Getting a crisp, clear picture of certain areas of the heart, particularly to find a blood clot in the left ventricle, can be a challenge. A new study provides guidance on when to use echocardiography contrast agents to improve those images.
Lantheus Medical Imaging (North Billerica, Massachusetts) reported results of a 600-patient study that reinforces the use and impact of its contrast agent, Definity, specifically in hospitalized and critically ill cardiac patients.
"This study found that physicians' ability to help patients was positively impacted by use of Definity," Mark Hibberd, MD, senior medical director for global medical affairs at Lantheus, told Cardiovascular Devices & Drugs. "In technically difficult cases, it improves clinical diagnoses, improves resource utilization and decision-making."
Up to 15% of routine echocardiograms have incomplete endocardial resolution. That figure reaches up to 30% for patients in the ICU. And although there are many studies on the benefits of contrast echocardiography to assess left ventricular function, very little data is available on the impact of contrast agents relative to patient management, which is what this study sought to accomplish.
The study results closely follow news that the American Society of Echocardiography (ASE; Morrisville, North Carolina) last fall issued a consensus statement on when and how ultrasound contrast agents should be used to enhance the diagnostic capability of ECG.
The new study, which appears in the Journal of the American College of Cardiology, was a prospective, single-center, cohort study of some 632 patients. It found the use of Definity in technically difficult cases improves endocardial visualization and significantly impacts cardiac diagnosis.
The study found that when contrast echocardiography was used, additional diagnostic procedures were avoided in 32.8% of patients and drug management was altered in 10.4%, with a total impact (procedures avoided, change in drugs, or both) observed in 35.6% of patients.
The patient population was recruited specifically from hospitalized patients and a significant portion of those were from the intensive care unit.
"The study found that Definity decreased the number of uninterpretable studies from 11.7% to 0.3% and the number of technically difficult studies decreased from 86.7% to 9.8%," Hibberd said. "In some cases, when you do an echo exam, depending on the clinical question, you can see clearly enough without contrast because echo windows are clear enough that answer the questions being asked by doctor. However, there are roughly 20%, by published estimates, of echo studies that don't provide clear crisp images. In those situations it's not possible to be confident about results."
Hibberd explained that physicians often don't know that they'll have a difficult time until the echo test gets under way. But there are categories of patients for which you can predict the need for contrast, such as patients with lung disease, chest wall deformities and for those who are obese.
"Another situation where you could often expect to have to use contrast is in the ICU setting because when an echo study is done, you need patients' cooperation to roll around," he said. "In the ICU, you can't do that with patients, so you just have to take images as is and they are quite poor without contrast."
A technically difficult study was defined as a one in which greater than two myocardial segments were not visualized at baseline from any imaging window. Quality of the studies, number of left ventricular (LV) segments visualized, estimated left ventricular ejection fraction (LVEF), the presence, absence or suspicion of apical thrombus and management decisions were compared before and after contrast in the study.
Since its launch in 2001, Definity has been used in more than 2 million patients. The current study may be the largest to evaluate use of contrast in this particular indication.
"Most of these studies are much smaller because the coordination involved in speaking with the many referring physicians is a great challenge," Hibberd said.
He said that results of another ongoing study started in 2008, Contrast Echocardiography REgistry for Safety Surveillance (CaRES), are due to be published next month. CaRES is a1,000-patient, multi-center, Phase IV observational registry that will further evaluate the safety profile of Definity.
"It's close to completion and I can say, as an interim evaluation, we're very pleased with the safety profile in this registry," Hibberd said.
Elsewhere in the product pipeline:
• Results from the PROTECT I trial evaluating the feasibility and effectiveness of the Abiomed (Danvers, Massachusetts) Impella 2.5 circulatory assist device in high-risk percutaneous coronary intervention (PCI) procedures have been published in the February issue of the Journal of the American College of Cardiology (JACC). The study concludes that "The Impella 2.5 system is safe, easy to use, and provides excellent hemodynamic support during high-risk PCI [percutaneous coronary intervention]." The Impella is inserted percutaneously in the catheterization lab (cath lab) via the femoral artery into the left ventricle. Up to 2.5 liters of blood per minute is delivered by the pump from the left ventricle into the ascending aorta, providing the heart with active support in critical situations.
