Sequential Chains of Adverse Events Post LVAD Implantation

Purpose Most post-LVAD Adverse Events (AEs) studies have focused on individual AEs in isolation, neglecting the possible interrelation, or causality between AEs. This study for the first time conducted a novel exploratory analysis to discover sequential chains of AEs following LVAD implantation. Methods This analysis was derived from 58,575 recorded AEs for 13,192 patients in INTERMACS who received a continuous-flow LVAD between 2006 and 2015. The data mining procedure involved three main steps: (1) create a bank of AE sequences, (2) group patients with similar AE sequences using hierarchical clustering, and (3) extract temporal chains of AEs for each group of patients using Markov modeling. Results The mined results indicate the existence of seven groups of sequential chains of AEs, characterized by common types of AEs that occurred in a unique order. A portion of the pattern analysis in this study is shown in Fig.1. The groups were identified as: GRP1(Recurrent bleeding) 862 patients with a minimum of 2 bleeding AEs, GRP2(Trajectory of device malfunction & explant) 1,591 patients who had device malfunction preceded by infection and bleeding, and then commonly had their LVADs removed, GRP3(Infection) 3,438 patients who suffered from recurrent infection or infection accompanied with bleeding, GRP4(Trajectories to transplant) 3,302 patients who received a heart transplant and commonly experienced bleeding, infection, and cardiac arrhythmia, GRP5(Cardiac arrhythmia) 1,275 patients who experienced one or recurrent cardiac arrhythmia commonly accompanied with infection and bleeding, GRP6(Trajectory of neurological dysfunction & death) 1,616 patients, and GRP7(Trajectory of respiratory failure, renal dysfunction & death) 1,108 patients who died with an average of 3 and 5 AEs, respectively, and median time to death of 6 and 3 post-LVAD months, respectively. Conclusion These chains of AEs disclose potential interdependence between post-LVAD AEs and may aid prediction, and prevention, of subsequent AEs - which is the topic of ongoing work. Most post-LVAD Adverse Events (AEs) studies have focused on individual AEs in isolation, neglecting the possible interrelation, or causality between AEs. This study for the first time conducted a novel exploratory analysis to discover sequential chains of AEs following LVAD implantation. This analysis was derived from 58,575 recorded AEs for 13,192 patients in INTERMACS who received a continuous-flow LVAD between 2006 and 2015. The data mining procedure involved three main steps: (1) create a bank of AE sequences, (2) group patients with similar AE sequences using hierarchical clustering, and (3) extract temporal chains of AEs for each group of patients using Markov modeling. The mined results indicate the existence of seven groups of sequential chains of AEs, characterized by common types of AEs that occurred in a unique order. A portion of the pattern analysis in this study is shown in Fig.1. The groups were identified as: GRP1(Recurrent bleeding) 862 patients with a minimum of 2 bleeding AEs, GRP2(Trajectory of device malfunction & explant) 1,591 patients who had device malfunction preceded by infection and bleeding, and then commonly had their LVADs removed, GRP3(Infection) 3,438 patients who suffered from recurrent infection or infection accompanied with bleeding, GRP4(Trajectories to transplant) 3,302 patients who received a heart transplant and commonly experienced bleeding, infection, and cardiac arrhythmia, GRP5(Cardiac arrhythmia) 1,275 patients who experienced one or recurrent cardiac arrhythmia commonly accompanied with infection and bleeding, GRP6(Trajectory of neurological dysfunction & death) 1,616 patients, and GRP7(Trajectory of respiratory failure, renal dysfunction & death) 1,108 patients who died with an average of 3 and 5 AEs, respectively, and median time to death of 6 and 3 post-LVAD months, respectively. These chains of AEs disclose potential interdependence between post-LVAD AEs and may aid prediction, and prevention, of subsequent AEs - which is the topic of ongoing work.