Improving Care for People With Coronary Artery Disease
Translating Research Into Practice
Improved health and life expectancy for people with heart disease ranks among the major achievements of modern medicine. The death rate from coronary artery disease—the major cause of heart attack—declined 29 percent from 1985 to 1995. Nevertheless, nearly 14 million Americans are affected with this disease and one dies about every minute from a coronary event.
Since 1989, the Agency for Health Care Policy and Research (AHCPR, now called the Agency for Healthcare Research and Quality), has supported over 200 studies on treatments for problems related to heart attack (also called myocardial infarction, or MI). Findings from AHRQ-funded research have led to changes by practitioners and other health system leaders in all aspects of care for patients with chest pain, confirmed heart attacks, and coronary artery disease.
Fostering Appropriate Treatment for Heart Attack
About 1.5 million Americans are admitted to hospitals yearly for serious chest pain, which is often a warning sign of heart attack. However, of those admitted to inpatient cardiac units, only 30 percent receive a diagnosis of threatened or confirmed MI. This means that 70 percent undergo an expensive evaluation before they know that they have not had a heart attack; this translates to more than $3 billion of unnecessary expenditures per year.
AHRQ (along with its predecessor, the National Center for Health Services Research) has a long history of funding research on the evaluation of patients with chest pain, which dates back to the 1970s. By seeding the initial research in this area, the Agency has enabled researchers to improve management of patients with chest pain.
Using chest pain observation units. AHRQ-funded investigators tested the effectiveness of locating a chest pain observation unit within the hospital's emergency department to treat patients with possible MI. Findings revealed that:
- Fewer heart attacks go undiagnosed in hospitals with these units than in comparison hospitals because fewer patients are mistakenly sent home without being observed.
- Hospital admission rates are reduced by 55 percent and average length of stay goes down by more than 25 percent when an exercise electrocardiogram (ECG) is added to the evaluation procedure used in the observation unit. Savings in total hospital costs are calculated at $567 per patient.
- Patients who receive treatment in chest pain units report being more satisfied with their care, compared to those admitted to inpatient cardiac units for observation.
Enhancing rapid diagnosis. Another AHRQ-funded study was able to improve rapid diagnosis and safely reduce inappropriate hospital admissions by developing a computerized instrument as an add-on to a standard ECG. By adding this tool to the emergency room evaluation of a patient with chest pain, a physician can quickly judge the probability that the heart is receiving inadequate oxygen. Results showed that use of this tool:
- Reduced hospital admissions for patients who had chest pain but no MI without reducing admissions for those who actually suffered a heart attack.
- Represented a potential savings of $728 million a year, or $100 for each emergency department visit for chest pain, without compromising care.
- Allowed physicians to determine more quickly which patients would benefit from immediate administration of cardiac drugs, which reduce complications and death when given very soon after MI.
Improving Care After Heart Attack
Twenty-seven percent of men and 44 percent of women die within a year after having a heart attack. Of those who initially survive, 23 percent of men and 31 percent of women will have another MI within 6 years.
Previous biomedical research on patients under age 75 has shown that use of aspirin, beta-blockers, and clot-busters prevents future MIs. However, two studies supported by AHRQ demonstrated the effectiveness of beta-blockers with older patients as well and led to increased appropriate use of these drugs. Findings showed that:
- A significant number of patients age 75 and older who had experienced a heart attack were not receiving beta-blockers even though these patients were 22 percent less likely to be hospitalized and 43 percent less likely to die from a future MI after receiving them.
- When consultations with local medical leaders were used to spread information about the drugs' benefits to other clinicians, appropriate use of beta-blockers increased by 63 percent.
Decreasing Risk of Future Heart Attack
Each year about 1 million Americans with coronary artery disease undergo a cardiac procedure to improve blood flow to the heart. Coronary artery bypass graft (CABG) surgery accounts for over half of these procedures. Complications and death from this increasingly common procedure are declining, in part because surgeons and hospitals that have been given feedback about their patients' health outcomes have subsequently undertaken specific quality improvement activities.
Two AHRQ studies examined the effects of this feedback in New York State by analyzing 4 years of publicly available data on CABG outcomes from the State's Cardiac Surgery Reporting System. Findings from the studies showed that:
- Deaths statewide from CABG surgery dropped a substantial 41 percent over the 1989-92 study period, even though the number of surgeries actually increased during that time.
- Lower mortality was associated with higher volume of CABG procedures for both the surgeons who performed them and for the hospitals where they were done.
- The dramatic drop in mortality was not due to shifting the sickest cases to the better performers but was found to be partly due to the exodus of surgeons who performed fewer procedures, partly to an influx of new, high-performing surgeons moving into the State, and partly to improved hospital policies for CABG surgery.
These studies have enabled decisionmakers to use CABG outcome measures with more confidence. Results of this research have influenced widespread and effective use of this strategy to improve health care quality.
Developing Research Tools and Data
AHRQ continues to fund investigations that provide hospitals and physicians with new tools to help them in their ongoing efforts to improve care for patients with heart disease. Among the current studies are the following:
- Development of performance indicators for treatment of heart disease. This project from Harvard Medical School, in cooperation with a number of health plans, will determine the usefulness of 95 new indicators of quality management for MI, congestive heart failure, and hypertension across several health care settings.
- Validation of guidelines for care of heart attack patients. This study is examining the extent to which national guidelines for care of MI patients undergoing bypass surgery were followed, and the relationship to cost and health outcomes.
- Race and gender differences in management of patients with heart disease. Recent AHCPR research has revealed distinct racial and gender biases in how physicians manage patients with chest pain.
Two projects are addressing aspects of the known problem of underestimation of heart disease risk for females and minorities. One study is investigating why cardiac tests and procedures that evaluate and treat coronary artery disease are used less often in African-Americans and women. Newly published findings from the other study that is exploring patterns of physician decisionmaking have shown there are distinct racial and gender biases in how physicians manage patients with chest pain.
Public and Private-Sector Initiatives
AHRQ-supported research has formed the basis for a number of public and private-sector care improvement initiatives.
- The American College of Cardiology and the American Heart Association have developed recommendations on the minimum number of CABG surgeries that can be performed by doctors and hospitals.
- Post-MI use of beta-blockers is one of the quality measures used by the National Committee on Quality Assurance to rate performance of managed care organizations.
- Beta-blocker administration is also a quality indicator for the 38 Medicare Peer Review Organizations participating in the Health Care Financing Administration's Cooperative Cardiovascular Project. Findings from a four-State pilot study showed that, after feedback to practitioners, use of beta-blockers improved from 7 to 68 percent; and, when used in conjunction with aspirin, deaths decreased by 10 percent. If the national proejct results in comparable improvements, the lives of 3,000 Medicare patients could be saved annually.
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