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International Normalized Ratio Targets for Left-Sided Mechanical Valve Replacement

Saurabh Gupta1,2, Emilie P Belley-Cote2,3,4, Anisha Sarkaria5

  • 1Department of Surgery, McMaster University, Hamilton, Ontario, Canada.

Thrombosis and Haemostasis
|April 4, 2018
PubMed

Insights

For patients with mechanical heart valves, current evidence suggests lower international normalized ratio (INR) targets reduce bleeding risk without increasing thromboembolic events. Higher INR targets are not supported by this low-quality evidence.

Area of Science:

  • Cardiology
  • Clinical Medicine
  • Evidence-Based Medicine

Background:

  • Current guidelines suggest higher international normalized ratio (INR) targets for mechanical heart valve patients at high risk of thromboembolism.
  • However, elevated INR targets are linked to an increased risk of bleeding complications.

Purpose of the Study:

  • To conduct a systematic review and meta-analysis.
  • To assess the effects of lower versus higher INR targets on thromboembolic and bleeding risks in patients with mechanical heart valves.

Main Methods:

  • Systematic review and meta-analysis of six randomized controlled trials (RCTs) involving 5,497 adults with bileaflet mechanical valves.
  • Data were pooled using a random effects model, and evidence quality was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework.

Main Results:

  • Lower INR targets were associated with significantly reduced bleeding risk (22% vs. 40%; RR: 0.54, 95% CI: 0.31-0.93).
  • No significant difference in thromboembolism (2% in both groups; RR: 1.28, 95% CI: 0.88-1.85) or mortality (5.5% vs. 8.5%; RR: 1.00, 95% CI: 0.82-1.21) was observed.
  • The quality of evidence for bleeding and thromboembolism was very low, while for mortality it was moderate.

Conclusions:

  • Higher INR targets are not substantiated by current evidence, which is of very low quality.
  • This systematic review indicates that lower INR targets provide a significantly lower bleeding risk without compromising thromboembolic risk for mechanical heart valve patients.
Abstract

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