Chicago, IL - Intensive medical treatment in elderly AMI patients, including use of beta blockers, can significantly boost overall population survival rates to a point where invasive strategies do not actually improve survival, a new study suggests.[1] Investigators say efforts should focus on using invasive clinical strategies in high-risk patients who are the most likely to benefit, while making sure that optimal medical therapies are prescribed across the board.

"For the vast majority of patients, these findings point to the need for caution about the routine use of cardiac technology in populations in which the marginal improvements may be small, when simpler, lower-cost, evidence-based medical alternatives exist," Dr Therese A Stukel (Dartmouth Medical School, Hanover, NH) and colleagues report in the March 15, 2005 issue of the Journal of the American Medical Association.

In an interview with heartwire, Stukel acknowledged that the study, which examined regional variations in use of medical and invasive therapies across the US, should hold a mirror up to physicians who are telling themselves that they are doing the right thing. The hardest part, she says, will be acknowledging that in some AMI patients, drug therapy alone may be all that's needed.

As a profession, we always want to do more, but doing more might mean just getting the drug therapy right.

"I think every physician truly wants to do the best thing for his or her patients, but when we look, as a group, at how we're practicing, and we find that we're not practicing optimally and that maybe we should be withholding certain services, that's a hard message to hear," Stukel suggested. "As a profession, we always want to do more, but doing more might mean just getting the drug therapy right."

The findings will no doubt produce rumblings of dissent from some corners of the medical community, where the debate over thrombolysis vs transferring patients to regional PCI centers in the setting of optimal medical therapy continues to simmer, as reported in a recent feature on www.theheart.org (see related links). Indeed, in a commentary accompanying Stukel et al's paper, Dr Saif S Rathore (Yale University, New Haven, CT) and colleagues voice their concerns over the "growing movement" supporting the treatment of ACS patients at regional centers.[2]

"As the article by Stukel and colleagues in this issue of JAMA suggests, treating ACS patients with high-quality medical care, which can be accomplished by all hospitals without additional facilities, may reduce the need for interventional procedures," Rathore et al write. "Also, focusing on the adoption of newer therapies ignores the fact that many inexpensive, readily available, established therapies remain underused in ACS patients."

Stukel et al's study set out to identify the health and policy implications of regional variations in the use of high-intensity invasive (defined as cardiac catheterization within 30 days) and medical management (defined as appropriate prescription of beta blockers at hospital discharge) in AMI patients. Using data from the Cooperative Cardiovascular Project (CCP), which included information on 158 831 elderly Medicare patients hospitalized with a confirmed AMI between 1994 and 1995, the investigators then followed the CCP cohort over seven years, assessing the relationship between survival rates, treatment intensity, and region.

"The most important study question was, if you have excellent rates of drug therapy, which we know work, what's the additional survival benefit of invasive treatment?" Stukel explained.

They found that across all regions, younger, healthier patients were more likely to receive invasive treatment and medical therapy. In regions with more-invasive practice styles, patients of all ages and risk levels were likely to undergo invasive procedures. In regions providing the highest rates of both appropriate medical therapy and invasive procedures, the absolute unadjusted seven-year survival rate was significantly higher than regions with the lowest rates of both therapies.

The investigators also analyzed the data according to quintiles of highest and lowest cardiac catheterization and beta-blocker prescription rates, over a mean follow-up of 3.6 years, for both STEMI and NSTEMI patients. They found that areas with the highest invasive-therapy rates and highest beta-blocker usage had similar overall survival rates to areas with high beta-blocker usage and low invasive therapy, meaning that invasive therapy offered no survival advantage over optimal medical therapy.

"The first point is, drug therapy works to improve survival; however, not all patients are getting it, only about 50%. That's not new to our paper," Stukel said. "The second point is, there is not good evidence that every AMI patient should be going down the road of invasive therapy, and what our paper showed was that in areas with more high-tech cardiac catheterization capacity, everybody was getting more invasive treatment."

Stukel knows the findings will be met with some opposition. "I know what the clinical-trial people will say," she told heartwire. "They'll say, we have several trials showing you that invasive therapy does work. And we're not disputing those findings, but we are saying that clinical trials operate under ideal conditions with ideal patients, and you don't get that in practice."

Clinical-trial participants will unfailingly also receive best medical therapy, so that trials comparing invasive therapy with conservative therapy will be performed on a background of optimal drugs.

"If you're giving invasive therapy to a larger, broader segment of the heart-attack population than what the clinical-trial evidence says, are you going to get that same survival benefit? The answer is no, for two reasons," she argues. "First of all, even in the best regions in our study, where they gave the best drug therapy, rates weren't 100%. The maximum was 75% to 80%, and the clinical trials usually have much higher rates than that. So one reason for reduced survival benefit is that we're not getting the full benefit of drug therapy. The other reason is, we're not choosing ideal patients, and we're not performing these invasive procedures at high-volume centers with experienced operators, with excellent time to catheterization."

She is quick to agree, however, that invasive therapy has a role. "We should be performing these procedures in the higher-risk patients. The ACC/AHA guidelines specify that it is the elderly, the high-risk, and the STEMI patients who should be getting this preferentially. So there are guidelines, but that's not how we're practicing."

Indeed, as Rathore et al point out in their commentary, none of the published studies examining transfer PCI strategies for AMI patients has evaluated the immediate transfer of patients with non-ST-elevation ACS from community-based hospitals to regional PCI centers. "Although non-ST-elevation ACS patients managed with an early invasive strategy instead of medical therapy had superior outcomes overall, this benefit was not observed in low-risk patients and may not be realized by a majority of patients with non-ST-elevation ACS," they write. No study has directly tested the hypothesis that routinely transferring these patients to obtain invasive treatment is superior to on-site management. Thus, the utility of transferring patients in this population is not clear."

Stukel points out that her study is not the first to question the effect of invasive procedures in a populationwide cohort, but it is one of the largest, with the most varied population. And while "one study is never enough" to change practice, she believes these new data should give physicians some pause for thought.

"This is less of a clinical study, telling physicians what they should do, than it is a picture of what they are doing, so they can ask themselves, is this what we want to be doing?"

Ultimately, she thinks change should come not from hospitals or from physicians in day-to-day practice, but from policy makers. As a start, she says, a revamped system could simply have "standing orders" that all AMI patients receive beta blockers, aspirin, and a statin, leaving physicians to override the order if need be.

Stukel and her coauthors also call for a "systems-minded approach" to delivering evidence-based medical management to AMI patients. As well, they write, "Because healthcare resources should be provided in such a way as to maximize clinical improvement and efficiency of Medicare spending, continuous large-scale population-based evaluations of the long-term community effectiveness of expensive, invasive cardiac technology must also be a national priority."

Systemwide changes will be key, Stukel elaborated to heartwire, given the difficulty of convincing physicians and their patients that, in some cases, less is more.

"It's hard to tell a physician to withhold a particular service, especially when you think that your patient is the exception to the rule. I think it's very hard for a physician to see a patient and say, there's not much I can do beyond what I'm doing. The patient may know there's a cardiac cath lab down the hall, and it's very difficult to tell him, we don't think that would work for you."