Growth differentiation factor-15 and all-cause mortality in patients with suspected myocardial infarction.

BACKGROUND: To assess the prognostic performance of Growth differentiation factor-15 (GDF-15) concentrations in unselected patients presenting with suspected acute myocardial infarction (AMI) and adjudication based on high-sensitivity cardiac troponin (hs-cTn). METHODS AND RESULTS: In an ongoing prospective multicenter diagnostic study, consecutive patients presenting with suspected AMI to the emergency department and available GDF-15 and hs-cTnT concentrations were included. Adjudication of AMI was performed central by two independent cardiologists using all available clinical information including cardiac imaging and serial hs-cTn concentrations. Overall, 718 patients were included, with 23% (162/718) having an adjudicated diagnosis of AMI. The cumulative incidence of death within 2 years was 19% in patients with AMI (30 deaths in 162 patients) versus 5% in patients without AMI (25 deaths in 556 patients; P < 0.001). In AMI patients, GDF-15 provided an AUC of 0.89 (95% confidence interval [CI] 0.83-0.94) for 2-year death versus 0.55 (95% CI 0.44-0.66) for hs-cTnT (P < 0.001). A GDF-15 cutoff of ≤1560 ng/L predicted 2-year survival in 47% (76/162) of AMI patients and had 100% sensitivity (95% CI 88-100%) for 2-year death. In patients without AMI, GDF-15 provided an AUC of 0.83 (95% CI 0.76-0.89) versus 0.76 (95% CI 0.67-0.85) for hs-cTnT (P = 0.096). A GDF-15 cutoff of ≤886 ng/L predicted 2-year survival in 37% (203/556) of non-AMI patients and had 100% sensitivity (95% CI 86-100%) for 2-year death. CONCLUSIONS: GDF-15 concentrations at emergency department presentation have a high predictive accuracy for all-cause death in patients with suspected AMI and allow the identification of a large proportion of AMI patients with very low mortality risk.

Diagnosis of acute myocardial infarction in the presence of left bundle branch block.

OBJECTIVE: Patients with suspected acute myocardial infarction (AMI) in the setting of left bundle branch block (LBBB) present an important diagnostic and therapeutic challenge to the clinician. METHODS: We prospectively evaluated the incidence of AMI and diagnostic performance of specific ECG and high-sensitivity cardiac troponin (hs-cTn) criteria in patients presenting with chest discomfort to 26 emergency departments in three international, prospective, diagnostic studies. The final diagnosis of AMI was centrally adjudicated by two independent cardiologists according to the universal definition of myocardial infarction. RESULTS: Among 8830 patients, LBBB was present in 247 (2.8%). AMI was the final diagnosis in 30% of patients with LBBB, with similar incidence in those with known LBBB versus those with presumably new LBBB (29% vs 35%, p=0.42). ECG criteria had low sensitivity (1%-12%) but high specificity (95%-100%) for AMI. The diagnostic accuracy as quantified by the receiver operating characteristics (ROC) curve of hs-cTnT and hs-cTnI concentrations at presentation (area under the ROC curve (AUC) 0.91, 95% CI 0.85 to 0.96 and AUC 0.89, 95% CI 0.83 to 0.95), as well as that of their 0/1-hour and 0/2-hour changes, was very high. A diagnostic algorithm combining ECG criteria with hs-cTnT/I concentrations and their absolute changes at 1 hour or 2 hours derived in cohort 1 (45 of 45(100%) patients with AMI correctly identified) showed high efficacy and accuracy when externally validated in cohorts 2 and 3 (28 of 29 patients, 97%). CONCLUSION: Most patients presenting with suspected AMI and LBBB will be found to have diagnoses other than AMI. Combining ECG criteria with hs-cTnT/I testing at 0/1 hour or 0/2 hours allows early and accurate diagnosis of AMI in LBBB. TRIAL REGISTRATION NUMBER: APACE: NCT00470587; ADAPT: ACTRN12611001069943; TRAPID-AMI: RD001107;Results.