Virtual reality simulation training in a high-fidelity procedure suite: operator appraisal.

PURPOSE: To assess the face and content validity of a novel, full physics, full procedural, virtual reality simulation housed in a hybrid procedure suite. METHODS AND MATERIALS: After completing 60 minutes of hands-on training in uterine artery embolization and coronary angioplasty, 24 radiologists and 18 cardiologists with mean 10 years of endovascular experience assessed the functionality of a comprehensive hybrid procedure suite simulation (Orcamp; Orzone, Gothenburg, Sweden). RESULTS: C-arm and operating table functionality and realism were reliably (α = 0.0.89-0.92) rated highly (80/100). Performance realism of the catheter, guide wire, fluoroscopy image, electrocardiogram, and vital signs readout also reliably and statistically significantly predicted subjects' overall positive assessment (mean = 87/100) of the simulation experience in a multiple regression model (α = .83; r = 0.85 and r(2) = 0.67; P < .0001). CONCLUSIONS: This study reports a quantitative evaluation of a comprehensive simulation of an authentic procedure suite for image-guided intravascular procedures. This new facility affords the opportunity for trainers to provide higher fidelity training of operative technical, procedural, and management skills in the realistic context of a complete procedure suite with all its complexities and potential distractions.

Plasma B-type natriuretic peptide levels in cardiac donors.

INTRODUCTION: Elevated levels of plasma brain natriuretic peptide (BNP) and amino-terminal BNP (NT-proBNP) are associated with adverse cardiac outcomes. It is not known whether BNP and NT-proBNP levels in heart donors can aid in selection and predict outcomes in transplant recipients. METHODS: Plasma BNP and NT-proBNP were measured in 32 organ donors prior to removal from life-support systems. Twelve hearts were accepted and 20 hearts were declined (no suitable recipient - 12, probable coronary artery disease - four, abnormal echocardiogram - three, other medical reasons - one). Records of heart transplant recipients were reviewed for: survival at 30 d, length of intensive care stay and need for intra-aortic balloon counter-pulsation (IABP). RESULTS: Donors were divided into three groups - Group 1 (n = 12): accepted hearts; Group 2 (n = 12): acceptable hearts not transplanted for logistic reasons; Group 3 (n = 8): declined because of probable cardiac disease. BNP and NT-proBNP levels were significantly lower in donors with acceptable hearts (n = 24) compared with those with unacceptable hearts (n = 8) (p = 0.02 and 0.032, respectively). Of the 12 patients transplanted, four suffered a suboptimal outcome (two died, one required inotropic support and IABP, one prolonged hospitalization) while eight had good outcomes with no significant difference in BNP/NT-proBNP levels between these groups. CONCLUSION: BNP and NT-proBNP levels were lower in organ donors whose hearts were acceptable for transplantation compared with those whose hearts were unsuitable. Measuring natriuretic peptides may be a useful adjunctive tool in the selection of donor hearts. We feel that further studies are warranted.

Frequency of recurrent ST-elevation myocardial infarction after fibrinolytic therapy in a different territory as a manifestation of multiple unstable coronary arterial plaques.

Multiple unstable plaques have been demonstrated by various imaging techniques in culprit and nonculprit arteries in patients with acute coronary syndromes, but the frequency with which clinical manifestations of multiple unstable plaques occur is unclear. To estimate this frequency in patients who present within 6 hours with ST-elevation myocardial infarction, we studied electrocardiograms and cardiac marker levels of 722 patients with suspected reinfarction in the HERO-2 trial of 17,073 patients; this trial compared intravenous bivalirudin with unfractionated heparin before administration of streptokinase. Twenty-six patients (3.6%) developed recurrent ST elevation in a different territory. Of all the patients who developed ST elevation in a different territory, 50% (13 of 26) did so during the 48 hours of randomized antithrombin therapy compared with 29% (140 of 487) of those who developed recurrent ST elevation in the index territory (p = 0.046). Recurrent index territory ST elevation occurred in 392 of 552 patients (71%) with confirmed reinfarction, and ST elevation in a new territory occurred in 21 patients (3.8%) with confirmed reinfarction (2.3% and 0.12% of all HERO-2 enrollees, respectively). These data suggest that clinical manifestation of multiple unstable plaques of recurrent ST elevation and reinfarction in a territory different from that of the index ST elevation myocardial infarction after intravenous fibrinolytic and antithrombin therapies is rare.

Adjunctive use of direct thrombin inhibitors in patients receiving fibrinolytic therapy for acute myocardial infarction.

