neutral ER had significantly higher adherence than their female counterparts (85.6% versus 57.1%, F value = 15.3, P = 0.0002). Adherence mediated ER's effect on SBP improvement: among participants with negative, but not positive or neutral, ER, increasing adherence and SBP improvement were correlated (Spearman's r = 0.49, P = 0.02). Conclusions. Negative, but not positive or neutral, ER predicted better medication adherence and a correlation between medication adherence and improvement in SBP.