A meta-analysis of the utility of pre-operative brain natriuretic peptide in predicting early and intermediate-term mortality and major adverse cardiac events in vascular surgical patients

B-type natriuretic peptide levels at admission predict the prognosis of patients with infective endocarditis undergoing cardiac surgery

Purpose: The objective of this study was to explore the relationship between elevated B-type natriuretic peptide (BNP) levels and the prognosis of patients with infective endocarditis (IE) undergoing cardiac surgery. Methods: In total, 162 IE patients with recorded BNP levels upon admission were included in the present study. The primary end point was all-cause mortality. Results: Multivariate Cox analysis revealed a significant association between log BNP and all-cause mortality. Kaplan-Meier analysis revealed a poorer prognosis for patients with BNP levels ≥ the 75th percentile. Furthermore, the linear trend test indicated a significant link between BNP quartiles and the primary end point within the models. Conclusion: Elevated BNP levels upon admission could predict all-cause mortality in IE patients undergoing cardiac surgery.

The Role of Natriuretic Peptides in Predicting Adverse Outcomes After Cardiac Surgery: An Updated Systematic Review

The increasing global burden of cardiovascular disease, particularly, in the aging population, has led to an increase in high-risk cardiac surgical procedures. The current preoperative risk stratification scores, such as the European System for Cardiac Operative Risk Evaluation and the Society for Thoracic Surgeons score, have limitations in their predictive accuracy and tend to underestimate the mortality risk in higher-risk populations. This systematic review aimed to evaluate the utility of natriuretic peptides, brain natriuretic peptide (BNP) and its precursor prohormone (N-terminal prohormone BNP), as predictive biomarkers for adverse outcomes after cardiac surgery. A comprehensive search strategy was performed, and 63 studies involving 40,667 patients who underwent major cardiac operations were included for data extraction. Preoperative levels of BNP and N-terminal prohormone BNP seemed to be associated with an increased risk of short- and long-term mortality, postoperative heart failure, kidney injury, and length of intensive care unit stay. However, their predictive value for postoperative arrhythmias and myocardial infarction was less established. Our findings suggest that natriuretic peptides may play an important role in risk prediction in patients who underwent cardiac surgery. The addition of these biomarkers to the existing clinical risk stratification strategies may enhance their predictive accuracy. However, this needs to be endorsed by data derived from wide-scale clinical trials.

Cardiovascular risk management in the peri-operative setting

Peri-operative cardiovascular events occur in up to 3% of patients undergoing non-cardiac surgery. Accurate cardiovascular risk assessment is important in the peri-operative setting, as it allows informed and shared decisions regarding the appropriateness of proceeding with surgery, guides surgical and anaesthetic approaches, and may influence the use of preventive medications and post-operative cardiac monitoring. Quantitative risk assessment may also inform a reconsideration of choosing a more limited lower risk type of surgery, or conservative management. Pre-operative cardiovascular risk assessment starts with clinical assessment and should include an estimate of functional capacity. Specialised cardiac investigations are rarely indicated specifically to assess pre-operative cardiovascular risk. The decision regarding cardiac investigations is influenced by the nature, extent and urgency of surgery. The strategy of performing pre-operative revascularisation to improve post-operative outcomes is not evidence-based and recent international guidelines recommend against this.

Evaluation of the cardiovascular risk in patients undergoing major non-cardiac surgery: role of cardiac-specific biomarkers. A consensus document by the Inter-Society Study Group on Cardiac Biomarkers of the Italian Societies of Clinical Biochemistry: European Ligand Assay Society (ELAS), Italian section; Società Italiana di Biochimica Clinica e Biologia Molecolare Clinica (SIBioC); Società Italiana di Patologia Clinica e Medicina di Laboratorio (SIPMel)

Major adverse cardiovascular events are frequently observed in patients undergoing major non-cardiac surgery during the peri-operative period. At this time, the possibility to predict cardiovascular events remains limited, despite the introduction of several algorithms to calculate the risk of adverse events, mainly death and major adverse cardiovascular events (MACE) based on the clinical history, risk factors (sex, age, lipid profile, serum creatinine) and non-invasive cardiac exams (electrocardiogram, echocardiogram, stress tests). The cardiac-specific biomarkers natriuretic peptides (NPs) and cardiac troponins (cTn) have been proposed as additional tools for risk prediction in the peri-operative period, particularly for the identification of myocardial injury in patients undergoing major non-cardiac surgery. The prognostic information from the measurement of BNP/NT-proBNP and hs-cTn is independent and complementary to other important indicators of risk, also including ECG and imaging techniques. Elevated levels of cardiac-specific biomarkers before surgery are associated with a markedly higher risk of MACE during the peri-operative period. BNP/NT-proBNP and hs-cTn should be measured in all patients during the clinical evaluation before surgery, particularly during intermediate- or high-risk surgery, in patients aged >65 years and/or with comorbidities. Several questions remain to be assessed in dedicated clinical studies, such as how to optimize the management of patients with raised cardiac specific biomarkers before surgery, and whether a strategy based on biomarker measurement improves patient outcomes and is cost-effective.

