Abstract
Objective: To assess the frequency of achieving therapeutic International Normalization Ratio (INR) in patients with mechanical prosthetic heart valves.
Methodology: This cross-sectional observational study was conducted in inpatient and outpatient department in cardiology unit Lady reading Hospital Peshawar from Sep 2013 to June 2014. All patients were interviewed for their basic demographics, type of valve implanted and their INR in last six months.
Results: A total of 57 patients were included in the study. Females were 36 (63.1%) females and males were 21(36.8%). Their mean age was34± 5.7 years. The reason for mechanical prosthetic valve were isolated rheumatic heart disease in 41(71.9%) rheumatic heart disease with infective endocarditis in 6(10.52%), bicuspid aortic valve in 3(5.26%) and mitral valve prolapse with severe mitral regurgitation in 7(12.28%). Isolated mitral valve replacement in 22(38.6%), isolated aortic valve replacement in 19(33.3%) and double valve (mitral and aortic valve replacement) in 16(28.07%). Of them 44(77.2%) were in sinus rhythm and 13(22.8%) were in atrial fibrillation. There was ischemic stroke or TIA (12.28%) in patients and peripheral arterial embolism in 5(7%). Mean INR was 2.2±1.3.The INR of only 17(29.82%) patients were found within target, set according to recent guidelines, while 35(61.4%) were below and 5(8.7%) were above the target.

Key words: Mechanical prosthetic valve, Target INR, Oral anticoagulation