Associations of antithrombotic agent use with clinical outcomes in critically ill patients with troponin I elevation in the absence of acute coronary syndrome

Introduction: To
evaluate efficacy of antithrombotic agents in critically ill patients with
elevated troponin I level during intensive care unit (ICU) admission.

Methods
and results: It was a retrospective observational study
which was conducted in a tertiary teaching hospital in Taipei, Taiwan. All patients
hospitalized in ICU for >3 days and with available serum troponin I data
from December 2015 to July 2017 were included. Patients with definite diagnosis
of acute myocardial infarction (AMI) were excluded. We divided patients with troponin
I elevation into three groups; no prescription, chronic prescription and new
prescription of antithrombotic agents during ICU admission. We defined new
prescription when patients were on antithrombotic agents, including
antiplatelet agents, direct oral anticoagulants, and warfarin after troponin I was
found to be elevated at ICU admission and chronic prescription, if antithrombotic
agents were on medication list more than 30 days before ICU admission. Primary
outcomes were 30-day and one-year all-cause mortality. Of 597 subjects who met
inclusion criteria, 407 (68%) patients had elevated troponin I (>0.1 ng/mL)
on ICU admission. These patients had increased 30-day [hazard ratio (HR),
1.679; 95% confidence interval (CI), 1.132–2.491; p = 0.009] and one-year (HR, 1.568; 95% CI, 1.180–2.083; p = 0.002) all-cause mortality compared with
those without elevated troponin I. In
patients with elevated troponin I, there was no significant difference of
30-day all-cause mortality among three groups (p = 0.051) whereas patients
on chronic prescription showed significant survival benefit in one-year
all-cause mortality when compared to those without or with new prescription (p
= 0.008).

Conclusions: In critically
ill patients, elevated troponin I in the absence of AMI was associated with
poor prognosis. Newly prescribed antithrombotic agents in ICU didn’t reveal the
difference in short and long-term prognosis while chronic antithrombotic agent use
was associated with better one-year survival rate, suggesting that these drugs
play a protective role in this high-risk population.