Long-term outcome of patients with perioperative myocardial infarction as diagnosed by troponin I after routine surgical coronary artery revascularization

Predictors of perioperative myocardial infarction in patients undergoing off-pump coronary artery bypass grafting

Background

Perioperative myocardial infarction (PMI) increases morbidity and mortality after off-pump coronary artery bypass grafting (CABG). The objective of the current study was to characterize patients with PMI after off-pump CABG and identify its predictors.

Results

We included 1181 patients who had off-pump CABG from 2010 to 2020; 59 patients (5%) had PMI. We compared patients with PMI to those without PMI. Patients with PMI were older (57 (25th–75th percentiles: 51–63) vs. 54 (48–60) years; P = 0.01) and had higher NYHA class (28 (47.46%) vs. 326 (29.06%): P = 0.01). The distal anastomosis time was longer in patients with PMI (28 (23–35) vs. 24 (16–30) min; P ˂ 0.001). Patients with PMI had higher postoperative low cardiac output (10 (18.18%) vs. 1 (0.1%): P ˂ 0.001), prolonged ventilation (12 (8–39) vs. 8 (6–10) h, P ˂ 0.001), ICU (71 (46–138) vs. 24 (23–42) h; P ˂ 0.001), and hospital stay (9 (6–15) vs. 7 (6–8) days; P ˂ 0.001). Mortality was significantly higher in patients with PMI (20 (33.9%) vs. 6 (0.53%); P ˂ 0.001). Older age (OR: 1.05 (95% CI: 1.01–1.1); P = 0.02), increased number of distal anastomoses (OR: 1.74 (95% CI: 1.20–2.50); P = 0.003), preoperative congestive heart failure (OR: 10.27 (95% CI: 2.58–40.95); P = 0.001), and thrombolysis within 24 h of surgery (OR: 15.34 (1.93–121.9); P = 0.01) were associated with increased PMI, while PMI was lower in male patients (OR: 0.42 (95% CI: 0.19–0.93); P = 0.03) and with higher body surface area (BSA) (OR: 0.08 (95% CI: 0.07–0.86); P = 0.04).

Conclusions

Post-off-pump CABG PMI was associated with increased morbidity and mortality. Risk factors for PMI were older age, lower BSA, females, increased distal anastomoses, preoperative heart failure, and thrombolysis.

Cardiac troponin T is an important predictor of mortality after cardiac surgery

PURPOSE

Serum troponin (cTnT) levels, a commonly measured biomarker of myocardial injury, has rarely been considered in risk models after cardiac surgery.

MATERIALS AND METHODS

Retrospective study of patients undergoing any cardiac surgery between 2004 and 2012. Patients with a history of recent myocardial injury (<21 days) were excluded. The minimum P value approach was used to determine categories of peak cTnT associated with in-hospital death. A multivariable analysis was performed to identify independent predictors of mortality.

RESULTS

A total of 5318 patients without evidence of preoperative ischemia underwent a number of cardiac surgical interventions ranging from isolated coronary revascularization to combined valve coronary artery bypass grafting. The unadjusted in-hospital mortality rate was 3.3% (n = 175 patients). Four categories of peak cTnT were identified using the minimum P value approach: less than or equal to 0.6 ng/mL, 0.7 to 1.9 ng/mL, 2.0 to 3.1 ng/mL, and greater than 3.1 ng/mL with unadjusted mortality rates of 1.0%, 3.6%, 10.1%, and 33.1%, respectively. Multivariate logistic regression demonstrated that all peak cTnT levels greater than 0.6 ng/mL were independent predictors of in-hospital mortality in a dose-dependent manner.

CONCLUSIONS

We demonstrate that in patients without preoperative myocardial ischemia, the demonstration of myocardial injury (>0.6 ng/mL) in the postoperative period is highly predictive of in-hospital death.

Late Post-Conditioning with Sevoflurane after Cardiac Surgery--Are Surrogate Markers Associated with Clinical Outcome?

Introduction

In a recent randomized controlled trial our group has demonstrated in 102 patients that late post-conditioning with sevoflurane performed in the intensive care unit after surgery involving extracorporeal circulation reduced damage to cardiomyocytes exposed to ischemia reperfusion injury. On the first post-operative day the sevoflurane patients presented with lower troponin T values when compared with those undergoing propofol sedation. In order to assess possible clinical relevant long-term implications in patients enrolled in this study, we performed the current retrospective analysis focusing on cardiac and non-cardiac events during the first 6 months after surgery.

Methods

All patients who had successfully completed the late post-conditioning trial were included into this follow-up. Our primary and secondary endpoints were the proportion of patients experiencing cardiac and non-cardiac events, respectively. Additionally, we were interested in assessing therapeutic interventions such as initiation or change of drug therapy, interventional treatment or surgery.

Results

Of 102 patients analyzed in the primary study 94 could be included in this follow-up. In the sevoflurane group (with 41 patients) 16 (39%) experienced one or several cardiac events within 6 months after cardiac surgery, in the propofol group (with 53 patients) 19 (36%, p=0.75). Four patients (9%) with sevoflurane vs. 7 (13%) with propofol sedation had non-cardiac events (p=0.61). While a similar percentage of patients suffered from cardiac and/or non-cardiac events, only 12 patients in the sevoflurane group compared to 20 propofol patients needed a therapeutic intervention (OR: 0.24, 95% CI: 0.04-1.43, p=0.12). A similar result was found for hospital admissions: 2 patients in the sevoflurane group had to be re-admitted to the hospital compared to 8 in the propofol group (OR 0.23, 95% CI: 0.04-1.29, p=0.10).

