P86 Can Central Blood Pressure be Accurately Estimated in Individuals with and Without Systolic Blood Pressure Amplification?

Abstract

Introduction

Systolic blood pressure (SBP) does not always amplify from central to peripheral arteries. Individuals without SBP amplification (SBPamp) have higher aortic blood pressure (BP) despite similar brachial cuff SBP. To circumvent this discrepancy, the aim of this study was to determine if aortic SBP can be accurately estimated non-invasively in patients with and without SBPamp.

Methods

Patients undergoing percutaneous coronary intervention were recruited. Individuals with atrial fibrillation, ≥10 mmHg between-arm SBP difference or severe aortic stenosis were excluded. Aortic and brachial intra-arterial BP were measured using a fluid-filled catheter. Simultaneously, brachial and central cuff BP were measured in triplicate (Mobil-o-Graph, IEM, Germany). Central BP was estimated by pulse wave analysis with Type I (SBP and diastolic BP) and Type II (mean and diastolic BP) calibrations. Aortic-to-brachial SBPamp was defined as ≥5 mmHg increase between intra-arterial aortic and brachial SBP.

Results

Of the 151 patients recruited, only 85 had SBPamp. SBPamp+ and SBPamp- patients had similar brachial cuff SBP (126 +/− 15 vs 126 +/− 16 mmHg, p = 0.8) and clinical characteristics, apart from lower augmentation index in SBPamp+ (18 +/− 10 vs 22 +/− 11, p = 0.03). Central BP estimated with Type I or Type II calibration could not accurately determine aortic SBPs in both phenotypes (Table 1). Using the mean of both estimates only provided a slightly better accuracy.

Conclusion

Central BP measurements cannot accurately identify the different aortic BP of the SBPamp phenotypes. A new central BP calibration may be needed to circumvent this problem.

Table 1