Until now, the primary system for monitoring fluid buildup, frequently termed "overload," has been extremely simple and less than low-tech the simple bathroom scale to measure weight gain. Now, Medtronic (Minneapolis) claims a large and definitely high-tech advance, using the November scientific sessions of the American Heart Association (AHA; Dallas) to report approval of its InSync Sentry cardiac resynchronization therapy (CRT) defibrillator systems. Medtronic calls the system the world's first implantable medical therapy offering automatic fluid status monitoring in the thoracic cavity, where fluid accumulation is a primary indicator of worsening heart failure and is a precursor to frequent hospitalizations.
"It is a completely new feature in these implantable devices, and what makes it so important is that for people with heart failure, the main reason they end up going to the hospital is because of this fluid build-up," Medtronic spokesman Scott Papillon told Cardiovascular Device Update's sister publication, Medical Device Daily. "They can't breathe, they feel like they're drowning and they end up in the emergency room."
The company said the technology that makes thoracic fluid measurement possible is OptiVol Fluid Status Monitoring, a system for measuring changes in impedance. OptiVol uses low electrical pulses traveling across the thoracic cavity to measure the level of resistance to these pulses, a measurement that indicates the fluid level in the thorax.
The feature, which Papillon said Medtronic believes no other company is working on, allows doctors to "monitor a trend" and provide a kind of "advance warning" that this fluid is building, even before the patient experiences symptoms, to allow for early intervention in either diet or medication. By helping CHF patients avoid ER visits and hospitals stays, the device offers potentially significant savings to the healthcare system, as well as offering an improved quality of life for heart failure patients
Medtronic said the system is available to physicians who implant CRT defibrillator systems and to those who manage the ongoing care of heart failure patients. The patient holds a mouse-like device over the Sentry to allow for transmission of data across the Medtronic Carelink Network remote monitoring service or through a programmer.
The product initially will be used by those involved in the testing of the devices until a separate device, a Sentry "check" device, becomes FDA-approved in March or April, Papillon said. That automatic device will be one the patient can read at home to know if fluid is building up, and the report can also be transmitted to their physicians. The approval to hook the devices into the CareLink Network also is expected to be received by that time, at which point the product will be "fully marketed," he said.
Papillon said a particular threshold for fluid buildup would be set for each patient, depending on his or her condition, from the outset. A physician would be able to get management reports from the device as often as every day, if he so chose. The report shows measurements in a graph form so that physicians can identify trends to know when the patient is in the "danger zone," he said.
Medtronic said it received approval of the new assessment technology "months earlier" than expected. It said the technology "signifies a new approach to managing heart failure by collecting physiologic information" indicating potential worsening of patient symptoms. It said the targeted population will be the 400,000 Americans with heart failure who have "dysynchronous beating in the heart's lower chambers and low blood output that places them at risk for sudden cardiac arrest."
William Abraham, MD, of the Ohio State University Heart Center (Columbus, Ohio), principal investigator of a clinical study evaluating the InSync Sentry, characterized the system as "a significant advancement in medical technology" and said its benefits would be "far-reaching." Noting the frequency of hospitalizations by CHF patients, he said, "With access to thoracic fluid status in combination with other symptom-gathering tools, we hope to improve the diagnosis of heart failure condition changes, better manage heart failure symptoms and keep patients out of the hospital."
Elsewhere in the product pipeline:
Acceleration Therapeutics (North Bay Village, Florida), a division of Non-Invasive Monitoring Systems, reported that its AT-101 device was used to prove that the cardioprotective effect associated with its use is due in part to the release of beneficial prostaglandins from the inner lining of the blood vessels. The study, using a model of experimental cardiopulmonary resuscitation (CPR), was led by Tony Adams, MD, of Mt. Sinai Medical Center and Miami Heart Research Institute Miami Beach and was presented at the AHA meeting in New Orleans. Adams said: "We knew that both nitric oxide and prostaglandins were released with the AT-101 in normal animals and this study now shows the importance of prostaglandins in the beneficial cardiac effects of AT-101 CPR. This suggests that the AT-101 might have a complementary or stand-alone role in human CPR in the future." The AT-101 moves the body repetitively in a back-and-forth motion, and is used as an aid to improve the circulation and joint mobility.
