Less may be more for mild heart attack
Study: Re-examine those reflex caths
Routine aggressive surgeries - bypass or angioplasty -immediately follow about half of the myocardial infarctions (MIs) in the United States. But there's new evidence that such hasty decisions may cause yet more heart attacks and even death.
Researchers from the U.S. Department of Veterans Affairs (VA) Cooperative Studies Program have confirmed initial findings of no clear benefit, and perhaps harm, from the aggressive, invasive treatment of uncomplicated MI patients. Publication of their study in June fuels the debate initiated by the group's presentation at last year's American College of Cardiology (ACC) meeting.1 (See a preliminary brief report of this finding in the May 1997 issue of Cost Management in Cardiac Care as it was announced at the ACC's 46th annual meeting in Anaheim, CA.) In publishing the results, lead author William E. Boden, MD, chief of medical service at the VA Upstate New York Health Care Systems in Syracuse, encourages cardiologists and clinicians to re-examine what is often a reflex of routinely catheterizing all non-Q-wave patients.
He says physicians should not do invasive procedures immediately post-MI, but selectively and later, when the patients are stable. "The results [of our study] should not be interpreted as 'anti-interventional,' since it's clear that [overall] clinical outcomes following angioplasty were comparable to those achieved with an initial, conservative, ischemia-guided strategy," he writes. "In fact, the rate of death or recurrent heart attack was two to three times higher [in aggressively treated patients] than in patients managed conservatively during the first month after an acute non-Q-wave MI," said Boden. He and his colleagues found that patients who underwent invasive catheterization and revascularization had significantly worse outcomes throughout the first year of follow-up than others treated with noninvasive radionuclide ventriculogram, predischarge thallium stress testing, medical therapy, and watchful waiting.
VANQWISH outcomes surprised the investigators as well as ACC members who heard them reported. Most expected similar, not more harmful, results from routine, early coronary angiography followed by myocardial revascularization. What they saw was a threefold higher mortality rate at the nine-day mark in patients managed aggressively compared to those managed conservatively. The one-month mortality rate was 34% higher among those aggressively managed.
The study results apply only to patients without recurrent angina, heart failure, or markedly abnormal stress tests. According to the investigators, heart attack management has become increasingly aggressive during the past 10 years. Non-Q-wave MIs affect 750,000 Americans a year.
"While it's clear that some patients may be at high risk and benefit from early intervention, the great majority [90%] stabilize with intensive medical therapy over the short term," said Boden. Patients stable at time of transfer from the coronary care unit fall into that category.
Investigators at 15 VA Medical Centers identified nearly 3,000 moderate- to high-risk patients with non-Q MI. After excluding patients with severe concomitant disease, half remained eligible, of whom about 900 agreed to randomization. The VA team compared both early and late outcomes - death or recurrent MI - to the half assigned to early invasive strategy and the half who received early conservative strategy. Patients were followed for 12 months.
Investigators found 152 cardiac events in the invasive arm and 139 in the conservative arm. Those were not statistically significant, but in the invasive group there were more deaths - 21 as compared to six - at discharge, 23 vs. nine deaths at one month, and 58 vs. 36 deaths at one year. The authors conclude that a routine early invasive strategy in non-Q MI worsens short-term outcome.
Reference
1. Boden WE, O'Rourke RA, Crawford MH, et al, for the Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) Trial Investigators. Outcomes in patients with acute non-Q-wave myocardial infarction randomly assigned to an invasive as compared with a conservative management strategy. N Engl J Med 1998;338:1785-92.
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