Intraoperative hypotension affects postoperative acute kidney injury depending on the invasiveness of abdominal surgery: A retrospective cohort study

Intraoperative hypotension (IOH) or highly invasive surgery adversely affects postoperative clinical outcomes. It is, however, unclear whether IOH affects postoperative acute kidney injury (AKI) depending on the invasiveness of abdominal surgery. We speculated that IOH in highly invasive abdominal surgery is a significant risk factor for postoperative AKI. We retrospectively reviewed the data of 448 patients who underwent abdominal surgery. Patients were divided into 3 groups: highly (such as pancreaticoduodenectomy and hepatectomy), moderately (open abdominal surgery), and minimally (laparoscopic surgery) invasive surgeries. The association between the time-weighted average (TWA) of mean arterial pressure (MAP) values (≤60 and ≤ 55 mm Hg) and AKI occurrences in each group was assessed. Postoperative AKI occurred after highly, moderately, and minimally invasive surgeries in 33 of 222 (14.9%), 14 of 110 (12.7%), and 12 of 116 (10.3%) cases, respectively (P = .526). The median [interquartile range] of TWA-MAP ≤ 60 mm Hg, as an IOH parameter, was 0.94 [0.33-2.08] mm Hg in highly, 0.54 [0.16-1.46] mm Hg in moderately, and 0.14 [0.03-0.57] mm Hg in minimally invasive surgeries (P < 0001). In addition, there was a significant association between TWA-MAP and AKI in highly invasive surgery, unlike in moderately and minimally invasive surgery, with adjusted odds ratios (95% confidence interval) for TWA-MAP ≤ 60 and ≤ 55 mm Hg associated with AKI of 1.23 [1.00-1.52] (P = .049) and 1.55 [1.02-2.36] (P = .041), respectively. Intraoperative MAP ≤ 60 mm Hg in highly invasive abdominal surgery is associated with postoperative AKI, compared to moderately and minimally invasive surgeries. Additionally, low MAP thresholds in highly invasive surgery increase postoperative AKI risk.

Brachial Blood Pressure Invasively and Non-Invasively Obtained Using Oscillometry and Applanation Tonometry: Impact of Mean Blood Pressure Equations and Calibration Schemes on Agreement Levels

The use of oscillometric methods to determine brachial blood pressure (bBP) can lead to a systematic underestimation of the invasively measured systolic (bSBP) and pulse (bPP) pressure levels, together with a significant overestimation of diastolic pressure (bDBP). Similarly, the agreement between brachial mean blood pressure (bMBP), invasively and non-invasively measured, can be affected by inaccurate estimations/assumptions. Despite several methodologies that can be applied to estimate bMBP non-invasively, there is no consensus on which approach leads to the most accurate estimation. Aims: to evaluate the association and agreement between: (1) non-invasive (oscillometry) and invasive bBP; (2) invasive bMBP, and bMBP (i) measured by oscillometry and (ii) calculated using six different equations; and (3) bSBP and bPP invasively and non-invasively obtained by applanation tonometry and employing different calibration methods. To this end, invasive aortic blood pressure and bBP (catheterization), and non-invasive bBP (oscillometry [Mobil-O-Graph] and brachial artery applanation tonometry [SphygmoCor]) were simultaneously obtained (34 subjects, 193 records). bMBP was calculated using different approaches. Results: (i) the agreement between invasive bBP and their respective non-invasive measurements (oscillometry) showed dependence on bBP levels (proportional error); (ii) among the different approaches used to obtain bMBP, the equation that includes a form factor equal to 33% (bMBP = bDBP + bPP/3) showed the best association with the invasive bMBP; (iii) the best approach to estimate invasive bSBP and bPP from tonometry recordings is based on the calibration scheme that employs oscillometric bMBP. On the contrary, the worst association between invasive and applanation tonometry-derived bBP levels was observed when the brachial pulse waveform was calibrated to bMBP quantified as bMBP = bDBP + bPP/3. Our study strongly emphasizes the need for methodological transparency and consensus for non-invasive bMBP assessment.

Elevated Brain Natriuretic Peptide and High Brachial Pulse Pressure in Patients With Diabetes

BACKGROUND

Heart failure (HF) is frequent in patients with diabetes mellitus (DM), and early detection improves prognosis. We investigated whether analysis of brachial blood pressure (BP) in daily practice can identify patients with DM and high risk for subsequent HF, as defined by brain natriuretic peptide (BNP) >50 pg/ml.

