A Deep Learning Ensemble Approach for Automated COVID-19 Detection from Chest CT Images.

BACKGROUND: The aim of this study was to evaluate the performance of an automated COVID-19 detection method based on a transfer learning technique that makes use of chest computed tomography (CT) images. METHOD: In this study, we used a publicly available multiclass CT scan dataset containing 4171 CT scans of 210 different patients. In particular, we extracted features from the CT images using a set of convolutional neural networks (CNNs) that had been pretrained on the ImageNet dataset as feature extractors, and we then selected a subset of these features using the Information Gain filter. The resulting feature vectors were then used to train a set of k Nearest Neighbors classifiers with 10-fold cross validation to assess the classification performance of the features that had been extracted by each CNN. Finally, a majority voting approach was used to classify each image into two different classes: COVID-19 and NO COVID-19. RESULTS: A total of 414 images of the test set (10% of the complete dataset) were correctly classified, and only 4 were misclassified, yielding a final classification accuracy of 99.04%. CONCLUSIONS: The high performance that was achieved by the method could make it feasible option that could be used to assist radiologists in COVID-19 diagnosis through the use of CT images.

Low-dose anticoagulation after isolated mechanical aortic valve replacement with Liva Nova Bicarbon prosthesis: A post hoc analysis of LOWERING-IT Trial.

Thromboembolic complications after cardiac valve replacement are due to a complex interplay between patients' characteristics, device features and anticoagulation intensity. Subtle design and material differences in available prostheses may thrombosis. We conducted a post-hoc sub-analysis of the LOWERING-IT database to test the safety and feasibility of a low-level oral anticoagulant regime in low-risk patients with aortic LivaNova prosthetic valve replacement. The study population included 148 patients randomized to a low INR target (1.5-2.5; LOW-INR group), and 144 patients to the standard INR (2.0-3.0; CONVENTIONAL-INR group). The non-inferiority of thromboembolic events between LOW-INR and CONVENTIONAL-INR groups was tested. Cumulative follow-up reached 1,545 patient/years. The mean INR was 1.91 ± 0.23 in the LOW-INR group, and 2.59 ± 0.26 in the CONVENTIONAL-INR group (P < 0.001). There were 3 thromboembolic events, all in the CONVENTIONAL-INR group. Comparison of thromboembolic events was not significant. The 1-sided 97.5% exact CI for the difference in primary event proportion was 0.54%, satisfying criteria non-inferiority. Bleeding events were significantly different: 6.61 per 1,000 patient-year in LOW-INR group vs 18.65 per 1,000 patient-year in CONVENTIONAL-INR group (p < 0.045, RR 0.37). In conclusions these data suggest that low-dose anticoagulation is safe in selected patients after aortic LivaNova Bicarbon prosthesis implantation.

Age and blood transfusion: relationship and prognostic implications in cardiac surgery.

BACKGROUND: Red blood cell (RBC) transfusion is a well-known predictor of acute kidney injury (AKI) and death after cardiac surgery. This study aimed to define the relationship between age and the need for RBC. METHODS: Study population included 1,765 consecutive patients undergoing on-pump procedures from 2013 to 2015. The relationship between RBC transfusion and both survival and AKI, and any interaction with age was estimated. A propensity score for the likelihood to receive RBC transfusion was calculated using multivariate logistic regression analysis to adjust for the effect of confounding factors. A logistic estimation curve was developed to investigate the interaction between this score and age. RESULTS: Patients receiving RBC transfusions had more comorbidities irrespective of age. Elderly patients underwent transfusion more often than younger patients with a 1.3-fold increase in the relative risk for transfusion. Age did not independently predict the need for RBC. AKI and mortality rates were significantly higher in transfused subsets irrespective of age. CONCLUSIONS: Comorbidity profile and not age per se confers an increased risk of transfusion.

Perioperative myocardial injury after adult heart transplant: determinants and prognostic value.

