Indices of cardiovascular function derived from peripheral pulse wave analysis using radial applanation tonometry: a measurement repeatability study

Pulse wave analysis (PWA) using applanation tonometry is a non-invasive technique for assessing cardiovascular function. It produces three important indices: ejection duration index (ED%), augmentation index adjusted for heart rate (AIX@75), and subendocardial viability ratio (SEVR%). The aim of this study was to assess within- and between-observer repeatability of these measurements. After resting supine for 15 minutes, 20 ambulant patients (16 male) in sinus rhythm underwent four PWA measurements on a single occasion. Two nurses (A & B) independently and alternately undertook PWA measurements using the same equipment (Omron HEM-757; SphygmoCor with Millar hand-held tonometer) blind to the other nurse's PWA measurements. Within- and between-observer differences were analysed using the Bland-Altman `limits of agreement' approach (mean difference ± 2 standard deviations, 2SD). Mean age was 56 (blood pressure, BP 136/79; pulse rate 64). BP/PWA measurements remained stable during assessment. Based on the average of two PWA measurements the mean ± 2SD between-observer difference in ED% was 0.3 ± 2.0; AIX@75 1.0 ± 3.9; and SEVR% 1.7 ± 14.2. Based on a single PWA measurement the between-observer difference was ED% 0.3 ± 3.3; AIX@75 1.7 ± 6.9; and SEVR% 0.6 ± 22.6. Within-observer differences for nurse-A were ED% 0.0 ± 5.4; AIX@75 1.5 ± 7.0; and SEVR% 1.7 ± 39.0 (nurse-B: 0.1 ± 3.8; 0.1 ± 8.0; and 0.6 ± 23.3, respectively). PWA demonstrates high levels of repeatability even when used by relatively inexperienced staff and has the potential to be included in the routine cardiovascular assessment of ambulant patients.

[1]  G. Buckberg,et al.  Experimental Subendocardial Ischemia in Dogs with Normal Coronary Arteries , 1972, Circulation research.

[2]  G. Buckberg,et al.  The myocardial supply:demand ratio--a critical review. , 1978, The American journal of cardiology.

[3]  J. Mckinlay.  From "promising report" to "standard procedure": seven stages in the career of a medical innovation. , 1981, The Milbank Memorial Fund quarterly. Health and society.

[4]  L. M. Anderson.  Statistics with Confidence. Confidence Intervals and Statistical Guidelines , 1989 .

[5]  Douglas G. Altman,et al.  Statistics with confidence: Confidence intervals and statistical guidelines . , 1990 .

[6]  M. O'Rourke,et al.  Pulse wave analysis. , 1996, Journal of hypertension. Supplement : official journal of the International Society of Hypertension.

[7]  W. Nichols,et al.  McDonald's Blood Flow in Arteries: Theoretical, Experimental and Clinical Principles , 1998 .

[8]  John G. Wood,et al.  MCDONALDʼS BLOOD FLOW IN ARTERIES: THEORETICAL, EXPERIMENTAL AND CLINICAL PRINCIPLES, 4TH EDITION , 1998 .

[9]  D. Webb,et al.  Reproducibility of pulse wave velocity and augmentation index measured by pulse wave analysis , 1998, Journal of hypertension.

[10]  D. Altman,et al.  Measuring agreement in method comparison studies , 1999, Statistical methods in medical research.

[11]  A. Siebenhofer,et al.  The reproducibility of central aortic blood pressure measurements in healthy subjects using applanation tonometry and sphygmocardiography , 1999, Journal of Human Hypertension.

[12]  D. Webb,et al.  The influence of heart rate on augmentation index and central arterial pressure in humans , 2000, The Journal of physiology.

[13]  J. Filipovský,et al.  Reproducibility of radial pulse wave analysis in healthy subjects , 2000, Journal of hypertension.

[14]  M E Safar,et al.  Arterial Wave Reflections and Survival in End-Stage Renal Failure , 2001, Hypertension.

[15]  M. O'Rourke,et al.  Prospective Evaluation of a Method for Estimating Ascending Aortic Pressure From the Radial Artery Pressure Waveform , 2001, Hypertension.

[16]  David J. Webb,et al.  Pulse‐Wave Analysis: Clinical Evaluation of a Noninvasive, Widely Applicable Method for Assessing Endothelial Function , 2002, Arteriosclerosis, thrombosis, and vascular biology.

[17]  J. Cockcroft,et al.  Assessment of arterial stiffness in clinical practice. , 2002, QJM : monthly journal of the Association of Physicians.

[18]  Daniel Duprez,et al.  Clinical applications of arterial stiffness, Task Force III: recommendations for user procedures. , 2002, American journal of hypertension.

[19]  C. Hayward,et al.  Assessment of endothelial function using peripheral waveform analysis: a clinical application. , 2002, Journal of the American College of Cardiology.

[20]  C. Ferro,et al.  Reproducibility of derived central arterial waveforms in patients with chronic renal failure. , 2002, Clinical science.

[21]  R. Asmar,et al.  Evaluation of two devices for self-measurement of blood pressure according to the international protocol: the Omron M5-I and the Omron 705IT , 2003, Blood pressure monitoring.

[22]  D. Webb,et al.  Noninvasive assessment of arterial stiffness and risk of atherosclerotic events. , 2003, Arteriosclerosis, thrombosis, and vascular biology.

[23]  D. Altman,et al.  Applying the right statistics: analyses of measurement studies , 2003, Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology.

[24]  Alain Simon,et al.  May subclinical arterial disease help to better detect and treat high-risk asymptomatic individuals? , 2005, Journal of hypertension.

[25]  Thomas Weber,et al.  Increased arterial wave reflections predict severe cardiovascular events in patients undergoing percutaneous coronary interventions. , 2005, European heart journal.

[26]  S. Strandgaard,et al.  Pulse‐wave morphology and pulse‐wave velocity in healthy human volunteers: Examination conditions , 2006, Scandinavian journal of clinical and laboratory investigation.

[27]  Alice Stanton,et al.  Differential Impact of Blood Pressure–Lowering Drugs on Central Aortic Pressure and Clinical Outcomes: Principal Results of the Conduit Artery Function Evaluation (CAFE) Study , 2006, Circulation.