AngioDynamics (Queensbury, New York) reported the release in the U.S. of the EvenMore chronic hemodialysis catheter designed for long-term use in dialysis patients. The EvenMore catheter is a non-position dependent, 14.5 Fr, end-hole design catheter. Offering less than 5% recirculation, the catheter's low-profile, lumen-to-wall ratio is designed to deliver high flow. The catheter also features a Durathane shaft, a biocompatible and durable material that offers high chemical resistance, which helps simplify site care since the material can be cleaned with either iodine or alcohol. AngioDynamics will be providing the EvenMore catheter in a kit that includes the EmboSafe Valved Splittable Sheath dilator, a sheath designed to reduce the risk of blood loss and air intake while allowing for smooth catheter insertion.
AusAm Biotechnologies (New York) reported that Accumin has received expanded labeling to its 510(k) from the FDA for "diagnostic use in quantitation of intact albumin in urine from patients with cardiovascular diseases associated with increased albumin levels." The early and accurate detection of urinary albumin could help in the identification of patients who are at risk for a cardiovascular event and warrant further testing. Accumin received its original FDA clearance for the early detection of albumin as an indicator of potential kidney disease in August 2003. The assay uses common laboratory equipment to separate albumin from the other compounds in urine to determine its precise quantity, which the company said offers the most accurate reading available.
Biotronik (Lake Oswego, Oregon) reported the first implant for a clinical investigation designed to demonstrate efficacy of both its Stratos LV and Protos DR/CLS (closed loop stimulation) pacemakers in congestive heart failure (CHF) patients who have undergone AV nodal ablation (ablate and pace) for persistent or permanent symptomatic atrial fibrillation (AF) with poorly controlled rapid ventricular heart rates. William Bailey, MD, of the Heart and Vascular Center (Lake Charles, Louisiana), implanted a Protos DR/CLS pacemaker in a biventricular (BiV) configuration in a 72-year-old male with a history of NYHA Class III CHF and permanent AF. The AVAIL CLS/CRT study randomizes patients into three groups: Stratos LV biventricular implants; Protos DR/CLS biventricular implants; and Stratos LV pacing in a standard right ventricular configuration as the control group. The primary endpoint is to demonstrate the clinical benefit of biventricular pacing for the Class II and Class III heart failure population who also have permanent AF and have undergone AV nodal ablation. The results will be compared to the traditional right ventricular pacing study arm.
Cardima (Fremont, California) reported a 70% rate of success in treating 22 atrial fibrillation patients with its Surgical Ablation System (SAS), based on data compiled by doctors at Lenox Hill Hospital (New York). Six-month follow-up data found that 70% of the patients treated with SAS remained in normal sinus rhythm. Cardima's SAS ablates cardiac tissue during heart surgery using radio frequency energy. The company said it believes that the system can significantly reduce the time required to form lesions and can sense tissue temperature interactively to ensure lesions are uniform, thin and linear.
Cook (Bloomington, Indiana) announced at the 2004 VEITHSymposium in New York in November the availability of its Abdominal Aortic Aneurysm (AAA) Physician Practice Builder Kit. The kit is designed to help healthcare professionals communicate with their patients about the treatment of AAAs and to enhance the understanding of AAA among physicians' referral networks.
Cordis (Miami Lakes, Florida) reported the publication of favorable eight-month data from the independent SES-SMART trial, which compared the company's Cypher sirolimus drug-eluting stent (DES) against one of the company's uncoated stents in small coronary arteries. Data from the randomized trial was published in the Journal of the American Medical Association. The trial randomized 257 patients with de novo native coronary arterial lesions in vessels of size 2.75 mm or less (mean reference diameter of 2.2 mm) to either a Cypher balloon-expandable stent (129 patients) or an uncoated Bx Sonic balloon-expandable stent (128 patients) in a 1:1 ratio according to a centralized list. The primary endpoint of binary in-stent restenosis between the two groups was striking, with a restenosis rate of 9.8% for patients receiving the sirolimus-eluting stent vs. 53.1% in patients receiving an uncoated stent with a relative risk reduction of 82%. Study authors noted that larger-scale trials would be needed to determine whether the dramatic angiographic benefits observed in the current trial will translate into real long-term clinical benefit. However, they noted that the study results "demonstrate that the implantation of a sirolimus-eluting stent to treat atherosclerotic lesions of small coronary arteries is safe, effective, and associated with a lower incidence of angiographic restenosis in comparison with an uncoated stent." Brian Firth, MD, PhD, vice president of medical affairs and health economics worldwide for Cordis, said, "This is a very important study because it really is the study of the smallest vessels yet reported. It shows that Cypher really works in patients who've been a real challenge, those patients with the smallest vessels because they're the ones that have very high restenosis rates and having a high risk of needing a repeat procedure," he said. Indeed, the study showed that the marked improvement in angiographic outcome was mirrored in the clinical outcome with target lesion revascularization performed in only 7% of patients treated with the sirolimus-eluting stent vs. 21.1% of those treated with the bare-metal stent.
