Hemodynamic Assessment in Patients on Chronic Continuous Flow Left Ventricular Assist Device Support

Abstract

Purpose We sought to characterize hemodynamic parameters in asymptomatic patients (AS) supported with a continuous flow left ventricular assist device (LVAD) as compared to those with symptoms of dyspnea or fluid overload (S) also supported with LVAD, using right heart catheterization (RHC). Methods and Materials A retrospective analysis for all patients that underwent RHC while on LVAD support was performed. Patients were grouped by indication to AS and S. Parameters were compared using the Wilcoxon rank sum test with p Results We identified 50 patients, 27 in the S and 23 in the AS groups. A HeartMate II was implanted in 48 and a Heartware in 2 patients, 34% were implanted as a bridge to transplant. Patient age was 61±10 years, 86% were males. The group included 5 patients with restrictive myopathy (3 amyloid, 2 hypertrophic), all in the S group. Patients in the AS group were younger (58±11 years, p=0.04) but otherwise baseline characteristics were similar. RHC was performed on average 6 months after implant. At time of RHC pump speed was mean 9400rpm; pulsatility index was 4.8±1 (higher in the AS group, p=0.045) and mean arterial pressure was 84mmHg. In the AS group mean right atrial (RA) pressure was 9±5mmHg, mean pulmonary pressure was 23±7mmHg, wedge was 11±6 mmHg, RVSWI was 6±3 grm/m 2 /beat and cardiac index was 2.3±0.5 lit/min/m 2 . In comparison the S group had higher right atrial pressure (17±8, p=0.0003), pulmonary pressure (31±12, p=0.009) and wedge (17±9, p=0.011) but similar RVSWI and cardiac index. Half the patients in the S group with elevated RA pressure (>15) had an RA to wedge ratio>1 indicating right heart failure and in 16 patients left heart failure was suggested by wedge>15. Conclusions Compared to asymptomatic patients, symptomatic patients supported by LVAD have elevated filling pressures. Hemodynamic evaluation may differentiate those with primarily right to those with left sided failure and help to direct treatment, and thus may improve symptoms and quality of life following LVAD implantation.