Conclusions

Sevoflurane does not seem to provide protection with regard to the occurrence of cardiac and non-cardiac events in the 6-month period following cardiac surgery with the use of extracorporeal circulation. However, there was a clear trend towards fewer interventions (less need for treatment, fewer hospital admissions) associated with sevoflurane post-conditioning in patients experiencing any event. Such results might encourage launching large multicenter post-conditioning trials with clinical outcome defined as primary endpoint.

Late pharmacologic conditioning with volatile anesthetics after cardiac surgery

INTRODUCTION

The aim of this randomized controlled trial was to investigate whether volatile anesthetics used for postoperative sedation have any beneficial effects on myocardial injury in cardiac surgery patients after on-pump valve replacement.

METHODS

Anesthesia was performed with propofol. After arrival in the intensive care unit (ICU), 117 patients were randomized to be sedated for at least 4 hours with either propofol or sevoflurane. Sevoflurane was administered by using the anesthetic-conserving device. Troponin T, creatine kinase, creatine kinase from heart muscle tissue, myoglobin, and oxygenation index were determined on arrival at the ICU, 4 hours after sedation, and in the morning of the first postoperative day (POD1). Primary end points were cardiac injury markers on POD1. As secondary end points oxygenation, postoperative pulmonary complications, and ICU and hospital stay were documented.

RESULTS

Fifty-six patients were analyzed in the propofol arm, and 46 patients in the sevoflurane arm. Treatment groups were comparable with regard to patient demographics and intraoperative characteristics. Concentration of troponin T as the most sensitive marker for myocardial injury at POD1 was significantly lower in the sevoflurane group compared with the propofol group (unadjusted difference, -0.4; 95% CI, -0.7 to -0.1; P < 0.01; adjusted difference, -0.2; 95% CI, -0.4 to -0.02; P = 0.03, respectively).

CONCLUSIONS

The data presented in this investigation indicate that late postconditioning with the volatile anesthetic sevoflurane might mediate cardiac protection, even with a late, brief, and low-dose application.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00924222.

Value of early cardiac troponin I to predict long-term adverse events after coronary artery bypass graft surgery in patients presenting with acute coronary syndromes

BACKGROUND

High values of both preoperative and postoperative cardiac troponin I (cTnI) contribute to higher rates of short-term cardiac events following coronary artery bypass graft (CABG) surgery in patients with acute coronary syndrome (ACS). The prognostic value of very early cTnI in this context is unclear.

HYPOTHESIS

Measurement of cTnI very early after admission to the emergency room can be used as a prognosticator for long-term outcomes after CABG.

METHODS

We conducted a cohort study on 160 consecutive patients with ACS undergoing CABG at The John H. Stroger Jr. Hospital of Cook County (Chicago, IL) representing a total follow-up of 290.42 person-years. Adverse outcomes were defined as death or reinfarction. We used robust multivariate survival analyses to determine whether early cTnI measurement can independently predict the adverse outcomes in the study subjects.

RESULTS

In univariate and stepwise multivariate Cox proportional hazards modeling we found that unit rise in early cTnI is associated with a 3% (95% confidence interval [CI]: 2%- 5%, p < 0.001) faster progression to long-term adverse events after CABG even after adjusting for the type of ACS. Prognostically, the most informative cut off value for cTnI was 5.6 ng/mL. Above this value, CABG patients progressed 2.58 times faster to adverse outcomes (95% CI: 1.05-6.36, p = 0.039). This effect remained after adjustment for other significant confounders namely, poor compliance to medications, female sex, Medicaid insurance, and electrocardiographic ischemia.

CONCLUSION

Early cTnI measurement after admission can predict adverse outcomes after CABG. This association extends to long-term adverse events after CABG.

Intraoperative myocardial acidosis as a risk for hospital readmission after cardiac surgery

BACKGROUND

This study elucidates the relationship between intraoperative myocardial acidosis/ischemia and the risk of unplanned hospital readmissions within 30 days and 6 months after cardiac surgery.

METHODS

Myocardial tissue pH (corrected to 37 degrees C: pH(37C)) was monitored in 221 patients during cardiac surgery. Regional myocardial acidosis was defined in terms of specific pH thresholds.

RESULTS

Fourteen percent and 27% of the patients were readmitted within 30 days and 6 months postoperatively, respectively. The mean number of readmissions was 1.67 +/- 1.24; pH(37C) <6.85 at the end of cardiopulmonary bypass (CPB) was identified as the threshold most significantly associated with readmission. This threshold was associated with a 6-fold increased risk of readmission within 30 days and a 5-fold increased risk within 6 months.

CONCLUSIONS

Persistent regional myocardial acidosis after weaning from CPB independently determines unplanned readmission rates up to 6 months postoperatively. This study underscores the importance of avoiding myocardial tissue acidosis during cardiac surgery.