Patients with acute coronary syndrome and normal high-sensitivity troponin
Christophe Meune1, Cathrin Balmelli, Raphael Twerenbold
1Department of Internal Medicine, Division of Cardiology, University Hospital, Basel, Switzerland.
Insights
Nearly one-third of acute coronary syndrome (ACS) patients present with normal high-sensitivity cardiac troponin T (hs-cTnT) levels, primarily those with unstable angina. These ACS patients experience low mortality but a higher risk of myocardial infarction within a year.
Area of Science:
- Cardiology
- Emergency Medicine
- Diagnostic Biomarkers
Background:
- Accurate identification of acute coronary syndrome (ACS) is critical in emergency care.
- The characteristics and outcomes of ACS patients with normal presentation high-sensitivity cardiac troponin T (hs-cTnT) levels are not well understood.
- Investigating normal hs-cTnT in ACS is essential for refining diagnostic and prognostic strategies.
Purpose of the Study:
- To determine the incidence and clinical characteristics of ACS patients with normal hs-cTnT levels.
- To evaluate the short-term and long-term outcomes, including mortality and myocardial infarction rates, in this subgroup.
- To identify factors associated with normal hs-cTnT levels in ACS patients.
Main Methods:
- Prospective, multicenter study involving 1181 consecutive patients presenting with acute chest pain.
- Blinded determination of hs-cTnT levels at presentation.
- Adjudication of ACS diagnosis by independent cardiologists and 12-month follow-up.
Main Results:
- 32% of ACS patients (351 total) had normal hs-cTnT levels (<.014 ug/L), predominantly those with unstable angina (UA).
- Factors associated with normal hs-cTnT included previous statin use, younger age, preserved renal function, and absence of ST deviation.
- ACS patients with normal hs-cTnT had 0% mortality at 30 and 90 days, and 2.0% at 360 days, compared to 17.5% in those with elevated levels (P <.001).
- However, the rate of acute myocardial infarction (AMI) at 360 days was higher in the normal hs-cTnT group (P=.004).
Conclusions:
- A significant proportion of ACS patients, mainly with UA, present with normal hs-cTnT levels.
- ACS patients with normal hs-cTnT demonstrate very low short-term mortality.
- Despite low mortality, normal hs-cTnT in ACS is associated with an increased risk of subsequent AMI within one year.
Background:
Failure to identify patients with acute coronary syndrome (ACS) is a serious clinical problem. The incidence, characteristics, and outcome of ACS patients with normal high-sensitivity cardiac troponin T (hs-cTnT) levels at presentation are unknown.
Methods:
In a prospective multicenter study, hs-cTnT was determined in a blinded fashion in 1181 consecutive patients presenting with acute chest pain to the emergency department. The final diagnosis of ACS was adjudicated by 2 independent cardiologists. Patients were followed for 12 months.
Results:
ACS was the adjudicated diagnosis in 351 patients (30%), including 187 patients with acute myocardial infarction (AMI) and 164 patients with unstable angina (UA). At presentation, hs-cTnT was normal (<.014 ug/L) in 112 ACS patients (32%), including 11 patients (6%) with AMI and 101 patients (62%) with UA (P <.001). Multivariable analysis revealed previous statin treatment, younger age, preserved renal function, and the absence of ST deviation on the electrocardiogram as independently associated with normal hs-cTnT levels. Mortality rates in ACS patients with normal hs-cTnT level were 0.0% at 30 days, 0.0% at 90 days, and 2.0% (95% confidence interval, 0.5-7.9) at 360 days, which was significantly lower than in ACS patients with elevated hs-cTnT level at presentation (17.5% at 360 days, P <.001). Conversely, AMI rates at 360 days was higher in ACS patients with normal versus elevated hs-cTnT levels (P=.004).
Conclusion:
Almost one third of ACS patients have normal hs-cTnT levels at presentation, mostly patients with UA. ACS patients with normal hs-cTnT have a very low mortality, but an increased rate of AMI during the subsequent 360 days.
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