Perioperative use of iloprost in cardiac surgery patients diagnosed with heparin-induced thrombocytopenia-reactive antibodies or with true HIT (HIT-reactive antibodies plus thrombocytopenia): An 11-year experience.

Thrombocytopenia and thromboembolism(s) may develop in heparin immune-mediated thrombocytopenia (HIT) patients after reexposure to heparin. At the Onassis Cardiac Surgery Center, 530 out of 17,000 patients requiring heart surgery over an 11-year period underwent preoperative HIT assessment by ELISA and a three-point heparin-induced platelet aggregation assay (HIPAG). The screening identified 110 patients with HIT-reactive antibodies, out of which 46 were also thrombocytopenic (true HIT). Cardiac surgery was performed in HIT-positive patients under heparin anticoagulation and iloprost infusion. A control group of 118 HIT-negative patients received heparin but no iloprost during surgery. For the first 20 patients, the dose of iloprost diminishing the HIPAG test to ≤5% was determined prior to surgery by in vitro titration using the patients' own plasma and donor platelets. In parallel, the iloprost "target dose" was also established for each patient intraoperatively, but before heparin administration. Iloprost was infused initially at 3 ng/kg/mL and further adjusted intraoperatively, until ex vivo aggregation reached ≤5%. As a close correlation was observed between the "target dose" identified before surgery and that established intraoperatively, the remaining 90 patients were administered iloprost starting at the presurgery identified "target dose." This process significantly reduced the number of intraoperative HIPAG reassessments needed to determine the iloprost target dose, and reduced surgical time, while maintaining similar primary clinical outcomes to controls. Therefore, infusion of iloprost throughout surgery, under continuous titration, allows cardiac surgery to be undertaken safely using heparin, while avoiding life-threatening iloprost-induced hypotension in patients diagnosed with HIT-reactive antibodies or true HIT.

Right ventricular endocardial thermography in transplanted and coronary artery disease patients: first human application.

BACKGROUND: We sought to evaluate for the first time in humans the safety and feasibility of right ventricular (RV) thermography in patients with coronary artery disease (CAD) and in patients after heart transplantation (Tx), in comparison to subjects without structural heart disease (controls). METHODS: Ninety-one RV thermography procedures were performed in 16 patients with CAD, 19 hearttransplant recipients and 6 patients without structural heart disease. We recorded the temperature of the RV intracavitary blood and RV endocardial septum, and calculated their difference using a dedicated commercially available thermography catheter. RESULTS: No complications were observed. CAD patients had a significantly higher temperature difference (0.19 +/- 0.11 degrees C) compared to both Tx patients (0.10 +/- 0.06 degrees C) and controls (0.07 +/- 0.04 degrees C) (p < 0.0001 and p = 0.003, respectively), whereas there was no significant difference between the Tx patients and controls (p = 0.65). CONCLUSION: RV thermography in humans is feasible and safe. Patients with stable CAD present a significantly higher temperature difference in the RV endocardium compared to controls; clinically stable transplant recipients have temperatures similar to controls. This novel method corroborates previous findings supporting the inflammatory hypothesis of coronary atherosclerosis.

Increased number of circulating progenitor cells after implantation of ventricular assist devices.

BACKGROUND: Bone marrow-derived circulating progenitor cells possess tissue repair potential, improving perfusion, left ventricular remodeling, and contractility in experimental models. We quantified and investigated the kinetics of 4 circulating progenitor cell sub-populations on the basis of CD34, CD133, and vascular endothelial growth factor receptor-2 (VEGFR-2) antigen expression. METHODS: CD34+, CD34+/CD133+/VEGFR-2-, CD34+/CD133+/VEGFR-2+, and CD34+/CD133-/VEGFR-2+ cells were counted in 10 male patients with end-stage congestive heart failure. Five underwent left ventricular/biventricular assist device (LVAD/BiVAD) implantation (VAD group), and 5 were ineligible for VAD implantation (no-VAD group). Peripheral blood was collected at 3 time points for each patient: before, 15, and 60 days after VAD placement in the VAD group and at the same time points in the no-VAD group. Purified CD34+ cells were stained with anti-CD34, anti-CD133, and anti-VEGFR-2 monoclonal antibodies and analyzed by flow cytometry. Serum levels of granulocyte-colony stimulating factor (G-CSF), interleukin-8, vascular endothelial growth factor-alpha (VEGF-alpha), and B-type natriuretic peptide (BNP) were also measured. RESULTS: In the VAD group the number of CD34+ cells/ml of blood tended to increase, from 159.6 +/- 137.0 at baseline to 428.9 +/- 224.3 at 15 days, and decreased to 343.8 +/- 165.7 at 60 days (p = 0.05 vs no-VAD group). In the other 3 cell populations, no significant differences occurred over time or between groups. A significant interaction between BNP levels and VAD status was observed (p = 0.005): BNP levels decreased over time in VAD patients vs no-VAD patients. G-CSF levels tended to decrease over time in both groups, but without a significant difference (p = 0.3). Serum levels of interleukin-8 and VEGF-alpha over time or between VAD and no-VAD patients were not significantly different. CONCLUSIONS: After VAD implantation, a transient increase occurs in the number of circulating CD34+ cells, in parallel to a reduction in BNP levels. Release of these cells from the bone marrow may contribute to the improvement of tissue perfusion and cardiac recovery occasionally seen after VAD placement.

