Recipient and surgical factors trigger severe primary graft dysfunction after heart transplant.

BACKGROUND: Primary graft dysfunction (PGD) is a major cause of early mortality following heart transplant (HT). The International Society for Heart and Lung Transplantation (ISHLT) subdivides PGD into 3 grades of increasing severity. Most studies have assessed risk factors for PGD without distinguishing between PGD severity grade. We sought to identify recipient, donor and surgical risk factors specifically associated with mild/moderate or severe PGD. METHODS: We identified 734 heart transplant recipients at our institution transplanted between January 1, 2012 and December 31, 2018. PGD was defined according to modified ISHLT criteria. Recipient, donor and surgical variables were analyzed by multinomial logistic regression with mild/moderate or severe PGD as the response. Variables significant in single variable modeling were subject to multivariable analysis via penalized logistic regression. RESULTS: PGD occurred in 24% of the cohort (n = 178) of whom 6% (n = 44) had severe PGD. One-year survival was reduced in recipients with severe PGD but not in those with mild or moderate PGD. Multivariable analysis identified 3 recipient factors: prior cardiac surgery, recipient treatment with ACEI/ARB/ARNI plus MRA, recipient treatment with amiodarone plus beta-blocker, and 3 surgical factors: longer ischemic time, more red blood cell transfusions, and more platelet transfusions, that were associated with severe PGD. We developed a clinical risk score, ABCE, which provided acceptable discrimination and calibration for severe PGD. CONCLUSIONS: Risk factors for mild/moderate PGD were largely distinct from those for severe PGD, suggesting a differing pathophysiology involving several biological pathways. Further research into mechanisms underlying the development of PGD is urgently needed.

Multi-parametric approach to predict prosthetic valve size using CMR and clinical data: insights from SAVR.

The purpose of this investigation was to characterize the CMR and clinical parameters that correlate to prosthetic valve size (PVS) determined at SAVR and develop a multi-parametric model to predict PVS. Sixty-two subjects were included. Linear/area measurements of the aortic annulus were performed on cine CMR images in systole/diastole on long/short axis (SAX) views. Clinical parameters (age, habitus, valve lesion, valve morphology) were recorded. PVS determined intraoperatively was the reference value. Data were analyzed using Spearman correlation. A prediction model combining imaging and clinical parameters was generated. Imaging parameters had moderate to moderately strong correlation to PVS with the highest correlations from systolic SAX mean diameter (r = 0.73, p < 0.0001) and diastolic SAX area (r = 0.73, p < 0.0001). Age was negatively correlated to PVS (r = - 0.47, p = 0.0001). Weight was weakly correlated to PVS (r = 0.27, p = 0.032). AI and bicuspid valve were not predictors of PVS. A model combining clinical and imaging parameters had high accuracy in predicting PVS (R2 = 0.61). Model predicted mean PVS was 23.3 mm (SD 1.1); actual mean PVS was 23.3 mm (SD 1.3). The Spearman r of the model (0.80, 95% CI 0.683-0.874) was significantly higher than systolic SAX area (0.68, 95% CI 0.516-0.795). Clinical parameters like age and habitus impact PVS; valve lesion/morphology do not. A multi-parametric model demonstrated high accuracy in predicting PVS and was superior to a single imaging parameter. A multi-parametric approach to device sizing may have future application in TAVR.

Video-assisted thoracoscopic surgery for complex mediastinal mass resections.

Minimally invasive surgery has changed the way operative procedures are performed in many specialties. As surgeons have become progressively facile with these techniques, the opportunities to use them have expanded. In thoracic surgery, many surgeons now use minimally invasive techniques to resect small, uncomplicated pathologies of the mediastinum as well as to perform thymectomy for myasthenia gravis. Experience with these techniques has allowed new knowledge to be gained and expansion of the use of these techniques for more complicated mediastinal pathology. This keynote address will outline the instrumentation and techniques that we have adopted over a decade of using these techniques for more complicated mediastinal pathology.

Coronary Artery Bypass Grafting During Acute Coronary Syndrome: Outcomes and Comparison of Off-Pump to Conventional Coronary Artery Bypass Grafting at a Veteran Affairs Hospital.

