Carotid Plaque Screening Trial in Smokers
Condition: Smoking
Study type: Interventional
Phase: Phase 4

Summary: 
      The purpose of this study is to determine the impact of carotid plaque screening on smoking
      cessation and control of other cardiovascular risk factors.
    

Detailed description: 
      Tobacco smoking is highly prevalent in Switzerland (31% of adults), and 50% of smokers die
      from a tobacco-related disease, mainly cardiovascular disease (CVD). The smoking prevalence
      makes the evaluation of new strategies for smoking cessation a crucial priority.

      The presence of plaques of atherosclerosis ("cholesterol" deposits in the artery wall), as
      measured by carotid ultrasound, increases the risk of future CVD. The use of plaque screening
      to motivate patients to improve smoking cessation has received little attention. In one
      study, screening for atherosclerotic plaques increased the self-reported rates of smoking
      cessation, but without biochemical validation of cessation and these smokers had only low
      nicotine dependence. Moreover, no trial has examined the impact of plaque screening on the
      control of other cardiovascular risk factors.

      We now propose a randomized controlled trial of carotid plaque screening in 530 regular
      smokers aged 40-70 years, recruited from the community, to measure the impact of plaque
      screening on smoking cessation(main outcome) and control of other cardiovascular risk factors
      (secondary outcomes) after 1-year follow-up. Secondary outcomes are low-density lipoprotein
      cholesterol, hemoglobin A1C (if diabetes), high-sensitivity C-reactive protein and blood
      pressure. Smokers will all receive advice for smoking cessation and, then, will be randomly
      assigned to either the intervention group (with plaque screening) or the control group
      (without plaque screening). Smokers with one or more carotid plaque will receive pictures of
      their own plaques with a standardized explanation. To ensure equal contact conditions,
      smokers not undergoing ultrasound or without plaque will receive a standardized explanation
      on the risks of tobacco smoking.

      This study is innovative because plaque screening is a promising and increasingly used
      strategy to motivate patients to stop smoking and improve control of cardiovascular risk
      factors, but its effectiveness has been poorly studied. Successful completion of this project
      will provide a strong scientific basis for using this strategy for smoking cessation and
      control of cardiovascular risk factors. If testing is not an effective tool, such testing
      might represent an important waste of expenditure, and healthcare expenditures should be used
      for other strategies. Given the scope of the global illness burden due to CVD, the simplicity
      of the proposed test (ultrasound of carotids) and the smoking prevalence in Switzerland, the
      evaluation of new strategies for smoking cessation in long-term smokers and the primary
      prevention of CVD is an important public health priority.

      Beyond the randomized 1-year study, we have extended the follow-up to 3 years and added
      abdominal aneurysm screening by ultrasound to the intervention group to assess the
      association between cardiovascular risk factors and the development of small abdominal aortic
      aneurysms.
    

Intervention name(s): Carotid ultrasound for plaque screening; Brief advice for smoking cessation
Intervention type(s): Device; Behavioral
Intervention description(s): Carotid ultrasound for plaque screening; We will use the 5A's heuristic (Ask about smoking, Advise on cessation, Assess willingness to change, and for those willing to make quit attempt: Assist with attempt to quit, and Arrange for follow-up) and the gold standard for brief smoking cessation advice. At each visit, smokers will receive smoking cessation counseling and nicotine replacement therapy, similar to the experimental group.
Other intervention name(s): B-mode ultrasound (Vingmed 5; General Electric Medical System, Wisconsin, USA), coupled with the M'ATH software (Metris, France).
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Care Provider, Outcomes Assessor)
Primary purpose: Screening
Keywords: Atherosclerosis; Smoking cessation; Diagnostic techniques, cardiovascular; Ultrasonography; Health behavior