Individuals at intermediate risk account for a large proportion of patients presenting with atherosclerotic events. The barriers to reducing this problem relate to the expense of an unselective primary prevention strategy among a group where the majority will not have events, as well as the difficulty of getting apparently well subjects to adhere to lifestyle and pharmacologic management.
An outcome-based study would require large numbers and would be unlikely to be funded without proof of concept. CIMT will be used as a validated surrogate of atherosclerotic status and future cardiovascular events in this study.
As such, this study will use CIMT (as both a delineator of risk and in the primary endpoint), a marker of atherosclerotic burden (the disease process rather than a surrogate), to address the unresolved issue about how to most efficiently manage intermediate risk subjects with a family history of premature atherosclerosis by combining better selection of such individuals for active treatment and recommended lifestyle changes with a DMP strategy to optimise their successful application in the longer-term.
The Intima-Media thickness guidance of Primary prevention in Relatives of individuals with Early onSet atherosclerosiS (IMPRESS) Study will test the following null hypothesis:
In intermediate risk, first-degree relatives (i.e. mother, father, brother or sister) of individuals with premature atherosclerosis, a CIMT-targeted DMP for primary prevention (the IMPRESS intervention) incorporating more intensive non-pharmacological and pharmacological management, provides no better reduction of atherosclerotic burden (as determined by the change in CIMT from baseline to follow-up completion) than usual health care management during three years follow-up.
Study Design The study hypotheses will be examined via a randomised controlled primary prevention/intervention trial comparing an individualised DMP with usual clinical care of middle-aged (40-65 years old) subjects who have a family history of premature cardiovascular disease and are determined to be at intermediate risk for a cardiovascular event within the next 5 years7, 22.
Study Centres
As a multicentre study, participants will be recruited from three centres:
* Princess Alexandra Hospital (Brisbane, Australia): responsible site investigator Associate Professor Karam Kostner
* Baker IDI Heart and Diabetes Institute/ The Alfred Hospital (Melbourne, Australia): responsible site investigator Dr Melinda Carrington
* National University Health System and Novena Heart Centre (Singapore): responsible site investigator Professor Desley Hegney
Participants This study will be conducted in a group of 40-65 year old adults.
IMPRESS Study will test the following null hypothesis:
In intermediate risk, first-degree relatives (i.e. mother, father, brother or sister) of individuals with premature atherosclerosis, a CIMT-targeted DMP for primary prevention (the IMPRESS intervention) incorporating more intensive non-pharmacological and pharmacological management, provides no better reduction of atherosclerotic burden (as determined by the change in CIMT from baseline to follow-up completion) than usual health care management during three years follow-up.
Primary End-Point Consistent with the study hypothesis, the primary study end-point is change in CIMT from baseline to three years, as determined by a blinded core laboratory and analysed on an intention-to-treat basis according to random study group allocation.
Secondary End-Points
The secondary endpoints are change from baseline to three years in the following variables:
i) Plaque length (carotid artery) ii) Internal CIMT iii) General health and well being (as measured by the SF-12 18 and EQ-5D 19) iv) Mental health (as determined by the Arrol 20 +/- CESD 21) v) Health care costs vi) Modifiable risk factors for atherosclerotic disease other than diabetes ( i.e. smoking, dyslipidaemia, obesity and hypertension) vii) Absolute cardiovascular risk profile 22 and risk of diabetes (as determined by the Type 2 Diabetes Risk Assessment Tool \[AUSDRISK\]) Score 23) viii) Diabetic status (as determined by fasting glucose) ix) All-cause mortality/ cardiovascular hospitalisation
