Cardiac Index Declines During Long‐Term Left Ventricular Device Support

Abstract

To investigate longitudinal trends in valvular and ventricular function with long-term left ventricular assist device (LVAD) therapy, we analyzed hemodynamic and echocardiographic data of patients with at least 2 years of continuous LVAD support. All 130 patients who underwent HeartMate II implantation at our institution between 2005 and 2012 were reviewed. Twenty patients had hemodynamic and echocardiographic evaluations in both the early (0-6 months) and late (2-3 years) postoperative period. Patients on inotropic therapy or temporary mechanical support were excluded. The average times of early and late hemodynamic evaluations were 59 ± 41 days and 889 ± 160 days, respectively. Cardiac index (CI) declined by an average of 0.4 L/min/m (P = 0.04) with concomitant increase in pulmonary capillary wedge pressure (PCWP; P = 0.02). The right atrial pressure to PCWP (RAP:PCWP) ratio decreased during LVAD support suggesting improvement in right ventricular function. While there was an increase in degree of aortic insufficiency (AI) at the late follow-up period (P = 0.008), dichotomization by median decline in CI (-0.4 L/min/m ) indicated no difference in prevalence of AI among the groups. CI declined in patients with HeartMate II after 2 years of continuous support. An increase in preload and afterload was observed in those with the greatest decline in CI.

Longitudinal Trajectories of Hemodynamics Following Left Ventricular Assist Device Implantation

“…18 The smaller study also excluded patients on inotropes, and was limited to a single device (HeartMate II). 19 In contrast, our study did not exclude these patients, in order to reduce selection bias and provide a more comprehensive view of the clinical course following LVAD. These differences in study population may explain the difference in hemodynamic trends.…”

“…Our findings regarding longitudinal hemodynamic trends in LVAD patients are different from two previous studies that found an overall improvement in RV parameters during longterm follow-up. 18,19 It is important to note that the larger of these two studies excluded patients on inotropes or pulmonary vasodilators by design, in order to examine RV load independent of medications that might impact the physiology. 18 The smaller study also excluded patients on inotropes, and was limited to a single device (HeartMate II).…”

Clinical implications of hemodynamic assessment during left ventricular assist device therapy

“…There are few studies reporting long-term trends in hemodynamics during LVAD support. Kalathiya et al showed in a longitudinal study that CI declined in patients with HeartMate II after 2 years of continuous support, possibly due to an increase in afterload [36]. …”