Carbon Dioxide, Blood Pressure, and Perioperative Stroke: A Retrospective Case-Control Study

Taurine levels and long-term adverse cerebrovascular risk in moyamoya disease: A prognostic perspective study

BACKGROUND

Taurine has been proven to play a significant role in cardiovascular and cerebrovascular diseases, but its relationship with moyamoya disease (MMD) remains unclear. This study aims to investigate the association between serum taurine levels and long-term adverse cerebrovascular events in patients with MMD after revascularization.

METHODS

This study involved 352 patients with MMD, from whom comprehensive clinical data and blood samples were collected. Serum taurine levels were measured using liquid chromatography-tandem mass spectrometry, and the relationship between serum taurine concentration and various blood indices was evaluated. Cerebrovascular adverse events included transient ischemic attack, ischemic stroke, and hemorrhagic stroke. Taurine, analyzed as a continuous variable, was found to predict a cut-off for postoperative cerebrovascular adverse events in MMD patients at 842.52 μmol/L. The impact of serum taurine levels on the risk of cerebrovascular events was analyzed using Kaplan-Meier (KM) curves, and univariate and multivariate Cox regression analyses were performed to identify predictive factors for postoperative prognosis.

RESULTS

Grouping MMD patients by serum taurine levels revealed that higher taurine levels were significantly associated with a lower proportion of hemorrhagic MMD (p = 0.044). Compared with ischemic MMD, patients with hemorrhagic MMD had lower taurine concentrations (p = 0.005). KM curves showed that the incidence of postoperative cerebrovascular adverse events in the high taurine group was significantly lower than in the low taurine group (p = 0.026). Univariate Cox regression analysis indicated that higher taurine concentrations significantly reduced the risk of postoperative cerebrovascular adverse events (Hazard Ratio [HR] = 0.334, 95 % Confidence Interval [CI] = 0.121-0.923, p = 0.035). Furthermore, the multivariate Cox regression model confirmed that taurine level is an independent predictor of long-term adverse cerebrovascular events, with the high concentration group showing a significantly reduced risk.

CONCLUSIONS

Low serum taurine levels are associated with a higher risk of long-term adverse cerebrovascular events following MMD revascularization. This suggests the significant potential of serum taurine as a prognostic biomarker for postoperative outcomes.

CLINICAL TRIAL REGISTRY NUMBER

URL: https://www.chictr.org.cn/. Unique identifier: ChiCTR2200061889.

A review of machine learning methods for non-invasive blood pressure estimation

Blood pressure is a very important clinical measurement, offering valuable insights into the hemodynamic status of patients. Regular monitoring is crucial for early detection, prevention, and treatment of conditions like hypotension and hypertension, both of which increasing morbidity for a wide variety of reasons. This monitoring can be done either invasively or non-invasively and intermittently vs. continuously. An invasive method is considered the gold standard and provides continuous measurement, but it carries higher risks of complications such as infection, bleeding, and thrombosis. Non-invasive techniques, in contrast, reduce these risks and can provide intermittent or continuous blood pressure readings. This review explores modern machine learning-based non-invasive methods for blood pressure estimation, discussing their advantages, limitations, and clinical relevance.

A Retrospective Comparative Study of the Frequency of Hypotension in Pediatric Cardiac Catheterization under General Anesthesia: Remimazolam versus Sevoflurane

OBJECTIVE

To compare the incidence of hypotension between remimazolam and sevoflurane under general anesthesia for cardiac catheterization in patients with congenital heart disease.

DESIGN

Retrospective observational study.

SETTING

A single university hospital with 300 pediatric cardiac catheterizations by general anesthesia performed annually.

PARTICIPANTS

Patients younger than 15 years who underwent cardiac catheterization under general anesthesia between March 1, 2021, and December 31, 2022. Exclusion criteria were general anesthesia maintained with other than remimazolam or sevoflurane, receipt of remifentanil, American Society of Anesthesiologists score 4 or 5, emergency procedures, and no direct arterial pressure measurement.

INTERVENTIONS

General anesthesia was maintained with remimazolam or sevoflurane.

MEASUREMENTS AND MAIN RESULTS

A total of 309 patients were analyzed, including 28 in the remimazolam group and 281 in the sevoflurane group. Propensity score matching adjusted for confounding factors resulted in 28 patients in each arm, with no apparent differences in background factors. Hypotension was defined as a time-averaged area > 1, in which systolic arterial pressure fell below 80% of the baseline from the start of anesthesia to the end of procedure. The significance level was set at P < .05. The incidence of hypotension was 39.3% in the remimazolam arm and 46.4% in the sevoflurane arm, with no significant difference (P = .79), although the ratio of the median systolic arterial pressure to the baseline value was significantly higher in the remimazolam arm (91.4 ± 15.2% vs 83.2 ± 11.4% in the sevoflurane arm; P = .03).