Natriuretic Peptides and Troponins to Predict Cardiovascular Events in Patients Undergoing Major Non-Cardiac Surgery

Patients undergoing major surgery have a substantial risk of cardiovascular events during the perioperative period. Despite the introduction of several risk scores based on medical history, classical risk factors and non-invasive cardiac tests, the possibility of predicting cardiovascular events in patients undergoing non-cardiac surgery remains limited. The cardiac-specific biomarkers, natriuretic peptides (NPs) and cardiac troponins (cTn) have been proposed as additional tools for risk prediction in the perioperative period. This review paper aims to discuss the value of preoperative levels and perioperative changes in cardiac-specific biomarkers to predict adverse outcomes in patients undergoing major non-cardiac surgery. Based on several prospective observational studies and six meta-analyses, some guidelines recommended the measurement of NPs to refine perioperative cardiac risk estimation in patients undergoing non-cardiac surgery. More recently, several studies reported a higher mortality in surgical patients presenting an elevation in high-sensitivity cardiac troponin T and I, especially in elderly patients or those with comorbidities. This evidence should be considered in future international guidelines on the evaluation of perioperative risk in patients undergoing major non-cardiac surgery.

ASA Status, NPPA/NPPB Haplotype and Coronary Artery Disease Have an Impact on BNP/NT-proBNP Plasma Levels

Plasma concentrations of natriuretic peptides (NP) contribute to risk stratification and management of patients undergoing non-cardiac surgery. However, genetically determined variability in the levels of these biomarkers has been described previously. In the perioperative setting, genetic contribution to NP plasma level variability has not yet been determined. A cohort of 427 patients presenting for non-cardiac surgery was genotyped for single-nucleotide polymorphisms (SNPs) from the NPPA/NPPB locus. Haplotype population frequencies were estimated and adjusted haplotype trait associations for brain natriuretic peptide (BNP) and amino-terminal pro natriuretic peptide (NT-proBNP) were calculated. Five SNPs were included in the analysis. Compared to the reference haplotype TATAT (rs198358, rs5068, rs632793, rs198389, rs6676300), haplotype CACGC, with an estimated frequency of 4%, showed elevated BNP and NT-proBNP plasma concentrations by 44% and 94%, respectively. Haplotype CGCGC, with an estimated frequency of 9%, lowered NT-proBNP concentrations by 28%. ASA classification status III and IV, as well as coronary artery disease, were the strongest predictors of increased NP plasma levels. Inclusion of genetic information might improve perioperative risk stratification of patients based on adjusted thresholds of NP plasma levels.

The Influence of Perioperative Fluid Therapy on N-terminal-pro-brain Natriuretic Peptide and the Association With Heart and Lung Complications in Patients Undergoing Colorectal Surgery: Secondary Results of a Clinical Randomized Assessor-blinded Multicenter Trial

OBJECTIVE

To investigate the influence of intravenous (iv) fluid volumes on the secretion of N-terminal-pro-brain natriuretic peptide (NT-Pro-BNP) in colorectal surgical patients and its association with cardiopulmonary complications (CPC). In addition, to examine if preoperative NT-Pro-BNP can predict the risk for postoperative CPC.

METHODS

Blood samples from patients enrolled in a previously published clinical randomized assessor-blinded multicenter trial were analyzed. Included were adult patients undergoing elective colorectal surgery with the American-Society-of-Anesthesiologists-scores of 1-3. Samples from 135 patients were available for analysis. Patients were allocated to either a restrictive (R-group) or a standard (S-group) iv-fluid regimen, commencing preoperatively and continuing until discharge. Blood was sampled every morning until the fourth postoperative day. The primary outcome for this study was NT-Pro-BNP changes and its association with fluid therapy and CPC.

RESULTS

The S-group received more iv-fluid than the R-group on the day-of-surgery [milliliter, median (range) 6485 (4401-10750) vs 3730 (2250-8510); P < 0.001] and on the first postoperative day. NT-Pro-BNP was elevated in the S-group compared with the R-group on all postoperative days [area under the curve: median (interquartile range) pg/mL: 3285 (1697-6179) vs 1290 (758-3719); P < 0.001 and in patients developing CPC vs no-CPC (area under the curve), median (interquartile range): 5196 (1823-9061) vs 1934 (831-5301); P = 0.005]. NT-pro-BNP increased with increasing fluid volumes all days (P < 0.003). Preoperative NT-Pro-BNP predicted CPC [odds ratio (confidence interval): 1.573 (0.973-2.541), P = 0.032; positive predictive value = 0.257, negative predictive value = 0.929].

CONCLUSIONS

NT-pro-BNP increases with iv-fluid volumes given to colorectal surgical patients, and the level of NT-Pro-BNP is associated with CPC. Preoperative NT-Pro-BNP is predictive for CPC, but the diagnostic value is low.Clinicaltrials.gov NCT03537989.

Non-cardiac surgery in patients with coronary artery disease: risk evaluation and periprocedural management

Perioperative cardiovascular complications are important causes of morbidity and mortality associated with non-cardiac surgery, particularly in patients with coronary artery disease (CAD). Although preoperative cardiac risk assessment can facilitate the identification of vulnerable patients and implementation of adequate preventive measures, excessive evaluation might lead to undue resource utilization and surgical delay. Owing to conflicting data, there remains some uncertainty regarding the most beneficial perioperative strategy for patients with CAD. Antithrombotic agents are the cornerstone of secondary prevention of ischaemic events but substantially increase the risk of bleeding. Given that 5-25% of patients undergoing coronary stent implantation require non-cardiac surgery within 2 years, surgery is the most common reason for premature cessation of dual antiplatelet therapy. Perioperative management of antiplatelet therapy, which necessitates concomitant evaluation of the individual thrombotic and bleeding risks related to both clinical and procedural factors, poses a recurring dilemma in clinical practice. Current guidelines do not provide detailed recommendations on this topic, and the optimal approach in these patients is yet to be determined. This Review summarizes the current data guiding preoperative risk stratification as well as periprocedural management of patients with CAD undergoing non-cardiac surgery, including those treated with stents.

