Pre-Operative Cardiac Risk Assessment in Noncardiac Surgery

Cardiovascular Risk Assessment for Noncardiac Surgery: Are We Ready for Biomarkers?

Biomarkers aided perioperative cardiac assessment is a relatively new concept. Cardiac biomarkers with historical significance (aspartate transaminase, dehydrogenase, creatinine kinase and myoglobin) have paved the way for traditional biomarkers (cardiac troponin, C-reactive protein, lipoprotein). Contemporary biomarkers like natriuretic peptides (BNP and ProBNP) are validated risk markers in both acute and chronic cardiac diseases and are showing remarkable promise in predicting serious cardiovascular complications after non-cardiac surgery. This review is intended to provide a critical overview of traditional and contemporary biomarkers for perioperative cardiovascular assessment and management. This review also discusses the potential utility of newer biomarkers like galectin-3, sST-2, GDF-15, TNF-alpha, MiRNAs and many others that can predict inflammation, cardiac remodeling, injury and endogenous stress and need further investigations to establish their clinical utility. Though promising, biomarker led perioperative care is still in infancy and it has not been determined that it can improve clinical outcomes.

High levels of preoperative and postoperative N terminal B-type natriuretic propeptide influence mortality and cardiovascular complications after noncardiac surgery: A prospective cohort study

BACKGROUND

Major noncardiac surgery is associated with a 5% incidence of serious cardiovascular complications and with a 1 to 2% probability of death from cardiac causes. Over the last few decades, researchers have assessed the perioperative predictive power of several risk indices. Research is currently focused on the evaluation of biomarkers.

OBJECTIVES

The objective was to determine the incidence of high serum levels of N terminal B-type natriuretic propeptide (NT-proBNP) before and after surgery in adults undergoing elective major noncardiac procedures and to evaluate its relationship with mortality and cardiovascular complications occurring up to 30 days after surgery.

DESIGN

Prospective cohort study.

SETTING

Enrolment was undertaken at a university hospital from October 2011 to July 2013.

PATIENTS

A total of 304 adults with cardiovascular risk factors who underwent noncardiac elective surgery.

MAIN OUTCOME MEASURES

The relationship between preoperative and postoperative NT-proBNP serum levels and the emergence of cardiovascular complications, including all-cause mortality, during the first 30 days after surgery.

RESULTS

The incidence of cardiovascular complications was 7.8% (n = 25), and the mortality rate was 4.3% (n = 13). Higher-than-normal NT-proBNP serum levels were found before surgery in 48.4% (n = 147) and after surgery in 50.7% (n = 154) of patients. The variables found to be independent predictors of cardiovascular complications, including all-cause 30-day mortality, were levels of NT-proBNP more than 300 pg ml before surgery and levels more than 1000 pg ml both before and after surgery.

CONCLUSION

High levels of preoperative and postoperative NT-proBNP are predictors of cardiovascular complications, including all-cause mortality, during the first 30 days after noncardiac surgery in adults with cardiovascular risk factors.

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.

N-terminal pro-brain natriuretic peptide and angiotensin-converting enzyme-2 levels and their association with postoperative cardiac complications after emergency orthopedic surgery

The prognostic usefulness of the cardiac biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP) and angiotensin-converting enzyme 2 (ACE-2), in predicting adverse cardiac outcomes after orthopedic surgery is not well studied. The aim of our study was to determine the usefulness of perioperative NT-proBNP and ACE-2 for predicting cardiac events after emergency orthopedic surgery. The perioperative NT-proBNP and ACE-2 levels were determined in 187 consecutive patients aged >60 years who underwent orthopedic surgery with 1 year of follow-up for any cardiac complications (defined as acute myocardial infarction, congestive cardiac failure, atrial fibrillation, or major arrhythmia) and death. Of the 187 patients, 20 (10.7%) sustained an in-hospital postoperative cardiac complication. The total all-cause in-hospital and 1-year mortality rate was 1.6% (3 of 187) and 8.6% (16 of 187), respectively. The median preoperative and postoperative NT-proBNP level was greater in patients who sustained an in-hospital cardiac event than in those who had not (386 vs 2,273 pg/ml, p <0.001, and 605 vs 4,316 pg/ml, p <0.001, respectively). Similarly, the postoperative median ACE-2 levels were significantly greater in the patients with an in-hospital cardiac event than in those without (25.3 vs 39.5 pmol/ml/min, p = 0.012). A preoperative NT-proBNP level of ≥741 pg/ml (odds ratio 4.5, 95% confidence interval 1.3 to 15.2, p = 0.017), postoperative troponin elevation (odds ratio 4.9, 95% confidence interval 1.3 to 18.9, p = 0.022), and number of co-morbidities (odds ratio 1.8, 95% confidence interval 1.2 to 2.8, p = 0.009) independently predicted in-hospital cardiac complications on multivariate analysis. The pre- and postoperative NT-proBNP level independently predicted 1-year cardiovascular complications but not the ACE-2 levels. In conclusion, elevated perioperative NT-proBNP predicted in-hospital and 1-year cardiac events in an emergency orthopedic population but the ACE-2 levels did not, which requires additional study for validation.

