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Safety of Contrast Agents in the Critically Ill

Safety of Contrast Agents in the Critically Ill

Ultrasound contrast agent safety in critically ill patients undergoing echocardiography has been questioned by the FDA. This controversy was the result of rare reports showing that deaths or life-threatening adverse reactions occurred in close proximity to the administration of ultrasound contrast agents. “Since these reports surfaced around 2007, many studies have been conducted to better define the safety profile of these agents,” says Michael L. Main, MD. An Observational Analysis In a large observational study published in JACC: Cardiovascular Imaging, Dr. Main and colleagues compared 48-hour all-cause mortalities and hospital stay mortalities among critically ill patients who underwent echocardiography either with or without an ultrasound contrast agent. Data were collected on more than a million participants through discharge information from a database that included information on primary and secondary diagnoses, procedure billing codes, and demographic and baseline patient information in addition to hospital characteristics. At discharge, more than 990,000 patients underwent echocardiography without a contrast agent, whereas 16,222 received a contrast agent for their exam. According to the results, ultrasound contrast agent use was associated with a 28% lower mortality rate at 48 hours among critically ill patients undergoing echocardiography when compared with no ultrasound contrast agent use. Recipients of ultrasound contrast agents also had significantly lower mortality rates over their entire hospital stay when compared with those who did not receive one (14.85% vs 15.66%). “Importantly, our findings were consistent across a wide variety of major comorbidities and important demographic subgroups, such as age and gender,” says Dr. Main. Overall, there were no groups with significantly greater odds for mortality after receiving a contrast agent. Impactful Findings Data...

Identifying Acute Aortic Dissection Patients

It has been estimated that 5,000 to 10,000 aortic dissections occur in patients each year in the United States, and nearly one-third of these individuals will die before hospital discharge. Despite recent advances in diagnostic tools and surgery, the tearing of the aorta can be challenging for even the most experienced cardiovascular specialists to diagnose. In 2010, the American Heart Association and American College of Cardiology released clinical guidelines—developed in collaboration with 10 professional societies—for the diagnosis and management of thoracic aortic disease, emphasizing high-risk clinical features that indicate the presence of acute aortic dissection (AAD). Validation of these risk markers had yet to occur until the results of a study by the University of Michigan Cardiovascular Center (UMCC) published in 2011 in Circulation, which suggested patients with certain characteristics were likely to be suffering from an aortic dissection. “Over the past 20 years, much progress has been made in various facets of thoracic aortic disease,” says Kim A. Eagle, MD, co-author of both the guidelines for thoracic aortic disease and the aforementioned UMCC study. “This includes a better understanding of the natural history of thoracic aortic disease and the potential genetic factors that may underlie some of the aortic problems of the thorax. There has also been an evolution of modern imaging techniques for more reliable and speedy diagnoses and follow-up. Furthermore, new strategies for both medical and interventional therapy have emerged.” (see also, Strategies for Managing Thoracic Aortic Disease With Surgery). When compared with coronary heart disease, hypertension, or heart failure, thoracic aortic diseases are rarer, and therefore, probably encountered by practitioners less frequently. “As a result,”...

Beta-Blockade: Minimizing Cardiac Risk During Non-Cardiac Surgery

An estimated 6 million people undergo non-cardiac surgery each year, and up to a quarter of these procedures (eg, major intra-abdominal, thoracic vascular, and orthopedic procedures) are associated with significant risk of perioperative cardiovascular morbidity and mortality. The American College of Cardiology Foundation (ACCF) and the American Heart Association (AHA) issued a practice guideline for the utilization of β-blockade in non-cardiac surgery. The update, published in the November 24, 2009 issue of Circulation and the Journal of the American College of Cardiology, identifies important new information regarding the risks and benefits of perioperative β-blockade. “Non-cardiac surgery represents a stress to the heart, particularly if the procedure is high risk or if patients have underlying risk factors for cardiac complications,” says Kirsten E. Fleischmann, MD, MPH, who chaired the committee that generated the focused update. As the aging population rises and the number of non-cardiac surgeries performed in them continues to increase, steps must be taken to minimize the risk of cardiac complications associated with these surgeries. Clinical Trial Evidence Drives Update Another impetus for the ACCF/AHA update was the publication of new randomized trial data, most notably the POISE (PeriOperative Ischemic Evaluation) and DECREASE (Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echocardiography)-IV trials. POISE confirmed that β-blocker therapy reduces perioperative cardiac events, but also clarified that routine perioperative β-blockade—particularly in fixed, higher-dose regimens initiated the day of surgery—was associated with risk. In POISE, the reduction in cardiac events was offset by a higher risk of stroke and death when using fixed higher-doses of metoprolol started on the day of surgery. The DECREASE-IV trial assigned intermediate cardiac risk patients to...
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