Nelson Americo Hossne

Monocyte transplantation for neural and cardiovascular ischemia repair.

•  Introduction •  Role of monocyte in neovascularization ‐  Angiogenesis in ischemia ‐  Angiogenesis in tumour and chronic inflammation •  Monocytes versus stem cells for transplantation ‐  Monocytes from umbilical cord blood •  Conclusions

Refractory angina cell therapy (ReACT) involving autologous bone marrow cells in patients without left ventricular dysfunction: a possible role for monocytes.

Autologous bone marrow mononuclear cell (BMMC) transplantation has emerged as a potential therapeutic option for refractory angina patients. Previous studies have shown conflicting myocardium reperfusion results. The present study evaluated safety and efficacy of CellPraxis Refractory Angina Cell Therapy Protocol (ReACT), in which a specific BMMC formulation was administered as the sole therapy for these patients. The phase I/IIa noncontrolled, open label, clinical trial, involved eight patients with refractory angina and viable ischemic myocardium, without left ventricular dysfunction and who were not suitable for conventional myocardial revascularization. ReACT is a surgical procedure involving a single series of multiple injections (40–90 injections, 0.2 ml each) into ischemic areas of the left ventricle. Primary endpoints were Canadian Cardiovascular Society Angina Classification (CCSAC) improvement at 18 months follow-up and myocardium ischemic area reduction (assessed by scintigraphic analysis) at 12 months follow-up, in correlation with a specific BMMC formulation. Almost all patients presented progressive improvement in angina classification beginning 3 months (p = 0.008) postprocedure, which was sustained at 18 months follow-up (p = 0.004), as well as objective myocardium ischemic area reduction at 12 months (decrease of 84.4%, p < 0.004). A positive correlation was found between monocyte concentration and CCSAC improvement (r = −0.759, p < 0.05). Improvement in CCSAC, followed by correlated reduction in scintigraphic myocardium ischemic area, strongly suggests neoangiogenesis as the main stem cell action mechanism. The significant correlation between number of monocytes and improvement strongly supports a cell-related effect of ReACT. ReACT appeared safe and effective.

Coronary artery and myocardial inflammatory reaction induced by intracoronary stent

Background: Intra-coronary stents have been extensively employed in percutaneous coronary revascularization. However, despite breakthroughs and developments associated to this new technology, novel complications and findings have emerged compelling the cardiac surgeon to cope with this new scenario. The presence of an intra-coronary foreign body (stent) might induce an inflammatory reaction carrying functional and structural repercussions of the coronary artery and surrounding cardiac muscle. Method: Patients, who had previously undergone stent implantation (6 to 18 months) and were submitted to coronary artery bypass surgery, had biopsies taken from the grafted coronary artery distal to the stent and from the adjacent muscle. The collected samples were processed and stained with hematoxylin-eosin and histologically studied. Results: The histology of the coronary artery distal to the stent revealed chronic inflammatory processes and an intimal acute inflammatory infiltrate, with polymorphonuclear leukocytes even at long term follow-up, 12 months after stent implantation, disclosing an ongoing inflammatory process. The myocardium adjacent to the stent implantation site exhibited a significant chronic inflammatory infiltrate and fibrosis compatible with myocarditis. Conclusion: The presence of an intra-coronary stent induces an acute and chronic inflammatory reaction, even over the long term, with involvement of the distal coronary artery and surrounding myocardium. Further studies are necessary to assess the inflammatory process extension and its consequences.

Myocardial revascularization in renal transplant patients

OBJECTIVE To assess the results of surgical myocardial revascularization in renal transplant patients. METHODS From 1991 to 2000, 11 renal transplant patients, whose ages ranged from 36 to 59 (47.5+/-8) years, 8 males and 3 females, underwent myocardial revascularization. The time interval between renal transplantation and myocardial revascularization ranged from 25 to 120 (mean of 63.8+/-32.7) months. RESULTS The in-hospital mortality rate was 9%. One patient died on the 4th postoperative day from septicemia and respiratory failure. The mean graft/patient ratio was 2.7+/-0.8. Only 1 patient required slow hemodialysis during 24 hours in the postoperative period, and no patient had a definitive renal lesion or lost the transplanted kidney. The actuarial survival curves after 1, 2, and 3 years were, respectively, 90.9%, 56.8%, and 56.8%. CONCLUSION Renal transplant patients may undergo myocardial revascularization with no lesion in or loss of the transplanted kidney.

