Does Preoperative Troponin Level Impact Outcomes After Coronary Artery Bypass Grafting?

The use of intraoperative transit time flow measurement can reduce postoperative myocardial injury

OBJECTIVE

This study investigates the relationship between the use of transit time flow measurement (TTFM) and postoperative myocardial injury in off-pump coronary artery bypass grafting (OPCABG).

METHODS

In this retrospective study, we collected basic data from patients hospitalized for OPCABG in the Department of Cardiothoracic Surgery, Changzhou Second People's Hospital Affiliated with Nanjing Medical University. According to the academic research consortium (ARC)-2 definition of significant myocardial injury, we used cardiac troponin I >2380 ng/L as a criterion for significant postoperative myocardial injury. We use logistic regression and forest plots to assess the association of TTFM use with myocardial injury outcomes.

RESULTS

One hundred and forty-six patients were included in this study. The overall median age of these patients was 65.05 years, and 32 (21.92%) experienced a postoperative myocardial injury. TTFM was independently associated with the incidence of postoperative myocardial injury (odds ratio = 0.34 [95% confidence interval = 0.15-0.78]; p = .01), and we found similar trends in regression analyses across subgroups of sex, age, number of bridging vessels, hypertension, diabetes mellitus, BMI, and percutaneous coronary revascularization. One hundred and six patients were followed for 1-year vessel permeability, and seven patients (6.6%) were occluded.

CONCLUSIONS

The use of TTFM is independently associated with a reduced incidence of postoperative myocardial lesions during off-pump coronary bypass surgery. The TTFM procedure in OPCABG deserves to be actively promoted to reduce the incidence of postoperative myocardial injury.

Improving the prediction of long-term readmission and mortality using a novel biomarker panel

OBJECTIVE

Several short-term readmission and mortality prediction models have been developed using clinical risk factors or biomarkers among patients undergoing coronary artery bypass graft (CABG) surgery. The use of biomarkers for long-term prediction of readmission and mortality is less well understood. Given the established association of cardiac biomarkers with short-term adverse outcomes, we hypothesized that 5-year prediction of readmission or mortality may be significantly improved using cardiac biomarkers.

MATERIALS AND METHODS

Plasma biomarkers from 1149 patients discharged alive after isolated CABG surgery from eight medical centers were measured in a cohort from the Northern New England Cardiovascular Disease Study Group between 2004 and 2007. We assessed the added predictive value of a biomarker panel with a clinical model against the clinical model alone and compared the model discrimination using the area under the receiver operating characteristic (AUROC) curves.

RESULTS

In our cohort, 461 (40%) patients were readmitted or died within 5 years. Long-term outcomes were predicted by applying the STS ASCERT clinical model with an AUROC of 0.69. The biomarker panel with the clinical model resulted in a significantly improved AUROC of 0.74 (p value <.0001). Across 5 years, the hazard ratio for patients in the second to fifth quintile predicted probabilities from the biomarker augmented STS ASCERT model ranged from 2.2 to 7.9 (p values <.001).

CONCLUSIONS

We report that a panel of biomarkers significantly improved prediction of long-term readmission or mortality risk following CABG surgery. Our findings suggest biomarkers help clinical care teams better assess the long-term risk of readmission or mortality.

[Peculiariities of diagnostic parameters in patients with acute myocardial lesion after coronary artery bypass grafting]

Annually, up to 850 000 coronary aortic bypass graft operations are performed worldwide. Despite modern technical equipment ensuring a high level of safety of the procedure, currently important remains a problem related to intraoperative myocardial damage in using artificial circulation. Early detection and clinical assessment of myocardial ischaemia often present a difficult task. This article deals with clinical, instrumental and laboratory methods of diagnosis, aimed at verification of an intraoperative cardiac lesion associated with graft dysfunction in coronary artery bypass grafting. Isolated electrocardiographic and echocardiographic signs of myocardial ischaemia between the comparison groups did not differ significantly. Analysing the markers of myocardial lesions, statistically significant differences were obtained only after 48 hours which, from the point of view of saving viable myocardium, is an utterly long-term interval. Studying the findings of intraoperative flowmetry showed statistically significant dependence between velocity characteristics, pulse index of shunts and their patency on angiographic examination. Thus, only combination of diagnostic parameters makes it possible to detect myocardial damage related to shunt dysfunction. This enables early determination of indications for performing bypass angiography and selection of the required therapeutic policy. Timely coronary artery angiography makes it possible to reveal defects of shunts and to timely perform surgical correction, preventing myocardial infarction.

Preoperative troponin levels and outcomes of coronary surgery following myocardial infarction

BACKGROUND

This study evaluates the impact of peak preoperative troponin level on outcomes of coronary artery bypass grafting (CABG) for non-ST-elevation myocardial infarction (NSTEMI).

METHODS

This was a retrospective review of patients undergoing isolated CABG from 2011 to 2018 with the presentation of NSTEMI. Patients were stratified into low- and high-risk groups based on median preoperative peak troponin (1.95 ng/dl). Major adverse cardiac and cerebrovascular events (MACCE) and mortality were compared. Multivariable analysis was performed to model risk factors for MACCE and mortality.