[Cardiac biomarkers in perioperative risk stratification]

OBJECTIVES

The field of new cardiac biomarkers has triggered physicians' enthusiasm because of their potential diagnostic and prognostic values for routine clinical practice in the surgical setting. The objective of the present article is to review the role of new cardiac biomarkers and their potential additive clinical value in predicting short- and long-term risk following cardiac and non-cardiac surgery.

DATA SOURCES

A PubMed(®) database research in English and French languages published until June 2010. Keywords were cardiac biomarkers, troponins, cardiac troponin I (cTnI), natriuretic peptides, B-type natriuretic peptide (BNP), C-reactive protein (CRP), multiple markers approach, risk stratification, clinical risk scores.

DATA SYNTHESIS

Numerous publications deal with the diagnostic and prognostic values of new cardiac biomarkers in cardiac and non-cardiac surgical settings and provide an increasing evidence of their interest, validating different hierarchical steps which are mandatory before recommending a wide use of biomarkers for routine practice. Even if the first studies demonstrating an additional prognostic value of serum postoperative cTnI and/or preoperative BNP when compared with clinical predictive models are now available, we still lack data concerning an actual positive impact of new biomarkers measurements on clinical decision making or practice, as well as patient care and outcome.

CONCLUSIONS

While use of new cardiac biomarkers in the perioperative period appears to be a simple and objective tool for risk stratification at the bedside, we still need to remain cautious concerning their additional clinical value on existing predictive models for routine practice.

Innovations in treating aortic diseases: the abdominal aorta

Patients with an abdominal aortic aneurysm (AAA) could benefit from earlier diagnosis to improve long-term outcomes. Candidate serum biomarkers for earlier AAA diagnosis include D-dimer, fibrinogen, low-density lipoprotein, high-density lipoprotein, lipoprotein(a), and the proteolytic enzymes known as matrix metalloproteinases. Furthermore, biomarkers such as brain natriuretic peptide significantly stratify perioperative risk in AAA repair. Statins significantly improve outcomes after AAA repair. They may also significantly slow AAA growth to allow pharmacologic arrest of AAA development. Recent trials have focused attention on fluid management for AAA repair. Although restrictive fluid management may significantly improve clinical outcomes, current evidence does not clearly support crystalloid or colloid for AAA repair. There may be an increased risk of renal dysfunction associated with hetastarch therapy. Endovascular repair has revolutionized the clinical management of AAAs. Recent trials have shown its significant outcome advantages. Furthermore, it is also applicable in high-risk operative cohorts and, in the future, may be suited for earlier AAA repair. This technology continues to advance with the development of branched and fenestrated grafts as well as total percutaneous endovascular AAA repair. Regardless of these advances, the clinical management of endoleaks will remain a major clinical focus. Taken together, these advances in the management of AAAs likely will significantly influence future clinical approaches to this challenging patient cohort.

Screening value of N-terminal pro-B-type natriuretic peptide as a predictor of perioperative cardiac events after noncardiac surgery

Preoperative cardiac risk assessment is the cornerstone of rationale perioperative management that guides invasive surgical interventions. In addition to clinical risk factors, a simple screening biomarker would be useful for identifying those surgical patients who might benefit from additional cardiac testing or therapeutic interventions. Preoperative plasma levels of N-terminal pro-B-type natriuretic peptide (NT-proBNP) are predictors of cardiac events after noncardiac surgery. NT–proBNP is synthesized in the ventricular myocardium in response to ventricular wall stress. To further increase the diagnostic accuracy of NT-proBNP for preoperative screening, it is important to identify confounding factors that influence NT-proBNP levels and their interaction with identifying risks for adverse cardiac events. Moreover, until now the available data from previous studies has been unable to consistently recognize the optimal discriminatory threshold for NT-proBNP. Currently, the ongoing DECREASE-VI study is conducted to evaluate whether current preoperative risk stratification can be improved by incorporating NT-proBNP measurements.

Natriuretic Peptides and Assessment of Cardiovascular Disease Risk in Asymptomatic Persons

Current tools for cardiovascular disease (CVD) risk assessment in asymptomatic individuals are imperfect. Preventive measures aimed only at individuals deemed high risk by current algorithms neglect large numbers of low-risk and intermediate-risk individuals who are destined to develop CVD and who would benefit from early and aggressive treatment. Natriuretic peptides have the potential both to identify individuals at risk for future cardiovascular events and to help detect subclinical CVD. Choosing the appropriate subpopulation to target for natriuretic peptide testing will help maximize the performance and the cost effectiveness. The combined use of multiple risk markers, including biomarkers, genetic testing, and imaging or other noninvasive measures of risk, offers promise for further refining risk assessment algorithms. Recent studies have highlighted the utility of natriuretic peptides for preoperative risk stratification; however, cost effectiveness and outcomes studies are needed to affirm this and other uses of natriuretic peptides for cardiovascular risk assessment in asymptomatic individuals.