Readmission rates after axial flow left ventricular assist device implantation stabilise after six months


A study published ahead of print in the Journal of the American College of Cardiology indicates that the rates of readmission following axial flow left ventricular assist device (LVAD) implantation decrease during the first six months and thereafter stabilise.

Authors Tal Hasin, Division of Cardiovascular Diseases, Mayo Clinic, Rochester, USA, and others wrote that, as studies have shown that readmissions after LVAD implantations are frequent, a comparative analysis of the major causes of readmission after LVAD implantation may “therefore be useful in providing perspective and categorising the relative importance of morbidity  associated with ongoing LVAD support”. They added that the aim of their study was “to determine the occurrence, causes, trends over time, and possible predictors of readmission to the implanting hospital after LVAD implantation.”

Hasin et al performed a retrospective review of readmissions to their centre (Mayo Clinic) of patients with a HeartMate II (Thoratec) LVAD between January 2008 and July 2011. Of 115 patients identified, the median age was 62, 83% were male, 49% had an ischaemic aetiology for heart failure, and 36% were bridged to transplantation. During the median follow-up period of 1.4±0.9 years, there were 224 readmissions in 83 of the patients. The authors reported: “The rate decreased during the first six months from 2.6 to 0.9 readmissions per patient-year and remained stable thereafter.”  

They added that during the first six months, the major causes of readmission were bleeding and cardiac-related causes. However, after the first six months, both the rate of cardiac-related readmissions and the rate of bleeding-related readmissions decreased, which lead to the overall decrease in the rate of readmissions. Hasin et al reported: “During the second year, there was an increased rate of readmissions for bleeding and fewer cardiac readmissions compared with the previous interval. During the third year, there were more cardiac admissions and fewer related to bleeding with an increase in the rate of thrombosis and hospitalisations for elective procedures.”

According to the authors, in a multivariate analysis, residence within the extended referral zone of their centre (Minnesota and neighbouring states), preoperative haemoglobin preoperative N-terminal pro-B-type natriuretic peptide per 1,000 units, and closed aortic valve (observed on echocardiography in the first month) were all associated with significant fewer readmissions.

Study author Sudhir Kuswaha, Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinical, Rochester, USA, told Cardiovascular News: “Despite the fact that the axial flow LVAD is used to treat heart failure, a significant cause of readmissions remain cardiac related, including right ventricular discussion, arrhythmias and pump malfunction. Prolonged admissions to the hospital were often related to thrombotic events. The majority of cardiac related admissions tend to occur early with fewer cardiac related admissions occurring. Thus, some of these admissions could possibly be anticipated and prevented. Causes such as arrhythmias for instance could be more actively treated pre-discharge. In the later period, pump thrombosis seems to increase in incidence and perhaps we should maintain some strictness in anticoagulation, which tends to become less stringent. It also seems important that patients who are able to see us more frequently, i.e. live in the surrounding areas, are admitted less frequently because problems can be anticipated and treated.”