Advancing medical devices for novel image-guided percutaneous cardiac interventions

Heart failure is a complex clinical syndrome, progressive in nature, and about half of patients who develop heart failure die within 5 years of diagnosis. This is a significant economic and healthcare burden that drives the need for novel and optimized cardiovascular treatment strategies. Current treatment strategies focus on prevention of further left ventricle (LV) deterioration and/or improvement of LV function, symptom relief, and prolongation of life. The complexity of cardiac interventions has increased due to technological development and the shift from complex surgical procedures to less invasive transcatheter-based procedures in combination with the rapid introduction of novel medical technology in clinical practice. A major focus to optimize the current cardiovascular treatment strategies has been hybrid imaging (HI). HI integrates multiple imaging modalities to provide visualization of the organs and soft tissues during the intervention.
This thesis describes the development of a new 3D navigation technique based on HI for image-guided cardiac interventions. From bench to bedside we have developed the imaging technology, designed the testing methods, and performed the (pre-)clinical studies to assess its accuracy and clinical safety and feasibility. The development of the navigation technique required a novel, standardized, and reproducible whole-heart myocardial tissue processing method to perform validation of the targeting accuracy of intramyocardial injections. The protocol enables a detailed assessment of the cardiac anatomy and pathology and the intramyocardial injections in both 2D and 3D.
Using the targeting accuracy validation protocol we demonstrated that the technology enables intramyocardial injections to be accurately guided towards predetermined target zones. Intramyocardial injection procedures were performed significantly faster compared to the clinical standard for intramyocardial injections. Since the technology uses the standard X-ray modality, procedures used significantly more fluoroscopy but was similar to an average percutaneous coronary intervention. Subsequently, the safety and feasibility of the technology was demonstrated in a first-in-man study, to provide per-procedural visualization of optimal pacing sites and image-guided LV lead placement during implantation of a cardiac resynchronization therapy device. We found similar CRT implant and fluoroscopy times compared to a historical cohort. Moreover, all LV leads were guided close to the target area, away from the myocardial scar and the course of the phrenic nerve.
In addition, we have gained novel clinical insights from pre-clinical voltage mapping. We developed a novel method to predict the presence of scar, as defined by gold standard scar identification, by a statistical prediction model which uses multivariate mixed model logistic regression based on multiple electromechanical-parameters. We showed that our model has a strong predictive ability for the presence of myocardial scar. The comparison of feature tracking derived strain parameters to electromechanical-derived parameters of local mechanical activity revealed only weak correlations.
All technologies were aimed at improving treatment planning, visualization, and guidance of complex cardiac interventions. The development steps described in this thesis accentuate how a medical technology specialist can be of importance for the clinical translation of medical technology. HI technology is an important technique in the growing need for optimization of complex cardiovascular interventions of heart failure patients.