METHODS

3,367 outpatients with DM without a history of cardiovascular disease were enrolled in a prospective study.

RESULTS

Age (mean ± SD) was 56 ± 14 years, 57% were male, 78% had type 2 DM, and HbA1C was 7.4 ± 1.4%. A history of hypertension was recorded in 43% of patients and uncontrolled BP was observed in 13%. BNP concentration (mean ± SD) was 21 ± 21 ng/l and 9% of patients had high risk of incident HF. Brachial pulse pressure (PP) was the best BP parameter associated with high risk of incident HF compared with diastolic, systolic, or mean BP (area under the receiver operating characteristic curve: 0.70, 0.65, 0.57, and 0.57, respectively). A multivariate analysis demonstrated that elevated PP was independently associated with high risk of incident HF (odds ratio [95% confidence interval, CI]: 2.1 [1.5-2.8] for PP ≥65 mm Hg). Study of central aortic BP and pulse wave velocity on 117 patients demonstrated that high risk of incident HF was associated with increased arterial stiffness and subendocardial ischemia. After a mean follow-up of 811 days, elevated PP was associated with increased all-cause mortality (hazard ratio [95% CI]: 1.7 [1.1-2.8]).

CONCLUSIONS

Brachial PP is powerful and independent "easy to record" BP parameter associated with high risk of incident HF in diabetic patients.

Arterial Stiffness Determinants for Primary Cardiovascular Prevention among Healthy Participants

Background: Arterial stiffness (AS), measured by arterial stiffness index (ASI), can be considered as a major denominator in cardiovascular (CV) diseases. Thus, it remains essential to highlight the risk factors influencing its increase among healthy participants. Methods: According to European consensus, AS is defined as ASI > 10 m/s. The purpose of this study was to investigate the determinants of the arterial stiffness (ASI > 10 m/s) among UK Biobank normotensive and healthy participants without comorbidities and previous CV diseases. Thus, a cross-sectional study was conducted on 22,452 healthy participants. Results: Participants were divided into two groups, i.e., ASI > 10 m/s (n = 5782, 25.8%) and ASI < 10 m/s (n = 16,670, 74.2%). All the significant univariate covariables were included in the multivariate analysis. The remaining independent factors associated with AS were age (OR = 1.063, threshold = 53.0 years, p < 0.001), BMI (OR = 1.0450, threshold = 24.9 kg/m2, p < 0.001), cystatin c (OR = 1.384, threshold = 0.85 mg/L, p = 0.011), phosphate (OR = 2.225, threshold = 1.21 mmol/L, p < 0.001), triglycerides (OR = 1.281, threshold = 1.09 mmol/L, p < 0.001), mean BP (OR = 1.028, threshold = 91.2 mmHg, p < 0.001), HR (OR = 1.007, threshold = 55 bpm, p < 0.001), Alkaline phosphate (OR = 1.002, threshold = 67.9 U/L, p = 0.004), albumin (OR = 0.973, threshold = 46.0 g/L, p < 0.001), gender (male, OR = 1.657, p < 0.001) and tobacco use (current, OR = 1.871, p < 0.001). Conclusion: AS is associated with multiple parameters which should be investigated in future prospective studies. Determining the markers of increased ASI among healthy participants participates in the management of future CV risk for preventive strategies.

A New Time-Window Prediction Model For Traumatic Hemorrhagic Shock Based on Interpretable Machine Learning

