Inter Arm Blood Pressure Difference in Patients Undergoing Coronary Angiography and Its Relationship to Coronary Artery Disease Complexity

BACKGROUND Blood pressure (BP) in the right and left arms can be different. This inter arm difference (IAD) in BP can be systolic (IAD - SBP) and / or diastolic (IAD - DBP). IAD of ≥ 10 mm of Hg is considered significant. SYNTAX score is used to assess the complexity of coronary artery lesions. Prevalence of IAD in patients undergoing coronary angiography (CAG) and its relationship to complexity of coronary artery disease is unclear. METHODS In 100 patients taken up for CAG, BP was recorded in both the arms simultaneously with automated devices using oscillometric method. Significant IAD was defined as ≥ 10 mm of Hg. Using SYNTAX score, patients were divided into two groups; those with a lower score < 22 and those with a higher score ≥ 22. Data was analysed using SPSS version 16. Mean difference of the variables was analysed using Independent t test. Association of interarm BP difference and high SYNTAX score was analysed using Chi Square test. RESULTS Significant IAD of ≥ 10 mm of Hg was noted in 16 out of 100 patients. SYNTAX score of ≥ 22 was seen in 30 patients. IAD - SBP ≥ 10 was noted in 23.3 % in patients with higher SYNTAX score as against 2.9 % in those with lower score (p 0.001). IAD - DBP ≥ 10 was seen in 20 % of patients with higher SYNTAX score as against 1.4 % in those with lower SYNTAX score (p 0.001). CONCLUSIONS Interarm blood pressure difference of ≥ 10 mm of Hg is seen in 16 % of cases taken up for coronary angiogram. Patients with IAD ≥ 10 mm of Hg had higher SYNTAX score of ≥ 22 suggesting more complex coronary artery disease.