BACKGROUND AND AIM OF THE STUDY: Implications of Cardiac troponin (cTnI) release after cardiac transplantation are still unclear. This study disclosed risk factors and prognostic implication of cTnI early levels in a single centre cohort operated on between January 1999 and December 2010. METHODS: Data on 362 consecutive recipients (mean age: 47.8±13.7, 20.2% female, 18.2% diabetics, 22.1% with previous cardiac operations, 27.6% hospitalized, 84.9±29.4 ml/min preoperative glomerular filtration rate) were analyzed using multivariable logistic regression modeling. Target outcomes were determinants of troponin release, early graft failure (EGF), acute kidney injury (AKI) and operative death. RESULTS: Mean cTnI release measured 24 hours after transplant was 10.9±11.6 µg/L. Overall hospital mortality was 10.8%, EGF 10.5%, and AKI was 12.2%. cTnI release>10 µg/L proved an independent predictor of EGF (OR 2.2; 95% CI, 1.06-4.6) and AKI (OR 1.031; 95% CI, 1.001-1.064). EGF, in turn, proved a determinant of hospital mortality. Risk factors for cTnI>10 µg/L release were: status 2B (OR 0.35; 95% CI, 0.18-0.69, protective), duration of the ischemic period (OR 1.006; 95% CI, 1.001-1.011), previous cardiac operation (OR 2.9; 95% CI, 1.67-5.0), and left ventricular hypertrophy (OR 3.3; 95% CI, 1.9-5.6). CONCLUSIONS: Myocardial enzyme leakage clearly emerged as an epiphenomenon of more complicated clinical course. The complex interplay between surgical procedure features, graft characteristics and recipient end-organ function highlights cTnI release as a risk marker of graft failure and acute kidney injury. The search for optimal myocardial preservation is still an issue.

Pattern of resolution of pulmonary hypertension, long-term allograft right ventricular function, and exercise capacity in high-risk heart transplant recipients listed under oral sildenafil.

Unresponsive pulmonary hypertension (PH) implies poor posttransplant outcomes. Data on late adaptation of the right ventricle (RV) are still few. This study evaluated three-yr RV function and remodeling, exercise capacity, and hemodynamic data in a selected group of patients initially disqualified because of PH. Between May 2005 and December 2009, 31 consecutive patients were qualified for oral sildenafil because of unresponsive PH at baseline right heart catheterization (RHC). After a 12-wk trial, RHC disclosed PH reversibility (mean PVR: 5.41 ± 3 Wood units, mean TPG 14.5 ± 5.6 mmHg, and mean systolic PAP 68.9 ± 15.1 mmHg), allowing listing even though as high-risk procedures. All patients underwent heart transplantation. RV failure developed in three patients (9.6%), and hospital mortality was 3.2%. Protocol RHC disclosed pulmonary hemodynamic profile normalization within the third postoperative month, allowing weaning from sildenafil in the 30 hospital survivors. One- and three-yr RHCs confirmed stable PH reversal (n = 26, all three-yr survivors). Parameters of late RV function and remodeling proved satisfactory. Parameters of functional capacity (Vo2 peak 19.7 ± 3.6 mL/kg/min and slope VE/Vco2 34.8 ± 2.7) proved homogeneous to those measured in transplant recipients with normal preoperative pulmonary artery pressure. Oral sildenafil is effective in allowing candidacy, safe transplantation, and long-term survival in PH recipients initially disqualified.

Heart transplant with donor-specific antibody after immunoadsorption plus rituximab: a case report.

Different desensitization strategies are available for treating patients with preformed human leukocyte antigen (HLA) antibodies. A highly presensitized heart recipient received immunoadsorption and rituximab therapy. The patient, with end-stage heart failure, was positive only for antibodies of HLA class I (anti-A2, A10, B17), and Luminex platform (One Lambda kit) showed a panel-reactive antibody score of 64%. The patient's serum was tested repeatedly in both complement-dependent cytotoxicity and flow-cytometry crossmatches against cells from different potential organ donors. The results of these crossmatches were positive on flow cytometry when tested with HLA-A2, A10, and B17 but were still negative on cytotoxicity. The patient was treated with a desensitization regimen; this treatment immediately decreased antibody levels of 70% and the patient subsequently received a transplant with donor-specific HLA antibody (HLA-A2). After more than 2 years, graft function remains normal and the clinical status of the patient is stable.