ABSTRACT

Early warning prediction of traumatic hemorrhagic shock (THS) can greatly reduce patient mortality and morbidity. We aimed to develop and validate models with different stepped feature sets to predict THS in advance. From the PLA General Hospital Emergency Rescue Database and Medical Information Mart for Intensive Care III, we identified 604 and 1,614 patients, respectively. Two popular machine learning algorithms (i.e., extreme gradient boosting [XGBoost] and logistic regression) were applied. The area under the receiver operating characteristic curve (AUROC) was used to evaluate the performance of the models. By analyzing the feature importance based on XGBoost, we found that features in vital signs (VS), routine blood (RB), and blood gas analysis (BG) were the most relevant to THS (0.292, 0.249, and 0.225, respectively). Thus, the stepped relationships existing in them were revealed. Furthermore, the three stepped feature sets (i.e., VS, VS + RB, and VS + RB + sBG) were passed to the two machine learning algorithms to predict THS in the subsequent T hours (where T = 3, 2, 1, or 0.5), respectively. Results showed that the XGBoost model performance was significantly better than the logistic regression. The model using vital signs alone achieved good performance at the half-hour time window (AUROC = 0.935), and the performance was increased when laboratory results were added, especially when the time window was 1 h (AUROC = 0.950 and 0.968, respectively). These good-performing interpretable models demonstrated acceptable generalization ability in external validation, which could flexibly and rollingly predict THS T hours (where T = 0.5, 1) prior to clinical recognition. A prospective study is necessary to determine the clinical utility of the proposed THS prediction models.

Visit-to-visit variability in blood pressure and the development of chronic kidney disease in treated general hypertensive patients

BACKGROUND

Data on the association between visit-to-visit variability (VVV) in blood pressure (BP) and the risk of chronic kidney disease (CKD) in general treated hypertensive patients were limited. We aimed to evaluate the relation of VVV in BP with the development of CKD, and examine any possible effect modifiers in hypertensive patients without prior cardiovascular diseases (CVDs) or CKD.

METHODS

This is a post hoc analysis of the Renal Sub-study of the China Stroke Primary Prevention Trial (CSPPT). A total of 10 051 hypertensives without CVD and CKD and with at least six visits of BP measurements from randomization to the 24-month visit were included. The main VVV in BP was expressed as standard deviation (SD). The primary outcome was the development of CKD, defined as a decrease in estimated glomerular filtration rate ≥30% and to a level of <60 mL/min/1.73 m2, or end-stage renal disease.

RESULTS

The median treatment duration was 4.4 years. After multivariable adjustment, including baseline systolic blood pressure (SBP) and mean SBP during the first 2-year treatment period, there was a significantly positive relationship of SD of SBP with the risk of CKD development (per SD increment; odds ratio, 1.27; 95% confidence interval: 1.10-1.46). The results were similar for coefficient of variation (CV) of SBP. Results across various subgroups, including age, sex, SBP at baseline, treatment compliance, concomitant antihypertensive medications and mean SBP during the first 24-month treatment period, were consistent.

CONCLUSIONS

SBP variability, irrespective of mean BP level, was significantly associated with the development of CKD in general treated hypertensive patients.

Effect of Mean Blood Pressure During Extracorporeal Life Support on Outcome After Out-of-Hospital Cardiac Arrest

Objective

Extracorporeal Life Support (ECLS) can help to improve the outcome of refractory cardiac arrest (CA). ECLS allows to maintain blood pressure and tissue perfusion until the cause of CA is treated. The aim of the present study was to describe the mean blood pressure (MBP) during the first 24 h of ECLS for out-of-hospital CA (OHCA).

Methods

We performed a retrospective analysis of consecutive refractory OHCA requiring ECLS admitted to the intensive care unit. MBP was examined after starting ECLS (H0) and every 6 h during the first 24 h (H6, H12, H18 and H24).

Results

Forty patients were analysed. MBP significantly differs between survivors and non-survivors since 6 h: 77 vs 44 mm Hg (p=0.002), 51 vs 87 mm Hg at H12 (p=0.008), 57 vs 75 mm Hg at H18 (p=0.015) and 79 vs 53 mm Hg at H24 (p=0.004), whereas no difference was observed at H0: 69 vs 55 mm Hg (p=0.06). An MBP lower than 65 mm Hg since 6 h is associated with a poor outcome (sensitivity and specificity of death of 87% and 66% at H6, 80% and 75% at H12, 100% and 75% at H18 and 70% and 80% at H24, respectively).

Conclusion

Despite high levels of catecholamine, the inability to maintain MBP higher than 60 mm Hg after starting ECLS for OHCA is associated with a poor outcome.

Associations of various blood pressure parameters with functional outcomes after endovascular thrombectomy in acute ischaemic stroke

BACKGROUND AND PURPOSE

High blood pressure (BP) at presentation is associated with poor outcomes in acute ischaemic stroke, but serial BP measurements may better delineate the clinical implications of BP. The aim was to investigate the association between various BP parameters and functional outcomes in acute ischaemic stroke patients treated with endovascular thrombectomy (EVT).

