Association of cardiac events with coronary artery disease detected by 64-slice or greater coronary CT angiography: a systematic review and meta-analysis.

BACKGROUND: The value of ≥64-slice coronary CT angiography (CCTA) to determine odds of cardiac death or non-fatal myocardial infarction (MI) needs further clarification. METHODS: We performed a systematic review and meta-analysis using publications reporting events/severity of coronary artery disease (CAD) in patients with suspected CAD undergoing CCTA. Patients were divided into: no CAD, non-obstructive CAD (maximal stenosis <50%), and obstructive CAD (≥50% stenosis). Odds ratios with 95% confidence intervals were calculated using a fixed or random effects model. Heterogeneity was assessed using the I(2) index. RESULTS: We included thirty-two studies comprising 41,960 patients with 363 all-cause deaths (15.0%), 114 cardiac deaths (4.7%), 342 MI (14.2%), 69 unstable angina (2.8%), and 1527 late revascularizations (63.2%) over 1.96 (SD 0.77) years of follow-up. Cardiac death or MI occurred in 0.04% without, 1.29% with non-obstructive, and 6.53% with obstructive CAD. OR for cardiac death or MI was: 14.92 (95% CI, 6.78 to 32.85) for obstructive CAD, 6.41 (95% CI, 2.44 to 16.84) for non-obstructive CAD versus no CAD, and 3.19 (95% CI, 2.29 to 4.45) for non-obstructive versus obstructive CAD and 6.56 (95% CI, 3.07 to 14.02) for no versus any CAD. Similar trends were noted for all-cause mortality and composite major adverse cardiovascular events. CONCLUSIONS: Increasing CAD severity detected by CCTA is associated with cardiac death or MI, all-cause mortality, and composite major adverse cardiovascular events. Absence of CAD is associated with very low odds of major adverse events, but non-obstructive disease significantly increases odds of cardiac adverse events in this follow-up period.

An algorithm for identification of ST-elevation myocardial infarction patients by emergency medicine services.

OBJECTIVE: ST-elevation myocardial infarction (STEMI) identification by emergency medicine services (EMS) leading to pre-hospital catheterization laboratory (CL) activation shortens ischemic time and improves outcomes. We examined the incremental value of addition of a screening clinical tool (CT), containing clinical information and a Zoll electrocardiogram (ECG)-resident STEMI identification program (ZI) to ZI alone. METHODS: All EMS-performed and ZI-analyzed ECGs transmitted to a percutaneous coronary intervention hospital from October 2009 to January 2011 were reviewed for diagnostic accuracy. ZI performance was also compared to ECG interpretations by 2 experienced readers The CT was then retrospectively applied to determine the incremental benefit above the ZI alone. RESULTS: ST-elevation myocardial infarction was confirmed in 23 (7.5%) of 305 patients. ZI was positive in 37 (12.1%): sensitivity: 95.6% and specificity: 94.6%, positive predictive value (PPV), 59.5%, negative predictive value (NPV), 99.6%, and accuracy of 93.8%. Moderate agreement was observed among the readers and ZI. CT criteria for CL activation were met in 24 (7.8%): 20 (83.3%) were confirmed STEMIs: sensitivity: 86.9%, specificity: 98.5%, a PPV: 83.3%, and NPV: 98.6%, accuracy of 97.7%. CT + ZI increased PPV (P<0.05) and specificity (P<0.003) by reducing false positive STEMI identifications from 15 (4.9%) to 4 (1.3%). CONCLUSIONS: In an urban cohort of all EMS transmitted ECGs, ZI has high sensitivity and specificity for STEMI identification. Whereas the PPV was low, reflecting both low STEMI prevalence and presence of STEMI-mimics, the NPV was very high. These findings suggest that a simplified CT combined with computer STEMI interpretation can identify patients for pre-hospital CL activation. Confirmation of these results could improve the design of STEMI care systems.

Prognostic significance of troponin T elevation in patients without chest pain.

Increased cardiac troponin with chest pain is important for the diagnosis, triage, and treatment of patients in the emergency department. However, the use of troponin for the diagnosis and triage of patients without chest pain is poorly established. The aim of this study was to determine 30-day and 1-year mortality and morbidity of troponin T increases in patients without chest pain. This retrospective study compared 92 hospitalized patients without (study group) and 91 patients with chest pain (control group), followed up for 1 year. Study group patients had troponin T >0.04 microg/L, normal creatine kinase or creatine kinase-MB fraction <5%, and no electrocardiographic ischemia. Excluded were high-risk patients with end-stage kidney disease, those with left ventricular ejection fraction <40%, and the critically ill. Outcome variables included 30-day and 1-year death, myocardial infarction, unstable angina, and coronary revascularization rates. Thirty-day (13.0% vs 4.4%; p = 0.032) and 1-year (33% vs 4.6%; p <0.001) mortality rates were significantly higher in the study group, whereas myocardial infarction, unstable angina, and revascularization were infrequent. In conclusion, patients with increased troponin T and no chest pain had a high mortality rate and required careful follow-up.