Presentation on theme: "Type D, or distressed personality and CHD. A new risk factor?"— Presentation transcript:
Type D, or distressed personality and CHD. A new risk factor?
Reading Type D is fairly new concept and may not figure in standard texts. Pedersen SS & Denollet (2003) Type D personality, cardiac events and impaired quality of life : A review. European Journal of Cardiology, Prevention and Rehabilitation. 10, 241-248. Available free http://www.ejcpr.com/. Important reading on this topic.http://www.ejcpr.com/ Pedersen, S.S., & Denollet, J. (2006). Is Type D personality here to stay? Emerging evidence across cardiovascular disease patient groups. Current Cardiology Reviews, 6(2), 205-213. Ask me about this paper Suls J & Bunde J (2005) Anger, anxiety, and depression as risk factors for Cardiovascular disease: the problems and implications of overlapping affective dispositions. Psychological Bulletin, 131, 260-300. Complex paper which helpfully summarises evidence for these negative emotions as risk factors (useful for other parts of the course) and argues that there may be considerable overlap between them and the link is the tendency to experience strong negative emotions. Not specifically on Type D, but relates to it as well as the other psychological risk factors. Valuable current paper but not essential reading.
Measuring Type D. DS14 (Denollet, (2005) Psychosomatic Medicine, 67, 89-97.) Assesses Negative affectivity (NA): tendency to feel dysphoria, anxiety and irritability” “I often feel unhappy”, I am often down in the dumps” “ I am often in a bad mood” Social Inhibition (SI): discomfort in social situations, lack of social poise, avoid confrontation in social interaction. “I find it hard to start a conversation”, “I would rather keep people at a distance” “I often feel inhibited in social interactions” Factor analysis of 3678 people (CHD & Healthy). Two clear factors. Cut off of 10 on both scales advocated.
Appears to relate to CHD & hypertension (a CHD risk factor)
If Type D is a personality measure it should be stable over time, unlike mood & health. Consider effects of rehabilitation
The early studies CHD patients recruited at cardiac rehabilitation. Does this show that both NA & SI have to be high to predict cardiac events?
303 CHD patients recruited at cardiac rehabilitation. Type D personality Odd Ratio 4.1 (1.9-8.8) when allowing for factors related to severity of MI. Figure suggests NA x SI interaction.
Type D and prognosis after medical interventions for CHD 875 patients received drug-eluting stents Percutaneous coronary intervention (PCI) (next slide) Type D measured 6 months later (SI from DS14, NA from HADS and DS14, why extra measures of NA?) Outcome: Major Adverse Cardiac Events (MACE: MI, CABG or PCI) 9 months after Type D assessed Type D the main predictor of MACE. HR (Hazard Ratio) 1.92. Only other significant predictor, previous coronary bypass (CABG) 1.90. DenolletJ et al, (2006). European Heart Journal, 27, 171-167.
Mechanism? Few studies. (HPA Hypothalamic- pituitary-adrenal axis)
When is a risk factor casual Apply to Type D TemporalityStrength of relationship ConsistencyBiological gradient Biological PlausibilityCoherence Outcome SpecificityIntervention evidence
Causality (cont) Temporality: are there prospective studies demonstrating that x precedes development of disease? Strength of relationship: How much of the variance in disease incidence explained by x? Consistency: Are studies consistent in their findings? Biological gradient: is severity and/or frequency of x associated with increasing risk of disease? Biological plausibility: what pathogenic mechanisms link x to disease?
Causality 3 Coherence: Does evidence for the relation between x and disease come from different samples (population, patient, animal models)? Outcome specificity: Is the risk associated with x exclusive to one disease? Intervention Effects: Is the disease prevented if x is treated early enough?