METHODS

This study reports a retrospective analysis of a prospective registry of a comprehensive stroke centre. Patients treated with EVT due to large vessel occlusion in the anterior circulation were enrolled. BP was measured hourly during the first 24 h after admission. Associations of various BP parameters, including BP variability, with functional outcomes at 3 months, including good outcomes (modified Rankin Scale score of 0-2), were analysed.

RESULTS

Of the 378 enrolled patients (mean age 70 ± 11 years, male 54.2%), 313 (82.8%) achieved successful reperfusion after EVT, and 149 (39.4%) had good outcomes at 3 months. Higher mean systolic BP [each 10 mmHg increase, odds ratio 0.82 (0.69-0.97)] and higher systolic successive variation (SV) [each 10% increase, odds ratio 0.37 (0.18-0.76)] were associated with a reduced likelihood of achieving good outcomes. In addition, reperfusion status after EVT moderated the influence of higher systolic SV on good outcomes (P_int  = 0.05).

CONCLUSION

The results showed that a higher mean systolic BP and systolic SV during the first 24 h of EVT reduced the likelihood of good outcomes at 3 months. The effects of these parameters on outcomes are more substantial amongst patients with successful reperfusion after EVT, suggesting that different BP control strategies should be employed according to reperfusion status.

Orthostatic hypotension in Parkinson disease: how much you fall or how low you go?

Orthostatic hypotension (OH) is frequent in patients with Parkinson's disease (PD) and can occur with or without symptoms. Pharmacological treatments are effective, but often exacerbate supine hypertension. Guidelines exist for the diagnosis, but not for the treatment of OH. We examined the relationship between blood pressure (BP) and symptoms in a cohort of PD patients with the goal of identifying a hemodynamic target to guide treatment. We measured BP supine and upright (tilt or active standing) and identified the presence or absence of symptomatic OH by using a validated patient-reported outcome questionnaire in 210 patients with PD. We evaluated the usefulness of the 20/10 and 30/15 mmHg diagnostic criteria (systolic/diastolic) to identify symptomatic OH. Fifty percent of the PD patient cohort met criteria for the 20/10 fall and 30% for the 30/15 BP fall. Among the patients who met either OH criteria, the percentage of those with symptoms was small (33% of those with 20/10 and 44% of those with 30/15 mmHg; 16% and 13%, respectively, overall). Symptomatic OH was associated with an upright mean BP below 75 mmHg. A mean standing BP <75 mmHg had a sensitivity of 97% and a specificity of 98% for detecting symptomatic OH. Although the prevalence of OH in PD is high, not all patients have symptoms of organ hypoperfusion. A mean standing BP below 75 mmHg appears to be a useful benchmark when deciding whether the benefits of initiating pharmacological treatment of OH outweigh the risks of exacerbating supine hypertension.

Factors influencing left ventricular hypertrophy in children and adolescents with or without family history of premature myocardial infarction

BACKGROUND

Cardiovascular diseases are the highest ranking cause of mortality. The prevalence of cardiovascular diseases is increasing among people in developed and developing countries. Since left ventricular hypertrophy is one of the risk factors leading to extremely dangerous heart diseases and even sudden death at early ages, investigating its contributing factors can be beneficial. The purpose of this study was to determine factors contributing to left ventricular hypertrophy in students aged 7-18 years in Isfahan. Statistical population of this case-control study was the 7-18 year old students in Isfahan, who were studied in two groups of children with premature myocardial infarction in their parents and the control group.

MATERIALS AND METHODS

After determining the sample size of 138 people, a two-part questionnaire was designed and demographic characteristics and anthropometric measures were recorded in students' profiles. The obtained information was analyzed using SPSS15 software and logistic regression model and the results were reported at P < 0.05.

RESULT

The results showed that among the studied variables, gender, age, body mass index, and blood pressure were associated with the left ventricular hypertrophy.

CONCLUSION

Considering the results and previous studies in this field, it was observed that left ventricular hypertrophy exists at early ages, which is very dangerous and can lead to heart diseases at early ages. Factors such as being overweight, having high blood pressure, and being male cause left ventricular hypertrophy and lead to undiagnosable heart diseases.

