Correlation of vascular risk age with pulse wave velocity in young patients with low absolute cardiovascular risk.

OBJECTIVE: The systematic coronary risk evaluation (SCORE) estimates the 10-year risk of fatal cardiovascular disease (CVD), and its application is recommended. The absolute risk of CVD, independent of risk factors, is relatively low in young individuals. Expressing the risk as their "risk age" may aid in understanding the risk. This study aimed to demonstrate a possible correlation between vascular risk age, SCORE risk value, and the level of subclinical atherosclerosis evaluated using a pulse wave velocity (PWV) device. METHODS: This work was designed to be a cross-sectional study. The SCORE 10-year fatal CVD risk and vascular risk age were calculated for patients below the age of 50 years and without any previous diagnosis of atherosclerotic disease or equivalents. The PWV of each patient was measured non-invasively using a PWV device. RESULTS: The study population included a total of 300 patients with a mean age of 35.1±9.5 years. The mean PWV and mean vascular age of the entire study population were 6.3±1.3 m/s and 44.3±5.5 years, respectively, and the median 10-year risk of fatal CVD score was 0.4 (0.04-2.74). There was a positive correlation between PWV and the 10-year risk of fatal CVD (r=0.613; P<0.001) and vascular risk age (r=0.684; P<0.001). CONCLUSION: Despite their young age and low to moderate 10-year risk of fatal CVD (<1%-5%) according to the SCORE chart, patients with a high vascular risk age were found to have high PWV values. These results show that calculations of vascular risk age might be used to assess the risk of fatal CVD in young patients and correlate with subclinical atherosclerosis.

Reference values of office central blood pressure, pulse wave velocity, and augmentation index recorded by means of the Mobil-O-Graph PWA monitor.

Assessment of central blood pressure (BP), pulse wave velocity (PWV), and augmentation index (AIx) measurements may improve cardiovascular risk stratification. This study aimed to establish reference office values for central BP, PWV, and AIx by means of a Mobil-O-Graph PWA monitor and to evaluate the impact of cardiovascular risk factors (CVRFs) on these measurements. We cross-sectionally evaluated clinical characteristics, central BP, PWV, AIx, and peripheral BP measurements among 867 apparently healthy individuals (age = 46.0 ± 15.5 years, 39% males) who were free of obesity, hypertension, active smoking, dyslipidemia, and diabetes (CVRF-No) and 5632 individuals (age = 57.0 ± 14.7 years, 44% males) with at least one of these major CVRFs (CVRF-Yes). Reference values for central BP, PWV, and AIx were provided for the CVRF-No and CVRF-Yes groups, stratified by age and sex. PWV and AIx exhibited curvilinear increases with age, and there was an interaction between age and sex for central systolic BP and PWV in both the CVRF-No and CVRF-Yes groups. The results of a multivariable analysis including the whole sample (n = 6499) showed that obesity had a direct association with central BP, while diabetes was directly related to PWV. In addition, alcohol intake was directly associated with central BP, while performance of physical activity was inversely related to AIx. In conclusion, values of office-measured central BP, PWV, and AIx obtained in an apparently healthy population and in a population with CVRFs are now available according to age and sex and may be useful to build thresholds for use in clinical practice.

The association between arterial pulse waveform analysis device and in-hospital mortality in high-risk non-cardiac surgeries.

BACKGROUND: Perioperative goal-directed fluid therapy is used for haemodynamic optimization in high-risk surgeries. Cardiac output monitoring can be performed by a specialized pressure transducer for arterial pulse waveform analysis (S-APWA). No study has assessed whether real-world use of S-APWA is associated with post-operative outcomes; therefore, using a Japanese administrative claims database, we retrospectively investigated whether S-APWA use is associated with in-hospital mortality among patients undergoing high-risk surgery under general anaesthesia. METHODS: Adult patients who underwent high-risk surgery under general anaesthesia and arterial catheterization between 2014 and 2016 were divided into S-APWA and conventional arterial pressure transducer groups, then compared regarding baseline factors and outcomes. Logistic regression analysis was performed to compare in-hospital mortality. Subgroup analyses evaluated S-APWA efficacy and outcomes based on the type of surgery and patients' comorbidity. RESULTS: S-APWA was used in 6859 of 23 655 (29.0%) patients; the crude in-hospital mortality rate was 3.5%. Adjusted analysis showed no significant association between S-APWA use and in-hospital mortality rate (adjusted odds ratio [aOR] = 0.91; 95% confidence interval [CI]: 0.76-1.07; P = .25). S-APWA use was associated with significantly lower in-hospital mortality in patients undergoing vascular surgery (aOR = 0.67; 95% CI: 0.49-0.94), and significantly higher in-hospital mortality in patients undergoing lower limb amputation (aOR = 2.63; 95% CI: 1.32-5.22). S-APWA use and in-hospital mortality were not significantly associated with other subgroups. CONCLUSION: S-APWA use was not associated with in-hospital mortality in the entire study population. However, S-APWA was associated with decreased in-hospital mortality among vascular surgery and increased in-hospital mortality among lower limb amputation.

