Risk of Hypovitaminosis and Vitamin C Deficiency in Pediatric Patients Undergoing Cardiopulmonary Bypass.

Vitamin C levels are known rapidly decrease in adult critical illness. Vitamin C scavenges free radicals, provides critical protection of the endothelial barrier, and improves endothelial responsiveness to catecholamines. Children with congenital heart disease and undergoing cardiac surgery might be at increased risk for low circulating vitamin C levels. A prospective single-center observational study investigated perioperative changes in vitamin C levels in critically ill Children who underwent congenital heart surgery using CPB. Vitamin C serum levels were collected preoperatively and postoperatively (upon admission to the ICU, 24 and 72 h). Linear mixed-effect model was used to estimate mean circulating concentration of vitamin C and to estimate changes in concentration over time. Primary outcome was change in circulating levels of vitamin C before and after CPB. Secondary outcomes were hospital length of stay (LOS), acute kidney injury (AKI), and illness severity. Forty-one patients with a median age of 4.5 [interquartile range (IQR) 2.6-65.6] months at the time of surgery were consented and enrolled. Median CPB duration was 130 [90-175] minutes, and hospital LOS was 9.1 [5.2-19] days. Mean vitamin C levels (µmol/L) before CPB, at PICU admission, 24 h, and 72 h were 82.0 (95% CI 73.4-90.7), 53.4 (95% CI 44.6,62.0), 55.1 (95% CI 46.3,63.8), and 59.2 (95% CI 50.3,68.1), respectively. Upon postoperative admission to the PICU, vitamin C levels decreased by 28.7 (95% CI 20.6-36.8; p < 0.001) µmol/L, whereas levels at 24 and 72 h recovered and did not differ substantially from concentrations reported upon PICU admission (p > 0.15). Changes in vitamin C concentration were not associated with CPB time, STAT mortality category, age, or PIM3. Three patients had post-CPB hypovitaminosis C or vitamin C deficiency. Reduction in vitamin C levels was not associated with hospital LOS (p = 0.673). A 25 µmol/L decrease in vitamin C levels upon PICU admission was associated with developing AKI (aOR = 3.65; 95% CI 1.01-18.0, p = 0.049). Pediatric patients undergoing cardiac surgery with CPB showed decreased vitamin C levels during the immediate postoperative period. Effects of hypovitaminosis C and vitamin C deficiency in this population remain unclear.

Consequences of anastomotic leaks after minimally invasive esophagectomy: A single-center experience.

Background: Anastomotic leak (AL) after minimally invasive esophagectomy (MIE) is a well-described source of morbidity for patients undergoing surgical treatment of esophageal neoplasm. With improved early recognition and endoscopic management techniques, the long-term impact remains unclear. Methods: A retrospective review was conducted of patients who underwent MIE for esophageal neoplasm between January 2015 and June 2021 at a single institution. Cohorts were stratified by development of AL and subsequent management. Baseline demographics, perioperative data, and post-operative outcomes were examined. Results: During this period, 172 MIEs were performed, with 35 of 172 (20.3%) complicated by an AL. Perioperative factors independently associated with AL were post-operative blood transfusion (leak rate 52.9% versus 16.8%; p = 0.0017), incompleteness of anastomotic rings (75.0% vs 19.1%; p = 0.027), and receiving neoadjuvant therapy (18.5% vs 30.8%; p < 0.0001). Inferior short-term outcomes associated with AL included number of esophageal dilations in the first post-operative year (1.40 vs 0.46, p = 0.0397), discharge disposition to a location other than home (22.9% vs 8.8%, p = 0.012), length of hospital stay (17.7 days vs 9.6 days; p = 0.002), and time until jejunostomy tube removal (134 days vs 79 days; p = 0.0023). There was no significant difference in overall survival between patients with or without an AL at 1 year (79% vs 83%) or 5 years (50% vs 47%) (overall log rank p = 0.758). Conclusions: In this large single-center series of MIEs, AL was associated with inferior short-term outcomes including hospital length of stay, discharge disposition other than to home, and need for additional endoscopic procedures, without an accompanying impact on 1-year or 5-year survival. Key message: In this large, single-center series of minimally invasive esophagectomies, anastomotic leak was associated with worse short-term outcomes including hospital length of stay, discharge disposition other than to home, and need for additional endoscopic procedures, but was not associated with worse long-term survival. The significant association between neoadjuvant therapy and decreased leak rates is difficult to interpret, given the potential for confounding factors, thus careful attention to modifiable pre- and peri-operative patient factors associated with anastomotic leak is warranted.

