Unplanned HM3 Heart Failure-Related Hospitalizations: Reclassifying Post-Discharge Right Ventricular Failure

Abstract

Heart failure-related hospitalization (HFH) after continuous-flow left ventricular assist device (CF-LVAD) implant remains prevalent. Our primary aim was to better elucidate the extent of HFH in patients supported by HM3 resulting from predominant right (RHFS) versus left (LHFS) HF syndrome. We also re-classified INTERMACS-defined RHF by the underlying HFS phenotype. Retrospective data were extracted on patients with HFH post-HM3 implant at our institution (January 2017-May 2019) for demographics, hemodynamics by echocardiogram and/or right heart catheterization, and detailed physical exam findings. Data from each HFH were used to categorize the underlying HFS phenotypes (Table 1). HFH is defined as re-hospitalization post-index implant with a fluid overload syndrome and use of parenteral diuretics. INTERMACS RHF is defined by elevated right atrial pressure requiring the use of varying degrees of right ventricular support, including the sole use of parenteral diuretics. Statistical analyses used the Fisher exact t-test (SAS, version 9.4). One hundred forty-three patients defined the HM3 study cohort. Twenty-three patients (mean age 57.7 ± 11.2 years) had HFH (16.1% prevalence), with a median time to first HFH of 65.6 days post-implant. HFH was due to LHFS in 11 patients (47.8%; 2 LHFS and 9 BiV HFS) and predominant RHFS in 12 patients (52.2%). Twenty-one patients met criteria for INTERMACS-defined RHF (14.7% prevalence). By categorical phenotyping, an elevated pulmonary capillary wedge pressure (PCWP) >15 mm Hg was noted in 42.9% of these cases. BiV HFS and predominant RHFS account for most HFH post-HM3 implant. LHFS account for nearly half of the post-discharge INTERMACS-defined RHF re-hospitalizations. Further examination of the predictors and underlying causes of partial LV unloading, and the implications on long-term outcomes including survival and functional capacity is warranted.