Preliminary Evaluation of Aortic Aneurysm Screening Using Oscillometric Device Equipped With Novel Algorithm Analyzing Pulse Wave Transfer.

BACKGROUND: Detection of aortic aneurysm (AA) prior to rupture is crucial to decreasing its mortality. Towards this purpose, a novel detection algorithm was developed from pulse volume recording (PVR), analyzing the propagation loss of pulse waves caused by expansion of the aortic wall. The diagnostic ability of the algorithm was evaluated in this prospective study.Methods and Results:PVR were measured for 30 s using the oscillometric device designed for automatic measurement of the ankle-brachial index (ABI). The algorithm processed the data automatically and assessed whether the patient had an AA. CT angiography was used as the reference standard. Sensitivity and specificity of the algorithm were evaluated. A total of 152 AA patients, including 21 patients with thoracic AAs (TAA), and 64 non-aneurysm control subjects were enrolled. The mean diameter of all AAs was 47.2±10.3 mm. After measurements, 121 AA patients and 33 control subjects were judged by the algorithm as having or not having AAs, resulting in sensitivity of 80% and specificity of 52%. The sensitivity was higher for larger AAs. There was no sensitivity difference according to the location of the AA. CONCLUSIONS: The new diagnostic algorithm installed in the oscillometric device detected AAs with high sensitivity, especially larger aneurysms. For application as a screening tool, the specificity needs to be improved.

The Effect of Revascularization on the Hemodynamic Profile of Patients with Infrarenal Aortic Occlusion.

BACKGROUND: Patients undergoing revascularization for infrarenal aortic occlusion (IAO) have been reported to present improved survival rates compared to those treated conservatively. Aim of this study was to investigate the hemodynamic changes induced after revascularization for IAO, as expressed with pulse wave velocity (PWV), augmentation index (Aix), augmentation pressure (AP), and pulse wave reflection coefficient (RC). MATERIALS AND METHODS: Twelve patients underwent revascularization (9 aortobifemoral/aortobiiliac bypasses, 2 primary iliac stenting, and 1 hybrid procedure of unilateral aortoiliac stenting and crossover bypass). Calculation of hemodynamic parameters was performed in all patients preoperatively, at 1 month, and 1 year postoperatively. Pulse wave analysis was performed noninvasively with a novel validated brachial cuff-based automatic oscillometric device (Mobil-O-Graph; IEM, Stolberg, Germany). The estimated hemodynamic parameters were AIx, AP, RC, and PWV. Data were analyzed with the Friedman analysis of variance test. RESULTS: Aix decreased significantly at 1 month and further at 1 year postoperatively compared to preoperative values (24 ± 11 and 17 ± 13 vs. 34 ± 13.5, respectively, P = 0.0006). AP decreased at 1 month and 1 year postoperatively compared to preoperative values (6.5 ± 4 mm Hg and 8 ± 6.5 mm Hg vs. 13 ± 12 mm Hg, respectively, P = 0.045). RC decreased also at 1-month and 1-year postoperatively compared to preoperative values (62 ± 5.5, 64 ± 4.3 vs. 73 ± 5.1, respectively, P = 0.002). However, changes in PWV were less prominent in this short-term postoperative period. CONCLUSIONS: Improved hemodynamic profile may theoretically contribute to the enhanced survival rates of these patients.

Clinical validation of a new wrist continuous noninvasive hemodynamic monitoring system in comparison with invasive radial artery measurement.

BACKGROUND: An ideal arterial pressure monitoring system for perioperative care is required to be accurate, noninvasive, continuous, and risk free. Although several continuous noninvasive arterial pressures (CNAP) are determined on the finger, a new wrist CNAP monitoring system was developed. This prospective study was designed as a randomized-controlled trial to assess its validity in comparison with invasive arterial pressure (IAP) monitoring. PATIENTS AND METHODS: Sixty patients undergoing elective surgery under general anesthesia were enrolled. One-side arm in each patient was selected randomly to assess the new monitoring system placed on the wrist; an arterial catheter for IAP was inserted at the radial artery in the contralateral arm. The Bland-Altman method for repeated measurements was used to assess agreement between measurement methods by the levels of agreement according to the American Association for the Advancement of Medical Instrumentation standards. RESULTS: A total of 6600 valid pressure readings were obtained from 60 patients, including 3000 beat data and 3600 pulse wave data, respectively. The mean differences in wrist CNAP versus IAP for beat data were as follows: systolic arterial pressure (SAP): -2.09±5.39 mmHg; mean arterial pressure (MAP): 0.27±3.64 mmHg; diastolic arterial pressure (DAP): and 2.63±6.44 mmHg. For pulse wave data, the mean difference (SD) values were as follows: SAP: -2.06±6.51 mmHg; MAP: 0.50±4.36 mmHg; and DAP: 3.06±6.81 mmHg. Percentage errors were less than 28.3%. Levels of agreements were detected to be -12.65-8.47 for SAP, -6.86-7.40 for MAP, and -9.99-15.26 for DAP. CONCLUSION: The new wrist CNAP monitoring system showed an acceptable agreement and interchangeability with the IAP.

