Boston Scientific (NYSE:BSX) released positive results from a clinical trial testing its heart devices, but unfortunately the data is likely to help its competitors as well.

The trial pitted traditional implantable cardioverter defibrillators (ICDs) -- devices that treat abnormal heart rhythms -- with newer, more expensive ones that include a cardiac resynchronization therapy function (CRT-Ds). That function makes sure the heart's ventricles are in synch and is usually reserved for patients with more advanced heart problems. In the study, patients treated with the CRT-Ds had a 29% reduction in death compared to those treated with just ICDs. More importantly, the trial was done with patients suffering from earlier stages of heart failure, patients where the more expensive CRT-D devices aren't routinely used.

Unfortunately, that's where the good news ends.

Unlike Intuitive Surgical (NASDAQ:ISRG) -- where improved results from robot-assisted surgery help only Intuitive Surgical -- Boston Scientific has significant competitors in the ICD market, which includes CRT-Ds. Doctors are likely to extend the findings from Boston Scientific's products to all CRT-Ds, which will help other makers of CRT-Ds, such as Medtronic (NYSE:MDT) and St. Jude Medical (NYSE:STJ). In fact, the results may help St. Jude more than Boston Scientific, because the $394 million in sales of ICDs at St. Jude made up nearly 35% of sales in the first quarter, compared to the $444 million at Boston Scientific, about 22% of total sales.

The reason for the study is obvious: According to Boston Scientific, 70% of the about 5.5 million Americans suffering from some form of heart failure are in the earlier stages, those stages tested in the clinical trial. Thus there are plenty of patients to go around.

It's just unfortunate that the trial results will also likely help its competitors, but Boston Scientific should be able to make up the cost of the trial and then some if it can expand the patient base for CRT-Ds.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. The Fool has a disclosure policy.