Body mass Index does not impact long-term survival of patients with idiopathic pulmonary fibrosis undergoing lung transplantation.

Objective: We investigated the impact of body mass index (BMI) on post-operative outcomes and survival of patients with interstitial pulmonary fibrosis (IPF) undergoing lung transplantation. Methods: We retrospectively reviewed 222 patients with IPF that underwent lung transplant (LT) at our institution from 2005 to 2019. Recipients were divided in 4 groups: group-1 consisted of underweight patients (BMI ≤18.5 kg/m2), group-2 of normal weight patients (BMI 18.5-25 kg/m2), group-3 of over-weight patients (BMI 25-29.9 kg/m2) and group-4 of obese patients (BMI ≥30 kg/m2). Results: Group-1 consisted of 13 (6%) patients, group-2 of 67 (30%) patients, group-3 of 79 (36%) patients, group-4 consisted of 63 (28%) patients. Median BMI for group-1 was 17 [interquartile range (IQR): 17, 18], for group-2 was 23 (22, 24), for group-3 was 29 (28, 29.5) and group-4 was 32 (31, 33). Patients in group-1 were significantly younger (p < 0.01). Single LT comprised the majority of operation type in group-2 to group-4 and it was significantly higher than group 1 (p < 0.01). Median follow-up time was 39 months (13-76). A total of 79 (35.5%) patients died by the end of study. Overall, five deaths occurred in group-1, 17 in group-2, 33 in group-3, and 24 in group-4. Kaplan-Meier analysis showed that mortality was not statistically significant between the groups (p = 0.24). Cox-regression analysis was used to assess other possible risk factors that could influence the effect of BMI on mortality, including transplant type (single, double), lung allocation score, and age, diabetes and creatinine levels at surgery. None of these factors were shown to affect patient mortality (p > 0.05). Overall reasons for death included graft failure (24%), infection (23%), respiratory failure (14%), and malignancy (13%). Conclusions: Body mass index does not impact long-term survival of patients with IPF undergoing lung transplantation.

Impact of distance from implant center on mechanical circulatory device patient outcomes.

OBJECTIVES: Patients on left ventricular assist device (LVAD) support receive extensive care and education before discharge home. We investigated the impact of patient's residential distance from LVAD implantation center on outcomes and survival. METHODS: A total of 214 patients received a LVAD between 2006 and 2018 at our institution. Patient's residential distance from the LVAD implantation center, LVAD complications, hospitalization, and death were recorded. Patients were divided into two groups: patients living less than or equal to 100 miles (Group 1), patients living more than 100 (Group 2). RESULTS: A total of 106 patients were assigned to Group 1 and 108 patients were assigned to Group 2. Destination therapy was intended in 20% of patients in Group 1 and 34% in Group 2 (p = .023). Mean length of stay was 13 ± 9 days for Group 1 and 21 ± 12 for Group 2 (p < .001). Major postoperative complications were unplanned readmissions due to infections (9% and 12%), gastrointenstinal bleeding (15% and 14%), cerebrovascular accidents (6% and 7.4%), and acute kidney injury (5% and 2%), respectively for Group 1 and Group 2. There was no difference in major complications (all p > .05) and survival between patients in both groups (p > .05). CONCLUSIONS: Distance from implanting center had no impact on adverse outcomes after LVAD implantation. There was a significant increase in hospital stay for patients who live far from the implanting center, suggesting that distance should not be a contraindication when considering patients for LVAD therapy, but plans should be made for prolonged hospital stay or extended local stay near the hospital for close follow-up.