Perioperative outcomes and risk assessment in dialysis patients: current knowledge and future directions

Perioperative medicine is rapidly emerging as a key discipline to address the specific needs of high-risk surgical groups, such as those on chronic dialysis. Crude hospital separation rates for chronic dialysis patients are considerably higher than patients with normal renal function, with up to 15% of admission being related to surgical intervention. Dialysis dependency carries substantial mortality and morbidity risk compared to patients with normal renal function. This group of patients has a high comorbid burden and complex medical need, making accurate perioperative planning essential. Existing perioperative risk assessment tools are unvalidated in chronic dialysis patients. Furthermore, they fail to incorporate important dialysis treatment-related characteristics that could potentially influence perioperative outcomes. There is a dearth of information on perioperative outcomes of Australasian dialysis patients. Current perioperative outcome estimates stem predominantly from North American literature; however, the generalisability of these findings is limited, as the survival of North American dialysis patients is significantly inferior to their Australasian counterparts and potentially confounds reported perioperative outcomes; let alone regional variation in surgical indication and technique. We propose that data linkage between high-quality national registries will provide more complete data with more detailed patient and procedural information to allow for more informative analyses to develop and validate dialysis-specific risk assessment tools.

Peri-operative cardiac biomarker screening: a narrative review

Peri-operative risk estimation has traditionally focused on assessing the likelihood of postoperative morbidity and mortality using pre-operative functional assessment. Although this strategy is currently recommended by most major society guidelines, contemporary evidence suggests that cardiac biomarker measurement has important advantages over pre-operative functional assessment. These advantages include superior predictive discrimination and inclusion of the postoperative course in risk estimation. In this review, we provide an overview of the evidence supporting the peri-operative utilisation, compare risk estimation methods and discuss which patients may benefit most from cardiac biomarker screening. We also discuss protocols for biomarker screening and management of patients with abnormal results.

Low and elevated B-type natriuretic peptide levels are associated with increased mortality in patients with preserved ejection fraction undergoing transcatheter aortic valve replacement: an analysis of the PARTNER II trial and registry

Aims

B-type natriuretic peptide (BNP) is a cardiac neurohormone that is secreted in response to ventricular volume expansion and pressure overload. There are conflicting data regarding the association between BNP levels and outcomes after transcatheter aortic valve replacement (TAVR). We therefore sought to assess the association between baseline BNP and adverse outcomes in patients with symptomatic, severe aortic stenosis (AS), and left ventricular ejection fraction (LVEF) ≥50%, undergoing TAVR in the PARTNER 2 Trial and Registry.

Methods and results

A total of 1782 patients were included in the analysis, and BNP was evaluated both as a continuous log-transformed value and by a priori categories: low (&lt;50 pg/mL), normal (≥50 and &lt;100 pg/mL), moderately elevated (≥100 and &lt;400 pg/mL), or markedly elevated (≥400 pg/mL). Clinical outcomes from discharge to 2 years were compared between patients according to their baseline BNP level, using Kaplan–Meier event rates and multivariable Cox proportional hazards regression models. After adjustment, spline curves revealed a non-linear association between log-transformed BNP and all-cause and cardiovascular mortality in which both the lowest and highest values were associated with increased mortality. Two-year all-cause mortality rates for those with low (n = 86), normal (n = 202), moderately elevated (n = 885), and markedly elevated (n = 609) baseline BNP were 20.0%, 9.8%, 17.7%, and 26.1%, respectively. In adjusted models, compared to a normal baseline BNP, low [adjusted hazard ratio (HR) 2.6, 95% confidence interval (CI) 1.3–5.0, P-value 0.005], moderately elevated (adjusted HR 1.6, 95% CI 1.0–2.6, P-value 0.06), and markedly elevated (adjusted HR 2.1, 95% CI 1.3–3.5, P-value 0.003) BNP were associated with increased all-cause mortality, driven by cardiovascular mortality.

Conclusions

In a large cohort of patients with severe symptomatic AS and preserved LVEF undergoing TAVR, all-cause and cardiovascular mortality rates at 2 years were higher in patients with low and markedly elevated BNP levels.

Clinical Trial Registration

https://clinicaltrials.gov/ unique identifier #NCT01314313, #NCT02184442, #NCT03222128, and #NCT03222141.

The role of cardiac rehabilitation using exercise to decrease natriuretic peptide levels in non-surgical patients: a systematic review

Exercise is recommended in patients with cardiac failure. In the perioperative patient, exercise is also gaining popularity as a form of prehabilitation. In this meta-analysis, we examine if exercise is able to reduce natriuretic peptide levels. Natriuretic peptide (NP) has strong prognostic ability in identifying patients who will develop adverse postoperative cardiovascular outcomes. The protocol was registered with PROSPERO (CRD42017051468). The database search included MEDLINE (PubMed), CINAHL (EBSCO host), EMBASE (EBSCO host), ProQuest, Web of Science, and Cochrane database. The primary outcomes were to determine whether exercise therapy was effective in reducing NP levels as compared to control group, the shortest time period required to reduce NP levels after exercise therapy, and whether reducing NP levels decreased morbidity and mortality. Full texts of 16 trials were retrieved for this review. Exercise therapy showed a significant reduction in natriuretic peptide levels between the intervention and control groups (SMD - 0.45, 95% CI - 0.88 to - 0.03) with significant heterogeneity between the included trials. This was also shown in the within a 12-week period.