CryoCath Technologies (Montreal) said it has received regulatory approval from the People's Republic of China to market both the Freezor CryoAblation System and the Arctic Circler CurviLinear. Freezor and Arctic Circler will complement the company's existing electrophysiology and interventional cardiology franchises. Pacific Medical, a dedicated cardiology company focused on the Chinese market, will exclusively distribute these products.
Dade Behring Holdings (Deerfield, Illinois) reported that its N-terminal pro brain natriuretic peptide (NT-proBNP) test has received FDA clearance for two additional claims: assessment of heart failure severity in patients diagnosed with congestive heart failure and risk stratification of patients with acute coronary syndrome and heart failure. Earlier, clearance was received for the use of NT-proBNP in the diagnosis of individuals suspected of having congestive heart failure. The automated test is available for use on the Dimension instruments with Heterogeneous Immunoassay Module.
LeMaitre Vascular (Burlington, Massachusetts) premiered its AnastoClip Vessel Closure System at the VEITHSymposium in New York in November. Acquired from U.S. Surgical (Norwalk, Connecticut), a unit of Tyco Healthcare, the device is cleared for sale in the U.S., European Union and Japan. The AnastoClip VCS Vessel Closure System provides rapid and precise vascular anastomosis, replacing traditional sutures. Titanium AnastoClips, placed in an interrupted fashion, facilitate a compliant anastomosis without penetrating the vessel lumen, the company said. That allows the anastomosis to contract and expand to accommodate pulsatile flow. The system is used in a variety of vascular procedures, most commonly in vascular access for hemodialysis patients.
Mallinckrodt (St. Louis), a Tyco Healthcare company, reported the introduction of the OptiVantage DH Contrast Delivery System for dual-head injector protocols. The OptiVantage system enhances patient safety and outcomes with three safety features. The fully programmable LCD powerhead allows technologists to monitor patients during the entire procedure, keeping them on top of possible problems, enhancing safety and reducing testing time by 25%. OptiVantage allows the technologist to interrupt the injection with the push of a button, preventing irritation from extravasion of the saline. And to reduce the risk of air embolism, the OptiVantage Tilt Enable feature allows an injection to occur only if the proper sequence has been followed and the powerhead is tilted downward.
MedicalCV (Inver Grove Heights, Minnesota) said that it received FDA 510(k) clearance to market its AtriLaze Surgical Ablation System for use on cardiac tissue in surgery. The company expects to begin marketing its AtriLaze System via a direct U.S. sales force this month. The laser device is used to ablate or cause scarring of soft tissue, with the long-term goal of treating atrial fibrillation.