Prophylactic Peritoneal Drainage is Associated with Improved Fluid Output after Congenital Heart Surgery.

Infants undergoing congenital heart surgery (CHS) with cardiopulmonary bypass (CPB) are at risk of acute kidney injury (AKI) and fluid overload. We hypothesized that placement of a passive peritoneal drain (PPD) can improve postoperative fluid output in such infants. We analyzed 115 consecutive patients, age birth to 60 days, admitted to the PICU after CHS with CPB between 2012 and 2018. Patients who needed postoperative ECMO were excluded. Linear and logistic regression models compared postoperative fluid balances, diuretics administration, AKI, vasoactive-inotropic scores (VIS), time intubated, and length of stay after adjusting for pre/operative predictors including STAT category, bypass time, age, weight, and open chest status. PPD patients had higher STAT category (p = 0.001), longer CPB times (p = 0.001), and higher VIS on POD 1-3 (p ≤ 0.005 daily). PPD patients also had higher AKI rates (p = 0.01) that did not reach significance in multivariable modeling. There were no postoperative deaths. Postoperative hours of intubation, hospital length of stay, and POD 1-5 fluid intake did not differ between groups. Over POD 1-5, PPD use accounted for 48.8 mL/kg increased fluid output (95% CI [2.2, 95.4], p = 0.043) and 3.41 mg/kg less furosemide administered (95% CI [1.69, 5.14], p < 0.001). No PPD complications were observed. Although PPD placement did not affect end-outcomes, it was used in higher acuity patients. PPD placement is associated with improved fluid output despite lower diuretic administration and may be a useful postoperative fluid management adjunct in some complex CHS patients.

Beyond 30 Days: Analysis of Unplanned Readmissions During the First Year Following Congenital Heart Surgery.

OBJECTIVE: We investigated the incidence and etiologies for unplanned hospital readmissions during the first year following congenital heart surgery (CHS) at our institution and the potential association of readmissions with longer term survival. METHODS: We retrospectively reviewed 263 patients undergoing CHS at our institution from August 2011 to June 2015. Scheduled readmissions were excluded. RESULTS: Seventy patients accrued a total of 120 readmissions (1.7 readmission/patient) within one year after surgery. The first readmission for 57% of the patients was within 30 days postdischarge. Twenty-two patients were first readmitted between 31 and 90 days postdischarge. Eight patients were first readmitted between 90 days and 1 year postdischarge. Median time-to-first readmission was 21 days. Median hospital length of stay at readmission was two days. Causes of 30-day readmissions included viral illness (25%), wound infections (15%), and cardiac causes (15%). Readmissions between 30 and 90 days included viral illness (27%), gastrointestinal (27%), and cardiac causes (9%). Age, STAT category, length of surgery, intubation, intensive care unit, and hospital stay were risk factors associated with readmissions based on logistic regression. Distance to hospital had a significant effect on readmissions (P < .001). Patients with higher family income were less likely to be readmitted (P < .001). There was no difference in survival between readmitted and non-readmitted patients (P = .68). CONCLUSIONS: The first 90 days is a high-risk period for unplanned hospital readmissions after CHS. Complicated postoperative course, higher surgical complexity, and lower socioeconomic status are risk factors for unplanned readmissions the first 90 days after surgery. Efforts to improve the incidence or readmission after CHS should extend to the first 3 months after surgery and target these high-risk patient populations.

Technical Performance Score Predicts Perioperative Outcomes in Complex Congenital Heart Surgery Performed in a Small-to-Medium-Volume Program.

