Ann Arbor, MI - Hospitals with greater specialization in primary PCI have shorter door-to-balloon times and lower in-hospital mortality in STEMI patients treated with the procedure, a new study shows [1].

Senior author Dr Harlan Krumholz (Yale University School of Medicine, New Haven, CT) said: "This study has direct policy implications for hospitals trying to decide what services to provide. It seems best to decide on a single approach to the care of MI patients and stick to it."

The study, published in the January 17, 2006, issue of Circulation, analyzed data from the US National Registry of Myocardial Infarction-4 on in-hospital mortality and times to treatment across different levels of hospital specialization for primary PCI.

The researchers, led by Dr Brahmajee Nallamothu (Ann Arbor VA Medical Center, MI), divided 463 hospitals into quartiles of specialization for primary PCI, defined as the relative proportion of reperfusion-treated patients who underwent primary PCI. They note that this is different from the overall number of STEMI patients treated or primary PCIs performed at a hospital (ie, hospital volume).

They found that the relative utilization of primary PCI over fibrinolytic therapy as a reperfusion strategy was directly related to the ability to provide primary PCI in an effective and timely manner, with in-hospital mortality among patients treated with primary PCI significantly lower in the hospitals in the highest quartile for primary PCI specialization, compared with those in the lowest quartile.

Adjusted door-to-balloon times and the likelihood of door-to-balloon times exceeding 90 minutes were also significantly lower in hospitals in the highest quartile for primary PCI specialization compared with those in the lowest quartile.

The researchers note that although earlier studies have evaluated the influence of primary PCI volume on clinical outcomes, none have specifically examined the effect of primary PCI specialization. They also point out that in their study the relation between primary PCI specialization and clinical outcomes was independent of primary PCI volume, with primary PCI specialization appearing equally important at low- and high-volume hospitals.

Nallamothu et al say their findings have important clinical implications for hospitals providing reperfusion therapy in the US. They suggest that when hospitals use both primary PCI and thrombolysis, times to treatment may be compromised because of confusion over which therapy to institute. "Hospitals that perform primary PCI may improve clinical outcomes by more exclusively committing to primary PCI as a reperfusion strategy," they write.

But they add that the ability to improve primary PCI specialization may be unattainable for some hospitals, given that substantial resources may be required to provide 24-hour availability. "Hospitals operating under this scenario may need to consider approaches for better coordinating the use of both types of reperfusion therapy, such as the development of explicit protocols to rapidly guide patients based on their risk and time of presentation," they conclude.

In an interview with heartwire, Krumholz explained that one of the reasons they did this study was because only one third of STEMI patients receiving primary PCI are treated within guideline targets and this does not seem to be improving. "We wanted to find out whether hospitals that can do both primary PCI or lysis should decide on a case-by-case basis which one would be preferable or whether they should pick one strategy and stick with it. And our results suggest the latter option is better.

"I think it turned out that way because hospitals that commit to one strategy can cut out the indecision and can execute that strategy faster. They know exactly what they are supposed to do and they just do it," he commented.

Krumholz believes it should be possible for hospitals to perform both primary PCI and lysis in an efficient way, but strict protocols need to be in place for different times of day. This may seem like common sense, but he says a surprising number of hospitals don't have such protocols in place. "This isn't a volume issue. It is a management issue.

"Everyone knows that we need to treat STEMI patients quickly, but quite often the system hasn't been optimized to make this happen. It doesn't matter what knowledge we gain if we can't implement it," he added.