B-type peptides to predict post–liver transplant mortality: systematic review and meta-analysis

Background: Cirrhotic patients undergoing liver transplantation are at risk of cardiac complications. Brain natriuretic peptide (BNP) and amino terminal brain natriuretic peptide (NT-BNP) are used in cardiac risk stratification. Their significance in predicting mortality risk in cirrhotic patients during or after liver transplantation is unknown. We conducted a systematic review and meta-analysis to answer this question. Methods: An electronic search of EMBASE, MEDLINE, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews (2005–September 2016), Google Scholar, and study bibliographies was conducted. Study quality was determined, and demographic and outcome data were gathered. Random effects meta-analyses of mortality-based BNP and NT-BNP level or presence of post-transplant heart failure were conducted. Results: Seven studies including 2,010 patients were identified. Demographics were similar between patients with high or low BNP or NT-BNP levels. Hepatitis C was the most prevalent etiology of cirrhosis (38%). Meta-analysis revealed a pooled relative risk of 3.1 (95% CI 1.9% to 5.0%) for post-transplant mortality based on elevated BNP or NT-BNP level. Meta-analysis also revealed a pooled relative risk of 1.6 (95% CI 1.3% to 2.1%) for post-transplant mortality if patients had demonstrated post-transplant heart failure. Conclusions: Our analysis suggests that BNP or NT-BNP measurement may help in risk stratification and provides data on post-operative mortality in cirrhotic patients undergoing liver transplantation. Discriminatory thresholds are higher in cirrhotic patients relative to prior studies with non-cirrhotic patients. However, the number of analyzed studies is limited, and our findings should be validated further through larger, prospective studies.

Potential New Approaches in Predicting Adverse Cardiac Events One Month after Major Vascular Surgery

OBJECTIVE

The aim of our study was to find the best model with sufficient power to improve the risk stratification in major vascular surgery patients during the first 30 days after this procedure. The discriminatory power of 4 biomarkers (troponin I [TnI], N-terminal prohormone of brain natriuretic peptide [NT-proBNP], creatine kinase-MB isoenzyme [CK-MB], high-sensitivity C-reactive protein [hs-CRP]) was tested as well as 2 risk assessment models and 13 different combinations of them.

SUBJECTS AND METHODS

The study included 122 patients (77% men, 23% women) with an average age of 67.03 ± 4.5 years. An aortobifemoral bypass was performed in 6.56% of the patients, a femoropopliteal bypass in 18.85%, and 49.18% received open surgical reconstruction of the carotid arteries. A total of 25.41% of the patients were given an aortobi-iliac bypass.

RESULTS

During the first 30 days, 13 patients (10.7%) had 17 cardiac complications. The most common complication was the new onset of atrial fibrillation (35.3%). During the first 10 days, 10 patients had 1 complication and 2 patients had 2 cardiac events, while 1 patient had 3 complications. By comparing combinations of scores and markers, it was shown that revised cardiac risk index (RCRI) + Vascular Portsmouth Physiological and Operative Severity Score (V-POSSUM) + hsTnI and RCRI + V-POSSUM + hsTnI + NT-proBNP with 100% sensitivity, > 80% specificity had the best discriminatory ability (AUC 0.924 and 0.933, respectively; p < 0.001 for both models) for cardiac complications during the 30 days after surgery.

CONCLUSION

Combinations of traditional preoperative risk factors and scores can enhance the assessment of major adverse cardiac events (MACE) in patients preparing for large vascular surgery. Using only one risk score in these patients seems to be underperforming in preoperative risk assessment.

Normalization of N-Terminal Pro-B-Type Natriuretic Peptide After Cardiac Surgery Among Children With Tetralogy of Fallot

The aim of this study was to temporally measure N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels over a period of 18 months after corrective surgery among children with tetralogy of Fallot (TOF) and to explore how commonly used pharmaceuticals (i.e., spironolactone and digoxin) might affect the normalization pattern. This retrospective study included 136 children with a median age of 7 months who underwent cardiac surgery for TOF. NT-proBNP level was measured at 1, 3, 6, 12, and 18 months after the surgery. Normalization of NT-proBNP was defined as an NT-proBNP level ≤250 pg/ml. The commonly used pharmaceuticals spironolactone and digoxin after discharge were collected. The normalization pattern, normalization time, and potential influence of the pharmaceuticals were determined. The rate of normalization was 24.2% (95% confidence interval [CI] 8.58% to 68.4%) per 100 person-days. Kaplan-Meier survival analysis showed a median normalization time of 517 (95% CI 429.6 to 604.3) days. The children whose NT-proBNP level did not normalize had a significantly higher readmission rate than those whose NT-proBNP level normalized (19.0% vs 2.8%, p = 0.018). Multivariable logistic regression models confirmed that the regular users of spironolactone, alone (odds ratio = 1.45, 95% CI 1.15 to 1.83) or in combination with digoxin (odds ratio = 1.28, 95% CI 1.03 to 1.58), had markedly faster recovery trajectories for measures of NT-proBNP than the irregular users of both. In conclusion, NT-proBNP normalization after cardiac surgery for TOF is a lengthy process, and irregular use of spironolactone could lead to failure in recovery and hospital readmission.

B-Type Natriuretic Peptide Assessment in Patients Undergoing Revascularization for Left Main Coronary Artery Disease

Background:

Elevated B-type natriuretic peptide (BNP) is reflective of impaired cardiac function and is associated with worse prognosis among patients with coronary artery disease (CAD). We sought to assess the association between baseline BNP, adverse outcomes, and the relative efficacy of percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) in patients with left main CAD.