• GE Global Research (Niskayuna, New York) said they have developed sophisticated signal processing algorithms for a wireless sensor that can classify different types of motion and closely monitor a person's breathing and heart rate. The company says this type of sensor could have advantages in monitoring premature babies in a neonatal intensive care unit (NICU). Premature infants have very sensitive and fragile skin, which can make it difficult to directly attach sensors to them. GE's new sensor could wirelessly monitor an infant's movements, including breathing and heart rate. Similarly, this sensor could be installed in a home for elder care or other outpatient monitoring.
• Immersion (San Jose, California) said it has introduced a product to accurately and efficiently train pulmonologists and thoracic surgeons on a breakthrough emerging procedure for diagnosing and staging lung cancer. This new module, Endobronchial Ultrasound with Transbronchial Needle Aspiration (EBUS-TBNA) provides realistic multi-modal (sight, sound, and touch) virtual reality training for this difficult but highly accurate procedure that diagnoses and stages lung cancer, the cause of the most cancer deaths worldwide. Immersion says it is the first and only haptic-enabled endoscopy simulator designed for EBUS-TBNA.
• InterCure (New York) said that its RESPeRATE hypertension treatment device, clinically-proven to significantly lower blood pressure, will be sold in more than 800 Rite Aid retail stores throughout the West Coast. The company says that RESPeRATE is the only medical device on the market clinically proven to lower blood pressure through paced breathing therapy. The device uses the body's natural tendency to follow external rhythms, interactively guiding the user to effortlessly reduce their breathing rate to a "therapeutic zone" of less than 10 breaths per minute. The breathing exercises with RESPeRATE relax the constricted muscles surrounding the small blood vessels, allowing the blood to flow more freely and yielding a significant and lasting reduction of blood pressure within weeks.
• Itamar Medical (Caesarea, Israel) reported the use of the company's Endo-PAT2000 in the Carolinas HealthCare System's study of the potential benefits of flavonoid supplementation on endothelial function. The Endo-PAT2000 was used to measure participants' endothelial function in a study designed to evaluate how flavonoid supplementation can prevent the adverse impact on endothelial function caused by a high-fat meal. Study results indicate that flavonoid supplementation can reduce the acute impairment of endothelial function caused by a high-fat meal, adding to the growing medical literature on the long-term benefits of flavonoid supplementation on endothelial dysfunction and cardiac health.
• Paieon (Wynnewood, Pennsylvania) reported FDA approval of its Guidance application. The Guidance application is now available as part of the second generation of the IC-PRO, an imaging workstation that supports the interventional cardiologist in all phases of the catheterization procedure. The Guidance application is a navigation system that is used in interventional cardiology procedures. Paieon says the Guidance application allows the user to take advantage of the existing captured images and add a new dimension of planning a roadmap and navigating the device to the desired location. After device selection and determination of its optimal position, the procedure roadmap is ready and the device can be inserted and advanced. Under fluoroscopy, the system detects the device and presents its position in relation to the roadmap. Once the device has reached its predetermined position, the Guidance indicates "Device in Position" and the physician can proceed with deployment of the delivered device.
• Oridion Systems (Needham, Massachusetts) reported FDA clearance for the Capnostream 20 Monitor with Integrated Pulmonary Index. The Integrated Pulmonary Index uses sophisticated algorithms to integrate the real time measures and interactions of four complex parameters end tidal CO2 (EtCO2), respiration rate, pulse rate and SpO2 (oxygen saturation) into a single index value. The result is displayed on a scale from 1-10, where 10 indicates optimal pulmonary status. The company claims that by using the Integrated Pulmonary Index, clinicians can quickly and easily assess a patient's ventilation status and monitor a patient's changing condition, thus facilitating more timely interventions to reduce patient risk and improve outcomes.
• Terumo Heart (Ann Arbor, Michigan) said that New York-Presbyterian Hospital/Columbia University Medical Center recently became the second U.S. center, and first in the Northeast, to implant the DuraHeart Left-Ventricular Assist System (LVAS) as part of the DuraHeart Bridge-To-Transplant U.S. pivotal trial. The trial will evaluate the safety and efficacy of the device in helping to sustain patients awaiting heart transplant who are at risk of death due to end-state left ventricular failure. The DuraHeart System features a small pump that is implanted in a pocket created in the abdomen. When the pump is activated, the impeller position is precisely controlled by the electromagnets and sensors to keep it centered within the blood chamber. Permanent magnets couple the impeller to the motor so when the motor spins, it causes the impeller to rotate and pump blood from the heart to the body. In its weakened state, the heart is not strong enough to supply sufficient blood for normal activities. The DuraHeart supplements the natural flow by pumping blood from the left ventricle to the aorta, increasing total flow to normal levels.