As the quality of surgical outcomes depend on many factors, the development of validated tools to assess the different aspects of complex multidisciplinary teams' performance is crucial. The Technical Performance Score (TPS) has only been validated to correlate with outcomes in large-volume surgical programs. Here we assess the utility of TPS in correlation to perioperative outcomes for complex congenital heart surgeries (CHS) performed in a small-to-medium-volume program. 673 patients underwent CHS from 4/2012 to 12/2017 at our institution. Of those, 122 were STAT 4 and STAT 5. TPS was determined for each STAT 4 and STAT 5 operation using discharge echocardiogram: 1 = optimal, 2 = adequate, 3 = inadequate. Patient outcomes were compared including mortality, length of stay, ventilation times, and adverse events. 69 patients (57%) were neonates, 32 (26%) were infants, 17 (14%) were children, 4 (3%) were adults. TPS class 1 was assigned to 85 (70%) operations, TPS class 2 was assigned to 25 (20%) operations, and TPS class 3 was assigned to 12 (10%) operations. TPS was associated with re-intubation, ICU length of stay, postoperative length of stay, and mortality. TPS did not correlate with unplanned 30-day readmissions, need for reoperation, and inotropic score. Technical performance score was associated with perioperative outcomes and is a useful tool to assess the adequacy of repair for high complexity CHS in a small-to-medium-volume surgical program. TPS should be a part of program review in congenital heart programs of all sizes to identify strategies that may reduce postoperative morbidity and potentially improve long-term outcomes.

The Mitral Monobloc: A Simplification for Intervalvular Fibrous Body Reconstruction in Endocarditis.

The only viable option in prosthetic valve endocarditis with extensive abscess of the aorto-mitral curtain is radical debridement and reconstruction of the intravalvular fibrous body. This report details a simplified intravalvular fibrous body reconstruction technique.

Cardiac Surgery Outcomes in Abdominal Solid Organ Transplant Recipients.

BACKGROUND: Cardiovascular disease is a cause of morbidity and mortality in organ transplant recipients. Cardiac surgery after organ transplantation is not uncommon in this population. We evaluated 30-day outcomes and long-term survival of abdominal transplant recipients undergoing cardiac surgery at our institution. METHODS: In all, 138 patients with previous kidney, kidney-pancreas, and liver transplants underwent cardiac surgery from 2000 to 2016. Propensity score (ratio 1:3) matched 115 abdominal transplant with 345 patients undergoing cardiac surgery without a history of abdominal transplant. They were matched for type and year of cardiac surgery, age, sex, body mass index, history of diabetes mellitus, and creatinine level before cardiac surgery. RESULTS: Median time from abdominal transplant to cardiac surgery was 7 years (interquartile range, 3 to 12 years). Perioperative variables, including surgery and cardiopulmonary bypass time, aortic cross-clamp and intubation time, and intensive care unit stay did not differ between the groups. Hospital length of stay and rate of 30-day hospital readmissions did not differ between the groups. Patients with abdominal transplants had more strokes (4% versus 0.6%; p = 0.005) within 30 days after surgery. There were no differences in renal failure, bleeding, site infections, atrial fibrillation, and pneumonia between the groups. Five patients (4%) died within 30 days after surgery in the abdominal transplant group (4 kidneys, 1 liver, 0 kidney-pancreas), and 7 patients (2%) died in the nontransplanted group (p = 0.24). CONCLUSIONS: Previous history of abdominal transplant is associated with an increased 30-day incidence of stroke after cardiac surgery. Abdominal transplant does not affect 30-day mortality after cardiac surgery, whereas long-term survival is significantly reduced. Regular patient follow-up and prevention and early treatment of postoperative complications are key to patient survival.

Digital PCR Quantitation of Muscle Mitochondrial DNA: Age, Fiber Type, and Mutation-Induced Changes.

Definitive quantitation of mitochondrial DNA (mtDNA) and mtDNA deletion mutation abundances would help clarify the role of mtDNA instability in aging. To more accurately quantify mtDNA, we applied the emerging technique of digital polymerase chain reaction to individual muscle fibers and muscle homogenates from aged rodents. Individual fiber mtDNA content correlated with fiber type and decreased with age. We adapted a digital polymerase chain reaction deletion assay that was accurate in mixing experiments to a mutation frequency of 0.03% and quantitated an age-induced increase in deletion frequency from rat muscle homogenates. Importantly, the deletion frequency measured in muscle homogenates strongly correlated with electron transport chain-deficient fiber abundance determined by histochemical analyses. These data clarify the temporal accumulation of mtDNA deletions that lead to electron chain-deficient fibers, a process culminating in muscle fiber loss.

