Outcome of long-term mechanical circulatory support : Quod bonum, faustum felixque est

Abstract

In patients with advanced systolic heart failure, heart transplantation or durable mechanical circulatory support (MCS) may be considered. Initially, MCS was only implanted as a bridge to heart transplantation. As a result of improved technology, together with the shortage of donor hearts, MCS is used for extended periods of time or even permanent support (‘destination therapy’). Since cf-LVADs were first implanted in 2006 at the University Medical Center Utrecht (UMCU), a lot of experience has been gained in the complex management of these patients. In this thesis, different outcome parameters in patients treated with MCS in our center were analyzed. The hemodynamic changes related to MCS are described in Chapter 2, together with adverse events, illustrated by cases. In Chapter 3, the 1, 3 and 5-year survival was analyzed, which was 83%, 72% and 57%, respectively. These results support long-term MCS. Also, adverse events associated with MCS were described. Chapter 4 elaborates on the prediction of major bleeding and thrombosis in MCS patients. A history of atrial fibrillation doubled the risk of thrombosis (TIA, ischemic stroke or pump thrombosis). Furthermore, older age showed to be an important factor in the prediction, frequency and timing of bleeding. As the risk of bleeding changes over time, we aimed to analyze the risk of bleeding at any moment during follow-up, as discussed in Chapter 5. In this study all data out of the electronic health records were entered into a self-developed data mining-based tool, named Auto-Crisp. Different models were created to predict major bleeding within 3, 7 and 30 days from any moment during MCS. The performance of these models was acceptable, represented by an area under the curve (AUC) of 0.792, 0.788, and 0.776, respectively. Chapter 6 focuses on the prediction of another important complication related to long-term MCS: late right heart failure (LRHF). In our study, which included both clinical and outpatient patients with signs and symptoms of LRHF, 19% of patients developed LRHF. Baseline echocardiographic and invasive hemodynamics did not predict LRHF, but it can be predicted by cardiogenic shock before implant, a history of atrial fibrillation, higher pre-operative body mass index and longer duration on the intensive care unit. Especially in long-term support, functional capacity after implantation is important for a better quality of life. In Chapter 7, exercise capacity in the first year after MCS was studied. Between 6 and 12 months, on routinely planned cardiopulmonary exercise tests (CPETs) power and peak oxygen uptake (pVO2) increased significantly. Almost half of patients (44%) showed an increase of >6% in maximal exercise capacity, which is defined as clinically relevant in heart failure patients. Chapter 8 summarizes the role of MCS in the Netherlands. Survival rates of the four implanting centers together and an overview of the indications, contraindications, patient selection, clinical outcome and optimal time of referral for long-term MCS were discussed. In Chapter 9, we further explored our findings on the long-term outcome of MCS patients.