MuSe is an implantable multisensor device developed by Cardiotechnica (Berlin, Germany) for monitoring for organ rejection after transplantation.
As an alternative to routine heart biopsies which are both hazardous and painful, the MuSe device is both less expensive and more accurate.
MuSe is implanted during the transplantation procedure and provides continuing monitoring of three different cardiac parameters after hospital discharge and during sleep.
Data on ECG, heart muscle impedance and ventricular wall motion are transferred telemetrically to an external receiver which is connected via modem to the cardiac clinic for daily evaluation.
Johannes Mueller of the Deutsches Herzcentrum (German Heart Institute; Berlin) said that the first 14 devices implanted diagnosed rejection with a sensitivity of 100% and a specificity of 96%.
The new procedure also would help to save costs, according to Mueller, as compared to the standard rejection test procedures where biopsies are performed every second week on an outpatient basis for the first few months and at increasing intervals thereafter. Cardiotechnica plans to start European marketing after completion of clinical trials in 2Q00
Diagnosis of coronary ischemia in women
At a recent Soci t Francaise de Cardiologie meeting in Arcachan, France, Damian le Goludec of Hopital Henri Mondor (Paris) and Daniel Herpin of Centre Hospitalier Regionale (Poitiers, France) reviewed problems associated with the diagnosis of myocardial ischemia in women.
A resting ECG is less valuable, according to le Goludec, because in women there are repolarization anomalies and T-wave inversions, possibly of hormonal origin. He also that a stress ECG also has a lower sensitivity and predictability in many women who have problems in achieving maximum cardiac frequency.
Scintigraphy is, for le Goludec, the best choice for the diagnosis of coronary disease in women. Using tomography, he routinely achieves 75% to 90% sensitivity and 70% to 94% specificity. He proposed using myocardial perfusion tomoscintigraphy augmented by a stress test or also with image synchronization of the ECG.
Herpin maintained that stress ECG testing has its place and that its predictive value can be improved using data processing technology. He identified in particular new criteria of myocardial ischemia, of which the most useful were adjusted criteria of cardiac frequency during both the effort phase and recuperation. Herpin concluded, however that ECG testing, when used to maximum effect, can provide prognostic information as valid as scintigraphy, but at a lower cost.
Hyperhomocysteinemia a risk factor
Among several recent studies searching for a relation between hyperhomocysteinemia (hyperHcy) and cardiovascular risk, the Leiden (the Netherlands) Thrombophilia study has shown that in their patient group 10% of patients with a deep vein thrombosis (DVP) also had hyperhomocysteinemia. The authors concluded a risk factor of 6% attributable to hyperHcy in these patients.
Homocysteinemia is a hereditary metabolic disease. Association with early atherosclerosis has led a number of researchers in Europe to suggest that a moderate increase in the blood plasma level of homocysteine (Hcy) may be indicative of a risk factor for atherothrombosis. Recent reports have noted hyperHcy associated with increased risks of coronopathy, cerebral vascular accidents, carotid stenosis and thromboembolic venous disease.
Among the enzymes implicated in Hcy metabolism, methylene tetrahydrofolate reductase (MTHFR) is particularly interesting since it includes a polymorphism. Brattstrom (Stockholm, Sweden), reviewing 23 studies including 5,869 patients, showed that the genotype prevalence of the therlolabile C677T MTHFR varies between 6.5% and 29.7% of the general population.
Pierre Cacoub (Paris) feels that the relationship between hyperhomocysteinemia and an ischemic heart is nevertheless well established. In his view, an increase of 5 micromoles/litre of Hcy increases the risk of a coronary event to the same extent as an increase of 0.5 millimoles/litre of cholesterol. Although the blood plasma level of Hcy, according to Cacoub, is closely related to variations in folate and vitamin B6 levels, he feels the role of the thermolabile MTHFR mutant in hyperhomocysteinemia is still not yet proven.
Jacques Emmerich of Centre Hospitalier Broussais (Paris) suggests that although it may be useful today to monitor plasma Hcy levels in young patients with evolving thromboembolic venous disease, it may be preferable to wait for results of a number of trials currently under way before using such monitoring on a general patient population with suspected venous thrombosis.
3-D/4-D ultrasound in cardiac applications
InViVo-Cardio is a new software tool from MedCom (Darmstadt, Germany) which makes possible the upgrade of any conventional 2-D ultrasound scanner to a dynamic 3-D tomographic system.
3-D/4-D applications for surgery support and pre-planning, assessment of valve defects and volumetric measurements use standard PC hardware under the Windows-NT operating system. MedCom says a 3-D acquisition is usually performed within 10 to 20 seconds, depending on the desired data size.
For 4-D cardiac application, the software supports the input of ECG trigger signals for the correct synchronization of B-mode images and cardiac cycles.
MedCom has added a new telemedicine component to allow the connection of two MedCom workstations via Internet, ISDN or even analog phone line. After connection is established, both users can interactively work on the dataset. Potential applications include remote medical consultation, teaching aids and online technical support.
Emergency brain hemorrhage scanner
The Smart Scan hand-held device developed by Thermamed (Hamm, Germany) is intended for use for assessing brain hemorrhage at the site of an accident. The device uses near-infrared light to assess the presence of blood in the cerebrospinal fluid space in the brain or in the outer layers of the brain. Thermamed expects typical users to include emergency room and trauma physicians, ambulance personnel and the military. The company also suggests that the Smart Scan device could be used to stratify the use of scarce facilities such as CT and MRI scanners
Guidant launches full line in Europe
Guidant (Indianapolis, Indiana) claims to be the first company to provide a full line of implantable devices in Europe, including the Contak CD pulse generator for biventricular stimulation; the Contak TR pulse generator, which also offers bradycardia pacing therapy; and the Easy Trak transvenous over-the-wire lead system for implantation in the venous system for the left side of the heart.
British Biotech goes to Phase II
British Biotech (London) has completed Phase I trials on its genetically engineered anti-clotting protein BB10153 and is ready for Phase II trials to start. The dual-action compound has produced good preclinical and Phase I results, but the current absence of a partner for a drug which will require large-scale trials is apparently worrying some analysts.
The heart attack and stroke market sectors are highly competitive, so British Biotech will have to put BB10153 through large clinical studies to show it really is better. This needs very deep pockets to finance the costs, and although the company still has a cash pile of around $140 million, a partner with similar products would help cushion British Biotech from the high costs involved.
da Vinci arterial graft system in Europe
Intuitive Surgical's (Mountain View, California) da Vinci computer-enhanced endoscopic surgical system has been used over the past year in 11 European cardiology centers on around 300 cardiac procedures.
Among procedures successfully performed are grafts of left inferior mammary artery (LIMA) to left anterior descending artery (LAD), LIMA to circumflex artery, right inferior mammary artery (RIMA) to right coronary artery (RCA), RIMA to LAD, RIMA to diagonal branch and sequential grafting of the internal mammary artery.
Drager to use Masimo oximetry technology
Drager Medical (Lubeck, Germany) has signed a licensing agreement with Masimo (Irvine, California) to integrate Masimo's Signal Extraction Technology (SET) into those of its patient monitors which incorporate pulse oximetry. "We spent considerable time evaluating the performance of the Masimo SET pulse oximetry and concluded it would be an ideal choice for our future monitors and our customers," said Frank Rochlitzer, president of Drager Medical Group.