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Introduction: Central arterial pressure rises to much higher levels during heavy isometric exercise compared to other forms of exercise. For this reason, patients with bicuspid aortic valves (BAV) are often restricted from heavy isometric exercise. Although this approach may be theoretically appealing, no data exists regarding the efficacy of this activity restriction. Methods: Patients between the 12-19 years old with BAV were approached during a routine clinic visit. Patients were excluded if they had a diagnosed syndrome or had undergone a procedure involving the aortic valve. Patients were assumed to have been exercise restricted, regardless of aortic dimensions. Patients completed a questionnaire regarding frequency and intensity of isometric exercise during the 12-month period prior to the visit. We then compared aortic dimensions and qualitative (1-4 scale) estimates of aortic insufficiency (AI) from an echocardiogram performed during the current visit and one obtained 2-5 years previously, using paired t-tests and multivariable regression controlling for age, gender, and participation in isometric exercise. Results: In this unique data set of 37 individuals (41% female, average age 14.8 years), 6 (16%) participated in isometric exercise. There was no significant increase in the aortic root Z-score (0.004 [95 th CI -0.20, 0.21) or in the ascending aorta Z-score (0.11 [95 th CI, -0.15, 0.37], p=0.4) between the first and second visits. Further, there was no differences in the change aortic root Z-score (β=-0.39, p=0.39) and ascending aorta Z-score (β=-0.30, p-0.699) between those who participated in isometric exercise and those who did not. However, although the sample size in this preliminary group of patients was small, the increase in AI severity among those participating in isometric exercise was clinically significant and approached statistical significance (β=0.37, p=0.1). These results did not change even after controlling for age, gender, and time between echocardiograms. Conclusion: Most adolescents with BAV follow recommendations to limit isometric exercise. Time-related changes in aortic dimensions were similar among patients who refrained from isometric exercise and those who engaged in isometric exercise. AI however may have progressed more rapidly in those who participated in isometric exercise.

Background— Noninvasive assessment of coronary atherosclerotic plaque and significant stenosis by coronary multidetector computed tomography (MDCT) may improve early and accurate triage of patients presenting with acute chest pain to the emergency department. Methods and Results— We conducted a blinded, prospective study in patients presenting with acute chest pain to the emergency department between May and July 2005 who were admitted to the hospital to rule out acute coronary syndrome (ACS) with no ischemic ECG changes and negative initial biomarkers. Contrast-enhanced 64-slice MDCT coronary angiography was performed immediately before admission, and data sets were evaluated for the presence of coronary atherosclerotic plaque and significant coronary artery stenosis. All providers were blinded to MDCT results. An expert panel, blinded to the MDCT data, determined the presence or absence of ACS on the basis of all data accrued during the index hospitalization and 5-month follow-up. Among 103 consecutive patients (40% female; mean age, 54±12 years), 14 patients had ACS. Both the absence of significant coronary artery stenosis (73 of 103 patients) and nonsignificant coronary atherosclerotic plaque (41 of 103 patients) accurately predicted the absence of ACS (negative predictive values, 100%). Multivariate logistic regression analyses demonstrated that adding the extent of plaque significantly improved the initial models containing only traditional risk factors or clinical estimates of the probability of ACS (c statistic, 0.73 to 0.89 and 0.61 to 0.86, respectively). Conclusions— Noninvasive assessment of coronary artery disease by MDCT has good performance characteristics for ruling out ACS in subjects presenting with possible myocardial ischemia to the emergency department and may be useful for improving early triage.

We read with interest the letter from Dr Bouzas-Mosquera about our published article.1 We appreciate both his comments and the opportunity to respond. We used a subjective assessment of the pretest probability of acute coronary syndrome (ACS) by the emergency department (ED) caregiver because it incorporates into a single metric all of the data available to decision makers before imaging. Its limitation is that it is too insensitive to use to discharge ED patients directly home without further testing for ACS. It was used because no well established, universally accepted, and validated risk score exists that can be applied to undifferentiated ED populations with chest pain. …

Background— Cardiac magnetic resonance (CMR) imaging permits early triage of patients presenting to the emergency department with acute chest pain but has been limited by the inability to differentiate new from old myocardial infarction. Our objective was to evaluate a CMR protocol that includes T2-weighted imaging and assessment of left ventricular wall thickness in detecting patients with acute coronary syndrome in the emergency department. Methods and Results— In this prospective cohort observational study, we enrolled patients presenting to the emergency department with acute chest pain, negative cardiac biomarkers, and no ECG changes indicative of acute ischemia. The CMR protocol consisted of T2-weighted imaging, first-pass perfusion, cine function, delayed-enhancement magnetic resonance imaging, and assessment of left ventricular wall thickness. The clinical outcome (acute coronary syndrome) was defined by review of clinical charts by a consensus panel that used American Heart Association/American College of Cardiology guidelines. Among 62 patients, 13 developed acute coronary syndrome during the index hospitalization. The mean CMR time was 32±8 minutes. The new CMR protocol (with the addition of T2-weighted and left ventricular wall thickness) increased the specificity, positive predictive value, and overall accuracy from 84% to 96%, 55% to 85%, and 84% to 93%, respectively, compared with the conventional CMR protocol (cine, perfusion, and delayed-enhancement magnetic resonance imaging). Moreover, in a logistic regression analysis that contained information on clinical risk assessment (c-statistic=0.695) and traditional cardiac risk factors (c-statistic=0.771), the new CMR protocol significantly improved the c-statistic to 0.958 ( P Conclusions— The present study indicates that a new CMR protocol improves the detection of patients with acute coronary syndrome in the emergency department and adds significant value over clinical assessment and traditional cardiac risk factors.

We thank Dr Hamon and colleagues1 for their interest in our work. We agree that our data demonstrate that both the absence of coronary artery plaque or stenosis on noninvasive coronary multidetector computed tomography (MDCT) angiography has high negative predictive value for the subsequent diagnosis of acute coronary syndrome. However, as …