Shares of Boston Scientific tumbled 6.67% in pre-market trading Wednesday, as the medical device maker’s cut to its full-year profit outlook and cautious commentary on its Watchman heart device business rattled investors.

The company lowered its 2026 adjusted earnings per share guidance to a range of $3.28 to $3.32, down from its prior view of $3.34 to $3.41 and below the FactSet consensus estimate of $3.36. Boston Scientific also trimmed its full-year organic sales growth forecast to 5% to 6%, from its previous expectation of 6.5% to 8%, citing softer-than-expected uptake of its Watchman implant used to prevent stroke-causing blood clots. The company said it expects flat Watchman revenue growth in the second and likely third quarter, as a decline in standalone procedures weighs on the business.

During a conference call, a Boston Scientific executive added that the company now expects the second half of 2026 to be more “pressured” than originally anticipated. The downbeat outlook overshadowed second-quarter results that topped analyst estimates, with adjusted earnings of 86 cents per share on revenue of $5.44 billion, both exceeding consensus.