The Year in Cardiology 2018: Acute Coronary Syndromes

Petr Widimsky; Filippo Crea; Ronald K. Binder; Thomas F. Lüscher

Disclosures

Eur Heart J. 2019;40(3):271-282. 

In This Article

Early Diagnosis

Troponin

The timing of Tn assessment in suspected AMI admitted to the emergency department remains controversial.[26] Badertscher et al.[27] compared the negative predictive value (NPV) for the presence of AMI (equivalent of diagnostic safety), and the proportion of patients triaged towards rule-out (equivalent of diagnostic accuracy) in a large multicentre study enrolling patients presenting with suspected AMI to the emergency department. Among 2547 patients eligible for analysis with hs-cTnT, AMI was the final adjudicated diagnosis in 387 patients (15%). The 0/1 h algorithm provided safety similar to that of the 0/3 h algorithm [NPV 99.8%, 95% confidence interval (CI) 99.4–99.9 vs. 99.7%, 95% CI 99.2–99.9; P 0.645] but allowed the rule-out of significantly more patients compared with the 0/3 h algorithm (60% vs. 44%; P < 0.001). Among 2197 patients eligible for analysis with hs-cTnI, AMI was the final diagnosis in 327 patients (15%). The 0/1 h algorithm provided higher safety compared with the 0/3 h algorithm (NPV 99.6%, 95% CI 99.1–99.9% vs. 97.8%, 95% CI 96.7–98.5; P < 0.01) and allowed the rule-out of a similar portion of patients compared with the 0/3 h algorithm (52% vs. 51%; P = 0.507). The authors concluded in line with the ESC guidelines that the 0/1 h algorithm is superior to the 0/3 h algorithm using hs-cTnT as well as hs-cTnI because it more favourably combines safety with efficacy.

In a prospective multicentre diagnostic study enrolling 3254 unselected patients presenting with suspected AMI to the emergency department, Twerenbold et al.[28] assessed the diagnostic performance of the ESC 0/1 h algorithm using hs-cTnT and hs-cTnI in patients with renal dysfunction defined as an estimated glomerular filtration rate below 60 mL/min/1.73 m. The prevalence of AMI was substantially higher in patients with than in those without renal dysfunction (31% vs. 13%, P < 0.001). Importantly, using hs-cTnT, the percentage of patients eligible for rule-out was much lower among patients with than among those without renal dysfunction (18% vs. 68%, P < 0.001). Similar findings were observed with hs-cTnI. The authors conclude that many of the challenges in patients with renal dysfunction admitted to emergency department with suspected AMI are related to the high prevalence of commonly yet undiagnosed cardiac comorbidities including hypertensive heart disease and diabetic cardiomyopathy associated with chronic cardiomyocyte injury and therefore increases in hs-cTn plasma concentrations and an increased prevalence of ECG abnormalities. These challenges need to be addressed in future studies.

Cardiac Myosin-binding Protein

In 1954, unselected patients presenting to the emergency department with symptoms suggestive of AMI, Kaier et al. measured concentrations of Cardiac Myosin-Binding Protein C (cMyC) and hs-cTn at presentation. In 17% of the patients, the final diagnosis was AMI.[29] The final diagnosis of AMI was independently adjudicated using all available clinical and biochemical information without knowledge of cMyC. Discriminatory power for AMI, as quantified by the area under the receiver operating characteristic curve was comparable for cMyC, hs-cTnT (0.927) and hs-cTnI (0.922) and superior to cTnI measured by a contemporary sensitivity assay (0.909). In early presenters (chest pain <3 h), the improvement in rule-in/rule-out classification with cMyC was larger compared with hs-cTnT and hs-cTnI (both P < 0.001). The authors conclude that cMyC at presentation provides discriminatory power comparable to hs-cTnT and hs-cTnI in the diagnosis of AMI, and may perform favourably in patients presenting early after symptom onset. A limitation of this study is lack of comparison of cMyC performance vs. the 0/1 h algorithm by hs-cTn proposed in this setting by the European Society of Cardiology.

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