May 8, 2017Open Access
View Full PaperAmbulatory Pulse Wave Velocity Is a Stronger Predictor of Cardiovascular Events and All-Cause Mortality Than Office and Ambulatory Blood Pressure in Hemodialysis Patients
Key Result
Ambulatory 48-hour pulse wave velocity was independently associated with a composite of all-cause death, nonfatal MI, and nonfatal stroke in hemodialysis patients (HR 1.579; 95% CI 1.187-2.102).
Study Design
Type
Cohort (n=170)
Structured PICO
Does ambulatory pulse wave velocity predict the combination of all-cause death, nonfatal myocardial infarction, and nonfatal stroke in hemodialysis patients?
P
Population
170 hemodialysis patients who underwent 48-hour ambulatory monitoring and were followed for 28.1±11.2 months.
E
Exposure
48-hour ambulatory monitoring of pulse wave velocity (PWV), central BP, and heart rate-adjusted augmentation index [AIx(75)] using Mobil-O-Graph-NG
C
Comparator
Office and ambulatory blood pressure (SBP, DBP)
O
Outcome
Combination of all-cause death, nonfatal myocardial infarction, and nonfatal strokecomposite
Ambulatory pulse wave velocity is a stronger independent predictor of cardiovascular events and mortality than traditional office or ambulatory systolic blood pressure in hemodialysis patients.
Main Result
Hazard Ratio: 1.579 (95% CI 1.187–2.102)
Abstract
Arterial stiffness and augmentation of aortic blood pressure (BP) measured in office are known cardiovascular risk factors in hemodialysis patients. This study examines the prognostic significance of ambulatory brachial BP, central BP, pulse wave velocity (PWV), and heart rate–adjusted augmentation index AIx(75) in this population. A total of 170 hemodialysis patients underwent 48-hour ambulatory monitoring with Mobil-O-Graph-NG during a standard interdialytic interval and followed-up for 28.1±11.2 months. The primary end point was a combination of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. Secondary end points included: (1) all-cause mortality; (2) cardiovascular mortality; and (3) a combination of cardiovascular death, nonfatal myocardial infarction, nonfatal stroke, resuscitation after cardiac arrest, coronary revascularization, or hospitalization for heart failure. During follow-up, 37(21.8%) patients died and 46(27.1%) had cardiovascular events. Cumulative freedom from primary end point was similar for quartiles of predialysis-systolic BP (SBP), 48-hour peripheral-SBP, and central-SBP, but was progressively longer for increasing quartiles for 48-hour peripheral-diastolic BP and central-diastolic BP and shorter for increasing quartiles of 48-hour central pulse pressure (83.7%, 71.4%, 69.0%, 62.8% log-rank P =0.024), PWV (93.0%, 81.0%, 57.1%, 55.8% log-rank P <0.001), and AIx(75) (88.4%, 66.7%, 69.0%, 62.8% log-rank P =0.014). The hazard ratios for all-cause mortality, cardiovascular mortality, and the combined outcome were similar for quartiles of predialysis-SBP, 48-hour peripheral-SBP, and central-SBP, but were increasing with higher ambulatory PWV and AIx(75). In multivariate analysis, 48-hour PWV was the only vascular parameter independently associated with the primary end point (hazard ratios, 1.579; 95% confidence intervals, 1.187–2.102). Ambulatory PWV, AIx(75), and central pulse pressure are associated with increased risk of cardiovascular events and mortality, whereas office and ambulatory SBP are not. These findings further support that arterial stiffness is the prominent cardiovascular risk factor in hemodialysis.