This contains recommendations of many specialists for the prevention of thromboembolism. It addresses anticoagulation in various diseases, conditions and other related topics. The exceptions are some types of mechanical prosthetic heart valves, postmyocardial infarction, and certain patients with thrombosis and the antiphospholipid syndrome, for which an INR of 2.5 to 3.5 is recommended. As recommendations are continuing to develop, there is still some variation of opinion concerning anticoagulation in cardiovascular conditions. Study of the relevant literature in this regard is important.
Patients are widely variable in response to oral anticoagulation.
In addition, early efforts to use the INR among laboratories has had some problems. The guidelines can be helpful in monitoring patients but they should not replace sound clinical judgment.