Location Matters: Getting Acute MI Care at a High-Quality Hospital Has Lasting Benefits

Medicare beneficiaries treated for acute MI in the mid-1990s enjoyed a longer life expectancy if they were admitted to hospitals that achieved the lowest 30-day mortality rates, even after accounting for differences in case mix across centers, a new analysis shows. The survival advantage appeared early on and did not disappear over time.

Patients treated at high-performing hospitals lived roughly 9 to 14 months longer than those admitted to centers with poorer 30-day mortality rates, researchers led by Emily Bucholz, MD, PhD (Boston Children’s Hospital, MA), report in a study published in the October 6, 2016, issue of the New England Journal of Medicine.

Although 30-day mortality has been used extensively as a metric to judge and compare hospital performance, it had been unknown whether differences across centers in terms of early outcomes were associated with long-term survival after acute MI, Bucholz told TCTMD.

“Where you go really does matter, both for the short term and for the long term,” she said. “High-performing hospitals aren’t just keeping patients alive in the short term. They’re doing great in that regard, but they’re also keeping patients who otherwise may have died healthier over the long term.”

Commenting for TCTMD, Robert Yeh, MD (Beth Israel Deaconess Medical Center, Boston, MA), said the study “is a really important demonstration of the meaningfulness of short-term mortality outcomes in hospitals.”

It’s not always completely understood what high-performing hospitals are doing to improve outcomes for their patients, he said. “We should really work hard to understand . . . what’s the sort of special sauce of what they’re doing that makes them perform better.”

Consistent Findings Across Levels of Expected Risk

Bucholz and colleagues looked at data from the Cooperative Cardiovascular Project, a quality improvement initiative of the Health Care Financing Administration (now the Centers for Medicare & Medicaid Services). The analysis included 119,735 Medicare beneficiaries who were hospitalized for acute MI between 1994 and 1996 and had 17 years of follow-up.

The investigators first divided the patients into five groups based on expected mortality at the treating hospitals in order to compare centers with similar case mixes. Within each case-mix stratum, hospitals were further divided into quintiles defined according to risk-standardized 30-day mortality rates. High-performing hospitals had the lowest mortality rates.

Regardless of case mix, patients admitted to high-performing hospitals had improved survival compared with those treated at low-performing hospitals, with the curves separating within the first 30 days and remaining parallel through the duration of follow-up. Estimated life expectancy fell as risk-standardized mortality at the hospital level rose.

In an analysis of patients who survived to 30 days, life expectancy did not differ according to hospital performance, a finding that was consistent across case-mix strata.

“If hospitals with low 30-day risk-standardized mortality rates achieved lower-than-expected mortality by forestalling death for the first 30 days, we might expect higher long-term mortality rates and thus shorter life expectancy in 30-day survivors,” the authors say. “Instead, our findings showed that patients treated at high-performing hospitals who survived the period of acute illness did not lose that advantage.”

“Alternatively, if high-performing hospitals admitted patients with lower risk than what was captured by the risk model, we would expect the survival curves to continue to diverge,” they continue. “The fact that the survival curves remain parallel after the first 30 days suggests that the association of early hospital performance with outcomes is the result of quality differences and not residual confounding.”

Culture of High-Performing Centers

When asked what centers with the lowest mortality rates are doing right, Bucholz pointed to previous studies attributing the benefits to an overall hospital culture that encourages communication across providers and a devotion to improving quality of care “rather than simply checking boxes to try to get people through.”

The study, she said, “shows that it’s really important to continue to try to invest in initiatives to improve short-term hospital performance because it not only improves the short-term outcomes but also long-term patient survival and outcomes.”

The benefits derived from being admitted to a high-performing center could be related to greater use of guideline-directed therapies, more appropriate care, or more timely treatment, Yeh said, noting that prior studies have shown that the top hospitals generally do better across various metrics of quality of care.

“If we believe fundamentally that these hospitals really are performing better, that we’ve adequately adjusted for the differences in patient characteristics . . . then what is it that they’re doing and how do we disseminate that information and make it so hospitals that aren’t doing quite as well can really step up their game and perform in a way that’s more commensurate with what these high-performing hospitals are doing?” Yeh asked.

If that can be figured out, he said, then “that would really lead to meaningful public health improvements and long-term survival benefits for patients across the country.”

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