Methods:

The EXCEL trial (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) randomized patients with left main CAD and low or intermediate SYNTAX scores (Synergy Between PCI With TAXUS and Cardiac Surgery) to PCI with everolimus-eluting stents versus CABG. The primary end point was the composite of all-cause death, myocardial infarction, or stroke. We used multivariable Cox proportional hazards regression to assess the associations between normal versus elevated BNP (≥100 pg/mL), randomized treatment, and the 3-year risk of adverse events.

Results:

BNP at baseline was elevated in 410 of 1037 (39.5%) patients enrolled in EXCEL. Patients with elevated BNP levels were older and more frequently had additional cardiovascular risk factors and lower left ventricular ejection fraction than those with normal BNP, but had similar SYNTAX scores. Patients with elevated BNP had significantly higher 3-year rates of the primary end point (18.6% versus 11.7%; adjusted hazard ratio [HR], 1.62; 95% confidence interval [CI], 1.16–2.28; P =0.005) and higher mortality (11.5% versus 3.9%; adjusted HR, 2.49; 95% CI, 1.48–4.19; P =0.0006), both from cardiovascular and noncardiovascular causes. In contrast, there were no significant differences in the risks of myocardial infarction, stroke, ischemia-driven revascularization, stent thrombosis, graft occlusion, or major bleeding. A significant interaction ( P interaction =0.03) was present between elevated versus normal BNP and treatment with PCI versus CABG for the adjusted risk of the primary composite end point at 3 years among patients with elevated BNP (adjusted HR for PCI versus CABG, 1.54; 95% CI, 0.96–2.47) versus normal BNP (adjusted HR, 0.74; 95% CI, 0.46–1.20). This interaction was stronger when log(BNP) was modeled as a continuous variable ( P interaction =0.002).

Conclusions:

In the EXCEL trial, elevated baseline BNP levels in patients with left main CAD undergoing revascularization were independently associated with long-term mortality but not nonfatal adverse ischemic or bleeding events. The relative long-term outcomes after PCI versus CABG for revascularization of left main CAD may be conditioned by the baseline BNP level.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT01205776.

Postoperative Remote Automated Monitoring: Need for and State of the Science

Worldwide, more than 230 million adults have major noncardiac surgery each year. Although surgery can improve quality and duration of life, it can also precipitate major complications. Moreover, a substantial proportion of deaths occur after discharge. Current systems for monitoring patients postoperatively, on surgical wards and after transition to home, are inadequate. On the surgical ward, vital signs evaluation usually occurs only every 4-8 hours. Reduced in-hospital ward monitoring, followed by no vital signs monitoring at home, leads to thousands of cases of undetected/delayed detection of hemodynamic compromise. In this article we review work to date on postoperative remote automated monitoring on surgical wards and strategy for advancing this field. Key considerations for overcoming current barriers to implementing remote automated monitoring in Canada are also presented.

Preoperative Midregional Pro-Adrenomedullin and High-Sensitivity Troponin T Predict Perioperative Cardiovascular Events in Noncardiac Surgery

OBJECTIVE

We evaluated the utility of preoperative midregional (MR) pro-adrenomedullin (proADM) and cardiac troponin T (TnT) for improved detection of patients at high risk for perioperative cardiac events and mortality after major noncardiac surgery.

SUBJECTS AND METHODS

This prospective, single-center, observational study enrolled 79 patients undergoing major noncardiac surgery. After initial clinical assessment (clinical history, physical examination, echocardiogram, blood tests, and chest X-ray), MR-proADM and high-sensitivity TnT (hsTnT) were measured within 48 h prior to surgery by immunoluminometric and electrochemiluminescence immunoassay. Patients were followed by the consulting physician until discharge or up to 14 days in the hospital after surgery. Perioperative cardiac events included myocardial infarction and development or aggravation of congestive heart failure. Data were compared between patients who developed target events and event-free patients.

RESULTS

Within 14 days of monitoring, 14 patients (17.72%) developed target events: 9 (11.39%) died and 5 (6.33%) developed cardiovascular events. The average age of the patients was 71.29 ± 6.62 years (range: 55-87). Sex, age, and hsTnT did not significantly differ between groups. MR- proADM concentration was higher in deceased patients (p = 0.01). The upper quartile of MR-proADM was associated with a fatal outcome (66.7 vs. 20.0%, p < 0.01) and with cardiovascular events (64.3 vs. 16.9%, p < 0.01). MR-proADM above the cutoff value (≥0.85) was associated with a fatal outcome (88.9 vs. 20.0%, p < 0.01) and cardiovascular events (71.4 vs. 28.6%, p < 0.01); this association was not observed for hsTnT.

CONCLUSION

Preoperative measurement of MR-proADM provides useful information for perioperative cardiac events in high-risk patients scheduled for noncardiac surgery.

Perioperative risk

The high-risk surgical patient is a growing challenge to modern health care. This cohort, although comprising only 10-15% of surgical procedures, accounts for approximately 80% of postoperative deaths and suffers a high rate of postoperative morbidity. Developing robust systems to help identify and better manage this patient group should be a priority. Risk stratification has become a valuable clinical tool for shared decision-making and the development of individualized care plans. Methods for stratifying individual risk include assessment tools, measures of functional capacity and plasma biomarker assays. Routine evaluation of perioperative risk is central to the delivery of high quality, appropriate surgical care.

