Diagnosis of acute myocardial infarction in the presence of left bundle branch block - Nestelberger, T.; Cullen, L.; Lindahl, B.; Reichlin, T.; Greenslade, J. H.; Giannitsis, E.; Christ, M.; Morawiec, B.; Miro, O.; Martin-Sanchez, F. J.; Wussler, D. N.; Koechlin, L.; et al. (Heart, 2019)
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.
Keywords: journalArticle; *Algorithms; *Bundle-Branch Block/diagnosis/epidemiology; *Myocardial Infarction/blood/diagnosis/epidemiology/therapy; Abbott Diagnostics, grants from Siemens, grants from Radiometer, personal fees; Abbott, during the conduct of the study, and grants from Roche, grants and; Area Under Curve; BMS, Boehringer Ingelheim, BRAHMS, Cardiorentis, Daiichi Sankyo, Novartis, Roche,; BRAHMS and Roche. EG has received honoraria for lectures from Roche Diagnostics,; BRAHMS, Thermo Fisher and Mitsubishi Chemical Europe. MC has received research; Beckman Coulter, bioMerieux, BRAHMS, Critical Diagnostics, Nanosphere, Roche,; Biomarkers/analysis; Canterbury District Health. All other authors declare that they have no conflict; Cardiovascular Research Foundation Basel, 8sense, Abbott, Alere, AstraZeneca,; Clinical Decision Rules; Diagnostic Errors/*prevention & control; Diagnostics, Radiometer Medical, bioMerieux Clinical Diagnostics, Philips; ECG/electrocardiogram; Electrocardiography/*methods; Emergency Service, Hospital/statistics & numerical data; Female; Healthcare and Fiomi Diagnostics. TR has received research grants from the Swiss; Heart Foundation. JB has received speaking honoria from Siemens. GB is an; Humans; Internal Medicine, University Hospital Basel, as well as speaker's honoraria from; Male; Middle Aged; National Science Foundation (PASMP3-136995), the Swiss Heart Foundation, the; Prospective Studies; Radiometer, personal fees from AstraZeneca, non-financial support from Bayer,; Sanofi, Singulex and Siemens. LC reports grants from Roche and from Abbott,; Science Foundation and the Swiss Heart Foundation, the European Union, the; Siemens, Singulex and the University Hospital Basel, as well as speaker or; Time-to-Treatment; Troponin I/*analysis; University of Basel, the Professor Max Cloetta Foundation, and the Department of; acute coronary syndromes; acute myocardial infarction; consulting honoraria from Abbott, Alere, AstraZeneca, BG Medicine, bioMerieux,; during the conduct of the study, grants from Roche, grants and personal fees from; employee of Roche Diagnostics. JWP is supported by a Senior Research Fellowship; from AstraZeneca, and grants from Alere, outside the submitted work. BL has; from the Canterbury Medical Research Foundation, Emergency Care Foundation and; has received speaking honoraria from Abbott and a research grant from the Swiss; of interest with this study; personal fees from Abbott Diagnostics, grants from Siemens, grants from; personal fees from Hospira and grants from Alere, outside the submitted work. MRG; served as a consultant for Roche Diagnostics, Beckman Coulter, Siemens Healthcare; speaker honoraria from BRAHMS and Roche. WP reports grants from Roche and from; support and speaking honoraria from Roche, Thermo Fisher and Novartis. RT reports