Blood transfusion after on-pump coronary artery bypass grafting: focus on modifiable risk factors.

OBJECTIVES: Perioperative transfusions are known to increase morbidity and mortality after coronary artery bypass grafting (CABG). The aims of the study were (1) to identify the clinical profile of the patient subset at highest risk from transfusion and (2) to disclose causative relationship and dose-dependency of transfusion on hospital mortality. METHODS: A prospective observational design was employed on a cohort of 1047 consecutive patients (median age 63.2 ± 9.3, 18.8% female, 30.6% diabetics, 31.9% urgent/emergent, 15.3% with low preoperative left ventricular ejection fraction (LVEF)) who underwent on-pump isolated CABG between January 2004 and December 2007. Univariate and multivariate regression analysis and post-hoc risk stratification, by means of propensity scoring and binary segmentation, were adopted. RESULTS: The following independent risk factors were identified: age, body surface area (BSA), preoperative glomerular filtration rate, preoperative haemoglobin, surgical priority, length of cardiopulmonary bypass, intraoperative haemodilution and early postoperative blood loss. The patient population was stratified in quintiles of transfusional risk, by means of propensity scoring. As to modifiable risk factors, patients in the highest quintiles of risk were those with BSA ( < 1.73, preoperative haemoglobin < 12 g/dl, intraoperative haemoglobin < 8.0 g/dl and those undergoing cardiopulmonary bypass > 90'). Binary segmentation was performed to avoid any association between red cell transfusion and worse outcomes being causative and dose-dependent. A dose-dependent pattern was disclosed, with patients receiving > 5 units being at highest risk. CONCLUSIONS: High exposure to blood transfusions may be prevented by preoperative patient stratification and by the close tailoring of management strategies on planning and implementing surgical timing, as well as by cardiopulmonary bypass technique.

Early graft failure after heart transplant: risk factors and implications for improved donor-recipient matching.

Early graft failure (EGF) is a dreaded complication after heart transplantation (HT). Despite several improvements, no effective therapy has been developed and the prognosis is poor. We evaluated the risk factors and clinical impact of EGF. In a consecutive series of 317 HTs performed at a single institution between January 1999 and December 2008, variables associated significantly with EGF were sought in bivariate and multivariable discriminant analyses. The deriving propensity score was used to stratify the study sample in to three groups (low, intermediate and high risk for EGF). Comparisons were performed between the higher-risk group and the remaining population in terms of preoperative features and outcomes. EGF occurred in 10.1% of the overall population (2.9, 3.8 and 23.6%, respectively, in the three groups). Overall, EGF-related mortality was 56.3% (100, 75 and 48%, respectively, in the three groups). Determinants of EGF in the highest-risk group were: redo procedure, valvular cardiomyopathy, status one at transplant, recipient male sex, donor-recipient (D/R) weight mismatch, high inotropic donor support, ischaemic time and first day troponin I release. In conclusion, several donor and recipient features predicted EGF. Since such characteristics are not readily modifiable but synergistically determine the occurrence of EGF, optimization of D/R matching is crucial to prevent it.

Pulmonary artery hypertension in heart transplant recipients: how much is too much?

