Effect of thrombus aspiration on infarct size and left ventricular function in high-risk patients with acute myocardial infarction treated by percutaneous coronary intervention. Results of a prospective controlled pilot study.

BACKGROUND: Thrombus aspiration devices have been shown to improve reperfusion criteria and to reduce distal embolization in patients treated by percutaneous coronary interventions (PCI) in the acute phase of ST-elevation myocardial infarction (STEMI). There are, however, little data about their efficacy in the reduction of infarct size. METHODS: We sought to assess in a prospective randomized trial the impact of thrombus aspiration on infarct size and severity and on left ventricular function in high-risk patients with a first STEMI. The primary end point was scintigraphic infarct size, and secondary end points were infarct severity and regional and global left ventricular function. Forty-four patients with completely occluded (Thrombolysis in Myocardial Infarction flow 0-1) proximal segments of infarct-related artery were randomly assigned to thrombus aspiration group with the Export catheter (n = 20) (Medtronic, Inc, Minneapolis, MN) or PCI-only group. A rest Tc-99-mibi gated single-photon emission computed tomographic and contrast-enhanced magnetic resonance imaging were performed 6 +/- 2 days later. RESULTS: Infarct size was comparable in patients in the thrombus aspiration group and PCI-only group (30.6% +/- 15.8% vs 28.5% +/- 17.9% of the left ventricle, P = .7) as was infarct severity in infarct-related artery territory (55% +/- 12% vs 55% +/- 14%, P = .9). Transmurality score as assessed by magnetic resonance imaging was similar in both groups (2.03 +/- 1.05 vs 2.16 +/- 1.21, P = .7). There was no impact of thrombus aspiration on other secondary end points. CONCLUSION: In our study, thrombus aspiration with the Export catheter performed as adjunctive therapy in high-risk patients with total occlusion of the proximal part of major coronary arteries does not decrease infarct size or severity and has no effect on left ventricular regional and global function.

Preliminary evaluation of a fuzzy logic-based automatic quantitative analysis in myocardial SPECT.

UNLABELLED: This study validates a new quantitative myocardial perfusion SPECT software. METHODS: The processing starts with the extraction of the morphologic skeleton of the left ventricular myocardium from reconstructed transverse sections. Fuzzy logic is used to decide whether a pixel belongs to the myocardium and any perfusion defect is filled according to a truncated bullet model. The resulting image is partitioned in 18 isovolumetric sectors. Sex-matched normal limits, criteria of abnormality for rest (201)Tl and (99m)Tc-labeled perfusion tracers, reproducibility studies, and detection of coronary artery disease were developed and validated in an overall population of 343 patients. The sex- and tracer-matched means and SDs of a normal response were calculated in 93 male and 93 female patients with a <5% likelihood of coronary artery disease. Reproducibility measurements and assignment of different sectors of the myocardium to a specific coronary were performed from data collected in 49 and 60 patients, respectively. The accuracy of the detection of a coronary artery occlusion was assessed in 48 patients who also underwent coronary angiography. RESULTS: The intra- and interoperator reproducibility of the sectorial activity was high with a linear regression coefficient of 0.97 and a SD of the difference measurement at 4.4% and 3.8%, respectively. Overall sensitivity and specificity for the detection of occluded coronary artery were 90% and 80%, respectively. For the detection of left anterior descending, left circumflex, and right artery coronary occlusion, sensitivity was 92%, 75%, and 92.5%, respectively, and specificity was 75%, 78%, and 90%, respectively. CONCLUSION: The new quantitative myocardial perfusion SPECT software appears to be a very helpful program for the objective analysis of perfusion tracer distribution in myocardial SPECT and a very accurate tool in the detection and localization of coronary artery occlusion.

Remote continuous cardiac arrhythmias detection and monitoring.

The current techniques used to diagnose cardiac arrhythmias such as Holter, Rtest and telemetry systems are partially efficient because they are limited either in time or in space. In this paper, a platform dedicated to the real-time remote continuous cardiac arrhythmias detection and monitoring is proposed. Such a platform allows to improve the accuracy and the efficiency of the diagnostic of ventricular tachycardia among the high-risk patients and enables the implantation of ICD to prevent sudden death. The new method allows the patient to lead a normal life while being remotely monitored in real-time by an ambulatory wireless ECG sensor. When a cardiac arrhythmia is detected a message including a sequence of ECG signals and the patient's images (indoors only) is sent to a remote surveillance server. According to the gravity of the symptom, the cardiologist can intervene in real time or later. The system has been evaluated on some ten patients with regard to heartbeat and cardiac rhythm disturbance. The real-time results are similar to those offered by HP telemetry systems.

