Optimisation of cardiac resynchronisation therapy device selection guided by cardiac magnetic resonance imaging: Cost-effectiveness analysis.

BACKGROUND: A recent study showed that the presence and characteristics of myocardial scar could independently predict appropriate implantable cardioverter-defibrillator therapies and the risk of sudden cardiac death in patients receiving a de novo cardiac resynchronisation device. DESIGN: The aim was to evaluate the cost-effectiveness of cardiac magnetic resonance imaging-based algorithms versus clinical practice in the decision-making process for the implantation of a cardiac resynchronisation device pacemaker versus cardiac resynchronisation device implantable cardioverter-defibrillator device in heart failure patients with indication for cardiac resynchronisation therapy. METHODS: An incidental Markov model was developed to simulate the lifetime progression of a heart failure patient cohort. Key health variables included in the model were New York Heart Association functional class, hospitalisations, sudden cardiac death and total mortality. The analysis was done from the healthcare system perspective. Costs (€2017), survival and quality-adjusted life years were assessed. RESULTS: At 5-year follow-up, algorithm I reduced mortality by 39% in patients with a cardiac resynchronisation device pacemaker who were underprotected due to misclassification by clinical protocol. This approach had the highest quality-adjusted life years (algorithm I 3.257 quality-adjusted life years; algorithm II 3.196 quality-adjusted life years; clinical protocol 3.167 quality-adjusted life years) and the lowest lifetime costs per patient (€20,960, €22,319 and €28,447, respectively). Algorithm I would improve results for three subgroups: non-ischaemic, New York Heart Association class III-IV and ≥65 years old. Furthermore, implementing this approach could generate an estimated €702 million in health system savings annually in European Society of Cardiology countries. CONCLUSION: The application of cardiac magnetic resonance imaging-based algorithms could improve survival and quality-adjusted life years at a lower cost than current clinical practice (dominant strategy) used for assigning cardiac resynchronisation device pacemakers and cardiac resynchronisation device implantable cardioverter-defibrillators to heart failure patients.

Real-Time X-MRI-Guided Left Ventricular Lead Implantation for Targeted Delivery of Cardiac Resynchronization Therapy.

OBJECTIVES: This study sought to test the feasibility of a purpose-built, integrated software platform to process, analyze, and overlay cardiac magnetic resonance (CMR) data in real time within a combined cardiac catheter laboratory and magnetic resonance imaging scanner suite (X-MRI) to guide left ventricular (LV) lead implantation. BACKGROUND: Suboptimal LV lead position is a major determinant of poor cardiac resynchronization therapy (CRT) response, and the optimal site is highly patient specific. Pacing myocardial scar is associated with poorer outcomes; conversely, targeting latest mechanical activation (LMA) may improve them. METHODS: Fourteen patients (age 74 ± 5.1 years; New York Heart Association functional class: 2.7 ± 0.4; 86% ischemic with ejection fraction 27 ± 7.6%; QRSd: 157 ± 19 ms) underwent CMR followed by immediate CRT implantation using derived scar and dyssynchrony data, overlaid onto fluoroscopy in an X-MRI suite. Rapid LV segmentation enabled detailed scar quantification, identification of LMA segments, and selection of myocardial targets. At coronary venography, the CMR-derived 3-dimensional shell was fused, enabling identification of viable venous targets subtended by target segments for LV lead placement. RESULTS: The platform was successful in all 14 patients, of whom 10 (71%) were paced in pre-procedurally defined target segments. Pacing in CMR-defined target segments (out of scar) showed a significant decrease in the LV capture threshold (mean difference: 2.4 [1.5 to 3.2]; p < 0.001) and shorter paced QRS duration (mean difference: 25 [15 to 34]; p < 0.001) compared with pacing in areas of CMR determined scar. In 5 (36%) patients with extensive scar in the posterolateral wall, CMR guidance enabled successful lead delivery in an alternative anatomically favorable site. Radiation dose and implant times were similar to historical controls (p = NS). CONCLUSIONS: Real-time CMR-guided LV lead placement is feasible and achievable in a single clinical setting and may prove helpful to preferentially select sites for LV lead placement.

Device-based impedance measurement is a useful and accurate tool for direct assessment of intrathoracic fluid accumulation in heart failure.

AIMS: Heart failure patients are often equipped with implanted devices and are frequently hospitalized due to volume overload. Reliable prediction of imminent fluid congestion has the potential to provide early detection of cardiac decompensation and therefore might be capable of enhancing therapy management. We investigated whether implant-based impedance (Z) measurement is closely correlated with directly assessed extravascular lung water and might thus be useful for patient monitoring. METHODS AND RESULTS: In sheep, pulmonary fluid congestion was induced. Continuous haemodynamic monitoring was performed and extravascular lung water index (EVLWI) assessed. An implanted device with a right ventricular lead measured Z using different electrode configurations. All animals developed gradual pulmonary fluid accumulation leading to inclining lung oedema: EVLWI did increase from 9.5 +/- 1 to 21.1 +/- 5.1 mL/kg (+127%). A concomitant decrease of Z by up to 23%, depending on the electrode configuration, was observed and regression analysis between Z and EVLWI yielded a significant inverse correlation. CONCLUSION: Changes of Z show a strong inverse correlation with changes of directly measured EVLWI. This allows the application of Z as a measure of intrathoracic fluid status and has the potential to optimize patient care, especially in the context of evolving telemedicine concepts.