Evaluation of novel diagnostic and therapeutic tools to improve outcomes in patients with coronary artery disease

Abstract

It was the aim of the present thesis to evaluate novel diagnostic and therapeutic tools and to investigate their impact on outcomes in patients with stable coronary artery disease and ACS. Heart catheterization and ICA has revolutionized the minimally invasive therapy of coronary stenosis with stents rather than coronary bypass surgery. However, stents are associated with potential side effects and compliations and some trials challenged the pracitce of low threshold stenting. A haemodynamic assessment of the coronary lesion with FFR is an easy to use tool to tailor stents only to those patients who will finally benefit. The number of stents may indeed be reduced by FFR guided PCI – with an excellent long-term prognosis. Apart from invasive FFR measurement, also non-invasive tests like coronary computed tomography may be used to assess for relevant coronary stenoses. Interestingly enough, these non-invasive tests are not used according to current guideline recommendations in many cases or test results are ignored and patients are forwarded to ICA despite negative test results. As highlighted above, stents do carry potential risks and side effects. One of them is the need for dual antiplatelet therapy up to 12 months after DES implantation. In a meta-analysis it was demonstrated, that DEB do indeed offer a valuable alternative in de-novo coronary lesions. Outcomes were indeed slightly superior to bare metal stents, but inferior to DES. Coronary artery disease is still one of the major causes of death. Although mortality rates after STEMI could be reduced to 3% with contemporary primary percutaneous intervention if compared to 8% with thrombolysis therapy in the 1990ies , morbidity due to heart failure following STEMI is still unaccepably high. Treating the reperfusion injury after restoration of blood flow to the culprit vessel would be an appealing new strategy on top of PPCI. A pilot randomized clinical trial could demonstrate that remote ischaemic preconditioning by inducing transient upper limb ischaemia with a blood pressure cuff may indeed reduce the final infarct size, as assessed by cardiac MRI. Now larger trials with clinical endpoints are needed to confirm these preliminary results.

Ziel der Habilitationsschrift war neue diagnostische und therapeutische Werkzeuge und deren Einfluss auf die Prognose von Patienten mit stabiler KHK und ACS zu untersuchen. Die Herzkatheteruntersuchung ist heute ein Standardverfahren, doch auch die Implantation von Stents hat potentiell Nebenwirkungen. Um nur noch dort Stents zu implantieren, wo es wirklich erforderlich ist, kann die sogenannte FFR (fractional flow reserve) ermittelt werden. Bei Patienten mit erhöhtem Blutungsrisiko kann an Stelle von Stents auch eine Ballondilatation mit Medikamenten beschichteten Ballons erfolgen. Die Therapieresultate sind hier wohl schlechter als mit Medikamenten beschichteten Stents, aber auch nicht schlechter als mit unbeschichteten Stents. Eine einfache Möglichkeit um die Infarktgröße bei Patienten mit akutem ST Hebungsinfarkt zu verringern ist das sogenannte "Remote Ischämic preconditioning". Hierbei wird mit einer Blutdruckmanschette eine Ischämie im Oberarm induziert und somit werden aus der Oberarmmuskulatur protektive Wirkstoffe freigesetzt, die dann den Herzmuskel schützen sollen.