OBJECTIVES: Unresponsive pulmonary hypertension (PH) may contraindicate heart transplant since it implies poor early outcomes. The present study reports the effectiveness of oral perioperative sildenafil in allowing heart transplant candidacy and surgery in a selected group of patients initially deemed ineligible because of PH. METHODS: Between May 2005 and December 2009, 31 consecutive patients (5 females, 9 with a history of idiopatic cardiomyopathy and 16 with a history of coronary artery disease, 10 with previous sternotomies, 71.42 ± 27.69 ml/min/m(2) mean preoperative epidermal growth factor receptor) were qualified for oral sildenafil because of unresponsive PH at baseline right heart catheterization (RHC). After a 12-week trial, RHC disclosed PH reversibility (mean pulmonary vascular resistance index: 9.57 ± 4.07 WU, mean transpulmonary gradient 14.47 ± 5.66 mmHg and mean systolic pulmonary artery pressure: 68.96 ± 15.15 mmHg), allowing listing despite a higher risk for early post-transplant RV failure. Transplant protocol included donor/recipient size matching ≥ 0.8 and inhaled nitric oxide in the early postoperative period followed by reinstitution of oral sildenafil. RESULTS: All patients underwent heart transplantation. Mean overall graft ischaemic time was 179 ± 47 min; mean donor recipient weight ratio was 1.04 ± 0.17. Right ventricular failure developed in three patients (9.6%) and hospital mortality was 3.2%. Protocol RHC disclosed pulmonary haemodynamic profile normalization within the third postoperative month allowing weaning from sildenafil in the 30 hospital survivors. One-year RHC confirmed PH reversal (n = 29 patients, all who survived up to 1 year). CONCLUSIONS: This pilot prospective uncontrolled trial suggests that oral sildenafil is effective in allowing candidacy, safe transplantation and postoperative pulmonary profile normalization in potential recipients initially disqualified because of PH.

Mechanical aortic valve replacement in young women planning on pregnancy: maternal and fetal outcomes under low oral anticoagulation, a pilot observational study on a comprehensive pre-operative counseling protocol.

OBJECTIVES: This pilot prospective observational study aimed to evaluate the maternal and fetal outcomes of pregnancies under low-dose oral anticoagulation therapy after aortic mechanical replacement. BACKGROUND: Need for valve replacement is still an issue for young women with native valve disease who are planning on future pregnancy. Choice of replacement device is a challenging clinical task. METHODS: A comprehensive pre-operative counseling protocol to guide choice of replacement device was developed. The pre-operative anticoagulation trial to determine the warfarin daily dosage needed to reach target international normalized ratio (INR) represented the main stem of such protocol. Pregnancies on low-dose anticoagulation therapy (target INR: 1.5 to 2.5) were allowed in a highly selected subset of mechanical aortic valve recipients. RESULTS: Twenty-two patients of 40 originally referred for native valve disease surgery requiring valve replacement, safely underwent the pre-operative anticoagulation challenge. No maternal or fetal complications were detected in 16 pregnancies under low oral anticoagulation. Patterns of warfarin daily dosage and induced INRs were characterized during pregnancy. CONCLUSIONS: In this small sample observational study, a pre-operative anticoagulation therapy trial helped young women scheduled for valve replacement to acquire complete information as to the choice of prosthetic device. In selected third-generation mechanical aortic prosthesis recipients, low-dose anticoagulation therapy seems safe and feasible for both mother and fetus. Further studies are needed to validate this approach.

Nutritional issues in heart transplant candidates and recipients.

Heart transplant is the golden standard in the management of end-stage heart failure. Recent studies have pointed out the role of nutritional issues in patients evaluated for heart transplant listing. In particular, extremes in body habitus, cachexia and obesity, have been characterized and identified as independent prognostic factors and clinically relevant target for therapeutic interventions. Effects of such conditions exert a prognostic implication well beyond waiting time up to early post transplant setting. Changes in posttransplant clinical conditions and nutritional status have been recently described in their pattern of presentation and implications on weight gain, reversal of preoperative cachexia and early and late morbidity and mortality. New onset diabetes mellitus and metabolic syndrome have been disclosed as relevant clinical conditions in this setting. Implications for tailoring of immunosuppressive therapy and dietary prescription emerged as main stem of long term recipient management. All this issues have been reviewed focusing on the clinical relevance of this growing body of knowledge and emphasizing the role of a multidisciplinary approach for selection and management of heart transplant recipients.

Implications of acute kidney injury after heart transplantation: what a surgeon should know.