Increased ischaemia modified albumin following coronary artery bypass grafting.

BACKGROUND: Any increase of cardiac biomarkers after coronary artery bypass grafting (CABG) indicates myocyte necrosis and is likely to be related to an impaired outcome. We investigated whether ischaemia-modified albumin (IMA), a biomarker of ischaemia, is also raised following CABG. METHODS: We studied 50 stable consecutive patients undergoing elective isolated CABG on cardiopulmonary bypass, of whom 46 were men and four women, aged 64 +/- 9 years. Blood samples were obtained the day before the operation (pre-op) as well as immediately after the operation, 24 h postoperatively (post-op) and the fourth day post-op and assayed for creatine kinase, the MB isoenzyme of creatine kinase, cardiac troponin-I, albumin and IMA. RESULTS: The typical rising and falling pattern of myocardial necrosis of all three cardiac enzymes was observed post-op (p <0.0001). IMA increased significantly following CABG at all three time points (113 +/- 43, 106.7 +/- 22.6 and 110.2 +/- 12.5 U ml(-1), respectively) compared with pre-op values (91.7 +/- 10.5 U ml(-1)), (p <0.0001); the sample immediately post-op was significantly higher compared with the following samples (immediately post-op vs 24 h, p = 0.008 and immediately post-op vs 4 days, p = 0.03, with no significant difference between the last two). IMA level changes during the study course were independent of the albumin changes. Haemoglobin decreased significantly post-op (p <0.0001 vs baseline) whereas serum creatinine did not differ during the study period. CONCLUSIONS: IMA increases significantly following CABG but whether or not this carries a prognostic significance remains to be elucidated.

Transcatheter aortic valve implantation: first Greek experience.

INTRODUCTION: Percutaneous aortic valve replacement represents an alternative to conventional open-heart surgery for selected high-risk patients without the need for sternotomy, aortotomy, or cardiopulmonary bypass. We present the first Greek series of transcatheter prosthetic aortic valve implantation procedures, performed in our centre. METHODS: All 12 patients (age 81 +/- 5 years) had severe, symptomatic, calcific aortic stenosis and were judged not to have a reasonable surgical option by a medical team including experienced cardiac surgeons. The patients' mean logistic EuroSCORE was 34 +/- 15% (min 11%, max 61%). Eight (8) of them underwent transfemoral (SAPIEN, Edwards 23 mm valve in 7 and 26 mm in 1 patient) and 4 transapical (26 mm in 2 and 23 mm in 2 patients) prosthetic aortic valve implantation, all in the cardiac catheterisation laboratory under general anaesthesia. RESULTS: The procedural, in-hospital and 2-month (mean follow up 50 days, min 17, max 122 days) mortality was 0%. The length of hospital stay was 8 +/- 2 days (min 5, max 12 days). The aortic valve area increased from 0.64 +/- 0.14 cm2 to 1.83 +/- 0.14 cm2 and the mean pressure gradient decreased from 57 +/- 23 mmHg to 10 +/- 3 mmHg post-implantation (p<0.001 for both). The patients' mean NYHA functional status improved from 2.8 +/- 0.7 to 1.3 +/- 0.5 at follow-up (p<0.001). CONCLUSIONS: Our initial experience with transcatheter prosthetic aortic valve implantation demonstrates that it can be performed safely and with excellent short and mid-term clinical outcomes.

Orthotopic heart transplantation: ten years' clinical experience.

INTRODUCTION: Heart transplantation is the "gold standard" in the treatment of patients with end-stage heart failure who satisfy strict selection criteria. METHODS: We reviewed ten years' clinical experience (1996-2006) from 53 orthotopic transplants in our centre. RESULTS: Low perioperative (3.7%) and long-term (7.5%) mortality rates yielded a 95% survival rate in the first year, 92% at five years, and 70% at ten years--significantly better than the corresponding rates worldwide. In addition, excellent functional recovery was achieved in all transplant recipients. CONCLUSIONS: The strict application of international criteria in the selection of both candidates and donors, together with uninterrupted, multidisciplinary follow up, have made it feasible to perform heart transplantation with excellent results, despite the curiously low number of potential recipients and the shortage of acceptable donor hearts.

Safety and efficacy of off-pump coronary artery bypass grafting in chronic dialysis patients.

Off-pump coronary artery bypass grafting (CABG) has been recently revived, because cardiopulmonary bypass (CPB) appears to worsen the multiple organ dysfunction after conventional CABG. To evaluate the safety and efficacy of the off-pump CABG in chronic dialysis patients, we compared the perioperative morbidity and mortality between 15 dialysis patients who underwent off-pump CABG at our center over the past 8 years with that of a concurrent group of 19 patients who underwent conventional CABG. Patients were selected for off-pump CABG only when complete revascularization was technically feasible. We found that off-pump CABG is as safe and effective as conventional CABG in selected dialysis patients. It might even be beneficial, because it is associated with less hematocrit drop and blood product use, a lower catabolic rate, and fewer dialysis requirements after surgery. However, the impact of off-pump technique on the long-term clinical outcome and resource utilization in renal patients requires further investigation.