Cardiac Output Assessed by the Fourth-Generation Arterial Waveform Analysis System Is Unreliable in Liver Transplant Recipients.

BACKGROUND: Liver transplant recipients often have violent hemodynamic fluctuation during surgery that may be related to perioperative and postoperative morbidity. Because there are some considerations for the risk of the pulmonary arterial catheter (PAC), the conventional invasive device for cardiac output (CO) measurement, a reliable and minimally invasive alternative is required. We validated the reliability of CO measurements with the use of a minimally invasive FloTrac system with the latest fourth-generation algorithm in liver transplant recipients. METHODS: Forty liver transplant recipients without atrial fibrillation, valvular pathology, or intracardiac shunt were recruited in this prospective, observational study. CO values measured by use of PAC with continuous thermodilution method (COTh) and FloTrac devices (COFT) were collected simultaneously throughout the operation for reliability validation. RESULTS: Four hundred pairs of CO data points were collected in total. The linear regression analysis showed a high correlation coefficient (73%, P < .001). However, the percent error between COTh and COFT was 42.2%, which is worse than the established interchangeability criterion of 30%. The concordance rates were calculated at 89% and 59% by 4-quadrant plot and polar plot analysis, respectively. Neither met the preset validation criteria (>92% for the 4-quadrant plot and >90% for polar plot analyses). CONCLUSIONS: Our study demonstrates that the CO measurements in liver transplant recipients by the latest FloTrac system and the PAC do not meet the recognized interchangeability criterion. Although the result showed improvement in linear regression analysis, it failed to display a qualified trending ability.

Monitoring arterial pulse waves with synchronous body sensor network.

A wireless body sensor network for arterial pulse wave (PW) measurements is presented and tested with ten subjects. The system is capable of recording both mechanical PW contours with sensors made of a low-cost polypropylene-based material called electromechanical film (EMFi) and volume pulse signal with photoplethysmographic transducers. By using both types of sensors, the PW contours can be recorded from various locations. The system combined with automatic analysis methods enables to easily analyze the PW contours in order to obtain a more comprehensive view on the vascular health. To demonstrate this, two parameters used in literature, reflection index and radial augmentation index were calculated for the test subjects as a function of time. The results show that these parameter values may vary more than 20% in a period of 100 s, which suggests that a large number of PWs should be analyzed before making conclusions based on the calculated indices. In addition, the effects of the static bias force to the mechanical PW signal recorded with the EMFi sensors were studied. The PW signal with the maximum amplitude is obtained when the pressure caused by the static bias force corresponds to the contact pressure between typical systolic and diastolic blood pressures. The EMFi sensors used in the proposed system are a potential low-cost alternative for tonometric sensors in collecting data in the PW analysis for arterial screening.

A new tonometric device for radial augmentation index and subendocardial viability ratio: potential use in health screening.

Augmentation index (AIx) and subendocardial viability ratio (SEVR) are widely accepted indices of wave reflection and myocardial oxygen demand relative to supply. This study aimed to validate a new tonometric device (IIM-2010A) for obtaining AIx and SEVR from radial artery. A total of 68 outpatients (32 men and 36 women) aged 20 to 76 years (44.7±16.6 years) recruited from a health screening center participated in the study. AIx was obtained from radial pressure using the HEM-9000AI and IIM-2010A devices, while SEVR was measured from carotid pressure with the tonometric method and from radial pressure by the IIM-2010A device. In a subgroup of 24 patients, the measurements of AIx and SEVR were repeated after an interval of 10 minutes. The correlation of radial AIx between the IIM-2010A and HEM-9000AI devices was highly significant (r=0.956, P<.01). Radial SEVR determined from IIM-2010A was also highly related to carotid SEVR (r=0.864, P<.01), although the value was about 13.1% lower. There was no statistically significant difference between the repeated measurements of both indices. The lower coefficient of variation (2.9% vs 4.3% for AIx, 3.3% vs 4.1% for SEVR) and higher intraclass correlation coefficient (0.96 vs 0.91 for AIx, 0.93 vs 0.86 for SEVR) of IIM-2010A confirmed better short-term reproducibility, compared with the HEM-9000AI device and carotid tonometry. The new tonometric device IIM-2010A is effective and reproducible in calculating radial AIx and SEVR and has potential use in health screening.