My best friend just had a mechanical valve replacement in August 2014. He is 49 and has high blood pressure and apnea as well. He is on coumadin for the valve. The anti-coag doctor is having a very hard time getting him theraputic. His most recent PT/INR was today and it was 2.2. The heart surgeon wanted him to be between 2.5 and 3.5. The anti-coag doctor is not having him come back to have his PT/INR done again for 3 weeks and he does not monitor at home on her request. I am curious if this is a safe idea to have so much time go between his PT/INR s when he is not theraputic. I am very worried that he will develop a clot and no one will know until it is too late.