RESULTS

This study included 1211 patients, 607 low-risk (≤1.95 ng/dl) and 604 high-risk (>1.95 ng/dl). Patients were well-matched with respect to age and comorbidity. High-risk patients had lower median preoperative ejection fraction (46.5% [interquartile range {IQR}: 35.0%-55.0%] vs. 53.0% [IQR: 40.0%-58.0%]) and higher incidence of preoperative intra-aortic balloon pump (15.9% vs. 8.73%). Intensive care unit and hospital length of stay were longer in the high-risk group, but increasing troponin level was not associated with prolonged intensive care or hospital length of stay (>4 and >14 days, respectively) after risk adjustment. Postoperative complications and 30-day, 1- and 5-year rates of both MACCE and survival were similar between groups. Peak troponin greater than 1.95 ng/dl was not associated with increased hazards for MACCE, mortality, or readmission in multivariable modeling. In subanalysis, neither increasing troponin as a continuous variable nor peak troponin greater than 10.00 ng/ml were associated with increased hazards for these outcomes.

CONCLUSIONS

Preoperative troponin levels do not appear to be predictive of short- or long-term outcomes following CABG, and clinical decisions regarding surgical revascularization should not be dictated by these measurements.

Impact of troponin I level on coronary artery bypass grafting outcomes

PURPOSE

The effect of preoperative cardiac troponin level on outcomes after coronary artery bypass grafting (CABG) is unclear. We investigated the impact of preoperative cardiac troponin I (cTnI) level as well as the time interval between maximum cTnI and surgery on CABG outcomes.

METHODS

All patients who underwent isolated CABG at our institution between 2009 and 2016 and had preoperative cTnI level available were identified using our Society of Thoracic Surgeons registry. Receiver operating characteristic (ROC) analysis was performed to identify a cTnI threshold level. Subjects were divided into groups based on this value and outcomes compared.

RESULTS

A total of 608 patients were included. ROC analysis identified 5.74 µg/dL as the threshold value associated with worse postoperative outcomes. Patients with peak cTnI >5.74 µg/dL underwent CABG approximately 1 day later, had twice the risk of adverse postoperative events, and had 2.8 day longer postoperative length of stay than those with peak cTnI ≤5.74 µg/dL. cTnI level was not associated with mortality or 30-day readmission. Time interval between peak cTnI and surgery did not affect outcomes.

CONCLUSION

Elevated preoperative cTnI level beyond a certain threshold value is associated with adverse postoperative outcomes but is not a marker for increased mortality. Time from peak cTnI does not affect postoperative outcomes or mortality and may not need to be considered when deciding timing of CABG.

Prognostic value of high-sensitivity troponin I after cardiac surgery according to preoperative renal function

Cardiac troponin levels can be elevated without myocardial injury in patients with renal impairment. However, the prognostic value of elevated troponin levels after cardiac surgery has not been well evaluated in patients with renal impairment. We evaluated the relationship between postoperative troponin levels and mortality following cardiac surgery according to preoperative renal function.Among 3661 patients underwent cardiac surgery between March 2005 and December 2015, 1909 patients were analyzed after excluding those with insufficient laboratory data, preoperative myocardial infarction, underwent Cox-Maze or redo surgery, or with a follow-up period <30 days. The primary outcome was risk of 30-day mortality according to elevated postoperative high-sensitivity cardiac troponin I (hs-cTnI) levels in varying degrees of renal function. Secondary outcomes included long-term cardiac-cause and all-cause mortality during the median follow-up of 52 months.After adjustment for risk factors, elevated peak postoperative hs-cTnI was associated with 30-day mortality [adjusted odds ratio 1.028, 95% confidence interval (CI) 1.013-1.043, P < .001], long-term cardiac-cause [adjusted hazard ratio (HR) 1.013, 95% CI 1.009-1.017, P < .001] and all-cause mortality (adjusted HR 1.013, 95% CI 1.009-1.016, P < .001), in patients with preoperative normal renal function [estimated glomerular filtration rate (eGFR) ≥60 ml/minute/1.73 m]. However, in patients with renal impairment (eGFR < 60 ml/minute/1.73 m), hs-cTnI levels were not associated with mortality following cardiac surgery.Elevated hs-cTnI levels following cardiac surgery did not predict short- and long-term mortality in patients with preoperative renal impairment.

Nitric oxide provides myocardial protection when added to the cardiopulmonary bypass circuit during cardiac surgery: Randomized trial

OBJECTIVES

The aim of this pilot study was to elucidate the effects of exogenous nitric oxide (NO) supply to the extracorporeal circulation circuit for cardioprotection against ischemia-reperfusion injury during coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB).

METHODS

A total of 60 patients with coronary artery disease scheduled for CABG with CPB were enrolled in a prospective randomized study. Patients were allocated randomly to receive treatment according to standard or modified CPB protocol where 40-ppm NO was added to the CPB circuit during cardiac surgery. The primary endpoint was the measurement of cardiac troponin I (cTnI). The secondary end points consisted in the measurements of creatine kinase-muscle/brain fraction (CK-MB) and vasoactive inotropic score (VIS).

RESULTS

NO delivered into the CPB circuit had a cardioprotective effect. The level of cTnI was significantly lower in NO-treated group compared with the control group 6 hours after surgery: 1.79 ± 0.39 ng/mL versus 2.41 ± 0.55 ng/mL, respectively (P = .001). The CK-MB value was significantly lower in NO-treated group compared with the control group 24 hours after surgery: 47.69 ± 8.08 U/L versus 62.25 ± 9.78 U/L, respectively (P = .001); and the VIS was significantly lower in the NO-treated group 6 hours after the intervention.

CONCLUSIONS

NO supply to the CPB circuit during CABG exerted a cardioprotective effect and was associated with lower levels of VIS and cardiospecific blood markers cTnI and CK-MB.