To use or not to use? Amiodarone before heart transplantation.

BACKGROUND: Amiodarone frequently is used in patients with heart failure. Concerns still exist about possible complications related to its lingering effect during and after heart transplantation. METHODS: We selected all consecutive patients who received a heart transplant at our institution between January 2004 and December 2015 (n = 220) and compared the peri- and postoperative outcomes of patients who were taking amiodarone for at least 120 days before heart transplant (n = 127) with patients who did not take amiodarone prior to heart transplant (n = 93). RESULTS: Compared with patients with no amiodarone use prior to transplant, those who had used amiodarone were similar in age, body mass index, sex, cause of cardiomyopathy, prevalence of diabetes, hypertension, presence of defibrillator, and had similar donor ischemic times during transplant (all P > .05). Median operative time, aortic cross clamp time, mechanical ventilation and median hospital duration of stay did not differ between the 2 groups (P > .05). Patients exposed to amiodarone had fewer cellular rejections (5% vs 20%; P = .001) but more primary graft dysfunction (4% vs 0%; P = .025) and post-transplant pneumonia (P = .047) compared with patients not taking amiodarone prior to transplant. Both groups had similar rate of atrial fibrillation, 30-day readmission, and 30-day mortality (P > .05). Even though 1-year survival was not affected by amiodarone use (P = .51), long-term (5-year) survival was significantly less in patients exposed to amiodarone (P = .03). CONCLUSION: Amiodarone use did not affect the incidence of atrial fibrillation nor 30-day and 1-year survival post-transplantation. Nevertheless, post-transplant pulmonary complications were significantly greater and 5-year survival was less among patients treated with amiodarone prior to transplant.

Short-term clinical outcomes after off-pump coronary artery bypass grafting at a single Veterans Affairs Medical Center.

BACKGROUND: We retrospectively assessed the outcomes after coronary revascularization at a single Veterans Affairs Medical Center when a strategy of assigning higher risk patients to off-pump coronary artery bypass grafting (CABG) was employed. METHODS: Over a 5 year period all consecutive patients that underwent CABG at our VA Medical Center were assigned to a surgeon who either performs the CABG exclusively off-pump or to one who performed the CABG on-pump. The higher risk patients were assigned preferentially for off-pump revascularization. VASQIP (VA Hospitals Surgical Quality Improvement Program) data between 10/2007 and 12/2012 were retrospectively reviewed at our VA Medical Center and the short term outcomes were assessed. RESULTS: A total of 252 consecutive patients underwent off-pump CABG (n = 170) and on-pump CABG (n = 82). There were significantly more patients with low LVEF (<45 %; p = 0.008) and cerebrovascular disease in the off-pump group (p = 0.024). The number of patients smoking at the time of surgery was significantly higher in the off-pump group (p = 0.002) as well. The 30-day composite morbidity and mortality was 6 % for all CABG patients and significantly lower with off-pump vs. on-pump CABG (3.5 % vs. 11 %; p = 0.019). There were no conversions from off-pump to on-pump surgery. CONCLUSIONS: A selective strategy to direct higher risk patients towards an off-pump revascularization yielded favorable outcomes in an unselected veteran population treated at a single VA Medical Center over a 5 year period.

Timely Post-discharge Telephone Follow-Up is a Useful Tool in Identifying Post-discharge Complications Patients After Congenital Heart Surgery.