The direct thrombin inhibitors hirudin and bivalirudin inhibit both fluid-phase and clot-bound thrombin. These agents have been extensively studied in clinical trials in comparison with intravenous unfractionated heparin (UFH), as adjuncts to fibrinolytic therapy for ST-elevation myocardial infarction (STEMI) and in percutaneous coronary intervention (PCI), and they are currently undergoing further evaluation in patients with non-ST elevation acute coronary syndromes (NSTEACS). In angiographic trials there were trends for patients treated with hirudin to be more likely to achieve Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow at 90 minutes than patients treated with UFH (65% versus 57% in TIMI-5; 41% versus 33% in Hirudin for the Improvement of Thrombolysis [HIT]-4; statistically nonsignificant differences in both trials). In Montréal Heart Institute trials and the multicenter Hirulog and Early Reperfusion or Occlusion (HERO)-1 trial the use of bivalirudin was associated with an increased incidence of TIMI grade 3 flow (85% versus 31%, p = 0.006; and 48% versus 35%, p = 0.02, respectively). These studies used streptokinase as the fibrinolytic agent except in TIMI-5 where alteplase was used. The initial clinical outcomes studies (Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes [GUSTO]-IIA and TIMI-9A) were discontinued early because of a high incidence of intracerebral bleeding (approximately 1.8%). Patients in these studies had either STEMI or NSTEACS, and thus not all were treated with fibrinolytic therapy. These studies were recommenced as GUSTO-IIB and TIMI-9B, using lower dosages of hirudin (0.1 mg/kg bolus + 0.1 mg/kg infusion for 96 hours). Neither TIMI-9B nor GUSTO-IIB showed an improvement in efficacy (death or reinfarction) or an increase in bleeding with hirudin. However, in the 1015 patients with STEMI treated with streptokinase in GUSTO-IIB, there was a 40% reduction in the combined incidence of death or myocardial infarction at 30 days (8.6% versus 14.4%, odds ratio [OR] 0.57, 95% confidence interval [CI] 0.38-0.87, p = 0.004). In the HERO-2 trial, 17073 patients receiving streptokinase for STEMI were randomized to receive either bivalirudin (0.25 mg/kg bolus and 0.5 mg/kg infusion for 12 hours followed by 0.25 mg/kg) or UFH (5000 IU bolus and 800-1000 IU/h infusion titrated to an activated partial thromboplastin time [APTT] of 50-75 seconds) for a total of 48 hours. Thirty-day mortality was similar in both groups (10.8% with bivalirudin versus 10.9% with UFH, OR 0.99, 95% CI 0.90-1.09, p = 0.85). There was a 30% reduction in the incidence of reinfarction before 96 hours (1.6% with bivalirudin versus 2.3% with UFH, OR 0.70, 95% CI 0.56-0.87, p = 0.001). Patients treated with bivalirudin had significantly more moderate bleeding (1.4% versus 1.1% with UFH, OR 1.32, 95% CI 1.0-1.74, p = 0.05). In a meta-analysis of patients with STEMI in the Direct Thrombin Inhibitor Trialists' collaboration, direct thrombin inhibitors were found to reduce the rate of reinfarction at 30 days (3.9% versus 4.8% with UFH, OR 0.80, 95% CI 0.71-0.90, p < 0.001), but did not reduce mortality (9.1% versus 9.0%, OR 1.02, 95% CI 0.94-1.11, p = 0.68) or the combined incidence of death/reinfarction at 30 days (11.8% versus 12.4%, OR 0.95, 95% CI 0.88-1.02, p = 0.18). There was no increase in major bleeding or intracerebral bleeding with direct thrombin inhibitor therapy. In conclusion, direct thrombin inhibitors reduce reinfarction, but not mortality, in patients with STEMI treated with fibrinolytic therapy. The major benefit of direct thrombin inhibitors appears to be in patients undergoing PCI, particularly after STEMI.

Prospective evaluation of a chest pain pathway at Green Lane Hospital.

AIMS: To prospectively evaluate the efficacy and safety of a chest pain pathway at Green Lane Hospital. METHODS: Between August 1999 and March 2000, patients with non-traumatic chest discomfort considered to be possibly ischaemic were assessed by history, physical examination, baseline electrocardiographic findings and point of care troponin T tests. Those considered not to be high risk entered the pathway which included repeat cardiac markers and electrocardiograms at 6-8 hours, followed by optional stress testing. The patients were followed for at least one year. RESULTS: Of 423 patients with chest discomfort compatible with myocardial ischaemia, 173 were enrolled in the pathway, with 19 later transferred off the pathway for clinical reasons. Of the remaining 154 patients, the median duration of hospital stay was 17.3 hours [IQR 8.2, 25.1] (median of 13.1 hours for those who did not undergo stress testing); 111 (72%) stayed in hospital for less than 24 hours. There were no readmissions within 30 days with an acute coronary syndrome. In the year following discharge, three patients had a myocardial infarction (one of whom later died) and four died of non-cardiac causes. At one year, freedom from cardiac death or non-fatal myocardial infarction was 98% [95%CI 95,100]. CONCLUSIONS: The chest pain pathway facilitated patient triage and patients had high event-free survival.

Stent deployment with distal vascular protection for the culprit vein graft stenosis in a patient with an acute infarct and cardiogenic shock.

A case of emergency stent deployment to a critical vein graft lesion in a patient with an acute myocardial infarction and cardiogenic shock is described. An Angioguard vascular protection device was used, retrieving a large amount of atheromatous debris. Use of filter-type protection devices to prevent distal atheroembolism may be lifesaving in such patients.