Therapeutic INR for Mechanical Heart Valves

Here are the results for last week’s Quick Question:
What is your target INR therapeutic range for patients who have a mechanical heart valve?
a. INR: 1.0-2.0: 2 (3.8%)
b. INR: 2.0-3.0: 5 (9.6%)
c. INR: 2.5-3.5: 40 (77.0%)
d. INR: 3.0-4.0: 5 (9.6%)
Unlike previous questions that functioned as surveys, this one has a correct answer. According to Salem DN, O’Gara PT, Madias C, Pauker SG. Valvular and structural heart disease. American College of Chest Physicians evidence-based clinical practice guidelines (8th edition). Chest 2008;133: 593-629S, the target INR range for mechanical heart valves is 2.5-3.5, which is the most effective for preventing rethrombosis while avoiding hemorrhage. There are mechanical valve subtypes or locations that may require a lower range, for instance, “In patients with a bileaflet mechanical valve or a Medtronic Hall tilting disk valve in the aortic position who are in sinus rhythm we recommend target INR 2.0-3.0.” Also, bioprosthetic valves, for example, porcine valves, require the standard INR of 2.0-3.0, not 2.5-3.5. Physicians regularly consult this reference for the correct range.