Different patterns of left ventricular enlargement and long-term prognosis after reperfused acute myocardial infarction.

BACKGROUND: Dilation of end-systolic and end-diastolic volumes (ESV, EDV) has been used to define left ventricular remodelling after acute myocardial infarction (MI), but the prognostic significance of different enlargement patterns has not been evaluated fully. AIM: To analyse the evolution of left ventricular volumes and parameters of global and regional contractility and their correlations with long-term prognosis in patients treated by angioplasty in the acute phase of MI. METHODS: Seventy-four patients (mean age 56+/-13 years; 77% men), treated successfully by angioplasty in the acute phase of MI, were included prospectively. Significant enlargement of left ventricular volumes was defined as a greater than 20% increase between acute phase and 6-month control, assessed by contrast ventriculography. Clinical follow-up was obtained for all patients at 82+/-19 months. RESULTS: Four groups were identified based on volume evolution: Group I (n=29, 39%; no volume enlargement); Group II (n=8, 11%; isolated EDV enlargement); Group III (n=10, 14%; isolated ESV enlargement); Group IV (n=27, 36%; ESV plus EDV enlargement). Global left ventricular ejection fraction increased in Groups I (p=0.001) and II (p=0.037), but decreased in Groups III (p=0.0002) and IV (p=0.019). The 6-year event-free survival rate was significantly (p=0.0039) better in Groups I and II (100%) than in Groups III and IV (80 and 78%, respectively). CONCLUSION: ESV enlargement in patients with reperfused acute MI impacts negatively on long-term prognosis, while isolated EDV enlargement does not.

A Real-Time Continuous Cardiac Arrhythmias Detection System: RECAD.

Cardiac arrhythmia is a class of serious heart diseases that threatens many people. Current arrhythmias diagnostic techniques seem to be partially efficient due to the application limitations either in time or in space. The paper presents a real-time continuous arrhythmias detection system (RECAD) platform based on the wireless sensor network technology. This system provides long-term real-time surveillance thanks to the low-resource and low power consumptions of ambulatory wireless ECG sensor (AWES). Moreover, the AWES is compact and friendly use, so it enables patients to lead a normal life every where (indoors or outdoors). RECAD platform contains four sub-systems: AWES, local access server, remote access server and remote surveillance server. Each subsystem is configurable to run in multiple operation modes according to different application scenarios. A lossless signal compression algorithm is adopted to reduce network traffics and a dedicated application layer protocol is provided to guarantee a real-time reliable on-line ECG analysis. This system is evaluated on about twenty patients at the hospital Gabriel Montpied of Clermont-Ferrand and the real-time results are similar to the HP telemetry system.

Influence of infarct-zone viability detected by rest Tc-99m sestamibi gated SPECT on left ventricular remodeling after acute myocardial infarction treated by percutaneous transluminal coronary angioplasty in the acute phase.

BACKGROUND: The purpose of this study was to assess the value of technetium 99m sestamibi gated single photon emission computed tomography (SPECT) in predicting the evolution of left ventricular volumes in patients treated successfully in the acute phase of a myocardial infarction (MI). METHODS AND RESULTS: Twenty-nine patients with acute MI and early percutaneous transluminal coronary angioplasty (PTCA) were included in this study. A rest Tc-99m sestamibi electrocardiography (ECG)-gated SPECT study was performed 21 +/- 5 days after PTCA. The myocardial perfusion index was calculated by use of a semiautomatic sectorial analysis. All patients had contrast ventriculography performed during the acute phase and 6 months later. The patients were separated into two groups according to the absence (group I, n = 21) or presence (group II, n = 8) of end-systolic enlargement. The perfusion index in the infarct sectors was -2.29 +/- 2.90 SD in group I and -6.40 +/- 2.85 SD in group II ( P < .01). With a cutoff value of -2.46 SD, the sensitivity and specificity of Tc-99m sestamibi SPECT for the prediction of end-systolic volume enlargement were 100% and 62%, respectively. When the functional data from ECG-gated acquisitions were added, specificity increased to 86%. CONCLUSIONS: Despite successful PTCA in the acute phase of MI, an increase in end-systolic volume was observed at 6 months in 28% of patients. Tc-99m sestamibi ECG-gated SPECT performed 3 weeks after the acute phase could predict this enlargement with a high accuracy.

Transluminal angioplasty in a patient with a single coronary artery during the acute phase of a myocardial infarction.

The prevalence of coronary artery abnormalities, in particular the single vessel form, is low among the general population. We report a case of a transluminal angioplasty of the left anterior descending artery arising from the right coronary artery during the acute phase of myocardial infarction.