Medtronic (Minneapolis) reported FDA approval of the Xcelerant Delivery System for use with the AneuRx AAA Stent Graft System. The AneuRx AAA Stent Graft System, approved for U.S. use in 1999, is used in the treatment of abdominal aortic aneurysms (AAAs). The Xcelerant Delivery System provides physicians with a smooth, controlled and more trackable delivery platform to implant the AneuRx AAA stent graft. The delivery system's intuitive, integrated handle contributes to precise placement of the stent graft. The Xcelerant Delivery System also employs kink-resistant catheter material, which serves to facilitate trackability of the stent graft through tortuous aortas and access arteries. The system also includes a distal radiopaque marker that improves the visibility of the device when viewed through angiography for more accurate deployment of the stent graft. Medtronic said it anticipates full market release of the Xcelerant Delivery System with the AneuRx AAA Stent Graft System in 1Q05. Separately, the company reported the first patient enrollment in a new controlled clinical study to evaluate the safety and efficacy of a procedure in which a heart surgeon uses saline-irrigated radio frequency (RF) ablation technology to treat atrial fibrillation (AF) at the same time they repair or replace a diseased or damaged heart valve. The first randomized procedure was performed by Dr. Michael Moront at Toledo Hospital of Ohio, one of several U.S. centers participating in the study. The CAFE (Cardioblate Atrial Fibrillation) study is the first prospective, randomized, blinded trial designed to study surgical ablation for the treatment of AF. The CAFE study will enroll adult patients suffering from both heart valve disease and AF. Medtronic's Cardioblate system creates lesions in the heart's upper chambers to block transmission through the tissue of abnormal electrical signals that may cause atrial fibrillation
St. Jude Medical (St. Paul, Minnesota) said in November that it had received FDA approval to add V-V (ventricle to ventricle) timing to new models of the Epic HF and Atlas+ HF family of cardiac resynchronization therapy devices (CRT-Ds). The company said it believes it is the first CRT-D supplier in the U.S. market to offer this expanded programmability. St. Jude said it was completing inventory build-up of the new models and expected shipments to begin last month. Michael Coyle, president of St. Jude's Cardiac Rhythm Management business, said, "V-V timing provides our physician customers significant flexibility to optimize therapy based on individual patient needs, which may benefit thousands of heart failure patients who also require an ICD." V-V timing refers to the delay between contraction of the left and right ventricles, compared with simultaneous pulses to both left and right ventricles. The V-V timing feature in the Epic HF and Atlas+ HF CRT-Ds allows physicians to adjust the delay between ventricular outputs, as well as choose which chamber is paced first. The company said patients who do not respond to simultaneous biventricular pacing systems may benefit from the sequential timing offered by V-V programmability.
3M (St. Paul, Minnesota) introduced Version 2.0 of its Littmann brand Sound Analysis Software, offering users of its Littmann Electronic Stethoscope Model 4000WS what it termed "a new option" for downloading recorded sounds. Version 2.0 enables users to download sounds from a Model 4000 stethoscope to either a personal computer or pocket PC. Version 1.0 allowed download only to a PC. The software can be used on any pocket PC that runs Windows Mobile Pocket PC 2002 or 2003 operating systems, including Pocket PCs from Hewlett Packard, Toshiba, Dell, ASUS, Viewsonic, Siemens and Samsung. It also can be used on Pocket PC-based mobile phones from ATT, Verizon and T-Mobile. Whether used with a Pocket PC or standard PC, 3M Sound Analysis Software enables users to "see and share what they hear," the company said. Once recorded sounds are downloaded, the software can display a phonocardiogram or spectrogram; play back the recorded sounds and display the wave forms in bell, diaphragm or extended range frequencies; and save recordings with patient information to monitor changes in conditions.
Ventracor (Sydney, Australia) confirmed last month that it would be submitting an investigational device exemption (IDE) application to the FDA for permission to conduct a bridge-to-transplant trial in the first half of 2005. Following clinical trials conducted under the IDE, Ventracor will then seek premarket approval to allow the VentrAssist left ventricular assist system to be used for bridge-to-transplant patients.
W. L. Gore (Flagstaff, Arizona) said it received FDA approval to market the Gore Viatorr Endoprosthesis, an advanced technology, implantable device to treat portal hypertension in both de novo and revision Transjugular Intrahepatic Portosystemic Shunt (TIPS) procedures. The Viatorr Endoprosthesis is also indicated for the treatment of tracheobronchial strictures. The Gore Viatorr TIPS Endoprosthesis is a flexible, self-expanding, implantable endoprosthesis with a proprietary, reduced permeability expanded polytetrafluoroethylene graft lining. Featuring improved radial compression strength, the Viatorr is designed to provide secure anchoring with minimal kinking. The Viatorr TIPS Endoprosthesis is available in diameters of 8 mm, 10 mm and 12 mm, and its graft-lined length ranges from 4 cm to 8 cm. The endoprosthesis is delivered over a guidewire diameter of less than or equal to 0.038". Placement is via a 10 Fr introducer sheath.