Prognosis of vascular surgery patients using a quantitative assessment of troponin T release: is the crystal ball still clear?

Asymptomatic myocardial injury identified on postoperative troponin testing after open or endovascular surgical procedures is a predictor of mortality

OBJECTIVE

Elevated troponin (TnT) levels after open or endovascular surgical procedures have been previously shown to correlate with significantly higher postoperative and short-term mortality. The incidence of asymptomatic myocardial injury after vascular surgical procedures has also been shown to be high. The aim of the present study was to evaluate the utility of routine postoperative TnT screening and long-term outcomes for patients with postoperative TnT elevation.

METHODS

Data from consecutive patients who had undergone open or endovascular surgery on an emergent or elective basis with routine postoperative TnT testing from January 2010 to December 2012 were retrospectively analyzed. Elevated postoperative TnT was considered >0.01 ng/mL. Patients with no documented postoperative TnT levels, those who had denied research authorization, and those with elevated TnT levels secondary to renal insufficiency alone were excluded. Patients were also excluded if they had required a dialysis access procedure, varicose vein procedure, or any procedure performed on an outpatient basis, because these were considered nonmajor surgeries. The end points were all-cause mortality at 30 days and 1, 2, 4, and 8 years postoperatively. Mortality data were retrieved from the electronic medical records and the Social Security Death Index and Accurint Death database.

RESULTS

During the 3-year study period, 1632 patients with postoperative TnT levels available had met the inclusion criteria (70% men; 30% women; mean age, 69.7 years). Postoperatively, 410 patients (25.1%) had had elevated TnT levels (TnT+) and 1222 (74.9%) had had nonelevated TnT levels (TnT-). Of the 410 TnT+ patients, 261 had undergone open, 143 had undergone endovascular, and 6 had undergone hybrid procedures. These included 180 aortic, 128 infrainguinal, 22 cerebrovascular, and 80 upper extremity or miscellaneous procedures. Of the 410 TnT+ patients, 168 had experienced asymptomatic myocardial injury. The 30-day mortality was significantly higher for the TnT+ patients than for the TnT- patients (3.9% vs 0.8%; P < .001). The cumulative probability of death for the TnT+ patients remained significantly higher than that for the TnT- patients at 1 (13% vs 3.2%), 2 (17.8% vs 4.8%), 4 (43% vs 18.5%), and 8 (81.4% vs 48.6%) years (P < .0001). The difference held true even for the 168 asymptomatic TnT+ patients compared with the TnT- patients at 30 days (2.4% vs 0.8%) and 1 (7.6% vs 3.2%), 2 (13.3% vs 4.8%), 4 (43.6 vs 18.5%) and 8 (80.8 vs 48.6%) years (P < .0001).

CONCLUSIONS

In the present study, patients with elevated TnT levels after vascular surgery had had significantly higher early and late all-cause mortality compared with those with normal postoperative TnT levels. This was true even for patients with asymptomatic TnT elevation, suggesting a role might exist for routine postoperative TnT screening to allow for long-term risk stratification and targeted medical management.

Cardiac Biomarkers Predicting MACE in Patients Undergoing Noncardiac Surgery: A Meta-Analysis

Objective: The present meta-analysis was aimed to systematically evaluate the effectiveness and accuracy of brain natriuretic peptide (BNP), cardiac troponin (cTn), high sensitive C reactive protein (hs-CRP) and CRP for predicting postoperative major adverse cardiovascular events (MACE) in patients undergoing noncardiac surgery.

Methods: A total of 26 relevant studies with 7,877 participants were collected from five databases, namely PubMed, Embase, China National Knowledge Infrastructure (CNKI), CQVIP and the Wanfang Database until August 10, 2018. And the Review Manager Version 5.3 and Stata/SE 12 software were used for data syntheses in the meta-analysis.

Results: Strong relationships of BNP/NT-proBNP, cTnI/cTnT and hs-CRP with MACE were detected in patients undergoing noncardiac surgery, and the five biomarkers all increased the risk of MACE. Compared to normal levels, elevated BNP/NT-proBNP could increase the MACE risk by almost 4-fold [RR:3.92, 95%CI: 3.23–4.75, P < 0.001]; elevated BNP corresponded to a 4.5-fold risk [RR:4.57, 95%CI: 3.37–6.20, P < 0.001]; elevated NT-proBNP led to a 3-fold higher risk [RR:3.48, 95%CI: 2.71–4.46, P < 0.001]. Comparing with normal levels of cTnI/cTnT, increased cTnI/cTnT was associated with nearly 5-fold more higher risk of MACE [RR:5.52, 95%CI: 4.62–6.58, P < 0.001]; elevated cTnI faced a 5-fold risk [RR:5.21, 95%CI: 3.96–6.86, P < 0.001]; elevated cTnT resulted in nearly 6-fold higher risk [RR:5.73, 95%CI: 4.55–7.22, P < 0.001]. The elevation of hs-CRP was associated with nearly 4-fold higher risk of MACE in comparison with normal concentration [RR:3.73, 95%CI: 2.63–5.30, P < 0.001].

Conclusion: According to the results of our meta-analysis, the elevations of BNP/NT-proBNP, cTnI/cTnT, and hs-CRP, pre-operation or post-operation immediately, can predict much higher risk of postoperative MACE in patients undergoing noncardiac surgery.

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.