A mHealth intervention to reduce perceived stress in patients with ischemic heart disease: study protocol of the randomized, controlled confirmatory intervention "mStress-IHD" trial. - Lortz, Julia; Rassaf, Tienush; Jansen, Christoph; Knuschke, Ramtin; Schweda, Adam; Schnaubert, Lenka; Rammos, Christos; Köberlein-Neu, Juliane; Skoda, Eva-Maria; Teufel, Martin; Bäuerle, Alexander (Trials, 2023)