Hemoglobin and B-type natriuretic peptide preoperative values but not inflammatory markers, are associated with postoperative morbidity in cardiac surgery: a prospective cohort analytic study

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.

Associations of Inflammatory Biomarkers With the Risk of Morbidity and Mortality After Cardiac Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Although inflammatory biomarkers have been associated with cardiovascular events in nonsurgical settings, these associations have not been systematically addressed in patients undergoing cardiac surgery. This review aimed to evaluate the relationships of inflammatory markers with mortality and adverse cardiovascular events in patients undergoing cardiac surgery.

METHODS

Medline, Embase, and Central databases were systematically searched for studies reporting pre- or postoperative levels of inflammatory biomarkers in patients undergoing cardiac surgery. Outcomes of interest were postoperative mortality, nonfatal myocardial infarction, stroke, congestive heart failure, and major adverse cardiovascular events (MACE). Studies reporting multivariable adjusted risk estimates were included. Risk estimates were pooled with the use of random-effects models and reported as summary odds ratios (ORs).

RESULTS

Among 14,465 citations identified, 29 studies including 29,401 participants met the eligibility criteria. The average follow-up time after surgery was 31 months. Preoperative C-reactive protein (CRP) levels were associated with an increased risk of all-cause mortality (OR 1.88, 95% CI 1.60-2.20; I2 = 19%; 11 studies) and MACE (OR 1.73, 95% CI 1.34-2.24; I2 = 0%; 3 studies). CRP levels measured on postoperative day 6 (OR 7.4, 95% CI 2.90-18.88, 1 study) and day 10 (OR 11.8, 95% CI 3.50-39.78, 1 study) were associated with a higher risk of all-cause mortality. Less, but overall similar, information was available for other inflammatory biomarkers.

CONCLUSIONS

In this large meta-analysis, inflammatory biomarkers measured before or after cardiac surgery were associated with mortality and adverse cardiovascular outcomes in patients undergoing cardiac surgery.

Clinical factors associated with arrhythmia and short-term prognosis following mitral valve repair: a retrospective cohort study

BACKGROUND

Postoperative arrhythmia (POA) is one of the common and serious postoperative complications. This retrospective study was conducted to investigate the clinical factors associated with POA and its short-term prognosis following mitral valve repair.

METHODS

A total of 618 patients receiving mitral valve repair between January 2015 and November 2020 in our hospital were included in this retrospective study, including 318 males and 300 females and aged 53.9±9.3 years. The patients were grouped into arrhythmia and non-arrhythmia groups and investigated for risk factors associated with the prognosis of POA using multivariate logistic regression based on their clinical data.

RESULTS

POA was observed in 314 (50.8%) patients and atrial fibrillation (AF) was the most frequent (43.3%) type of POA. Compared with non-arrhythmia patients, arrhythmia patients had significantly longer time to use vasoactive drug use, longer intensive care unit (ICU) stay and longer hospital stay. In addition, the incidence of postoperative heart failure was significantly higher (P<0.05). Logistic regression analysis showed that preoperative arrhythmia [odds ratio (OR) =9.17; 95% confident interval (CI): 4.49-18.10], postoperative pain (OR =4.70; 95% CI: 1.55-6.12) and postoperative hypoxemia (OR =3.25; 95% CI: 1.04-6.28) were independently associated with POA.

CONCLUSIONS

This study demonstrates that the incidence of arrhythmia is relatively high after mitral valve repair and is associated with preoperative arrhythmia, postoperative pain and postoperative hypoxemia.

Clinical Applications of Biomarkers in Atrial Fibrillation

While biomarkers have greatly impacted the diagnosis and management of myocardial infarction and heart failure, the use of biomarkers has been slow to permeate management of atrial fibrillation. Guideline recommendations on the use of biomarkers in atrial fibrillation were virtually nonexistent until the 2016 European Society of Cardiology guidelines on atrial fibrillation offered a class IIb recommendation to consider using biomarkers such as high-sensitivity troponin and natriuretic peptide to further refine stroke and bleeding risk in atrial fibrillation patients. Biomarker levels have been associated with incident atrial fibrillation, postoperative atrial fibrillation, acute atrial fibrillation, diagnosis of myocardial infarction and heart failure in atrial fibrillation, and prognosis in atrial fibrillation. This review will offer an in-depth survey of current evidence on the use of biomarkers in atrial fibrillation and propose clinical algorithms to aid the internist in using biomarkers in atrial fibrillation management.