The objective of this study was to evaluate the effect of structured post-discharge telephone follow-up (TFU) on the time to the first postoperative clinic visit and early unplanned hospital readmissions in patients after congenital heart surgery. Structured phone calls delivered by senior surgical practitioners were made 1-4 days post-discharge. Demographics and clinical outcomes of pediatric patients receiving a TFU from 2012 to 2014 were assessed. In total, 196 phone calls were made in 165 patients. Thirty-four health problems were identified in 32 (19 %) patients (15 infants, 9 children, 8 neonates). Sixty-nine percent (n = 22) of the patients with problems identified at TFU were males. Fifty-three percent (n = 17) of the patients with problems identified at TFU were RACHS 2. Most of the problems (53 %) were identified in middle-class economic families. Gastrointestinal and incision site complications were the most common problems identified. Eighteen (56 %) patients had adjustments of medications. Six (19 %) TFUs resulted in earlier than scheduled post-op clinic visits. Overall incidence of unplanned readmissions was 16 % and similar between the patients that had problems during TFU (13 %) and patients that did not have problems identified at TFU (18 %; p = 0.50). Our study demonstrates the potential impact of the timely and structured post-discharge TFU in identifying post-discharge complications and modifying discharge instructions. When TFU identifies a problem, the interventions may be successful in preventing readmissions before first postoperative clinic visit. TFUs may be helpful, as a supplement standard of care with specific focus on patients <1 year of age to help identify adverse events that could otherwise escalate.

Recurrent severe aortic stenosis one year after transcatheter aortic valve-in-valve implantation: Successful treatment with balloon aortic valvuloplasty.

Transcatheter aortic valve-in-valve (VIV) implantation has evolved as one of the primary therapeutic modalities in patients with failed surgical bioprosthesis allowing a reduction in rate of surgical reintervention. We report a case of a 90-year-old woman who had previously undergone aortic valve replacement with 21-mm Carpentier-Edwards valve in 1999 followed by 23 mm Sapien VIV in March 2013. She developed severe recurrent aortic stenosis 1-year post-VIV which was successfully treated with balloon aortic valvuloplasty (BAV). BAV can be a favorable treatment option allowing considerable symptomatic relief and improvement in performance of daily activities in extreme age patients who develop restenosis after VIV implantation and are high-risk candidates for both redo-surgical aortic valve replacement and redo-VIV implantation. .

Hospital Readmissions After Continuous-Flow Left Ventricular Assist Device Implantation: Incidence, Causes, and Cost Analysis.

BACKGROUND: We investigated the incidence and causes of unplanned hospital readmissions after continuous-flow (CF) left ventricular assist device (LVAD) implantation. We also analyzed the impact of unplanned readmissions on post-CF-LVAD survival and the costs associated with each cause of readmission. METHODS: We retrospectively reviewed 126 patients who underwent implantation with a CF-LVAD from January 2007 to December 2013. The timing of readmissions, hospital length of stay, and total length of device support were evaluated. Patients were followed up while receiving support, until transplantation, or until death. Direct hospital costs associated with each readmission were analyzed. RESULTS: In all, 103 patients underwent implantation for bridge to transplantation and 19 patients for destination therapy; 68 patients were readmitted 156 times (2.2 times/patient) as of the end of follow-up. The median follow-up period was 11 months. While receiving device support, patients spent 93% of their time out of the hospital. The causes of readmission included gastrointestinal bleeding (19%), driveline infection (13%), and stroke (8%). The median time to first readmission was 35 days. Thirty (44%) patients were readmitted within 30 days after discharge. The median direct hospital cost of a single readmission was $7,546. Device malfunction and arrhythmias were the most costly causes of readmission. There was no significant difference in long-term survival between readmitted patients and those who were not readmitted. CONCLUSIONS: Gastrointestinal bleeding and CF-LVAD-related infections were the leading causes of readmission. Patients with a CF-LVAD spent 93% of their time out of hospital after implantation, and readmissions did not have a negative impact on long-term survival. New approaches to minimize these adverse events will continue to improve the efficacy and decrease the cost of CF-LVAD therapy.

Impact of age on outcomes following continuous-flow left ventricular assist device implantation.