OBJECTIVE: Data regarding risks and consequences of acute kidney injury (AKI) after cardiac transplantation are dismissingly few and unclear. This study defined the incidence, risk factors and prognostic implication of AKI in a single-center cohort operated on between January 1999 and December 2008. METHODS: Data from 307 consecutive recipients (mean age: 47.42 ± 13.58, 20.5% female, 18.9% diabetics, 19.5% with previous cardiac operations, 26.4% hospitalized, 78.4 ± 33.7 ml min(-1) preoperative glomerular filtration rate (eGFR)) were analyzed using multivariable logistic regression modeling. AKI was defined according to RIFLE (Risk, Injury, and Failure; and Loss, and End-stage kidney disease) criteria. RESULTS: RIFLE scores of I or F were detected in 14%, and continuous venovenous hemofiltration was needed in 6.1%. Risk factors for AKI were: previous cardiac operation (odds ratio (OR) 2.35; 95% confidence interval (CI), 1.11-4.9), blood transfusion (OR 1.08; 95% CI, 1.011-1.16), troponin I release >10 (OR 1.031; 95% CI, 1.001-1.064), length of ischemic time (OR 1.008; 95% CI, 1.011-1.16). Overall hospital mortality averaged 7.8% and overall 1-year mortality was 10.4%; both mortality rates increased with each RIFLE stratification (Normal 3.4%, RIFLE R = 7.1%; RIFLE I = 25.7%; and RIFLE F = 37.5% and Normal 5.6%, RIFLE R = 11.8%, RIFLE I = 25.7%, and RIFLE F = 37.5%, respectively). AKI proved independent predictors of both early and 1-year mortality. The burden of AKI significantly affected 1-year kidney function (Δ preoperative GFR-1-year GFR in AKI vs no AKI = -25.872 ± 22.54 vs -7.968 ± 34.18, p = 0.015). CONCLUSIONS: AKI is a highly prevalent and prognostically important complication. Some of the risk factors for AKI identified may be modifiable.

Minimally-invasive coronary surgery in dextrocardia and situs inversus totalis.

Dextrocardia associated to situs inversus totalis is a rare congenital conditions (prevalence of 1:10,000) in which the organs are located in a symmetric or mirror position in the opposite side of the body. These individuals usually have a normal life expectancy and the same propensity to develop ischaemic coronary disease as the general population. We report a case of a 59-year-old female patient with a single-vessel obstructive coronary disease successfully resolved via a right anterior small thoracotomy on a beating-heart using the right internal thoracic artery as a conduit for 'left' anterior descending coronary artery.

Leukoreduction program for red blood cell transfusions in coronary surgery: association with reduced acute kidney injury and in-hospital mortality.

OBJECTIVE: Leukocytes in allogeneic blood transfusions cause several immunomodulatory events. This before-and-after cohort study evaluated clinical outcomes after adoption of prestorage leukoreduction program for blood transfusions, with particular focus on acute kidney injury. METHODS: One thousand thirty-four consecutive patients who underwent on-pump coronary artery bypass grafting between January 2004 and December 2007 were included. Propensity score analysis for transfusion was performed in the whole population; patients who were actually transfused were then divided according to leukoreduction. From these 2 groups, 147 pairs matched for propensity score were considered to evaluate with bivariate and multivariable analyses the effects of leukoreduction, with all-cause in-hospital mortality and morbidity as main outcomes. RESULTS: Unadjusted in-hospital mortalities were 6.6% for the entire cohort and 44.2% for those with acute kidney injury. In the matched population, after introduction of leukoreduction, mortality rates decreased to 5.4% (vs 11.4%) and acute kidney injury (RIFLE [Risk, Injury, Failure, Loss of function, End-stage renal disease] class R or greater) dropped from 51.7% to 41.5% (relative risk -20%, P < .045). No difference emerged regarding other major complications. At multivariable analysis, intra-aortic balloon pump, RIFLE score, and propensity score for transfusion proved independent predictors of in-hospital mortality. Intra-aortic balloon pump and nonleukodepleted transfusion emerged as independent predictors of acute kidney injury. Multivariable analysis on the overall cohort of transfused patients confirmed that nonleukodepleted transfusion was an independent predictor of acute kidney injury. CONCLUSIONS: Leukoreduction of allogeneic blood products is associated with decreased acute kidney injury and mortality in highly transfused patients.

RIFLE criteria for acute kidney injury in valvular surgery.

