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Invasive Hemodynamics in Severely Obese Patients Following Continuous-Flow Left Ventricular Assist Device Implantation

      Purpose

      Patients with a body mass index (BMI) > 40 kg/m2 were excluded from continuous-flow left ventricular assist device (CF-LVAD) clinical trials; however, in the post approval era, those patients were not precluded from undergoing CF-LVAD implantation. This study examines whether CF-LVADs can improve hemodynamic profiles of morbidly obese patients with advanced heart failure.

      Methods

      A retrospective chart review of CF-LVAD implants from 2008-2013 at a large academic medical center was performed. Right heart catheterization data before and at least 3 months after CF-LVAD implantation were collected. Patients were stratified by BMI < 40 or ≥ 40, which is considered morbidly obese. The outcomes examined include the percentage of patients in each group with cardiac index (CI) ≥ 2.1 L/min/m2, right atrial pressure (RAP) < 12 mmHg, and pulmonary capillary wedge pressure (PCWP) < 18 mmHg after LVAD implantation.

      Results

      Fifty-four patients were included in the study, six of which had a BMI ≥ 40. Average BMI in the morbidly obese group was 43.0 ± 4.5 kg/m;2 as compared to 28.6 ± 5.7 kg/m2 in the remaining population (p < 0.0001). Average time to right heart catheterization was 168 ± 62 days after CF-LVAD implantation. Pre-LVAD CI was similar between the two groups (1.7 ± 0.6 L/min/m2 vs 1.8 ± 0.4 L/min/m2, p = 0.93) as was the change in CI following CF-LVAD implantation (0.8 ± 0.8 L/min/mˆ2 vs. 0.5 ± 0.5 L/min/m2, p = 0.46). Post-implantation CI was comparable (2.5 ± 0.6 L/min/mˆ2 vs 2.3 ± 0.4 L/min/m2, p = 0.47) (Figure 1). Among the morbidly obese patients, 66.7% had a cardiac index ≥ 2.1 L/min/m2 after CF-LVAD implantation as compared to 77.1% of the group with a BMI < 40 (p = 0.62) (Figure 2). After CF-LVAD implantation, the RAP was less than 12 mmHg in 60.4% and 83.3% of patients in the BMI < 40 and severely obese groups (p = 0.39), respectively and PCWP was less than 18 mmHg in 64.6% and 66.7% of patients in the BMI < 40 and severely obese groups (p = 1.0), respectively.

      Conclusion

      CF-LVADs normalize CI, RAP, and PCWP in the majority of morbidly obese patients.
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