Paraplegia after off-pump coronary artery bypass grafting.

We report the case of a young patient who developed paraplegia after CABG without CPB. It is important to point out that this patients aorta was not manipulated in any way because the only graft performed was a left internal mammary artery to left anterior descending artery.

Extended-time of Noninvasive Positive Pressure Ventilation ImprovesTissue Perfusion after Coronary Artery Bypass Surgery: a Randomized ClinicalTrial

Objective To compare the effects of extended- versus short-time noninvasive positive pressure ventilation on pulmonary function, tissue perfusion, and clinical outcomes in the early postoperative period following coronary artery bypass surgery in patients with preserved left ventricular function. Methods Patients were randomized into two groups according to noninvasive positive pressure ventilation intensity: short-time noninvasive positive pressure ventilation n=20 (S-NPPV) and extended-time noninvasive positive pressure ventilation n=21 (E-NPPV). S-NPPV was applied for 60 minutes during immediate postoperative period and 10 minutes, twice daily, from postoperative days 1-5. E-NPPV was performed for at least six hours during immediate postoperative period and 60 minutes, twice daily, from postoperative days 1-5. As a primary outcome, tissue perfusion was determined by central venous oxygen saturation and blood lactate level measured after anesthetic induction, immediately after extubation and following noninvasive positive pressure ventilation protocols. As a secondary outcome, pulmonary function tests were performed preoperatively and in the postoperative days 1, 3, and 5; clinical outcomes were recorded. Results Significant drop in blood lactate levels and an improvement in central venous oxygen saturation values in the E-NPPV group were observed when compared with S-NPPV group after study protocol (P<0.01). The E-NPPV group presented higher preservation of postoperative pulmonary function as well as lower incidence of respiratory events and shorter postoperative hospital stay (P<0.05). Conclusion Prophylactic E-NPPV administered in the early postoperative period of coronary artery bypass surgery resulted in greater improvements in tissue perfusion, pulmonary function and clinical outcomes than S-NPPV, in patients with preserved left ventricular function. Trial Registration Brazilian Registry of Clinical trial - RBR7sqj78 - http://www.ensaiosclinicos.gov.br

Oxygen uptake on-kinetics during six-minute walk test predicts short-term outcomes after off-pump coronary artery bypass surgery

Abstract Purpose: We aimed to investigate the ability of oxygen uptake kinetics to predict short-term outcomes after off-pump coronary artery bypass grafting. Methods: Fifty-two patients aged 60.9 ± 7.8 years waiting for off-pump coronary artery bypass surgery were evaluated. The 6-min walk test distance was performed pre-operatively, while simultaneously using a portable cardiopulmonary testing device. The transition of oxygen uptake kinetics from rest to exercise was recorded to calculate oxygen uptake kinetics fitting a monoexponential regression model. Oxygen uptake at steady state, constant time, and mean response time corrected by work rate were analysed. Short-term clinical outcomes were evaluated during the early post-operative of off-pump coronary artery bypass surgery. Results: Multivariate analysis showed body mass index, surgery time, and mean response time corrected by work rate as independent predictors for short-term outcomes. The optimal mean response time corrected by work rate cut-off to estimate short-term clinical outcomes was 1.51 × 10−3 min2/ml. Patients with slower mean response time corrected by work rate demonstrated higher rates of hypertension, diabetes, EuroSCOREII, left ventricular dysfunction, and impaired 6-min walk test parameters. The per cent-predicted distance threshold of 66% in the pre-operative was associated with delayed oxygen uptake kinetics. Conclusions: Pre-operative oxygen uptake kinetics during 6-min walk test predicts short-term clinical outcomes after off-pump coronary artery bypass surgery. From a clinically applicable perspective, a threshold of 66% of pre-operative predicted 6-min walk test distance indicated slower kinetics, which leads to longer intensive care unit and post-surgery hospital length of stay. Implications for rehabilitation Coronary artery bypass grafting is a treatment aimed to improve expectancy of life and prevent disability due to the disease progression; The use of pre-operative submaximal functional capacity test enabled the identification of patients with high risk of complications, where patients with delayed oxygen uptake kinetics exhibited worse short-term outcomes; Our findings suggest the importance of the rehabilitation in the pre-operative in order to “pre-habilitate” the patients to the surgical procedure; Faster oxygen uptake on-kinetics could be achieved by improving the oxidative capacity of muscles and cardiovascular conditioning through rehabilitation, adding better results following cardiac surgery. Trial registration: ClinicalTrials.gov identifier: NCT02758600.

