Statin initiation linked to reduced risk for venous thromboembolism

  • Skajaa N & al.
  • Thromb Res
  • 6 Nov 2019

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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Takeaway

  • First-time statin initiators were slightly at lower risk for unprovoked venous thromboembolism (VTE) independent of statin potency, compared with statin non-initiators.
  • The risks for deep vein thrombosis and pulmonary embolism were similar.
  • At the same time, statin initiators were at increased risk for myocardial infarction (MI) and ischaemic stroke than general population, indicating no “healthy-user effect”

Why this matters

  • Current evidence suggests that statins have weak thromboprophylactic effects.

Study design

  • This population-based, matched cohort study included 601,011 first-time statin initiators and 1,803,033 sex-, age- and calendar year-matched statin non-initiators without VTE, MI or IS.
  • Primary outcome: first-time inpatient or outpatient diagnosis of VTE.
  • Funding: None.

Key results

  • After 11 years of follow-up, the cumulative risk was 2.84% (95% CI, 2.75-2.93%) for all VTE, 0.93% (95% CI, 0.88-0.98%) for provoked VTE and 1.92% (95% CI, 1.84-2.01%) for unprovoked VTE in both first-time statin initiators and non-initiators.
  • The risk for MI (4.72% [95% CI, 4.57-4.86%] vs 2.89% [95% CI, 2.83-2.96%]) and IS (7.05% [95% CI, 6.89-7.22%] vs 5.20% [95% CI, 5.12-5.28%]) was higher in statin initiators vs non-initiators.
  • After adjustment for confounders, first-time statin initiators vs non-initiators were at lower risk for VTE (adjusted HR [aHR], 0.93; 95% CI, 0.91-0.96), driven by a reduced risk for unprovoked VTE (aHR, 0.91; 95% CI, 0.88-0.94).
  • The reduced risks for VTE were more pronounced in patients who received an ultrasound or a computed tomography scan (aHR, 0.89; 95% CI, 0.86-0.92).
  • First-time statin use was associated with an increased risk for MI (aHR, 1.41; 95% CI, 1.38-1.44) and IS (aHR, 1.19; 95% CI, 1.17-1.21).

Limitations

  • Risk for residual and uncontrolled confounding.  
  • Indication bias.