Troponin elevation as a marker of short deterioration and one-year death in a high-risk surgical patient cohort in a low and middle income country setting: a postoperative approach to increase surveillance

PURPOSE

Myocardial injury after noncardiac surgery is common and mostly asymptomatic. The ideal target population that will benefit from routine troponin measurements in low and middle income countries (LMICs) is unclear. This study aims to evaluate the clinical outcomes of a cohort of high-risk surgical patients according to high-sensitivity troponin T (hsTnT) in an LMIC setting.

METHODS

We conducted a prospective cohort study of 442 high-risk patients undergoing noncardiac surgery at a Brazilian hospital between February 2019 and March 2020. High-sensitivity troponin T levels were measured preoperatively, 24 hr, and 48 hr after surgery and stratified into three groups: normal (< 20 ng·L-1); minor elevation (20-65 ng·L-1); and major elevation (> 65 ng·L-1). We performed survival analysis to determine the association between myocardial injury and one-year mortality. We described medical interventions and evaluated unplanned intensive care unit (ICU) admission and complications using multivariable models.

RESULTS

Postoperative myocardial injury occurred in 45% of patients. Overall, 30-day mortality was 8%. Thirty-day and one-year mortality were higher in patients with hsTnT ≥ 20 ng·L-1. One-year mortality was 18% in the unaltered troponin group vs 31% and 41% for minor and major elevation groups, respectively. Multivariable analysis of one-year survival showed a hazard ratio (HR) of 1.94 (95% confidence interval [CI], 1.22 to 3.09) for the minor elevation group and a HR of 2.73 (95% CI, 1.67 to 4.45) for the troponin > 65 ng·L-1 group. Patients with altered troponin had more unplanned ICU admissions (13% vs 5%) and more complications (78% vs 48%).

CONCLUSION

This study supports evidence that hsTnT is an important prognostic marker and a strong predictor of all-cause mortality after surgery. Troponin measurement in high-risk surgical patients could potentially be used as tool to scale-up care in LMIC settings.

STUDY REGISTRATION

ClinicalTrials.gov (NCT04187664); first submitted 5 December 2019.

Enhanced peri-operative care to improve outcomes for high-risk surgical patients in Brazil: a single-centre before-and-after cohort study

Mortality and morbidity for high-risk surgical patients are often high, especially in low-resource settings. Enhanced peri-operative care has the potential to reduce preventable deaths but must be designed to meet local needs. This before-and-after cohort study aimed to assess the effectiveness of a postoperative 48-hour enhanced care pathway for high-risk surgical patients ('high-risk surgical bundle') who did not meet the criteria for elective admission to intensive care. The pathway comprised of six elements: risk identification and communication; adoption of a high-risk post-anaesthesia care unit discharge checklist; prompt nursing admission to ward; intensification of vital signs monitoring; troponin measurement; and prompt access to medical support if required. The primary outcome was in-hospital mortality. Data describing 1189 patients from two groups, before and after implementation of the pathway, were compared. The usual care group comprised a retrospective cohort of high-risk surgical patients between September 2015 and December 2016. The intervention group prospectively included high-risk surgical patients from February 2019 to March 2020. Unadjusted mortality rate was 10.5% (78/746) for the usual care and 6.3% (28/443) for the intervention group. After adjustment, the intervention effect remained significant (RR 0.46 (95%CI 0.30-0.72). The high-risk surgical bundle group received more rapid response team calls (24% vs. 12.6%; RR 0.63 [95%CI 0.49-0.80]) and surgical re-interventions (18.9 vs. 7.5%; RR 0.41 [95%CI 0.30-0.59]). These data suggest that a clinical pathway based on enhanced surveillance for high-risk surgical patients in a resource-constrained setting could reduce in-hospital mortality.

Open transaortic implantation of 'Medlab-KT' prosthesis

AIM

The study was aimed at comparing the immediate clinical and haemodynamic results of open implantation of the balloon-expandable aortic prosthesis 'MedLab-KT' with the respective parameters of standard replacement of the aortic valve by a mechanical prosthesis in high-risk surgical patients.

PATIENTS AND METHODS

We analysed a total of 209 cases of prosthetic repair of the aortic valve. The Study Group comprised 28 patients subjected to open implantation of the 'MedLab-KT' prosthesis in conditions of extracorporeal circulation and myocardial ischaemia and belonging to a high-surgical risk cohort. The Comparison Group included 181 patients who endured standard open prosthetic repair of the aortic valve with a mechanical prosthesis. Using the ppropensity score matching method, we selected 28 patients from the Comparison Group, followed by assessing the incidence of adverse clinical events and haemodynamic parameters of the aortic valve prosthesis at the in-hospital stage.

RESULTS

There were no lethal outcomes in the study group, with one in the group of standard aortic valve repair - 3.6%. The mean operative time in the Study and Comparison Group patients amounted to 121.5±51.2 and 274.2±55.3 min (p=0.04), the duration of extracorporeal circulation to 56.1±19.5 and 119.9±23.4 min (p=0.04), that of myocardial ischaemia to 38.4±17.1 and 96.7±20.8 (p=0.03), respectively. The mean gradient on the aortic valve in the 'MedLab-KT' group was less (7.5±3.2 mm Hg) than in those of the second group (9±3.5 mm Hg), with no statistically significant differences in the parameters revealed (p=0.096). All patients of the study group were discharged from hospital in a satisfactory condition, with the haemodynamic result of the operation regarded as satisfactory.

CONCLUSION

Comparing the main clinical characteristics and haemodynamic parameters in the groups of 'MedLab-KT' and aortic valve prosthetic repair at the hospital stage revealed no statistically significant differences. Open implantation of the 'MedLab-KT' prosthesis proved safe and effective.