Anticoagulation: biological prosthetic heart valve: fewer bleeds on less intensive INR.

Clinical bottom line (level 1b)

  1. Patients with biological prosthetic heart valves who were anticoagulated to INR 2.0 to 2.25 had fewer major bleeds than patients anticoagulated to INR 2.5 to 4.0 (NNT = 22 at 3 months) .
  2. The effect on major embolic events was unclear.
Turpie et al: Lancet 1988; 1: 1242-1245
Expires June 2003

The study

Unblinded concealed randomised trial without intention-to-treat
Setting: university hospital, Canada

210 patients (aged range 28 to 87 years; mean 62, 53% male) tissue heart valve replacement

Excluded if
  • geographically inaccessible for follow-up
  • contraindication to anticoagulation


    • Control Group: (n = 108, 108 analysed): anticoagulated to INR 2.5 to 4.0
    Experimental Group: (n = 102, 102 analysed): anticoagulated to INR 2.0 to 2.25

    100% followed for 3 months
    Outcome notes:
    • major haemorrhage : overt and a fall > or = 2 g/dl, or transfused > or = two units, or intracranial or retroperitoneal
    • major embolism : stroke lasting >24 hours, MI in a patient with previously normal coronary arteries, or systemic arterial occlusion documented by angiography or by surgical removal

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    major haemorrhage 3 months 5
    (4.63%)    		 0
    (0.00%)    		 100%
    (% to %)    		 4.63%
    (0.67% to 8.59%)    		 22
    (12 to 150)
    major embolism 3 months 2
    (1.85%)    		 2
    (1.96%)    		 -6%
    (-638% to 85%)    		 -0.11%
    (-3.81% to 3.59%)    		 -920
    (NNT = 28 to infinity;
    NNH = 26 to infinity)

    Comments

    1. Patients were stratified for site of valve and presence of atrial fibrillation before randomisation.

    Citation

    1. Turpie AA, Gunstensen J, Hirsh J, et al: Randomised comparison of two intensities of oral anticoagulant therapy after tissue heart valve replacement. Lancet 1988; 1: 1242-1245
    Search Terms: reference from review article
    Contributor: Chris Ball and Clare Wotton, June 2000
    Reviewer:

    Clinical Question.
    Patient prosthetic heart valve
    Intervention or Exposure low-intensity anticoagulation
    Comparison high-intensity anticoagulation
    Outcome major embolism, haemorrhage