CONCLUSIONS

Remimazolam was not associated with a lower incidence of hypotension compared to sevoflurane during pediatric cardiac catheterization for congenital heart disease while maintaining significantly higher blood pressure overall.

Influencing and prognostic factors of end-stage hypertrophic cardiomyopathy

AIMS

End-stage hypertrophic cardiomyopathy (ES-HCM) is a disease with severe complications and a poor prognosis. This study aimed to explore the influencing and prognostic factors of ES-HCM.

METHODS AND RESULTS

A total of 1282 patients with HCM who were hospitalized for the first time at Fujian Medical University Union Hospital between 1 January 2013 and 30 September 2021 were recorded. The patients with HCM and left ventricular ejection fraction (LVEF) < 50% were defined as having ES-HCM, and a control group (LVEF ≥ 50%) was generated from the collected medical records of HCM. The patients were matched in a ratio of 4:1 based on age and sex. Logistic regression analysis was used to determine the influencing factors of ES-HCM. Kaplan-Meier survival analysis was performed to analyse the clinical outcomes of ES-HCM patients. A total of 250 inpatients with HCM were enrolled in the study; 50 patients had ES-HCM, and 200 had HCM with LVEF ≥ 50%. The mean age of the patients at enrolment was 62.5 ± 10.3 years, and 215 patients (215/250, 86.0%) were male. The median follow-up time of the patients was 2.8 (1.4-5.4) years. The incidence of all-cause death and cardiovascular death in patients with ES-HCM was higher than those in patients with HCM and LVEF ≥ 50% (22/50 [44.0%] vs. 13/200 [6.5%]; 12/50 [24.0%] vs. 4/200 [2.0%], all P < 0.001). Multivariate logistic regression analysis showed that the influencing factors associated with ES-HCM included age at first symptom onset (odds ratio [OR] = 0.95, 95% CI [0.90, 1.00], P = 0.042), New York Heart Association (NYHA) class (OR = 7.73, 95% CI [2.93, 20.41], P < 0.001), heart rate (OR = 1.07, 95% CI [1.02, 1.12], P = 0.003), QRS duration (OR = 1.03, 95% CI [1.00, 1.05], P = 0.020), left ventricular end-diastolic diameter (LVEDD) (OR = 1.15, 95% CI [1.04, 1.28], P = 0.006), left atrial anteroposterior diameter (LAD) (OR = 1.13, 95% CI [1.03, 1.24], P = 0.012), and maximum left ventricular wall thickness (MLVWT) (OR = 0.80, 95% CI [0.68, 0.93], P = 0.005). Among the 50 patients with ES-HCM, NYHA class (P < 0.001) and heart rate (P = 0.017) were each associated with a higher likelihood and earlier occurrence of heart transplantation or all-cause mortality in univariate analyses.

CONCLUSIONS

The influencing factors for ES-HCM included the age at first symptom onset, NYHA class, heart rate, QRS duration, LVEDD, LAD, and MLVWT. Both NYHA class and heart rate were related to the prognosis of ES-HCM.

Perioperative care of patients with recent stroke undergoing nonemergent, nonneurological, noncardiac, nonvascular surgery: a systematic review and meta-analysis

PURPOSE OF REVIEW

To systematically review and perform a meta-analysis of published literature regarding postoperative stroke and mortality in patients with a history of stroke and to provide a framework for preoperative, intraoperative, and postoperative care in an elective setting.

RECENT FINDINGS

Patients with nonneurological, noncardiac, and nonvascular surgery within three months after stroke have a 153-fold risk, those within 6 months have a 50-fold risk, and those within 12 months have a 20-fold risk of postoperative stroke. There is a 12-fold risk of in-hospital mortality within three months and a three-to-four-fold risk of mortality for more than 12 months after stroke. The risk of stroke and mortality continues to persist years after stroke. Recurrent stroke is common in patients in whom anticoagulation/antiplatelet therapy is discontinued. Stroke and time elapsed after stroke should be included in the preoperative assessment questionnaire, and a stroke-specific risk assessment should be performed before surgical planning is pursued.

SUMMARY

In patients with a history of a recent stroke, anesthesiology, surgery, and neurology experts should create a shared mental model in which the patient/surrogate decision-maker is informed about the risks and benefits of the proposed surgical procedure; secondary-stroke-prevention medications are reviewed; plans are made for interruptions and resumption; and intraoperative care is individualized to reduce the likelihood of postoperative stroke or death.

