Last month, the FDA approved Boston Scientific’s Promus Element Heart Stent, a tiny tubular device designed to open diseased arteries. Interestingly, the agency issued its approval of the device, even after receiving reports that the stent could potentially become deformed after it is implanted.

The problem, officially known as longitudinal stent deformation, also occurs in similar devices manufactured by competitors like Medtronic and Abbott Labs, but the largest number of reported issues are linked to Boston Scientific’s product.

Given the issues associated with the Promus Element stent, the FDA has required that Boston Scientific include a section about longitudinal compression on the device’s 20-page instruction label. The company must describe the exact problem with the stent, discuss situations where the problem occurs more often, provide guidance and also suggest techniques that could minimize the onset of adverse events. Despite the fact competing devices often have the same issues with deformation, the FDA did not require Abbott Labs or Medtronic to outline similar precautions for their stents.

Boston Scientific is currently the largest manufacturer of stents, with more than a third of the $4 billion global market. Problems with the Promus Element, the company’s basis for future generations of heart stents, could spell big trouble for Boston Scientific.