OBJECTIVES: The goal of our study was to analyse the impact of age on outcomes in patients who underwent continuous-flow left ventricular assist device (CF-LVAD) placement at our institution. METHODS: One hundred and twenty-eight patients were implanted with a CF-LVAD between January 2008 and June 2014. Eighty-five patients were implanted with the device as a bridge to transplant (BTT); the remaining (n = 43) were on destination therapy (DT). Each group was divided into patients <65 years old and ≥ 65 years old at device implantation. Patients were followed up for at least 24 months or until transplant or death. RESULTS: Eighty-five patients (66%) received a CF-LVAD as BTT. Patients ≥ 65 years old (n = 8) had a lower preoperative cardiac index and prothrombin time-international normalized ratio (P = 0.009), and a longer stay in the intensive care unit (P = 0.008). Adverse events including infections, re-exploration for bleeding, ischaemic and haemorrhagic stroke, renal failure and right heart failure were comparable in both age groups. Eighty-two percent (n = 63) of the young patients and 75% (n = 6) of the older patients, who were on LVAD as BTT, underwent heart transplant within the first 24 months of LVAD implantation. Overall survival at 3, 6, 12 and 24 months were 95, 95, 77 and 70%, respectively, post-CF-LVAD implantation as BTT for the younger group and 73% for the older group at 3, 6 and 12 months (P = 0.35). Forty-three patients (34%) received a CF-LVAD as DT. Patients ≥ 65 years old (n = 14) on DT had a higher incidence of peripheral vascular disease (P = 0.048), higher serum sodium (P = 0.004) and serum creatinine values (P = 0.002), preoperatively. There were more strokes in the older patients post-LAVD implantation (14 vs 0%; P = 0.048). Overall survival at 3, 6, 12 and 24 months were 85, 79, 75 and 62%, respectively, for the younger group and 93, 77, 67 and 34% for the older group, respectively (P = 0.26). CONCLUSIONS: This study demonstrates that LVAD therapy can be used in the older patients with acceptable mortality and morbidity, and age alone should not be used as the sole criterion for exclusion from LVAD implantation.

Functional evaluation of human donation after cardiac death donor hearts using a continuous isolated myocardial perfusion technique: Potential for expansion of the cardiac donor population.

OBJECTIVE: To investigate the resuscitation potential and contractile function in adult human donation after cardiac death (DCD) hearts by ex vivo perfusion. METHODS: With institutional review board approval and under the DCD protocol at the University of Wisconsin (UW) Organ Procurement Organization, 5 brain dead (BD) and 5 DCD donor hearts were evaluated. All BD hearts were declined for clinical transplantation because of coronary artery disease, advanced age, or social history. All hearts were preserved by flushing and cold storage with UW solution. By using our ex vivo perfusion system, the left ventricular end systolic pressure-volume relationship (LV-ESPVR) was assessed for 2 hours of oxygenated blood reperfusion. RESULTS: All BD (n = 5) and 4 DCD hearts were successfully resuscitated. One DCD heart was unable to be resuscitated due to prolonged warm ischemic time (WIT; 174 minutes). Mean WIT for resuscitated DCD hearts (from extubation to flushing with cold UW solution) was 34 ± 3 minutes (range, 26 to 40 minutes); mean cold ischemic time for BD donors was 211 ± 31 minutes compared with 177 ± 64 minutes for DCD donors. The calculated LV-ESPVRs for BD hearts after 1 and 2 hours of reperfusion were 6.9 ± 0.7 and 5.7 ± 1.0 mm Hg/mL, respectively; LV-ESPVRs for DCD hearts after 1 and 2 hours of reperfusion were 5.6 ± 1.5 (P = .45) and 3.0 ± 0.7 mm Hg/mL (P = .07), respectively. CONCLUSIONS: We successfully resuscitated and measured ex vivo cardiac function in human DCD and BD donor hearts. Resuscitation potential in DCD hearts was achieved when the WIT was less than 40 minutes. Contractile performance in DCD hearts tended to be lower compared with BD hearts. Further investigation with longer reperfusion periods seems warranted.

Acuity adaptable patient care unit system shortens length of stay and improves outcomes in adult cardiac surgery: University of Wisconsin experience.

