Results
Base-line pre-LVAD implantation patients’ characteristics were presented
in Table 1.
Three male and one female were included in the study. The mean age for
patients was 33 ±10.1 years. Overall baseline characteristics of the
patients are presented in term as follows: BMI (26.1±3.7), EF:11±1.2,
cardiac index was 1.7±0.3, Hb 12±1.6, HbA%62.6±7.8, HbA2% 2.8±0.3, HbS
% 34±6, HbF% 2±0.5, Platelets 103/ μL 299±181, total Bilirubin
mg/dL21±13, direct Bilirubin mg/dl8.5±6, serum creatinine mg/dL 84±10,
Urea mg/dL5.2±2, AST u/l 14.1±7, ALT u/l 22.1±13, LDH u/l 159±45. More
detailed preoperative characteristics for each patient are shown in
table.1
Two patients underwent aortic clamping and cardiac arrest with warm
blood cardioplegia to perform associated procedures. The potential risk
of sickling within the coronary arteries with the administration of cold
cardioplegia under the cross clamp was avoided with an initial
normothermic (36°C) blood cardioplegia dose until cardiac arrest
followed by a blood cardioplegia dose of 20 mL/kg at normothermic
temperature. Subsequently, 10 mL/kg blood cardioplegia was administered
every 20 minutes. Patient 2 underwent combined aortic valve replacement
surgery with bioprothesis implantation; the duration of CBP was 188
minutes and the cross clamp was 86 minutes. Patient 4 underwent combined
mitral valve repair; the duration of CBP was 139 minutes and the
cross-clamp time was 55. The bypass circuit volume was arranged to be 3
times the patient’s circulating volume (7,8). These volumes were
adjusted according to the age, weight,1and body surface area of each
individual patient to reach a hematocrit value of 30% during CPB in two
patients and to decrease HbS levels to ≤ 10% of circulating hemoglobin.
Additional crystalloid, colloid, or red blood cells were added to the
CPB circuit as needed according to the desired hematocrit levels (7,8).
The flow was adjusted as body surface area times cardiac index (2.2 to
2.4 for the adult patients). To avoid the risk of sickling, rectal
temperature was kept around 34°C, while pH was maintained between 7.34
and 7.44 (9). None of the patient received blood or any blood products
transfusion preoperatively. Exchange transfusion was not performed
preoperatively and during surgery in all patients. Three patients
received all three types of blood components intra-operatively, while
one patient received only platelets and plasma (Table 2). Neither
sickling crisis nor acidosis occurred in any patient. There were no
complications related to hemoglobinopathy in the immediate
post-operative period, and at 3 and 6 months after discharge (no
macroscopic or microscopic evidence of hemolysis were seen, nor
hematuria or other clinical evidence of sickling). Anticoagulation for
the LVAD was started with low molecular weight heparin on the ICU after
12-24 hours, depending on bleeding amount. No antiplatelet drugs were
used in the first few days after LVAD implantation. The following days
concomitant warfarin was administered to the patient until INR
> 2.0. Target INR for the devices was 2.0—3.0. During
postoperative hospital stay, International Normalized Ratio (INR) was
daily monitored (10). Then, we combined warfarin and acetylsalicylic
acid. There was neither mortality nor complication within 30 days, 3
months and 6 months postoperatively. Currently, all patients remain free
of significant signs and symptoms of cardiac failure. Patient 1 received
heart transplant 22 months after LVAD implantation without complications
up to 30 days after heart transplant.
As a routine for our institution the follow up of the patients after
discharge were performed by VAD Team every week in the outpatient
clinic. There were variations in hematological markers among the
patients, during follow-up. Figure 1 shows the mean hemoglobin remained
below 10 g/dl after the procedure for all patients until first month of
follow-up, then it gradually increased until it reached 12 g/dl (range
1.3 - 3.9 g/dl). Mean total bilirubin (Figure 3) decreased from 43.8
mg/dL on the first day of the operation to 11.9 mg/dl after six-month of
follow-up (range 8.8 - 60 mg/dl). While mean direct bilirubin
significantly decreased from 34 mg/dL on the first post-implant day to 6
mg/dl in six-month follow-up respectively (Figure 2). However, mean
creatinine (Figure 4) decreased gradually from 124 mg/dl on day one post
operation to 64 mg/dl in first month of follow-up, then started to
increase to 83 mg/dl in the sixth months of follow-up. The elevation of
the mean creatinine level was due to increase in the creatinine level of
patient3 and patient 4 (Figure 4). However, there was statistically
significant difference in mean creatinine (124 vs. 63 mg/dl;
P<0.001) for day one and after one-month of follow-up
respectively (Table 3, Figure 4). There was statistically significant
increase in mean of LDH in day one compared to baseline (616 vs.159 U/L;
P=0.002) respectively (Figure 5). However, the level of LDH decreased
gradually until it reached 239 U/L in month six of follow-up. There was
a remarkable increase in mean platelet counts for all patients on the
first postoperative day compared to baseline mean (164 vs. 299; p=0.2),
but the increase was not statistically significant and was within the
normal platelet range. Marked decrease in platelets was observed only in
patient 3 in the first postoperative day. At six-months follow-up, the
overall mean of platelets count remained within normal range. In spite
of decrease in average platelet count at six months of follow-up, we
didn’t observe any bleeding event in any patient (Figure 6). No patient
received platelets transfusion in the postoperative period.