Diagnostics in the ER

Diagnostics Provide Critical Information in the ER: Saving Lives & Resources

Cardiovascular disease remains the leading cause of death in America , killing 700,000 people annually. Congestive heart failure (CHF) alone accounts for as much as three percent of all US health care expenditures. Like most diseases, early intervention is predictive of long-term survival, so it's important to get care at the first sign of a problem.

Yet, many people who enter the emergency department with chest pain or shortness of breath may be admitted to the hospital unnecessarily, costing the health care system more than $12 billion each year. Even worse, an estimated one of every 10 patients who truly are experiencing a heart attack or congestive heart failure are mistakenly sent home without treatment, increasing their risk of sudden death or heart damage and setting the hospital up for a potentially expensive lawsuit.

But today, two relatively new diagnostic tests are improving a physician's ability to correctly diagnose a heart attack or heart failure, saving lives, time and money.

New Diagnostics More Accurately Detect Deadly Heart Conditions

Since the 1970s heart attacks were ruled in or out using a diagnostic tool called CK-MB (creatine kinase-MB isoenzyme). An elevated CK-MB level in the blood could mean that the patient is having a heart attack—but it could mean other things as well. So when a new test arrived that was 100 percent cardiac specific, the medical community embraced it.

Troponin is a protein that is only found in cardiac tissue; its role is to manage the strength of the heart muscle. But when the muscle is injured—such as during a heart attack—Troponin is released from the heart into the bloodstream. Within four hours after cardiac injury, troponin levels in the blood will rise, and they will remain elevated as long as 10-14 days.

The troponin diagnostic tests are correct 99 percent of the time . In 2000, a joint consensus statement of the European and American Colleges of Cardiology re-defined the standard of care from CK-MB to a Troponin standard. Because the Troponin tests are much more sensitive, doctors miss fewer heart attacks; because they are more specific, doctors make fewer false diagnoses.

“The troponins are extraordinarily valuable to physicians because they allow us to determine injury to the heart with much greater accuracy”, said James L. Januzzi, MD, a cardiologist at Massachusetts General Hospital in Boston . “For just a couple of dollars, we have an accurate test that can help us recognize a patient's risk early, and exclude people who don't need to undergo an urgent catheterization. Also those who have had a heart attack may get more aggressive care earlier on, reducing their risk of another MI and saving money downstream—both for the patient and the system .”

Troponin is now the gold standard to rule in or out a heart attack and is associated with a $900 savings per patient. Now, new point-of-care troponin tests are providing ER personnel with an even faster tool to rule in or rule out a heart attack. These portable handheld devices can provide the critical information in 2-3 minutes, right by the patient's bedside.

Another new blood test is showing similar success in ruling in or out heart failure; it involves natriuretic peptides (BNP and NT-proBNP), cardiac hormones that are released into the blood due to the stress on the heart that accompanies CHF.

Until 2002, the tools available to help physicians diagnose CHF were the patient history, physical exam, and a chest X-ray. The history and physical are important, but not enough to exclude CHF; chest X-ray is insensitive and non-specific.

Two recent large studies looked at using BNP and NT-proBNP respectively to diagnose CHF in patients who came to the emergency department having trouble breathing. The research evaluated the success rates of ER doctors' diagnoses with and without using BNP or NT-proBNP in addition to their clinical evaluation. The studies showed that, when the doctors used the natriuretic peptide tests, they made correct diagnoses about 90 percent of the time; without these valuable tests they were correct only about 75 percent.

When the ER doctors weren't correct, they were often in the ballpark but they lacked the confidence to move forward on a heart-failure treatment path. If ER doctors cannot rule out heart failure, they might spend more time evaluating the patient with potentially unnecessary further testing, or even send the patient to a cardiologist when the actual diagnosis might be a lung problem such as pneumonia, wasting time for the patient to get the appropriate treatment.

Though BNP and NT-proBNP are not purely markers for CHF, their usefulness in detecting CHF is significant: Januzzi noted recent data demonstrating the importance of elevation in NT-proBNP as the single strongest predictor of death in patients with breathlessness. So an elevated BNP or NT-proBNP level leads to a faster, more accurate diagnosis than with the previous standard evaluations, which include an echocardiogram, heart work-up and/or catheterization. When physicians see a high reading for either BNP or NT-proBNP, they can more accurately diagnose CHF in a timely manner and more quickly prescribe ACE inhibitors or other medications proven to reduce the chance of death.

A BNP test costs about $15 and provides a faster diagnosis, and more confidence in excluding incorrect diagnoses. Fewer patients are admitted to the hospital unnecessarily, fewer unwarranted, expensive tests are ordered, and patients whose hearts are failing are quickly prescribed life-prolonging medications.

Ensuring Patient Access

According to a new report by The Lewin Group, Medicare reimbursement for new clinical laboratory tests is “archaic, impractical and severely flawed” and discourages the use and development of new tests. The authors found that Medicare often pays the same or less for a new test than an existing test, despite the fact that the new test may offer greater benefits to patients and physicians.

Congress must take action now to modernize the 20-year-old Medicare Clinical Laboratory Fee Schedule before patients and the health care system suffer.