OBJECTIVES: The Acuity Adaptable Patient Care (AAC) unit system allows all beds within a nursing unit to negate the need for transfer with changes in patient status. The unit is specialty specific to all levels of patient care. This system was implemented in March 2006 for cardiothoracic surgery at our institution. The purpose of this study was to evaluate the impact of the AAC system on the outcomes after adult cardiac surgery. METHODS: We retrospectively reviewed 2930 consecutive patients who underwent major adult cardiac procedures between January 2003 and December 2010. The cohorts were divided into the pre-AAC group (January 2003 to February 2006, n = 1029) and the AAC group (March 2006 to December 2010, n = 1901). Patient demographics and postoperative outcomes were assessed. RESULTS: The proportion of coronary artery bypass grafting was significantly lower (pre-AAC vs AAC: 43 vs 35%, P < 0.01), while those of aortic procedure (4 vs 11%, P < 0.01) and mechanical assist device insertion (3 vs 5%, P = 0.02) were higher in the AAC group. After the implementation of the AAC system, the incidence of all complications defined by the Society of Thoracic Surgeons (STS) database (49 vs 34%, P < 0.01), the median length of intensive care unit (ICU) stay (49 [interquartile range (IQR), 27-99] vs 26 [19-45] h, P < 0.01), that of hospital stay (6 [4-10] vs 5 [4-7] days, P < 0.01) and the readmission rate of ICU (5 vs 2% P < 0.01) were significantly decreased. Significant reductions in hospital mortality and the rate of hospital readmission <30 days were not observed. CONCLUSIONS: The implementation of the AAC system has improved the outcomes after major cardiac procedures. The incidence of postoperative complications and length of stay have all decreased significantly without increasing readmission rate. AAC creates a system of fluid care with specialty-trained nursing and other ancillary support that expedites discharge and improves overall patient outcomes.

Mitochondrial DNA deletion mutations in adult mouse cardiac side population cells.

We investigated the presence and potential role of mitochondrial DNA (mtDNA) deletion mutations in adult cardiac stem cells. Cardiac side population (SP) cells were isolated from 12-week-old mice. Standard polymerase chain reaction (PCR) was used to screen for the presence of mtDNA deletion mutations in (a) freshly isolated SP cells and (b) SP cells cultured to passage 10. When present, the abundance of mtDNA deletion mutation was analyzed in single cell colonies. The effect of different levels of deletion mutations on SP cell growth and differentiation was determined. MtDNA deletion mutations were found in both freshly isolated and cultured cells from 12-week-old mice. While there was no significant difference in the number of single cell colonies with mtDNA deletion mutations from any of the groups mentioned above, the abundance of mtDNA deletion mutations was significantly higher in the cultured cells, as determined by quantitative PCR. Within a single clonal cell population, the detectable mtDNA deletion mutations were the same in all cells and unique when compared to deletions of other colonies. We also found that cells harboring high levels of mtDNA deletion mutations (i.e. where deleted mtDNA comprised more than 60% of total mtDNA) had slower proliferation rates and decreased differentiation capacities. Screening cultured adult stem cells for mtDNA deletion mutations as a routine assessment will benefit the biomedical application of adult stem cells.

Intravital microscopy to study myocardial engraftment.

Tissue engineering and stem cell transplantation are promising novel therapies for myocardial repair. A major barrier to cell survival after transplantation involves inadequate vascularization. Continuous observation of cardiac tissue engraftment and angiogenesis could help understand these processes and allow for identification of the optimal conditions for these therapeutic interventions. We investigated the ability of a skin-fold chamber model to allow for engraftment of differentiated myocardial tissue in mice. Neonatal atrial and ventricular tissues were implanted in the in vivo chambers. All myocardial implants had a high rate of engraftment (86-95%). Tissue engraftment was preceded by a 'bleeding phase' in both the atrial and ventricular implants. This occurred earlier in ventricular compared with atrial implants. Spontaneous contractions were observed after an average of 13 days after implantation in all chambers but occurred earlier in ventricular compared with atrial implants. The host cells surrounded the myocardial implants circumferentially, but have limited infiltration into these grafts. This is the first report of successful ectopic engraftment of differentiated myocardium using a skin-fold chamber. This model is invaluable for real-time observation of early angiogenesis and tissue growth during in vivo myocardial engineering and myocardial regeneration.