title: Central aortic reservoir-wave analysis improves prediction of cardiovascular events in elderly hypertensives.
abstract: Several morphological parameters based on the central aortic pressure waveform are proposed as cardiovascular risk markers, yet no study has definitively demonstrated the incremental value of any waveform parameter in addition to currently accepted biomarkers in elderly, hypertensive patients. The reservoir-wave concept combines elements of wave transmission and Windkessel models of arterial pressure generation, defining an excess pressure superimposed on a background reservoir pressure. The utility of pressure rate constants derived from reservoir-wave analysis in prediction of cardiovascular events is unknown. Carotid blood pressure waveforms were measured prerandomization in a subset of 838 patients in the Second Australian National Blood Pressure Study. Reservoir-wave analysis was performed and indices of arterial function, including the systolic and diastolic rate constants, were derived. Survival analysis was performed to determine the association between reservoir-wave parameters and cardiovascular events. The incremental utility of reservoir-wave parameters in addition to the Framingham Risk Score was assessed. Baseline values of the systolic rate constant were independently predictive of clinical outcome (hazard ratio, 0.33; 95% confidence interval, 0.13-0.82; P=0.016 for fatal and nonfatal stroke and myocardial infarction and hazard ratio, 0.38; 95% confidence interval, 0.20-0.74; P=0.004 for the composite end point, including all cardiovascular events). Addition of this parameter to the Framingham Risk Score was associated with an improvement in predictive accuracy for cardiovascular events as assessed by the integrated discrimination improvement and net reclassification improvement indices. This analysis demonstrates that baseline values of the systolic rate constant predict clinical outcomes in elderly patients with hypertension and incrementally improve prognostication of cardiovascular events.
authors.affiliation: From the Monash Cardiovascular Research Centre, School of Clinical Sciences at Monash, Monash University, Melbourne Australia (O.N., J.D.C.); International Centre for Circulatory Health (J.E.D.), and Department of Bioengineering (K.H.P.), Imperial College, London, United Kingdom; UCL Institute of Cardiovascular Science, University College London, United Kingdom (A.D.H.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (A.M.D.); Department of Epidemiology & Preventative Medicine, Monash University, Melbourne, Australia (C.R.); and MonashHeart, Monash Health, Victoria, Australia (O.N., J.D.C.).
authors.forename: Om
authors.initials: O
authors.lastname: Narayan
authors.affiliation: From the Monash Cardiovascular Research Centre, School of Clinical Sciences at Monash, Monash University, Melbourne Australia (O.N., J.D.C.); International Centre for Circulatory Health (J.E.D.), and Department of Bioengineering (K.H.P.), Imperial College, London, United Kingdom; UCL Institute of Cardiovascular Science, University College London, United Kingdom (A.D.H.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (A.M.D.); Department of Epidemiology & Preventative Medicine, Monash University, Melbourne, Australia (C.R.); and MonashHeart, Monash Health, Victoria, Australia (O.N., J.D.C.).
authors.forename: Justin E
authors.initials: JE
authors.lastname: Davies
authors.affiliation: From the Monash Cardiovascular Research Centre, School of Clinical Sciences at Monash, Monash University, Melbourne Australia (O.N., J.D.C.); International Centre for Circulatory Health (J.E.D.), and Department of Bioengineering (K.H.P.), Imperial College, London, United Kingdom; UCL Institute of Cardiovascular Science, University College London, United Kingdom (A.D.H.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (A.M.D.); Department of Epidemiology & Preventative Medicine, Monash University, Melbourne, Australia (C.R.); and MonashHeart, Monash Health, Victoria, Australia (O.N., J.D.C.).
authors.forename: Alun D
authors.initials: AD
authors.lastname: Hughes
authors.affiliation: From the Monash Cardiovascular Research Centre, School of Clinical Sciences at Monash, Monash University, Melbourne Australia (O.N., J.D.C.); International Centre for Circulatory Health (J.E.D.), and Department of Bioengineering (K.H.P.), Imperial College, London, United Kingdom; UCL Institute of Cardiovascular Science, University College London, United Kingdom (A.D.H.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (A.M.D.); Department of Epidemiology & Preventative Medicine, Monash University, Melbourne, Australia (C.R.); and MonashHeart, Monash Health, Victoria, Australia (O.N., J.D.C.).
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Dart
authors.affiliation: From the Monash Cardiovascular Research Centre, School of Clinical Sciences at Monash, Monash University, Melbourne Australia (O.N., J.D.C.); International Centre for Circulatory Health (J.E.D.), and Department of Bioengineering (K.H.P.), Imperial College, London, United Kingdom; UCL Institute of Cardiovascular Science, University College London, United Kingdom (A.D.H.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (A.M.D.); Department of Epidemiology & Preventative Medicine, Monash University, Melbourne, Australia (C.R.); and MonashHeart, Monash Health, Victoria, Australia (O.N., J.D.C.).
authors.forename: Kim H
authors.initials: KH
authors.lastname: Parker
authors.affiliation: From the Monash Cardiovascular Research Centre, School of Clinical Sciences at Monash, Monash University, Melbourne Australia (O.N., J.D.C.); International Centre for Circulatory Health (J.E.D.), and Department of Bioengineering (K.H.P.), Imperial College, London, United Kingdom; UCL Institute of Cardiovascular Science, University College London, United Kingdom (A.D.H.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (A.M.D.); Department of Epidemiology & Preventative Medicine, Monash University, Melbourne, Australia (C.R.); and MonashHeart, Monash Health, Victoria, Australia (O.N., J.D.C.).
authors.forename: Christopher
authors.initials: C
authors.lastname: Reid
authors.affiliation: From the Monash Cardiovascular Research Centre, School of Clinical Sciences at Monash, Monash University, Melbourne Australia (O.N., J.D.C.); International Centre for Circulatory Health (J.E.D.), and Department of Bioengineering (K.H.P.), Imperial College, London, United Kingdom; UCL Institute of Cardiovascular Science, University College London, United Kingdom (A.D.H.); Baker IDI Heart and Diabetes Institute, Melbourne, Australia (A.M.D.); Department of Epidemiology & Preventative Medicine, Monash University, Melbourne, Australia (C.R.); and MonashHeart, Monash Health, Victoria, Australia (O.N., J.D.C.). james.cameron@monash.edu.
authors.forename: James D
authors.initials: JD
authors.lastname: Cameron
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D062186:Arterial Pressure / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002318:Cardiovascular Diseases / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006973:Hypertension / Q000150:complications* / Q000503:physiopathology*; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D063177:Pulse Wave Analysis / Q000379:methods*; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D014655:Vascular Resistance / Q000502:physiology; D059289:Vascular Stiffness / Q000502:physiology
keywords: aging; blood pressure; cardiovascular diseases; hypertension; pulse wave analysis; vascular stiffness