OBJECTIVE: The management of acute coronary syndrome (ACS) has evolved dramatically over the last 50 years. Currently, management includes a multidisciplinary approach potentially including catheter-based therapy, surgery, or purely medical management. Where surgical therapy is indicated, data regarding long-term outcomes are limited. In particular, little data exist regarding on-pump (conventional coronary artery bypass grafting, cCABG) versus off-pump (OPCABG) outcomes for this group. METHODS: A retrospective review of prospectively collected data was undertaken. Patients undergoing isolated CABG from January 2000 to December 2011 with ACS were identified (n = 271); non-ACS patients (n = 854) were established as a control. Data were analyzed with a χ or a t test, where appropriate. Survival was compared using Kaplan-Meier analysis and Cox proportional hazards model. RESULTS: Thirty-day mortality between the ACS and the control groups was similar; however, long-term mortality was worse for the ACS group (P = 0.032; median follow-up, 5.5 years). Length of stay and composite morbidity were higher in the ACS group (P < 0.01). Subgroup analysis of ACS patients (OPCABG vs cCABG) demonstrated worse preoperative comorbidities in the OPCABG group, but similar 30-day and long-term mortality. However, the cCABG group had higher rates of reoperation (P = 0.034) and longer length of stay (P = 0.017) and operative time (P < 0.0001). Cox proportional hazards model was applied. Risk factors for the non-ACS cohort included age, diabetes, OPCABG, and ACS (P < 0.05). Among the ACS cohort, only age remained a statistically significant factor (P < 0.0001). CONCLUSIONS: ACS appears to negatively impact long-term, but not short-term, mortality. Within the ACS group, OPCABG compares favorably to cCABG in the long-term and also improves short-term morbidity.

Long-term outcomes after off-pump or conventional coronary artery bypass grafting within a veteran population.

OBJECTIVE: Recently published data indicate that outcomes for off-pump coronary artery bypass grafting (OPCABG) may be inferior to conventional CABG (cCABG) within the Veteran population, but this has been only partly addressed within high-volume off-pump centers. Here, we seek to examine the long-term outcomes for these patients within the Veteran population at a single institution well experienced with OPCABG. METHODS: With the use of a preexisting in-house database, all patients who had undergone isolated CABG from 2000 to 2011 (n = 1125) were identified. From these data, 18 demographic and risk factors were compared and used to create a propensity score, which was used for matching between groups (OPCABG vs cCABG). The primary end point examined was death. Survival was analyzed using the Kaplan-Meier method and the log-rank test. Groups were compared using a Student t test or Fisher exact test, where appropriate. RESULTS: Unmatched OPCABG and cCABG groups were found to have significant differences in risk factors, with the OPCABG being a higher-risk population by ejection fraction, chronic obstructive pulmonary disease status, age, and renal function, among others (all P < 0.05). Kaplan-Meier analysis of the unmatched groups demonstrated an increased mortality rate within the higher-risk OPCABG group (P = 0.0002). With the use of propensity score matching, 337 OPCABG patients were then matched to 337 cCABG controls. Comparison of demographic and risk factors between these matched groups did not demonstrate any statistically significant difference. When Kaplan-Meier analysis was performed for the matched groups, there was no statistically significant difference in survival. In addition, in the matched data set, OPCABG patients had a shorter average length of stay (8.2 vs 9.7 days, P = 0.022), shorter operative time (205 vs 270 minutes, P < 0.001), and lower rate of bleeding complications (0.9% vs 3.6%, P = 0.032). CONCLUSIONS: In this high-volume off-pump center, matched OPCABG survival is similar to cCABG. Although recent data indicate that OPCABG survival may be worse than that of cCABG within the entire Veteran population, in centers well experienced with OPCABG, this does not seem to hold true. In addition, the benefit of decreased length of stay and lower morbidity rates seems to be significant. Further study of the long-term outcomes of OPCABG in high-volume Veteran's centers is warranted.

Using cardiac magnetic resonance imaging to evaluate cardiac function and predict outcomes in patients with valvular heart disease.

OBJECTIVE: In valvular heart disease, elevated left atrial and pulmonary pressures contribute to right ventricular strain and, ultimately, right ventricle failure. Elevated pulmonary artery (PAP) and left ventricular end diastolic pressures are used as markers of right ventricle dysfunction and correlate with poor outcomes. Using cardiac magnetic resonance imaging (CMR), it is possible to directly quantify both left and right ventricular ejection function (LVEF and RVEF), and here, we compare CMR with traditional markers as outcome predictors. METHODS: A retrospective review of prospectively collected data was performed for patients from January 2004 to February 2008 at a single center (n = 103). Patients were divided into those receiving CMR (n = 56) and those receiving only catheterization (n = 47). Univariate and multivariate logistic regression models were applied to determine predictors of mortality. Finally, predictive models for mortality using PAP, mean PAP, and left ventricular end diastolic pressure were compared to models using LVEF and RVEF obtained from CMR. RESULTS: Preoperative average CMR LVEF and RVEF were 57% and 46%, respectively. Only age emerged as an isolated predictor of mortality (P = 0.01) within the univariate models. Stepwise regression models were created using the catheterization or CMR data. When compared, the CMR model has a slightly better R, c (prediction accuracy), and sensitivity/specificity (0.22 vs 0.28, 0.77 vs 0.82, and 0.63/0.62 vs 0.69/0.64, respectively). CONCLUSIONS: Within our population, LVEF and RVEF predict mortality as least as well as traditional catheterization values. Additionally, CMR may identify of elevated PAPs caused by right ventricle dysfunction and those due to other causes, allowing these other causes to be addressed preoperatively.