Absolute Postoperative B-Type Natriuretic Peptide Concentrations, but Not Their General Trend, Are Associated With 12-Month, All-Cause Mortality After On-Pump Cardiac Surgery

BACKGROUND

B-type natriuretic peptide (BNP) is a predictor of mortality after on-pump cardiac surgery. However, previous limited and heterogeneous studies have focused on peak concentrations at 3 to 5 days after surgery and may not offer clinicians much help in early decision-making. After confirming the predictive value of first-postoperative-day BNP in a preliminary analysis, we explored the association between isolated second-postoperative-day BNP concentrations, second-day BNP concentrations in conjunction with first-day BNP concentrations, and the change in BNP (ie, ΔBNP) from the first to the second postoperative day and 12-month, all-cause mortality.

METHODS

We included consecutive patients undergoing on-pump cardiac surgery in this observational, secondary analysis of prospectively collected data. We analyzed biomarkers on the first and second postoperative day. ΔBNP was defined as BNP on the second postoperative day minus BNP on the first postoperative day. The primary end point was 12-month, all-cause mortality. The secondary end point was a composite of major adverse cardiac events (MACEs) at 12 months and/or all-cause mortality at 12 months. MACE was defined as nonfatal cardiac arrest, myocardial infarction, and congestive heart failure. The association between BNP and outcomes was examined by receiver operating characteristic curves, as well as univariate and multivariable logistic regression, adjusting for the EuroSCORE II, cross-clamp time, and first-postoperative-day troponin T.

RESULTS

We included 1199 patients in the preliminary analysis focused on BNP on postoperative day 1. In the analyses examining BNP variables requiring second-postoperative-day BNP measurement (n = 708), we observed 66 (9.3%) deaths, 48 (6.8%) MACE, and 104 (14.7%) deaths and/or MACE. Both first- and second-postoperative-day BNP were significant independent predictors of all-cause, 12-month mortality per 100 ng/L increase (adjusted odds ratio [aOR], 1.040 [95% confidence interval (CI), 1.019-1.065] and 1.064 [95% CI, 1.031-1.105], respectively). When used in conjunction with one another, first-day BNP was not significant (aOR, 1.021 [95% CI, 0.995-1.048]), while second-day BNP remained significant (aOR, 1.046 [95% CI, 1.008-1.091]). The ΔBNP per 100 ng/L increase was not associated with 12-month, all-cause mortality in the univariable (OR, 0.977 [95% CI, 0.951-1.007]) or multivariable analysis (aOR, 0.989 [95% CI, 0.962-1.021]).

CONCLUSIONS

Both absolute concentrations of first- and second-postoperative-day BNP are independent predictors of 12-month, all-cause mortality. When modeled together, second-postoperative-day BNP is more predictive of 12-month, all-cause mortality. Although intuitively appealing, the change in BNP from the first to the second postoperative day is a complex variable and should not routinely be used for prognostication.

Postoperative atrial fibrillation in non-cardiac and cardiac surgery: an overview

Postoperative atrial fibrillation (POAF) is the most common perioperative cardiac arrhythmia. A major risk factor for POAF is advanced age, both in non-cardiac and cardiac surgery. Following non-cardiac surgery, it is important to correct reversible conditions such as electrolytes imbalances to prevent the occurrence of POAF. Management of POAF consists of rate control and therapeutic anticoagulation if POAF persists for > 48 h and CHADS2 score > 2. After cardiac surgery, POAF affects a larger amount of patients. In addition to age, valve surgery carries the greatest risk for new AF. Rate control is the mainstay therapy in these patients. Prediction, prevention, and management of POAF should be further studied.

Cardiac biomarkers and acute kidney injury after cardiac surgery

OBJECTIVES

To examine the relationship of cardiac biomarkers with postoperative acute kidney injury (AKI) among pediatric patients undergoing cardiac surgery.

