Acute left circumflex coronary artery occlusion detected on nongated CT.

We describe a patient with chest pain and a nondiagnostic electrocardiogram in whom computed tomographic (CT) aortography demonstrated myocardial hypoperfusion in the distribution of the circumflex artery as well as an abrupt cutoff of contrast in the left circumflex artery. Subsequent cardiac catheterization confirmed occlusion of the circumflex artery and led to revascularization. The diagnosis of acute myocardial infarction on CT can dramatically alter the clinical management of a patient, especially in cases in which other tests are equivocal.

Coronary Computed Tomography Angiography Versus Radionuclide Myocardial Perfusion Imaging in Patients With Chest Pain Admitted to Telemetry: A Randomized Trial.

BACKGROUND: The role of coronary computed tomography angiography (CCTA) in the management of symptomatic patients suspected of having coronary artery disease is expanding. However, prospective intermediate-term outcomes are lacking. OBJECTIVE: To compare CCTA with conventional noninvasive testing. DESIGN: Randomized, controlled comparative effectiveness trial. (ClinicalTrials.gov: NCT00705458). SETTING: Telemetry-monitored wards of an inner-city medical center. PATIENTS: 400 patients with acute chest pain (mean age, 57 years); 63% women; 54% Hispanic and 37% African-American; and low socioeconomic status. INTERVENTION: CCTA or radionuclide stress myocardial perfusion imaging (MPI). MEASUREMENTS: The primary outcome was cardiac catheterization not leading to revascularization within 1 year. Secondary outcomes included length of stay, resource utilization, and patient experience. Safety outcomes included death, major cardiovascular events, and radiation exposure. RESULTS: Thirty (15%) patients who had CCTA and 32 (16%) who had MPI underwent cardiac catheterization within 1 year. Fifteen (7.5%) and 20 (10%) of these patients, respectively, did not undergo revascularization (difference, -2.5 percentage points [95% CI, -8.6 to 3.5 percentage points]; hazard ratio, 0.77 [CI, 0.40 to 1.49]; P = 0.44). Median length of stay was 28.9 hours for the CCTA group and 30.4 hours for the MPI group (P = 0.057). Median follow-up was 40.4 months. For the CCTA and MPI groups, the incidence of death (0.5% versus 3%; P = 0.12), nonfatal cardiovascular events (4.5% versus 4.5%), rehospitalization (43% versus 49%), emergency department visit (63% versus 58%), and outpatient cardiology visit (23% versus 21%) did not differ. Long-term, all-cause radiation exposure was lower for the CCTA group (24 versus 29 mSv; P < 0.001). More patients in the CCTA group graded their experience favorably (P = 0.001) and would undergo the examination again (P = 0.003). LIMITATION: This was a single-site study, and the primary outcome depended on clinical management decisions. CONCLUSION: The CCTA and MPI groups did not significantly differ in outcomes or resource utilization over 40 months. Compared with MPI, CCTA was associated with less radiation exposure and with a more positive patient experience. PRIMARY FUNDING SOURCE: American Heart Association.

A rapid, safe, and low-cost technique for the induction of mild therapeutic hypothermia in post-cardiac arrest patients.

AIM OF STUDY: The benefits of inducing mild therapeutic hypothermia (MTH) in cardiac arrest patients are well established. Timing and speed of induction have been related to improved outcomes in several animal trials and one human study. We report the results of an easily implemented, rapid, safe, and low-cost protocol for the induction of MTH. METHODS: All in-hospital cardiac arrest (IHCA) and out-of-hospital cardiac arrest (OHCA) patients admitted to an intensive care unit meeting inclusion criteria were cooled using a combination modality of rapid, cold saline infusion (CSI), evaporative surface cooling, and ice water gastric lavage. Cooling tasks were performed with a primary emphasis on speed. The main endpoints were the time intervals between return of spontaneous circulation (ROSC), initiation of hypothermia (IH), and achievement of target temperature (TT). RESULTS: 65 patients underwent MTH during a 3-year period. All patients reached target temperature. Median ROSC-TT was 134min. Median ROSC-IH was 68min. Median IH-TT was 60min. IH-TT cooling rate was 2.6°C/h. Complications were similar to that of other large trials. 31% of this mixed population of IHCA and OHCA patients recovered to a Pittsburgh cerebral performance score (CPC) of 1 or 2. CONCLUSION: A protocol using a combination of core and surface cooling modalities was rapid, safe, and low cost in achieving MTH. The cooling rate of 2.6°C/h was superior to most published protocols. This method uses readily available equipment and reduces the need for costly commercial devices.

Rationale and design of a randomized controlled trial comparing stress myocardial perfusion imaging with coronary CT angiography as the initial imaging study for intermediate-risk patients admitted with chest pain.

BACKGROUND: Noninvasive cardiac imaging plays an important role in the diagnosis and management of coronary artery disease (CAD). Prior studies have focused on the diagnostic performance of noninvasive modalities using angiographically significant stenoses as the reference standard. Recent trends in evidence-based medicine and increasing imaging utilization call for validation of diagnostic algorithms with well-designed, controlled trials with clinical outcome endpoints. OBJECTIVE: To compare the performance of stress radionuclide myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CTA) in terms of outcomes. METHODS: We designed a single-center, randomized controlled trial that compares MPI and CTA as the initial modality for the evaluation of patients hospitalized for chest pain without known CAD or acute myocardial infarction. Patients with intermediate-risk characteristics and a clinical need for noninvasive imaging are included. The primary outcome measured is the incidence of conventional angiography not leading to subsequent coronary revascularization within 1 year. The study is powered to detect a reduction from 11% to 3% in catheterization not leading to an intervention with a sample size of 400. Secondary outcomes include procedural complications and posttest renal dysfunction (safety outcomes), major adverse cardiovascular events, length of hospital stay, subsequent hospitalizations and imaging, changes in medical management, and tolerability of the noninvasive test. CONCLUSIONS: The results of this trial will further our understanding of the relative appropriateness of CTA and MPI in evaluating intermediate-risk patients hospitalized with chest pain. It will also have implications for the design and probability of success of multicentered trials that are currently being planned.