Outcomes of tracheostomy following congenital heart surgery: a contemporary experience.

INTRODUCTION: Following congenital heart surgery, pediatric patients may experience persistent respiratory failure that requires tracheostomy placement. Currently, definitive knowledge of the optimal timing for tracheostomy placement in this patient population is lacking. METHODS: An 8-year retrospective review of 17 pediatric patients who underwent congenital heart surgery and subsequently required tracheostomy placement was performed. Patients were evaluated with regard to the timing of tracheostomy and mortality. RESULTS: The overall study mortality was 24%. The median duration of intubation prior to tracheostomy was 60 days (interquartile range: 19-90 days); there was no difference in the average time between intubation and tracheostomy for survivors compared with nonsurvivors (51 vs. 73 days, P = .37). No difference was observed in the overall duration of positive pressure ventilation when tracheostomy was performed within 30 days of intubation compared with greater than 30 days following intubation (481 vs. 451 days, P = .88). Overall, 18% of patients were successfully weaned from the ventilator after a median duration of positive pressure ventilation of 212 days. CONCLUSION: The timing of tracheostomy placement may be an important factor in clinical outcomes for pediatric patients with persistent dependence on mechanical ventilatory support following congenital heart surgery. A larger, multi-institution study may help further elucidate our observed clinical findings in this patient population.

Intermediate-term results of extracorporeal membrane oxygenation support following congenital heart surgery.

BACKGROUND: Although there are considerable data regarding in-hospital results of congenital heart surgery (CHS) patients requiring postoperative extracorporeal membrane oxygenation (ECMO) support, there is limited information on intermediate-term outcomes. METHODS: A single-institution retrospective review of 25 consecutive postoperative CHS patients who required ECMO and survived to hospital discharge between January 2003 and June 2008. Survival was estimated by the Kaplan-Meier method. RESULTS: At a median follow-up of 3.3 years (interquartile range: 1.2-5.9 years), there was one death which occurred at six months postsurgery. Kaplan-Meier-estimated survival at three years was 95% (95% confidence interval: 90%-100%). Indications for ECMO included extracorporeal cardiopulmonary resuscitation (48%), systemic hypoxia (4%), postoperative low-cardiac output syndrome (28%), and intraoperative failure to wean off cardiopulmonary bypass (20%). Following ECMO support, 65% of patients had unplanned cardiac reinterventions (three requiring operative interventions, six requiring percutaneous interventions, and four requiring both), and 47% of patients required unplanned hospitalizations. In all, 29% of patients developed neurological deficits and 12% of patients developed chronic respiratory failure. No patients developed renal failure. Overall, systemic ventricular (SV) function normalized in 83% of patients, whereas 17% of patients had persistent mild-to-moderate SV dysfunction. CONCLUSIONS: Intermediate-term patient survival of ECMO following CHS is encouraging. However, neurological impairment and unplanned cardiac reinterventions remain significant concerns. Further delineation of risk factors to improve patient outcomes is warranted.

The microvasculature in cutaneous wound healing in the female red Duroc pig is similar to that in human hypertrophic scars and different from that in the female Yorkshire pig.

The female red Duroc pig has been found to be a promising model of hypertrophic scarring. The female Yorkshire pig has been demonstrated to heal in a very different manner, more resembling human normotrophic scarring. Given these observations, we studied microvessel density, an important aspect of wound healing, in human hypertrophic scars and the scars of the female Duroc and Yorkshire pigs. We studied microvessel density in uninjured skin; hypertrophic scars at 6 months or less, 7 to 12, and longer than 12 months; female Duroc tissues at 3 weeks and 3 and 5 months; and similar Yorkshire tissue, including uninjured skin and shallow and deep wounds. Antifactor VIII-related antigen was used to mark the endothelial cells. Computed assessment of microvessel density was used to quantify the microvasculature. In human hypertrophic scars, the microvessels were increased dramatically, and microvessel density and area were significantly elevated. We found similar results in the Duroc tissues at 5 months after deep wounding. In contrast, we found far less microvasculature and, at 5 months, the values had returned to normal in the Yorkshire tissues. This quantitative study of microvessel density further validates the female Duroc pig as an animal model of hypertrophic scarring and the female Yorkshire pig as a control.