Sleep apnea in total joint arthroplasty patients and the role for cardiac biomarkers for risk stratification: an exploration of feasibility

Obstructive sleep apnea (OSA) is highly prevalent in patients undergoing total joint arthroplasty (TJA) and is a major risk factor for postoperative cardiovascular complications and death. Recognizing this, the American Society of Anesthesiologists urges clinicians to implement special considerations in the perioperative care of OSA patients. However, as the volume of patients presenting for TJA increases, resources to implement these recommendations are limited. This necessitates mechanisms to efficiently risk stratify patients having OSA who may be susceptible to post-TJA cardiovascular complications. We explore the role of perioperative measurement of cardiac troponins (cTns) and brain natriuretic peptides (BNPs) in helping determine which OSA patients are at increased risk for post-TJA cardiovascular-related morbidity.

Canadian Cardiovascular Society Guidelines on Perioperative Cardiac Risk Assessment and Management for Patients Who Undergo Noncardiac Surgery

The Canadian Cardiovascular Society Guidelines Committee and key Canadian opinion leaders believed there was a need for up to date guidelines that used the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system of evidence assessment for patients who undergo noncardiac surgery. Strong recommendations included: 1) measuring brain natriuretic peptide (BNP) or N-terminal fragment of proBNP (NT-proBNP) before surgery to enhance perioperative cardiac risk estimation in patients who are 65 years of age or older, are 45-64 years of age with significant cardiovascular disease, or have a Revised Cardiac Risk Index score ≥ 1; 2) against performing preoperative resting echocardiography, coronary computed tomography angiography, exercise or cardiopulmonary exercise testing, or pharmacological stress echocardiography or radionuclide imaging to enhance perioperative cardiac risk estimation; 3) against the initiation or continuation of acetylsalicylic acid for the prevention of perioperative cardiac events, except in patients with a recent coronary artery stent or who will undergo carotid endarterectomy; 4) against α₂ agonist or β-blocker initiation within 24 hours before surgery; 5) withholding angiotensin-converting enzyme inhibitor and angiotensin II receptor blocker starting 24 hours before surgery; 6) facilitating smoking cessation before surgery; 7) measuring daily troponin for 48 to 72 hours after surgery in patients with an elevated NT-proBNP/BNP measurement before surgery or if there is no NT-proBNP/BNP measurement before surgery, in those who have a Revised Cardiac Risk Index score ≥1, age 45-64 years with significant cardiovascular disease, or age 65 years or older; and 8) initiating of long-term acetylsalicylic acid and statin therapy in patients who suffer myocardial injury/infarction after surgery.

N-terminal pro B type natriuretic peptide in high cardiovascular-risk patients for noncardiac surgery: What is the current prognostic evidence?

As millions of surgical procedures are performed worldwide on an aging population with multiple comorbidities, accurate and simple perioperative risk stratification is critical. The cardiac biomarker, brain natriuretic peptide (BNP), has generated considerable interest as it is easy to obtain and appears to have powerful predictive and prognostic capabilities. BNP is currently being used to guide medical therapy for heart failure and has been added to several algorithms for perioperative risk stratification. This review examines the current evidence for the use of BNP in the perioperative period in patients who are at high-cardiovascular risk for noncardiac surgery. In addition, we examined the use of BNP in patients with pulmonary embolism and left ventricular assist devices. The available data strongly suggest that the addition of BNP to perioperative risk calculators is beneficial; however, whether this determination of risk will impact outcomes, remains to be seen.

Predicting the occurrence of major adverse cardiac events within 30 days of a vascular surgery: an empirical comparison of the minimum p value method and ROC curve approach using individual patient data meta-analysis

We aimed to compare the minimum p value method and the area under the receiver operating characteristics (ROC) curve approach to categorize continuous biomarkers for the prediction of postoperative 30-day major adverse cardiac events in noncardiac vascular surgery patients. Individual-patient data from six cohorts reporting B-type natriuretic peptide (BNP) or N-terminal pro-B-type natriuretic peptide (NTproBNP) were obtained. These biomarkers were dichotomized using the minimum p value method and compared with previously reported ROC curve-derived thresholds using logistic regression analysis. A final prediction model was developed, internally validated, and assessed for its sensitivity to clustering effects. Finally, a preoperative risk score system was proposed. Thresholds identified by the minimum p value method and ROC curve approach were 115.57 pg/ml (p < 0.001) and 116 pg/ml for BNP, and 241.7 pg/ml (p = 0.001) and 277.5 pg/ml for NTproBNP, respectively. The minimum p value thresholds were slightly stronger predictors based on our logistic regression analysis. The final model included a composite predictor of the minimum p value method’s BNP and NTproBNP thresholds [odds ratio (OR) = 8.5, p < 0.001], surgery type (OR = 2.5, p = 0.002), and diabetes (OR = 2.1, p = 0.015). Preoperative risks using the scoring system ranged from 2 to 49 %. The minimum p value method and ROC curve approach identify similar optimal thresholds. We propose to replace the revised cardiac risk index with our risk score system for individual-specific preoperative risk stratification after noncardiac nonvascular surgery.

Preoperative Laboratory Testing

Routine preoperative testing is not cost-effective, because it is unlikely to identify significant abnormalities. Abnormal findings from routine testing are more likely to be false positive, are costly to pursue, introduce a new risk, increase the patient's anxiety, and are inconvenient to the patient. Abnormal findings rarely alter the surgical or anesthetic plan, and there is usually no association between perioperative complications and abnormal laboratory results. Incidental findings and false positive results may lead to increased hospital visits and admissions. Preoperative testing needs to be done based on a targeted history and physical examination and the type of surgery.