Experimental Study and Early Clinical Application Of a Sutureless Aortic Bioprosthesis

INTRODUCTION The conventional aortic valve replacement is the treatment of choice for symptomatic severe aortic stenosis. Transcatheter technique is a viable alternative with promising results for inoperable patients. Sutureless bioprostheses have shown benefits in high-risk patients, such as reduction of aortic clamping and cardiopulmonary bypass, decreasing risks and adverse effects. OBJECTIVE The objective of this study was to experimentally evaluate the implantation of a novel balloon-expandable aortic valve with sutureless bioprosthesis in sheep and report the early clinical application. METHODS The bioprosthesis is made of a metal frame and bovine pericardium leaflets, encapsulated in a catheter. The animals underwent left thoracotomy and the cardiopulmonary bypass was established. The sutureless bioprosthesis was deployed to the aortic valve, with 1/3 of the structure on the left ventricular face. Cardiopulmonary bypass, aortic clamping and deployment times were recorded. Echocardiograms were performed before, during and after the surgery. The bioprosthesis was initially implanted in an 85 year-old patient with aortic stenosis and high risk for conventional surgery, EuroSCORE 40 and multiple comorbidities. RESULTS The sutureless bioprosthesis was rapidly deployed (50-170 seconds; average=95 seconds). The aortic clamping time ranged from 6-10 minutes, average of 7 minutes; the mean cardiopulmonary bypass time was 71 minutes. Bioprostheses were properly positioned without perivalvar leak. In the first operated patient the aortic clamp time was 39 minutes and the patient had good postoperative course. CONCLUSION The deployment of the sutureless bioprosthesis was safe and effective, thereby representing a new alternative to conventional surgery or transcatheter in moderate- to high-risk patients with severe aortic stenosis.

Myocardial Revascularization in Dyalitic Patients: In-Hospital Period Evaluation

Background Coronary artery bypass grafting currently is the best treatment for dialytic patients with multivessel coronary disease, but hospital morbidity and mortality related to procedure is still high. Objective Evaluate results and in-hospital outcomes of coronary artery bypass grafting in dialytic patients. Methods Retrospective unicentric study including 50 consecutive and not selected dialytic patients, who underwent coronary artery bypass grafting in a tertiary university hospital from 2007 to 2012. Results High prevalence of cardiovascular risk factors was observed (100% hypertensive, 68% diabetic and 40% dyslipidemic). There was no intra-operative death and 60% of the procedures were performed off-pump. There were seven (14%) in-hospital deaths. Postoperative infection, previous heart failure, cardiopulmonary bypass, abnormal ventricular function and surgical re-exploration were associated with increased mortality. Conclusion Coronary artery bypass grafting is feasible to dialytic patients although high in-hospital morbidity and mortality. It is necessary better understanding about metabolic aspects to plan adequate interventions.

Sildenafil improves right ventricular function in a cardiac transplant recipient

We report the case of a male patient who underwent orthotopic cardiac transplantation. A marginal donor was used, because the recipients clinical condition was critical. He experienced cardiogenic shock due to right ventricular dysfunction secondary to pulmonary hypertension associated with vasoplegia. After the introduction of sildenafil, the patient recovered hemodynamically, his pulmonary vascular resistance decreased, the vasoactive drugs were withdrawn, and his right ventricular function improved.