BACKGROUND AND AIM OF THE STUDY: The RIFLE classification, which defines three grades of increasing severity of acute kidney injury--risk (RIFLE R), injury (RIFLE I) and failure (RIFLE F), and two outcome classes (L, loss) and E (end-stage kidney disease)--represents a valuable method for evaluating acute renal failure. Risk factors for acute kidney injury (AKI) according to the RIFLE criteria and for operative mortality were identified in patients undergoing valvular procedures. METHODS: A single-center prospective cohort study of 1424 patients who were not receiving renal replacement therapy preoperatively was conducted between January 2004 and December 2007. A total of 100 variables was collected from each patient. RESULTS: The main features were: mean age 61.9 +/- 12.9 years (range: 15-88 years), 47% females, 6% endocarditis, 11% redo surgery, 8% urgent/emergent surgery, 30% combined procedures, 5% complex, and 16% associated coronary artery bypass grafting (CABG). The overall AKI prevalence was 10%, with RIFLE scores of I or F being detected in 8% and continuous veno-venous hemofiltration being required in 5%. Risk factors for AKI were age (OR 1.03; 95% CI 1.14-4.15), time of extracorporeal circulation (ECC) (OR 1.09; 95% CI 1.005-1.013), redo procedure (OR 2.35; 95% CI 1.42-3.8), chronic kidney disease (OR 3.2; 95% CI 1.6-6.1), and blood transfusion (OR 3.8; 95% CI 2.5-6.5). The transfusion of leukodepleted blood exerted a protective effect on AKI development (OR 0.6; 95% CI 0.4-0.9). The average overall hospital mortality was 4.8%. Risk factors for operative mortality included: ECC time (OR 1; 95% CI 1.002-1.014), age (OR 1.043; 95% CI 1.01-1.07), chronic kidney disease (OR 4.8; 95% CI 2.2-10.6), blood transfusion (OR 6.43; 95% CI 2.8-14.7), surgical priority (OR 6.5; 95% CI 2.8-14.7), RIFLE class I (OR 11.9; 95% CI 5.5-25.7), and RIFLE class F (OR 30; 95% CI 8.1-111.7). Mortality increased with each RIFLE stratification (Normal 1.7%, RIFLE R = 4.1%, RR = 2.5; RIFLE I = 27.6%, RR = 16.2; and RIFLE F = 43.8% RR = 25.8). CONCLUSION: AKI is a highly prevalent and prognostically important complication, for which the majority of risk factors that have been identified are not modifiable. The transfusion of leukodepleted blood products was seen to exert a preventive effect.

Preoperative anemia in patients undergoing coronary artery bypass grafting predicts acute kidney injury.

OBJECTIVES: Recent authoritative studies suggested that low preoperative hemoglobin concentration may affect cardiac surgery outcomes. This study aimed, primarily, to investigate whether preoperative anemia is an independent determinant of adverse events after coronary artery bypass grafting and, secondarily, to evaluate the potential dose responsiveness between anemia severity and primary end points. METHODS: This single-center prospective study investigated 1214 consecutive patients undergoing coronary artery bypass grafting between January 2004 and June 2007, collecting 100 variables per patient. In 1047 patients (median age 64 years, 18.8% female, 38.9% diabetic, 31.9% urgent/emergency, 15.3% with low preoperative left ventricular ejection fraction) who underwent on-pump procedures and received no preoperative transfusion, the prevalence of preoperative anemia (according to World Health Organization definition) and its unadjusted and adjusted relationships with in-hospital death, cardiac morbidity, and acute kidney injury (AKI-RIFLE [Risk, Injury, Failure, Loss, End-stage kidney disease] criteria) were obtained. RESULTS: The prevalence of preoperative anemia was 28%. In-hospital death averaged 3.9%, cardiac morbidity 7.3%, and acute kidney injury 4%. Unadjusted odds ratios (Ors) for in-hospital death, cardiac morbidity, and acute kidney injury were 3.8 (95% confidence interval [CI] 2.0-7.3), 1.7 (95% CI 1.1-2.8), and 4.0 (95% CI 2.1-7.6), respectively. Adjusting for anemia in confounders proved an independent predictor of acute kidney injury (OR 2.06; 95% CI 1.14-3.70), whereas the cardiac morbidity and in-hospital mortality were independently predicted by kidney function. No dose-response relationship emerged between anemia severity and acute kidney injury. CONCLUSIONS: Preoperative anemia is independently associated with acute kidney injury after coronary artery bypass grafting. Further studies are warranted to determine whether preoperative low hemoglobin concentration is a marker of severity of illness or a modifiable risk factor.

