An atrial septal defect (ASD) is one of the most common congenital heart defects in children and the most frequent congenital defect found in adults. Currently, several types of kits are available for percutaneous closure of ASD. The design of these implants is based on the Nitinol alloy. Despite the good biocompatibility of Nitinol alloys, the use of these materials for long-term implantation is questionable due to the high nickel content and the risk of releasing nickel ions as a result of corrosion in the body’s environment. A way to improve the hemocompatibility of Nitinol alloys is to modify their surface. As part of this work, the conditions for the production of SiO2 surface layers using the atomic layer deposition (ALD) method and laser surface modification with three different laser cutting speeds were developed to improve biocompatibility. This allowed us for the comparison of different surface modifications (ALD and laser modification) in terms of their impact on cell-material interactions. The general analysis concerning biocompatibility confirmed the biological usability of the designed ALD deposited coatings. Surface nanostructuring had a positive effect on the natural biological layer formation. The analysis performed indicated the appropriate behaviour of the natural biological layer, known in the literature as pseudointima, in contact with blood. It was evident that platelet activation on the surface was reduced.