Effects of imperatorin, the active component from Radix Angelicae (Baizhi), on the blood pressure and oxidative stress in 2K,1C hypertensive rats

The 2-kidney, 1-clip (2K,1C) model of hypertension was used to investigate the potential antihypertensive and antioxidant effect of imperatorin extracted from the root of radix angelicae. After 10 weeks treatment of imperatorin, mean blood pressure (MBP) of 2K,1C hypertensive rats was obtained, and superoxide dismutase (SOD), nitric oxide (NO) and nitric oxide synthase (NOS) were measured. Malondialdehyde (MDA) and glutathione (GSH) levels, catalase (CATA), xanthine oxidase (XOD), angiotensinII (Ang II) and endothelin (ET) levels of kidney were evaluated with commercial kits. Nicotinamide adenine dinucleotidephosphate (NADPH) oxidase subunits of the renal cortial tissues were determined by RT-PCR and Western blot. 8-Iso-prostaglandin F2α (8-iso-PGF2α) of 24h urinary excretion was also measured by ELISA. MBP was significantly reduced by treatment with IMP (6.25, 12.5 and 25 mg/kg/day, i.g.) in 2K,1C hypertensive rats. Meanwhile, we found that renal CATA and XOD activities, GSH levels, plasma NO and NOS contents were significantly increased in IMP-treated groups. Plasma ET, renal Ang II levels, MDA and the 24h urinary excretion of 8-iso-PGF2α in the IMP treated group were lower than control SD group. After that, we found the mRNA expressions and protein levels of NADPH oxidase subunits in the clipped kidney were markedly reduced after IMP treated in 2K,1C hypertensive rats. IMP showed antihypertensive and antioxidant effects in the renal injury of renovascular hypertensive rats, suggesting that IMP could be of therapeutic use in preventing renal injury related hypertension.

Hydroxypropyl-β-cyclodextrin impacts renal and systemic hemodynamics in the anesthetized dog

Hydroxypropyl-β-cyclodextrin (HPβCD) is a complexation agent used to enhance drug solubilization and formulation stability. Although its toxicity is well characterized, its cardiovascular effects are less known. To investigate them, HPβCD was infused intravenously over 10 min in anesthetized dogs (10-40% (w/v, i.e. 200-800 mg/kg) in non-denervated animals and at 40% in denervated animals). HPβCD increased renal arteriolar resistance and decreased renal blood flow at all doses, almost immediately after infusion start, more drastically in females. A less pronounced increase in total peripheral resistance occurred in females only due to sex difference in sympathetic tone. Pulmonary hemodynamic parameters remained unaffected, suggesting that the renal effect was rather selective. As a consequence of the increased systemic blood pressure, heart rate decreased in normal animals without direct effect on cardiac conductance. This effect was abolished in denervated animals. This suggests that autonomous nervous feedback loops are functional in normal animals and that HPβCD has no direct chronotropic effect. In conclusion, systemic and renal hemodynamic changes should be considered as potential background effects at 200-400 mg/kg. At higher doses (800 mg/kg), changes are more pronounced and could mask/exacerbate hemodynamic response of drug candidate; such doses should be avoided in nonclinical safety studies.

Pattern of aortic dilatation in different bicuspid aortic valve phenotypes and its association with aortic valvular dysfunction and elasticity

OBJECTIVES

We aim to study the pattern of aortic dilatation in different BAV phenotypes and to find any correlations between aortic dilatation, aortic elasticity and AS and/or AR in our local population.

METHODS

All BAV patients and controls were retrospectively studied. Aortic distensibility and stiffness index of the ascending aorta were calculated.

RESULTS

A total of 191 patients with BAV and 180 controls were enrolled. Aortic dilatation involving a single site was more common with dilatation involving only the ascending aorta (R-N phenotype) and aortic root (N-L phenotype). AR was most common in patients with N-L and R-L phenotypes and AS in R-N phenotype. Aortic elasticity had no correlation with the different BAV phenotypes.

CONCLUSIONS

There are different patterns of aortic dilatation in different BAV phenotypes, which may further contribute to the development of aortic stenosis or regurgitation. Aortic elasticity is independent of the BAV phenotypes and is impaired in BAV patients regardless of AS or AR severity.