RESULTS
During the study period, 83 patients underwent LTHS dLVAD placement. Of
these, 50 did not require tMCs, while 22 (26%) were bridged with IABP
and 11 (13%) with ECMO. Preoperative data are summarized in Table 1.
Baseline demographics were similar among groups. Indication for dLVAD
was primarily bridge to candidacy. Two ECMO patients (18%) and none in
the other two groups required mechanical ventilation (p=0.001). All ECMO
patients were INTERMACS 1, while IABP recipients were predominantly
INTERMACS 2 (45%), and non-tMCS patients INTERMACS 3 (56%)
(p<0.001). ECMO patients were hospitalized for median 14 days
prior to dLVAD, versus 10 for IABP and 2.5 for no tMCS (p=0.002). Median
ECMO duration was longer than for IABP (10 vs. 6 days, p=0.02).
Prior to dLVAD, ECMO patients had lower albumin and hemoglobin and
higher AST, while IABP patients had higher creatinine. Echocardiographic
variables were similar among the groups. Both tMCS groups displayed
worse baseline hemodynamics (higher PCWP, CVP, and PAD; lower PA
pulsatility index [PAPi]) compared to non-tMCS patients.
Table 2 compares pre- and post-tMCS end-organ function and net fluid
balance during tMCS between IABP and ECMO recipients. Pre-tMCS ECMO
patient values tended to be higher for all variables except BUN.
Post-tMCS, IABP patients had significant decreases in BUN, creatinine,
bilirubin, and MELD-XI, while ECMO patients had significantly decreased
creatinine and MELD-XI. Decrease in creatinine was significantly greater
for ECMO patients. Net fluid balance for the duration of tMCS and net
fluid balance per day were not significantly different.
Operative data are presented in Table 3. Operative and cardiopulmonary
bypass times did not differ among the groups. In addition to ECMO
removal, 7 (64%) ECMO patients underwent concomitant procedures. These
included: percutaneous septostomy closure in three; and septostomy
closure with femoral artery repair, VT ablation, femoral thrombectomy,
and veno-venous (VV) ECMO in one each. Fewer IABP (1 [5%]) and
non-tMCS (4 [8%]) patients had concomitant procedures
(p<0.001). In these patients, procedures were: VT ablation;
splenectomy (for infarct) and femoral artery repair; surgical PFO
closure with RVAD/VV ECMO; aortic valve plication; and left atrial
appendage closure with VV ECMO.
One IABP and one non-tMCS patient required conversion to sternotomy, the
former for coronary graft injury and the latter for hypoxemia and
ventricular arrhythmias in the setting of an open PFO. That patient was
one of two who required an RVAD. The other was an ECMO patient with
intractable inotrope-dependent RV failure who underwent late RVAD
insertion. ECMO patients more frequently required ≥4 units
intraoperative red blood cells (64%, vs. 23% IABP and 4% no tMCS,
p<0.001). No ECMO patient underwent transfusion-free implant.
Despite this, no ECMO patient required reoperation for bleeding or
delayed chest closure.
Post-dLVAD inotropic support duration did not differ among groups
(median 7-10 days). Median ICU length of stay was slightly higher for
ECMO (9 days vs. 6 in the other groups, p=0.08). Median hospital length
of stay ranged from 16 days for no tMCS to 19 days for ECMO (p=0.21).
Two operative deaths (18%) occurred in the ECMO group, one from
multiorgan failure and one from a hemorrhagic CVA. There were no
operative deaths in the IABP group and 2 (4%) in the no tMCS group
(p=0.06).
Figure 1 compares rates (in events/100 patient-months [EPPM]) of
postoperative adverse events. In the early phase (<3 months),
major and GI bleeds were most common. Rates were similar in ECMO and
non-tMCS groups. Device-related infections and CVAs were rare, and no
ECMO patient suffered an early infection or ischemic CVA. One early
hemorrhagic CVA occurred in an ECMO patient.
There were also no significant differences in rates of late
(>3 months post-dLVAD) complications. In this phase,
device-related infections were predominant. These occurred at a higher
rate in IABP patients, although the trend is not significant (p=0.14).
No late hemorrhagic CVAs occurred in ECMO or IABP patients, versus 0.93
EPPM in non-tMCS patients. Likewise, no ECMO patient had an ischemic
CVA, compared to 0.62-0.71 EPPM in the other groups.
Figure 2 illustrates Kaplan-Meier survival and Figure 3 competing
outcomes for the three groups. Overall survival curves are not different
among groups (p=0.45). For ECMO patients, no late mortality occurred
after two operative deaths, yielding 81% 3- and 12-month survival. By
12 months, 41% were transplanted. In IABP recipients 3- and 12-month
survival were 100% and 88%. By 12 months, 36% were transplanted. In
the no-tMCS cohort, 3- and 12-month survival were 94% and 86%, and
32% were transplanted by 12 months.