Stroke Monitoring Inhibits Recurring Events

Stroke ranks as the third leading cause of death and the leading cause of serious long-term disabilities in the U.S., according to the American Heart Association (AHA). Direct and indirect costs of stroke were $40.9 billion in 2007, with ischemic stroke having an individual lifetime cost of about $140,000. With the development of acute stroke centers, outcomes are improving for patients. By monitoring for stroke risk factors, such as atrial fibrillation, neurologists now can intervene before a second stroke occurs.

Where to admit?

While stroke patients often are hard to monitor and manage, many argue that which hospital unit takes care of these patients could drastically impact outcomes, particularly in detecting cardiac abnormalities.

In 2003, Geert A. Sulter, MD, a neurologist at Academic Hospital Groningen in Groningen, The Netherlands, and colleagues confirmed in a pilot study what many stroke specialists had reported anecdotally: Patients with a diagnosis of acute ischemic stroke who were admitted to a stroke-care monitoring unit had better outcomes than patients placed in a conventional stroke unit (Stroke 2003;34:101-104). Patients in the monitoring unit were continuously monitored for at least 48 hours for body temperature, oxygen saturation, blood pressure and cardiac rhythm using a five-lead electrocardiogram to allow immediate intervention, if indicated. In the conventional stroke unit, measurements were taken manually four times a day. The researchers found that cardiac monitoring detected newly diagnosed atrial fibrillation (AF) in 18 percent of patients in the stroke-care monitoring unit compared with only 3 percent of patients in the conventional stroke unit.

Also in 2003, Michael J. Schneck, MD, director of the neuro-intensive care program at Loyola University Health System in Maywood, Ill., was helping to establish a stroke unit at the suburban Chicago hospital using the Brain Attack Coalition's published recommendations as a blueprint (JAMA 2000;283:3102-3109). To justify adding comprehensive monitoring to Loyola's program, he and colleagues designed a study based on data on 337 stroke patients between 2003 and 2004 to determine what additional information is gained through telemetry.

"I felt strongly that stroke patients might have undetected cardiac abnormalities," Schneck says. "We found that roughly 20 percent of the patients who came in had an abnormal rhythm, which was either undetected or different from the reading when they were admitted."

Making monitoring mainstream

Those who survive an initial stoke are at high risk of recurrence, with 5 to 12 percent of patients likely to experience a second stroke within a year. AF is considered a significant risk factor for a second stroke, making detection and management of arrhythmias critical to short- and long-term survival.

In 2005, the Brain Attack Coalition added continuous cardiac and respiratory monitoring to its updated recommendations, based on Sulter et al's findings. Loyola's Stroke Center now provides continuous monitoring with telemetry for virtually all stroke patients, and has been certified by the Joint Commission as a Primary Stroke Center (PSC). The Brain Attack Coalition estimates there are 700 Joint Commission-accredited PSCs across the U.S., and another 200 hospitals with state-certified PSCs (Stroke 2010;41;1100-1101).

Risk Factors for Ischemic Stroke & Systemic
Embolism in Patients With Nonvalvular Atrial Fibrillation
Risk FactorsRelative Risk
Previous stroke or TIA*2.5
Diabetes mellitus1.7
History of hypertension1.6
Heart failure1.4
Advanced age (continuous, per decade)1.4
Data derived from collaborative analysis of five untreated control
groups in primary prevention trials. As a group, patients with
nonvalvular atrial fibrillation (AF) carry about a six-fold increased
risk of thromboembolism compared with patients in sinus rhythm.
Relative risk refers to comparison of patients with AF to patients
without these risk factors.
*TIA indicates transient ischemic attack.
Continuous monitoring allows neurologists to pick up transient cardiac abnormalities that otherwise could go undetected. Patients receive an electrocardiogram at admission, but unless a condition such as AF or atrial flutter is present at that time, it will not be recorded. Also, asymptomatic patients may develop arrhythmia during their hospitalization. If identified, the condition can be appropriately treated with anticoagulants, such as warfarin or dabigatran (Pradaxa, Boehringer Ingelheim). If undetected, the patient could continue treatment, such as aspirin, which may increase the chance of a second stroke.

"The major value of cardiac monitoring is to detect patients who have atrial fibrillation," says Piero Verro, MD, director of the University of California, Davis Medical Center's Stroke Program, which is a certified PSC. "The prophylactic treatment is very different for patients who have AF as opposed to atherosclerotic-type strokes. It is important to pick it up because it changes your management significantly."

Verro estimates that monitoring may detect AF in 5 to 10 percent of stroke patients in the stroke unit. "It is relatively small," he says, "but for that 10 percent, it makes a big difference."

'Brain-heart connection'

Neurologists emphasize that not only is AF a risk factor for stroke, but stroke is also a risk factor for heart disease. "When patients are having a stroke, particularly if it affects certain parts of the brain, it puts them at higher risk of cardiac arrhythmias," explains Jennifer J. Majersik, MD, director of the Stroke Center at University of Utah Health Care in Salt Lake City, which also is a certified PSC.

"There is a brain-heart connection that affects rhythm," Majersik says. "We like to monitor both at the same time because it is a complex situation."

At the Utah Stroke Center, monitoring is continuous throughout the inpatient stay. With the help of telemetry, neurologists concentrate on treatment, the prevention of complications and then determine appropriate rehabilitation. But just as important, she says, is identifying a cause for the first stroke to initiate preventive measures to lessen the chances of a second stroke. If they can't pinpoint a cause at discharge, then they send the patient home with a Holter ambulatory monitor for up to one month.

While stroke remains a serious health problem, the actual number of stroke deaths declined almost 15 percent between 1997 and 2007. The AHA attributes this decline in part to improvements in acute stroke care.

Scientific evidence is in the favor of PSCs as well. While small studies, such as Sulter et al's, have shown better outcomes for patients followed to discharge, a recent large-scale observational study from Finland is pointing to longer term benefits.

Atte Meretoja, MD, a neurologist at Helsinki University Hospital in Finland, and colleagues found that patients who were treated at PSCs that met the Brain Attack Coalition's standards fared much better than patients treated at a general hospital. Patients were 11 percent less likely to die, 11 percent less likely to require institutional care and 16 percent more likely to live at home one year after their stroke (Stroke 2010;41:1102-1107).

Monitoring is one of many recommendations  by the Brain Attack Coalition that may contribute to recent gains, but it potentially adds costs. In addition to the expense of the bedside telemetry, hospitals pay for staff to run remote stations and track data. But given the burden a second stroke might put on the patient, his or her family and the healthcare system, the costs are minor.

"The cost-benefit ratio, in my estimation, is well worth it," says Verro.
Candace Stuart, Contributor

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