Correlation between Interarm Systolic Blood Pressure Difference and Carotid Intima Media Thickness in Patients with Coronary Artery Disease and Stroke

AIM AND OBJECTIVES: 1. To record the interarm systolic blood pressure difference in hypertensive patients with coronary artery disease and stroke. 2. To measure carotid intima media thickness in above patients by Carotid Doppler ultrasound. 3. To find out the correlation between interarm systolic blood pressure difference and carotid intima media thickness in above group. 4. To recommend the recording of interarm systolic blood pressure difference in hypertensive patients as a routine for identification of patients at risk of cardiovascular diseases at an early stage. MATERIALS AND METHODS: After obtaining clearance from ethical committee, this cross sectional study was conducted in Government Rajaji Hospital, Madurai. 100 hypertensive patients with coronary artery disease and stroke admitted in the inpatient Department of Medicine were selected for the study. Both males and females in the age group of 45 to 70 years were included in the study. Recording of Inter arm systolic BP difference (IASBPD): After getting informed consent, BP was recorded in both the arms simultaneously for 3 times at an interval of 2 minutes in the sitting position by using automated blood pressure measuring device (OMRON). The average systolic BP for right arm and left arm was calculated. The difference between right arm systolic BP and left arm systolic BP was calculated. Large interarm difference was defined as interarm pressure difference of ≥ 10 mm/Hg. Absolute interarm systolic BP difference (IASBPD) = |average right arm systolic BP - average left arm systolic BP| Measurement of Carotid intima media thickness (CIMT). Carotid intima media thickness was measured in above patients by using Doppler USG Philips with linear phased array transducer 7- 14MHz in the Department of Radiology, Madurai Medical College. Carotid intima media thickness ≥ 0.8 was considered abnormal. RESULT: Correlation between interarm systolic BP difference and carotid intima media thickness was analysed by using Pearson correlation coefficient test. Association between sex and IASBPD and CIMT was analysed by chi-square test. By means of SPSS (Statistical Package for Social Sciences) software version 21, analysis of statistics was performed. The statistical significance was drawn at ‘p’ value < 0.05. In this study there was a statistically significant positive correlation between IASBPD and CIMT (r = 0.88, P < .05). There was no association between gender and IASBPD and CIMT (p= 0.33, p= 0.78 respectively). CONCLUSION: In this study there was a statistically significant positive correlation between Interarm systolic blood pressure difference and Carotid intima media thickness. As recording of inter-arm systolic BP difference is a simple, economical and effective tool that can be used to screen hypertensive patients at risk of cardiovascular disease at the Primary Health Care system itself