DAANISH: A mnemonic to aid in memorizing and recalling important strategies contributing to the prevention of perioperative stroke

Background

Perioperative stroke, defined as a stroke occurring within 30 days post-surgery, typically emerges within the first week. The incidence of perioperative stroke among adults undergoing non-cardiac and non-neurological surgeries ranges from 0.1% to 1% after a surgical intervention. Mortality rates following perioperative stroke surge, reaching up to eight times higher than controls, with approximately one in four cases resulting in death. Fortunately, various strategies are available to potentially prevent perioperative strokes. However, the vast amount of data poses challenges for physicians in memorization and recall for clinical use. This study aims to summarize essential perioperative stroke prevention strategies and determine an effective mnemonic for their memorization and recall.

Method

The initial search in PubMed focused solely on review articles published within the last 10 years. It utilized the keywords "perioperative stroke" and "prevention."

Results

An initial search found 39 articles, with two suitable for review. Using data from selected review articles, further searches were conducted on Google Scholar and PubMed for articles from 2000 to 2024, identifying 30 additional suitable references. From these 32 articles, the author developed a mnemonic, "DAANISH," to aid in remembering strategies for preventing perioperative stroke.

Conclusion

Implementing this mnemonic may help reduce the risk of perioperative stroke and improve patient outcomes. Future research is needed to confirm its effectiveness.

New findings on the risk of hypertension from organophosphorus exposure under different glycemic statuses: The key role of lipids?

BACKGROUND AND OBJECTIVE

Considering the widespread use of organophosphorus pesticides (OPs) and the global prevalence of hypertension (HTN), as well as studies indicating that different glycemic statuses may respond differently to the biological effects of OPs. Therefore, this study, based on the Henan rural cohort, aims to investigate the association between OPs exposure and HTN, and further explores whether lipids mediate these associations.

METHODS

We measured the plasma levels of OPs in 2730 participants under different glycemic statuses using gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). A generalized linear model, Quantile g-computation (QGC), adaptive elastic net (AENET), and Bayesian kernel machine regression (BKMR) models were used to assess the impact of OPs exposure on HTN, with least absolute shrinkage and selection operator (LASSO) penalty regression identifying main OPs. Mediation models were used to evaluate the intermediary role of blood lipids in the OPs-HTN relationship.

RESULTS

The detection rates for all OPs were high, ranging from 76.35 % to 99.17 %. In the normal glucose tolerance (NGT) population, single exposure models indicated that malathion and phenthoate were associated with an increased incidence of HTN (P-FDR < 0.05), with corresponding odds ratios (ORs) and 95 % confidence intervals (CIs) of 1.624 (1.167,2.260) and 1.290 (1.072,1.553), respectively. QGC demonstrated a positive association between OP mixtures and HTN, with malathion and phenthoate being the primary contributors. Additionally, the AENET model's Exposure Response Score (ERS) suggested that the risk of HTN increases with higher ERS (P < 0.001). Furthermore, BKMR revealed that co-exposure to OPs increases HTN risk, with phenthoate having a significant impact. Furthermore, triglycerides (TG) mediated 6.55 % of the association between phenthoate and HTN. However, no association was observed in the impaired fasting glucose (IFG) and type 2 diabetes mellitus (T2DM) populations.

CONCLUSIONS

Our findings suggest that in the NGT population, OPs may significantly contribute to the development of HTN, proposing TG as a potential novel target for HTN prevention.

Incidence and risk factors of peri-operative stroke in major non-cardiovascular, non-neurologic surgery-A retrospective register-based cohort study

BACKGROUND

Peri-operative stroke is a rare but serious surgical complication. Both overt and covert stroke, occurring in approximately 0.1% and 7% of cases, respectively, are associated with significant long-term effects and increased morbidity.

METHODS

Retrospective register data for patients >18 years old, presenting for major non-cardiovascular, non-neurosurgical and non-ambulatory surgical procedures at 23 hospitals in Sweden between 2007 and 2014 was collected and linked with various quality registers. The primary outcome was stroke within 30 days from surgery. Using multivariable logistic regression, significant independent risk factors influencing the primary outcome were identified and their adjusted odds ratios (ORs) were calculated. Mortality was assessed, along with the composite score of days alive and at home within 30 days after surgery (DAH 30).

