Direct comparison of high-sensitivity cardiac troponin T and I in the early differentiation of type 1 vs. type 2 myocardial infarction.

AIMS: To directly compare the diagnostic accuracy of high-sensitivity cardiac troponin (hs-cTn) T vs. hs-cTnI in the early non-invasive differentiation of Type 1 myocardial infarction (T1MI) due to plaque rupture and atherothrombosis from Type 2 myocardial infarction (T2MI) due to supply-demand mismatch. METHODS AND RESULTS: In a prospective multicentre diagnostic study, two independent cardiologists centrally adjudicated the final diagnosis of T1MI vs. T2MI according to the fourth universal definition of myocardial infarction (MI), using all available clinical information including cardiac imaging in patients presenting with acute chest pain. Diagnostic accuracy was quantified by the area under the receiver operating characteristics curve (AUC). The most extensively validated hs-cTnT-Elecsys and hs-cTnI-Architect assays were measured at presentation, 1 h, and 2 h. Among 5887 patients, 1106 (19%) had a final diagnosis of MI, including 860 (78%) T1MI and 246 (22%) T2MI. The AUC of hs-cTnT-Elecsys to differentiate T1MI from T2MI was moderate and comparable to that provided by hs-cTnI-Architect: hs-cTnT-Elecsys AUC-presentation 0.67 [95% confidence interval (CI) 0.64-0.71], AUC-1 h 0.70 (95% CI 0.66-0.74), and AUC-2 h 0.71 (95% CI 0.66-0.75) vs. hs-cTnI-Architect AUC-presentation 0.71 (95% CI 0.67-0.74), AUC-1 h 0.72 (95% CI 0.68-0.76), and AUC-2 h 0.74 (95% CI 0.69-0.78), all P = not significant (NS). Similarly, the AUC of absolute changes was moderate and comparable for hs-cTnT-Elecsys and hs-cTnI-Architect (all P = NS). Cut-off concentrations achieving at least 90% specificity for the differentiation of T1MI vs. T2MI were >114 ng/L for hs-cTnT-Elecsys [odds ratio (OR) 4.2, 95% CI 2.7-6.6] and >371 ng/L for hs-cTnI-Architect (OR 4.0, 95% CI 2.6-6.2). CONCLUSION: hs-cTnT-Elecsys and hs-cTnI-Architect provided comparable, albeit only moderate, diagnostic accuracy for the early differentiation of T1MI vs. T2MI. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov number, NCT00470587, https://clinicaltrials.gov/ct2/show/NCT00470587.

Incremental value of high-frequency QRS analysis for diagnosis and prognosis in suspected exercise-induced myocardial ischaemia.

AIM: Exercise stress testing is used to detect myocardial ischaemia, but is limited by low sensitivity and specificity. The authors investigated the value of the analysis of high-frequency QRS components as a marker of abnormal depolarization in addition to standard ST-deviations as a marker of abnormal repolarization to improve the diagnostic accuracy. METHODS AND RESULTS: Consecutive patients undergoing bicycle exercise stress nuclear myocardial perfusion imaging were prospectively enrolled. Presence of myocardial ischaemia, the primary diagnostic endpoint, was adjudicated using MPI and coronary angiography. Automated high-frequency QRS analysis was performed in a blinded fashion. The prognostic endpoint was major adverse cardiac events (MACEs) during two years of follow-up. Exercise-induced ischaemia was detected in 147/662 patients (22%). The sensitivity of high-frequency QRS was similar to ST-deviations (46% vs. 43%, p=0.59), while the specificity was lower (75% vs. 87%, p<0.001). The combined use of high-frequency QRS and ST-deviations classified 59% of patients as 'rule-out' (both negative), 9% as 'rule-in' (both positive) and 32% in an intermediate zone (one test positive). The sensitivity for 'rule-out' and the specificity for 'rule-in' improved to 63% and 97% compared with ST-deviation analysis alone (both p<0.001). MACE-free survival was 90%, 80% and 42% in patients in the 'rule-out', intermediate and 'rule-in' groups (p<0.001). After adjustment for age, gender, ST-deviations and clinical post-test probability of ischaemia, high-frequency QRS remained an independent predictor for the occurrence of MACEs. CONCLUSION: The use of high-frequency QRS analysis in addition to ST-deviation analysis improves the diagnostic accuracy during exercise stress testing and adds independent prognostic information.

Ultrasound indications for maternal STORCH testing in pregnancy.

AIMS OF THE STUDY: Fetal abnormalities found on ultrasonography lead to a variety of diagnostic procedures, including a panel of serologies to detect possible maternal STORCH infections encompassing syphilis, Toxoplasma gondii, rubella, cytomegalovirus, herpes simplex, and others (human immunodeficiency virus, hepatitis B and C, parvovirus B19, enterovirus, varicella zoster, and Leptospira interrogans). The value of indiscriminate testing for infections upon the detection of fetal ultrasound abnormalities has been questioned. The aim of this study was to review the ultrasonographic abnormalities leading to maternal STORCH panels at the obstetrics department of a university hospital. METHODS: Laboratory results of all maternal STORCH tests requested after the detection of ultrasonographic abnormalities during a 5-year period (2008-2012) were analysed. The main ultrasound findings possibly caused by congenital infection were noted, and the outcomes of confirmed maternal and fetal infections were studied. RESULTS: In our study period, 392 maternal STORCH tests were performed because of fetal ultrasound abnormalities. The most common findings leading to STORCH testing were intrauterine growth restriction (30.4%) including microcephaly (1.5%), polyhydramnios (14.8%), and intrauterine fetal demise (13.3%). Maternal STORCH infections were found in 3.4% of growth-restricted fetuses, 5.2% of polyhydramnios, and 1.9% of intrauterine fetal demise. The leading aetiologies were cytomegalovirus and parvovirus B19. All seven congenital infections displayed multiple ultrasonographic abnormalities. CONCLUSION: Ultrasonographic findings associated with fetal infection are neither sensitive nor specific. Testing for STORCH infections should take into account exposure history, clinical signs and symptoms, obstetric history, and fetal ultrasound findings, but with special attention paid to cytomegalovirus and parvovirus B19.