N-terminal pro-B-type Natriuretic Peptides’ Prognostic Utility Is Overestimated in Meta-analyses Using Study-specific Optimal Diagnostic Thresholds

Background:

N-terminal fragment B-type natriuretic peptide (NT-proBNP) prognostic utility is commonly determined post hoc by identifying a single optimal discrimination threshold tailored to the individual study population. The authors aimed to determine how using these study-specific post hoc thresholds impacts meta-analysis results.

Methods:

The authors conducted a systematic review of studies reporting the ability of preoperative NT-proBNP measurements to predict the composite outcome of all-cause mortality and nonfatal myocardial infarction at 30 days after noncardiac surgery. Individual patient-level data NT-proBNP thresholds were determined using two different methodologies. First, a single combined NT-proBNP threshold was determined for the entire cohort of patients, and a meta-analysis conducted using this single threshold. Second, study-specific thresholds were determined for each individual study, with meta-analysis being conducted using these study-specific thresholds.

Results:

The authors obtained individual patient data from 14 studies (n = 2,196). Using a single NT-proBNP cohort threshold, the odds ratio (OR) associated with an increased NT-proBNP measurement was 3.43 (95% CI, 2.08 to 5.64). Using individual study-specific thresholds, the OR associated with an increased NT-proBNP measurement was 6.45 (95% CI, 3.98 to 10.46). In smaller studies (&lt;100 patients) a single cohort threshold was associated with an OR of 5.4 (95% CI, 2.27 to 12.84) as compared with an OR of 14.38 (95% CI, 6.08 to 34.01) for study-specific thresholds.

Conclusions:

Post hoc identification of study-specific prognostic biomarker thresholds artificially maximizes biomarker predictive power, resulting in an amplification or overestimation during meta-analysis of these results. This effect is accentuated in small studies.

The effect of anesthesia method on serum level of pro-brain natriuretic Peptide in patients undergoing orthopedic surgery

Background:

Surgical stress response is among the most severe stress tolerated by the patient, which needs suppression by anesthesia.

Objectives:

We assessed the effect of three methods of anesthesia on postoperative levels of pro-brain natriuretic peptide (pro-BNP) to determine the most effective one in preventing surgical stress response.

Patients and Methods:

In a randomized clinical trial, 120 patients who were 18 to 65 years old and met inclusion and exclusion criteria were selected and randomly allocated to three groups of 40:Group A, general anesthesia plus epidural catheter; Group B, general anesthesia and intravenous patient-controlled analgesia; and Group C, spinal anesthesia plus intravenous patient-controlled analgesia.

Results:

There was no difference between three groups for basic characteristics and variables and baseline pro-BNP levels; however, postoperative pro-BNP levels in Groups A, B, and C were respectively63.8 ± 10.1, 83.2 ± 12.3, and 51.5 ± 8.5 ng/L (ANOVA, P = 0.01).

Conclusions:

The results of the current study suggested that spinal anesthesia plus intravenous patient-controlled analgesia have the most favorable cardiac effects regarding postoperative levels of pro-BNP.

Prediction of perioperative cardiac events through preoperative NT-pro-BNP and cTnI after emergent non-cardiac surgery in elderly patients

Objectives

Clinical risk stratification has an important function in preoperative evaluation of patients at risk for cardiac events prior to non-cardiac surgery. The aim of this study was to determine whether the combined measurement of pre-operative N-terminal pro-brain natriuretic peptide (NT-pro-BNP) and cardiac troponin I (cTnI) could provide useful prognostic information about postoperative major adverse cardiac events (MACE) within 30 days in patients aged over 60 years undergoing emergent non-cardiac surgery.

Methods

The study group comprised 2519 patients aged over 60 years that were undergoing emergent non-cardiac surgery between December 2007 and December 2013. NT-pro-BNP and cTnI were measured during hospital admission. The patients were monitored for MACE (cardiac death, non-fatal myocardial infarction, or cardiac arrest) during the 30-day postoperative follow-up period.

Results

MACE occurred in 251 patients (10.0%). Preoperative NT-pro-BNP and cTNI level were significantly higher in the individuals that experienced MACE than in those who did not (P < 0.001). The confounding factors of age, sex, co-morbidities and preoperative medications were adjusted in a multivariate logistic regression analysis. This analysis showed that preoperative NT-proBNP level > 917 pg/mL (OR 4.81, 95% CI 3.446–6.722, P < 0.001) and cTnI ≥ 0.07 ng/mL (OR 8.74, 95% CI 5.881–12.987, P < 0.001) remained significantly and independently associated with MACE after the adjustment of the confounding factors. Kaplan-Meier event-free survival curves demonstrated that patients with preoperative simultaneous NT-proBNP level > 917 pg/mL and cTnT ≥0.07 ng/mL had worse event-free survival than individual assessments of either biomarker.

Conclusion

Preoperative plasma NT-proBNP and cTnI are both independently associated with an increased risk of MACE in elderly patients after emergent non-cardiac surgery. The combination of these biomarkers provides better prognostic information than using either biomarker separately.

B-type natriuretic peptide-guided therapy for perioperative medicine?