RESULTS

In total, 318,017 patients were included, with 687 (0.22%) suffering a stroke within 30 days of surgery. The strongest significant risk factors included: increasing ASA-class (OR [95% confidence interval, CI]: 2.23 [1.53-3.36], 3.91 [2.68-5.93] and 7.82 [5.03-12.5] for ASA 2, 3 and 4, respectively) and age (OR [95% CI]: 4.47 [2.21-10.3], 9.9 [5.15-22.1], 16.3 [8.48-36.5] and 21 [10.6-48.1], for age 45-59, 60-74, 75-89 and >90, respectively), along with non-elective procedures, male gender and a history of cerebrovascular disease (OR [95%]: 2.72 [2.25-3.27]). Mortality was increased and DAH 30 was reduced in patients suffering a stroke.

CONCLUSIONS

Increasing ASA-class and age was clearly associated with an increased risk of peri-operative stroke, which in turn was associated with increased mortality and poorer outcome. Detailed pre-operative risk stratification and individualised peri-operative management could potentially improve patient-centred outcomes and, in turn, have positive implications for public health.

Perioperative stroke

Ischaemic or haemorrhagic perioperative stroke (that is, stroke occurring during or within 30 days following surgery) can be a devastating complication following surgery. Incidence is reported in the 0.1-0.7% range in adults undergoing non-cardiac and non-neurological surgery, in the 1-5% range in patients undergoing cardiac surgery and in the 1-10% range following neurological surgery. However, higher rates have been reported when patients are actively assessed and in high-risk populations. Prognosis is significantly worse than stroke occurring in the community, with double the 30-day mortality, greater disability and diminished quality of life among survivors. Considering the annual volume of surgeries performed worldwide, perioperative stroke represents a substantial burden. Despite notable differences in aetiology, patient populations and clinical settings, existing clinical recommendations for perioperative stroke are extrapolated mainly from stroke in the community. Perioperative in-hospital stroke is unique with respect to the stroke occurring in other settings, and it is essential to apply evidence from other settings with caution and to identify existing knowledge gaps in order to effectively guide patient care and future research.

Prevention of perioperative stroke in patients undergoing non-cardiac surgery

About 300 million adults undergo non-cardiac surgery annually. Although, in this setting, the incidence of perioperative stroke is low, the absolute number of patients experiencing a stroke is substantial. Furthermore, most patients with this complication will die or end up with severe disability. Covert brain infarctions are more frequent than overt strokes and are associated with postoperative delirium, cognitive decline, and cerebrovascular events at 1 year after surgery. Evidence shows that traditional stroke risk factors including older age, hypertension, and atrial fibrillation are also associated with perioperative stroke; previous stroke is the strongest risk factor for perioperative stroke. Increasing evidence also suggests the pathogenic role of perioperative events, such as hypotension, new atrial fibrillation, paradoxical embolism, and bleeding. Clinicians involved in perioperative care should be aware of this evidence on prevention strategies to improve patient outcomes after non-cardiac surgery.

Carbon Dioxide, Blood Pressure, and Perioperative Stroke: A Retrospective Case-Control Study

BACKGROUND

The relationship between intraoperative physiology and postoperative stroke is incompletely understood. Preliminary data suggest that either hypo- or hypercapnia coupled with reduced cerebrovascular inflow (e.g., due to hypotension) can lead to ischemia. This study tested the hypothesis that the combination of intraoperative hypotension and either hypo- or hypercarbia is associated with postoperative ischemic stroke.

METHODS

We conducted a retrospective, case-control study via the Multicenter Perioperative Outcomes Group. Noncardiac, nonintracranial, and nonmajor vascular surgical cases (18 yr or older) were extracted from five major academic centers between January 2004 and December 2015. Ischemic stroke cases were identified via manual chart review and matched to controls (1:4). Time and reduction below key mean arterial blood pressure thresholds (less than 55 mmHg, less than 60 mmHg, less than 65 mmHg) and outside of specific end-tidal carbon dioxide thresholds (30 mmHg or less, 35 mmHg or less, 45 mmHg or greater) were calculated based on total area under the curve. The association between stroke and total area under the curve values was then tested while adjusting for relevant confounders.

RESULTS

In total, 1,244,881 cases were analyzed. Among the cases that screened positive for stroke (n = 1,702), 126 were confirmed and successfully matched with 500 corresponding controls. Total area under the curve was significantly associated with stroke for all thresholds tested, with the strongest combination observed with mean arterial pressure less than 55 mmHg (adjusted odds ratio per 10 mmHg-min, 1.17 [95% CI, 1.10 to 1.23], P < 0.0001) and end-tidal carbon dioxide 45 mmHg or greater (adjusted odds ratio per 10 mmHg-min, 1.11 [95% CI, 1.10 to 1.11], P < 0.0001). There was no interaction effect observed between blood pressure and carbon dioxide.

CONCLUSIONS

Intraoperative hypotension and carbon dioxide dysregulation may each independently increase postoperative stroke risk.

EDITOR’S PERSPECTIVE