Noninvasive positive-pressure ventilation for extubation failure after cardiac surgery: Pilot safety evaluation.

OBJECTIVE: Extubation failure is a serious complication after cardiac surgery. The role of noninvasive positive-pressure ventilation for acute respiratory failure in patients undergoing cardiac surgery is unknown. This study aimed to assess the safety of implementing noninvasive positive-pressure ventilation in this setting and its impact on lung function and operative outcomes. METHODS: In a 6-month pilot prospective survey, the study population comprised 43 patients (32 were male with a mean age of 65.73 +/- 9 years; 3 heart transplantations, 18 coronary artery bypass grafts, 5 aortic dissections, and 17 valvular procedures; 34 active smokers, 25 with medically treated chronic obstructive pulmonary disease, 21 emergency/urgency procedures) who required noninvasive positive-pressure ventilation for acute respiratory failure after initial weaning from a respirator. The cause of acute respiratory failure (classified as post-cardiopulmonary bypass lung injury in 48.8% [21 patients], cardiogenic edema in 30.2% [13 patients], and pneumonia in 21% [9 patients]), length of noninvasive positive-pressure ventilation support, respiratory ratios (arterial oxygen tension/fraction of inspired oxygen assessed immediately before noninvasive positive-pressure ventilation, and every 6 hours after institution of pressure ventilation), and need for reintubation along with a set of predefined safety parameters were recorded. RESULTS: The mean length of noninvasive positive-pressure ventilation support was 33.8 +/- 24.04 hours. Plotting respiratory ratios with length of noninvasive positive-pressure ventilation supports a significant improvement was already evident within the first 6-hour frame (133.6 +/- 39.5 vs 205 +/- 65.7; P < .001) for all causes. Noninvasive positive-pressure ventilation prevented intubation in 74.4% of the patients, with satisfactory recovery for post-cardiopulmonary bypass lung injury and cardiogenic dysfunction (90.5% and 69.2%, respectively) and poor results (55% reintubated) in those treated for pneumonia. Noninvasive positive-pressure ventilation safety approached 97.7%. CONCLUSION: In appropriate candidates, noninvasive positive-pressure ventilation exerts favorable effects on lung function, preventing reintubation. The cost-effectiveness of its systematic use in this setting should be assessed.

Acute hemodynamic and functional effects of surgical ventricular restoration and heart transplantation in patients with ischemic dilated cardiomyopathy.

OBJECTIVES: Peak oxygen uptake (VO(2)) and ventilatory efficiency have prognostic implications in the population with congestive heart failure. This study evaluated quality-of-life functional capacity after the 2 treatment strategies of surgical ventricular restoration and transplantation for severe left ventricular dysfunction of ischemic cause. METHODS: The 75-patient study population (between 2004 and 2006) with severe heart failure included 35 patients undergoing surgical ventricular restoration (mean age, 62.6 +/- 8.7 years), sometimes together with coronary artery bypass grafting or mitral surgery, and 40 cardiac transplant recipients (mean age, 55.6 +/- 7.7 years). Preoperative and 6-month postoperative function (peak VO(2), the anaerobic threshold, and the slope of minute ventilation/carbon dioxide uptake), cardiac catheterization parameters (left and right), and hospital and early outcomes were evaluated. RESULTS: The 2 groups had comparable baseline functional impairment and experienced similar hospital stay and early outcomes. They also showed similar improvements in left ventricular volume indexes and hemodynamic parameters and sustained significant improvements of median VO(2), anaerobic threshold, and minute ventilation/carbon dioxide uptake values. CONCLUSIONS: Both surgical strategies resulted in a significant and comparable improvement of functional capacity at the 6-month evaluation. These early studies must be repeated to determine the long-term benefits of surgical ventricular restoration because maximal VO(2) and ventilatory efficiency lose their prognostic survival role after transplantation.