Virtual Histology Findings and Effects of Varying Doses of Atorvastatin Treatment
Condition: Coronary Disease; Ultrasonography, Interventional; Hydroxymethylglutaryl-CoA Reductase Inhibitors
MeSH terms: Coronary Disease; Coronary Artery Disease
Study type: Interventional
Phase: Phase 4

Summary: 
      While statin treatment may induce plaque regression, the effect of statin on plaque
      composition with varying doses is unknown. This study assessed such effects by volumetric
      virtual histology intravascular ultrasound (VH-IVUS).

      In this prospective, randomized, double-blinded pilot study, statin-naïve patients with
      stable angina requiring percutaneous coronary intervention (PCI) were randomized to receive 6
      months of either atorvastatin 10mg or 40 mg daily. VH-IVUS was performed in all non-PCI
      lesions at baseline and 6 months; all analyses were performed by core laboratory.
    

Detailed description: 
      Statin therapy, especially at intensive doses, is beneficial in atherosclerotic coronary
      disease. Detecting subtle plaque regression after statin therapy is difficult by coronary
      angiogram; intravascular ultrasound (IVUS) is a far better method. Volumetric IVUS has been
      used in statin trials to evaluate plaque regression. Intensive statin therapy in the REVERSAL
      Trial and ASTEROID Trial appeared to achieve better regression outcomes. Stable fibrous
      plaque is likely to be responsible for stable ischemia, while unstable plaque (large lipid
      core, calcified nodule and necrotic core), thin-cap fibroatheroma, plaque erosion and plaque
      rupture may be responsible for acute coronary syndrome (ACS). In vivo tissue characterization
      of plaque composition is therefore important, yet in this regard grayscale IVUS is
      insufficient. The development of Virtual Histology (VH) utilizing IVUS generated
      radiofrequency backscattering signals to virtually separate plaque composition into 4
      components corresponding to histopathology has made possible in vivo assessment of plaque
      composition and stability. We believed plaque regression and VH-IVUS plaque modification with
      statin therapy could be statin dose dependent, and may affect clinical outcomes. This study
      was designed to prove our hypothesis, utilizing VH-IVUS.

      This study is the first prospective, randomised, double-blinded pilot study designed to
      investigate the varying statin dose effects on plaque regression and VH composition
      modulation. For ethical reasons, a placebo arm was not designed. Based on available data,
      clinically realistic doses of atorvastatin 10mg (low dose) and 40mg (moderate dose) were
      chosen. Only statin-naïve patients without previous history of myocardial infarction (MI)
      would be selected, aiming to show the "pure" effects of varying doses of statin and to better
      reveal the subtle differences in the changes.
    

Intervention name(s): Atorvastatin 10mg versus 40mg.
Intervention type(s): Drug
Intervention description(s): 2 arms comparing atorvastatin 10mg daily for 6 months to atorvastatin 40mg daily for 6 months. The primary endpoint would be the 6 months VH-IVUS findings and clinical outcomes.
Other intervention name(s): Lipitor 10mg versus 40mg daily for 6 months.
Intervention MeSH terms: Atorvastatin
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Volumetric virtual histology intravascular ultrasound.; Statin-naive patient.; Varying doses atorvastatin.; Clinical outcomes.