The recent guideline from the European Society of Cardiology and European Society of Anesthesiology recommended the use of B-type natriuretic peptide (BNP) as preoperative testing for high-risk cardiac patients undergoing non-cardiac surgery. In this article, the potential benefits, risks and details for implementing BNP testing in perioperative medicine are discussed. Review of four related lines of research including the use of BNP test for preoperative prognosis, BNP test for screening asymptomatic heart failure, BNP as prognostic test in asymptomatic, non-heart failure patients and using BNP for detecting silent myocardial ischaemia showed converging cut-off levels of BNP for risk stratification. BNP has better OR and relative risk in comparison with Revised Cardiac Risk Index (RCRI) in predicting perioperative cardiac risk. BNP-guided therapy can be low risk based on current evidence on non-surgical patients, including treating asymptomatic patients without heart failure to prevent cardiovascular complications. At present, there is lack of direct evidence supporting perioperative BNP testing. Further research with randomised controlled trials is needed to confirm the benefit of BNP-guided management. Preoperative BNP testing may be considered in patients with RCRI above 0 undergoing intermediate or high-risk surgery. BNP-guided therapy is likely a beneficial addition to perioperative medicine. Its combination with β-blocker titration, RCRI and perioperative cardiovascular monitoring can be a major advance in reducing cardiac risk resulting in a dynamic, individualised optimisation process.

Cardiac biomarkers in the prediction of risk in the non-cardiac surgery setting

B-Type natriuretic peptides and troponin measurements have potential in predicting risk in patients undergoing non-cardiac surgery. Using the American Heart Association framework for the evaluation of novel biomarkers, we review the current evidence supporting the peri-operative use of these two biomarkers. In patients having major non-cardiac surgery who are risk stratified using clinical risk scores, the measurement of natriuretic peptides and troponin, both before and after surgery, significantly improves risk stratification. However, only pre- and postoperative natriuretic peptide measurement and postoperative troponin measurement have shown clinical utility. It is now important for trials to be conducted to determine whether integrating pre- and postoperative natriuretic peptide and postoperative troponin measurement into clinical practice is able to improve clinical outcomes in patients undergoing non-cardiac surgery.

Predictive value of plasma brain natriuretic peptide for postoperative cardiac complications--a systemic review and meta-analysis

BACKGROUND

We aimed to undertake a systematic review and meta-analysis of studies addressing perioperative natriuretic peptide (NP) levels to predict postoperative major adverse cardiac events (MACE) after major surgery.

METHODS

We searched MEDLINE and Embase with no language restrictions up to May 2013. The end points were major cardiac complications. We summarized test performance characteristics with the use of forest plots, hierarchical summary receiver operating characteristic curves, and bivariate random effects models.

RESULTS

Of the 662 retrieved articles, 24 studies satisfied the predefined eligibility criteria, including 5438 patients along with 712 (13.1%) events. After major surgery, the diagnostic odds ratio (DOR) of NP in predicting postoperative MACE was 14.3 (95% confidence interval [CI], 9.87-20.7) for overall population, 13.9 (8.43-22.8) for patients undergoing cardiac surgery, and 15.0 (8.84-25.5) for patients undergoing noncardiac surgery. The pooled sensitivity was 0.84 (95% CI, 0.79-0.88) and specificity was 0.76 (95% CI, 0.71-0.81). Postoperative measurement (DOR, 18.9; 7.68-46.3) was associated with higher predictive value than preoperative measurement (DOR, 13.6; 7.68-46.3). Results were similar for a subgroup with the composite outcome including mortality (DOR, 16.4; 10.6-25.5). B-type natriuretic peptide was associated with higher predictive accuracy (area under the summary receiver operating characteristic, 0.84; 0.81-0.87) than N-terminal pro-b-type natriuretic peptide (area under the summary receiver operating characteristic, 0.90; 0.87-0.92).

CONCLUSIONS

The existing literature suggests that perioperative NP testing have reasonable accuracy and can be useful in perioperative risk stratification. Natriuretic peptide testing has high rule-out value and low rule-in value for predicting postoperative MACE. Medical decisions should be made in the context of these characteristics.

Value of plasma brain natriuretic peptide levels for predicting postoperative atrial fibrillation: a systemic review and meta-analysis

BACKGROUND

Blood natriuretic peptide (NP) levels have been reported to be useful for predicting postoperative atrial fibrillation (AF). We aimed to quantitatively synthesize the current evidence of the accuracy of using NP levels in predicting postoperative AF.

METHODS AND RESULTS

Medline, Embase, and reference lists were searched. Studies were included if either brain natriuretic peptide (BNP) or N-terminal pro-b type natriuretic peptide (NT-proBNP) had been evaluated perioperatively to predict postoperative AF. Data were analyzed to obtain summary accuracy estimates. Data from 1,844 patients in 10 studies were analyzed. Summary estimates for the sensitivity and specificity of using NP levels for predicting postoperative AF were 75 % [95 % confidence interval (CI) 67-79 %] and 80 % (95 % CI 62-91 %), respectively. The overall diagnostic odds ratio was 3.28 (95 % CI 2.23-4.84). Subgroup analysis showed that elevated NP levels in the perioperative period were a strong independent predictor of postoperative AF. NT-proBNP appeared to have better predictive value than BNP, as did postoperative assessment over preoperative assessment. BNP had a better correlation with postoperative AF in patients undergoing thoracic surgery than in patients undergoing cardiac surgery.

CONCLUSIONS

Perioperative assessment of the natriuretic peptide level in patients undergoing major cardiothoracic surgery could be a valuable diagnostic aid for identifying patients at high risk of developing postoperative AF, and for providing critical clinical information to guide prophylactic antiarrhythmic therapy in the perioperative period.