1208 Abstracts

for whom transfusions may or may not be indicated. The age ofpRBCs should be taken into account before transfusion.

, USEFULNESS OF HIGH-SENSITIVITY TROPONINT FORTHE EVALUATIONOF PATIENTSWITH ACUTECHEST PAIN AND NO OR MINIMAL MYOCARDIALDAMAGE. Sanchis J, Bardaji A, Bosch X, et al. Am Heart J2012;164-2:194–200.

High-sensitivity troponin has been shown to be an effectivediagnostic tool in assessment of patients with acute myocardialinfarction (MI). This study aimed to evaluate the role of high-sensitivity troponin in the diagnosis of acute coronary syndrome(ACS). Patients presenting to the Emergency Department withacute chest pain and two normal serial troponins were includedin this prospective multicenter study. A total of 446 patientswere included; mean age was 60 years old. Two blood samplesfrom each participant were measured for high-sensitivity tropo-nin T. The primary end point was diagnosis of acute coronarysyndrome as measured by angiography, stress test, or cardiacevent at a 30-day follow-up. Eighty-four patients were diag-nosed with acute coronary syndrome, 62 of whom underwentin-hospital revascularization or were found to have a cardiacevent at 30-day follow-up (composite end point). The studyshowed that a maximum high-sensitivity troponin > 3 ng/L ex-hibited a high sensitivity for detection of ACS and the compositeend point (87% and 92%) and a negative predictive value (93%and 97%). A value $ 14 ng/L was found to be highly specific(90% and 89%), with positive predictive values of 40% and33%. A high-sensitivity troponin level of # 3 ng/L provideda high negative predictive value for ACS. One limitation tothe study was the strict exclusion criteria, such as patientswith known coronary artery disease, non-ST elevation acuteMI, or those unable to undergo an exercise stress test. Overall,the utility of high-sensitivity troponin, when added to electro-cardiogram and clinical history, was found to be marginal.

[Mariah Bellinger, MD

Denver Health Medical Center, Denver, CO]

Comments: Although the study’s objectives were intriguing,it seems that many patients who present to the Emergency De-partment with chest pain were excluded from the study. The util-ity of high-sensitivity troponin T seems to be low whencompared to electrocardiogram, history, and clinical gestalt.

, THE NATURAL COURSE OF UNRUPTURED CE-REBRAL ANEURYSMS IN A JAPANESE COHORT.Morita A, Kirino T, Hashi K, et al., UCAS Japan Investigators.N Engl J Med 2012;366:2474–82.

This study from Japan identified 6697 newly diagnosed un-ruptured aneurysms in 5720 patients, 20 years of age or older(mean age 62.5 years; 68%women), from January 2001 throughApril 2004. Only saccular aneurysms that were 3 mm or greaterin the largest dimension, and patients presenting with no morethan a slight disability were included in the study. Previous stud-ies have shown that aneurysms smaller than 7 mm in the largestdimension rarely rupture, and that aneurysms in the posteriorcirculation have higher tendency to rupture when compared toanterior circulation. This prospective cohort study sought to elu-

cidate the natural course of unruptured cerebral aneurysms inthe Japanese population and to identify specific independentrisk factors associated with rupture. Follow-up data were ob-tained at 3, 12, and 36 months after initial visit and at 5 and 8years if data were available. Data collection ended after aneu-rysm rupture or when the patient died. If any surgical interven-tion took place, data were still collected but no longer includedin the risk analysis. The patients studied had a total of 111 aneu-rysm ruptures, which resulted in 0.95% annual risk of rupture(95% confidence interval [CI] 0.79–1.15). When comparedwith 3- to 4-mm-size aneurysms, larger aneurysms were associ-ated with higher rates of rupture. The hazard ratios (95% CI)were as follows: 5–6 mm, 1.13 (0.58–2.22); 7–9 mm, 3.35(1.87–6); 10–24 mm, 9.09 (5.225–15.74); and > 25 mm, 76.26(32.76–177.54). Aneurysms in the posterior and anterior com-municating arteries were more likely to rupture when comparedto the middle cerebral arteries (hazard ratios and 95% CI 1.90[1.12–3.21] and 2.02 [1.13–3.58], respectively). Aneurysmswith an irregular wall, called a daughter sac, were also morelikely to rupture when compared to smooth wall aneurysms(hazard ratio 1.63 [95% CI 1.08–2.48]). The authors concludedthat size, location, and shape of the aneurysm influence the nat-ural course of unruptured aneurysms. Factors that were foundnot to significantly influence the risk of rupture included: thepresence of another aneurysm causing subarachnoid hemor-rhage (SAH), former or current smoker, a family history ofSAH, hypertension, and the presence of multiple aneurysms.Limitations of the study included the factor that the data fromaneurysms treated surgically were not included in analysis,which led to a selection bias, and the fact that the study only in-cluded Japanese patients.

[Sabrina Adams, MD

Denver Health Medical Center, Denver, CO]

Comments: This study provides us with a better understand-ing of the risk of rupture of cerebral aneurysms, and treatmentchoice can be guided after obtaining the size, location, andshape of saccular aneurysms. However, caution must be usedwhen extrapolating the overall risk of rupture to our population.-

, FACTORS COMPLICATING INTERPRETATION OFCAPNOGRAPHY DURING ADVANCED LIFE SUPPORTIN CARDIAC ARREST—A CLINICAL RETROSPEC-TIVE STUDY IN 575 PATIENTS. Heradstveit BE, Sunde K,Sunde GA, Wentzel-Larsen T, Heltne JK. Resuscitation2012;83:813–8.

This study from Norway evaluated the levels of end-tidalcarbon dioxide (ETCO2) capnography in patients with out-of-hospital cardiac arrest (OHCA), and its interpretation limita-tions based on initial heart rhythm, cause of the arrest, presenceof bystander cardiopulmonary resuscitation (CPR), and time de-pendency on a retrospective study. Capnography data wereavailable for 575 non-traumatic OHCA patients that were intu-bated and treated by the Helicopter EmergencyMedical Serviceat Haukelend University Hospital over a period of 6 years. Cap-nography data were recorded manually by the anesthesiologistafter 1 min of normal ventilation and included the minimal,