METHODS

Data from TRIBE-AKI, a prospective study of children undergoing cardiac surgery, were used to examine the association of cardiac biomarkers (N-type pro-B-type natriuretic peptide, creatine kinase-MB [CK-MB], heart-type fatty acid binding protein [h-FABP], and troponins I and T) with the development of postoperative AKI. Cardiac biomarkers were collected before and 0 to 6 hours after surgery. AKI was defined as a ≥ 50% or 0.3 mg/dL increase in serum creatinine, within 7 days of surgery.

RESULTS

Of the 106 patients included in this study, 55 (52%) developed AKI after cardiac surgery. Patients who developed AKI had higher median levels of pre- and postoperative cardiac biomarkers compared with patients without AKI (all P < .01). Preoperatively, higher levels of CK-MB and h-FABP were associated with increased odds of developing AKI (CK-MB: adjusted odds ratio 4.58, 95% confidence interval [CI] 1.56-13.41; h-FABP: adjusted odds ratio 2.76, 95% CI 1.27-6.03). When combined with clinical models, both preoperative CK-MB and h-FABP provided good discrimination (area under the curve 0.77, 95% CI 0.68-0.87, and 0.78, 95% CI 0.68-0.87, respectively) and improved reclassification indices. Cardiac biomarkers collected postoperatively did not significantly improve the prediction of AKI beyond clinical models.

CONCLUSIONS

Preoperative CK-MB and h-FABP are associated with increased risk of postoperative AKI and provide good discrimination of patients who develop AKI. These biomarkers may be useful for risk stratifying patients undergoing cardiac surgery.

Mitral valve repair versus replacement in patients with ischaemic mitral regurgitation and depressed ejection fraction: risk factors for early and mid-term mortality†

OBJECTIVES

Mitral valve (MV) surgery for ischaemic mitral regurgitation (IMR) in patients with depressed left ventricular ejection fraction (LVEF) is associated with poor outcomes. The optimal surgical strategy for IMR in these patients remains controversial. The objective of this study was to compare the early mortality and mid-term survival of MV repair versus MV replacement in patients with IMR and depressed LVEF undergoing coronary artery bypass grafting (CABG).

METHODS

A retrospective, observational, cohort study was undertaken of prospectively collected data on 126 consecutive CABG patients with IMR and LVEF <40% undergoing either MV repair (n = 98, 78%) or MV replacement (n = 28, 22%) between July 2002 and February 2011.

RESULTS

The overall mortality rate was 7.9% (n = 10). MV replacement was associated with a 4-fold increase in the risk of death compared with MV repair [17.9%, n = 5 vs 5.1%, n = 5; odds ratio (OR) 4.04, 95% confidence interval (CI) 1.08-15.1, P = 0.04]. However, after adjusting for preoperative risk factors, the type of surgical procedure was not an independent risk factor for early mortality (OR 0.1, 95% CI 0.01-31, P = 0.7). Multivariable analysis showed that preoperative LVEF (OR 0.8, 95% CI 0.6-0.9, P = 0.018), preoperative B-type natriuretic peptide (BNP) levels (OR 1.01, 95% CI 1-1.02, P = 0.025), preoperative left ventricle end-systolic diameter (OR 0.8, 95% CI 0.7-1.0, P = 0.05) and preoperative left atrial diameter (OR 1.3, 95% CI 1.0-1.6, P = 0.015) were independent risk factors of early mortality. At the median follow-up of 45 months (interquartile range 20-68 months), the mid-term survival rate was 74% in the MV repair group and 70% in the MV replacement group (P = 0.08). At follow-up, predictors of worse survival were BNP levels [hazard ratio (HR) 1.0, 95% CI 1.0-1.01, P = 0.047], preoperative renal failure (HR 4.6, 95% CI 1.1-20.3, P = 0.039) and preoperative atrial fibrillation (HR 3.3, 95% CI 1.1-10, P = 0.032).

CONCLUSIONS

MV repair in CABG patients with IMR and depressed LVEF is not superior to MV replacement with regard to operative early mortality and mid-term survival.