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.