Objective This study was designed to identify why the central blood pressure (cSBP) values obtained using the catheter method tend to be higher than brachial systolic blood pressure (bSBP) values obtained using the cuff method.
Methods This study enrolled 20 patients who underwent coronary angiography (CAG) (mean age, 68.9 years; 13 men). Using the catheter method, a pressure guide wire was inserted via the radial artery at the time of CAG to measure the cSBP. The guide wire was then removed and the bSBP was obtained using two methods (the pressure guide wire method and the cuff method). The cSBP obtained with the catheter and the bSBP obtained with the cuff were compared, as were the bSBP obtained with the cuff and the bSBP obtained with the catheter.
Results The cSBP obtained with the catheter was 4.6 mmHg higher than the bSBP obtained with the cuff. The bSBP obtained with the cuff was 8.3 mmHg lower than the bSBP obtained with the catheter. The cSBP obtained with the catheter was 1.7 mmHg lower than the bSBP obtained with the catheter.
Conclusion In elderly patients with evident or suspected coronary heart disease, the finding of a higher cSBP measured using the catheter method than the bSBP obtained using the cuff method is attributable to bSBP underestimation (by 8.3 mmHg) using the cuff method compared to the bSBP directly obtained using the catheter method.