Marc Najjar

Acute kidney injury after aortic valve replacement: incidence, risk factors and outcomes

The occurrence of acute kidney injury (AKI) following aortic valve replacement (AVR) has very serious clinical implications and has therefore been the focus of several studies. The authors report the results of previous studies evaluating both transcatheter AVR (TAVR) and indirectly surgical AVR (SAVR) through looking at cardiopulmonary bypass (CPB) cardiac surgeries, and identify the incidence, predictors and outcomes of AKI following AVR. In most studies, AKI was defined using the Risk, Injury, Failure, Loss and End Stage, Valve Academic Research Consortium (modified Risk, Injury, Failure, Loss and End Stage) or Valve Academic Research Consortium-2 (Acute Kidney Injury Network) AKI classification criteria. Twelve studies including more than 90,000 patients undergoing cardiac surgery on CPB were considered as well as 26 studies with more than 6000 patients undergoing TAVR. Depending on the definition used, AKI occurred in 3.4–43% of SAVR cases with up to 2.5% requiring dialysis, and in 3.4–57% of TAVR cases. Factors identified as independent predictors of AKI were: baseline kidney failure, EUROSCORE, diabetes mellitus, hypertension, chronic obstructive pulmonary disease, anemia, peripheral vascular disease, heart failure, surgical priority, CPB time, reoperation, use of intra-aortic balloon pump, need for re-exploration, contrast agent volume, transapical access, blood transfusion, postoperative thrombocytopenia, postoperative leukocytosis as well as demographic variables such as age and female gender. The 30-day mortality rate for patients with AKI following SAVR ranged from 5.5 to 46% and was 3- to 16-times higher than in those without AKI. Similarly, patients who developed AKI after TAVR had a mortality rate of 7.8–29%, which was two- to eight-times higher than those who did not suffer from AKI. AKI confers up to a fourfold increase in 1-year mortality. Finally, hospital length of stay was significantly increased in patients with AKI in both SAVR and TAVR groups, with increases up to 3- and 2.5–times, respectively.

Del Nido Cardioplegia can be safely administered in high-risk coronary artery bypass grafting surgery after acute myocardial infarction: a propensity matched comparison

ObjectiveDel Nido (DN) cardioplegia solution provides a depolarized hyperkalemic arrest lasting up to 60 minutes, and the addition of lidocaine may limit intracellular calcium influx. Single-dose DN cardioplegia solution may offer an alternative myocardial protection strategy to multi-dose cold whole blood (WB) cardioplegia following acute myocardial infarction (AMI).MethodsWe retrospectively reviewed 88 consecutive patients with AMI undergoing coronary artery bypass (CABG) surgery with cardioplegic arrest between June 2010 to June 2012. Patients exclusively received WB (n = 40, June 2010-July 2011) or DN (n = 48, August 2011-June 2012) cardioplegia. Preoperative and postoperative data were retrospectively reviewed and compared using propensity scoring.ResultsNo significant difference in age, maximum preoperative serum troponin level, ejection fraction, and STS score was present between DN and WB. A single cardioplegia dose was given in 41 DN vs. 0 WB patients (p < 0.001), and retrograde cardioplegia was used 10 DN vs. 31 WB patients (p < 0.001). Mean cardiopulmonary bypass and cross clamp times were significantly shorter in the DN group versus WB group. Tranfusion rate, length of stay, intra-aortic balloon pump requirement, post-operative inotropic support, and 30-day mortality was no different between groups. One patient in the WB group required a mechanical support due to profound cardiogenic shock.ConclusionsDN cardioplegia may provide equivalent myocardial protection to existing cardioplegia without negative inotropic effects in the setting of acute myocardial infarction.

Myocardial Protection Using del Nido Cardioplegia Solution in Adult Reoperative Aortic Valve Surgery

The immediate postischemic period is marked by elevated intracellular calcium levels, which can lead to irreversible myocyte injury. Del Nido cardioplegia was developed for use in the pediatric population to address the inability of immature myocardium to tolerate high levels of intracellular calcium following cardiac surgery. Our aim in this study is to determine if this solution can be used safely and effectively in an adult, reoperative population.

Attenuation of the unfolded protein response and endoplasmic reticulum stress after mechanical unloading in dilated cardiomyopathy

Abnormal intracellular calcium (Ca(2+)) handling can trigger endoplasmic reticulum (ER) stress, leading to activation of the unfolded protein response (UPR) in an attempt to prevent cell death. Mechanical unloading with a left ventricular assist device (LVAD) relieves pressure-volume overload and promotes reverse remodeling of the failing myocardium. We hypothesized that mechanical unloading would alter the UPR in patients with advanced heart failure (HF). UPR was analyzed in paired myocardial tissue from 10 patients with dilated cardiomyopathy obtained during LVAD implantation and explantation. Samples from healthy hearts served as controls. Markers of UPR [binding immunoglobulin protein (BiP), phosphorylated (P-) eukaryotic initiation factor (eIF2α), and X-box binding protein (XBP1)] were significantly increased in HF, whereas LVAD support significantly decreased BiP, P-eIF2α, and XBP1s levels. Apoptosis as reflected by C/EBP homologous protein and DNA damage were also significantly reduced after LVAD support. Improvement in left ventricular dimensions positively correlated with P-eIF2α/eIF2α and apoptosis level recovery. Furthermore, significant dysregulation of calcium-handling proteins [P-ryanodine receptor, Ca(2+) storing protein calsequestrin, Na(+)-Ca(2+) exchanger, sarcoendoplasmic reticulum Ca(2+)-ATPase (SERCA2a), ER chaperone protein calreticulin] was normalized after LVAD support. Reduced ER Ca(2+) content as a causative mechanism for UPR was confirmed using AC16 cells treated with a calcium ionophore (A23187) and SERCA2a inhibitor (thapsigargin). UPR activation and apoptosis are reduced after mechanical unloading, which may be mediated by the improvement of Ca(2+) handling in patients with advanced HF. These changes may impact the potential for myocardial recovery.

Acute kidney injury following surgical aortic valve replacement.

Acute kidney injury (AKI) is a significant complication of surgical aortic valve replacement (SAVR). This study sought to describe AKI following SAVR, its risk factors, predictors and effect on long‐term survival.

Reversibility of chronic kidney disease and outcomes following aortic valve replacement

OBJECTIVES Chronic kidney disease (CKD) is prevalent in patients undergoing aortic valve replacement (AVR). We sought to evaluate the impact of AVR on estimated glomerular filtration rate (eGFR) levels and determine the impact of reversibility of CKD on postoperative outcomes. METHODS We retrospectively reviewed 2169 patients who underwent isolated AVR between 2000 and 2012. eGFR was calculated using the CKD-EPI formula. Based on preoperative eGFR, patients were divided into three groups: NoCKD (eGFR >60, n = 1417), ModCKD (eGFR = 30-60, n = 619) and SevCKD (eGFR = 15-30, n = 86). End-stage renal disease patients (eGFR <15 and/or dialysis, n = 47) were excluded from the study. RESULTS Before AVR, eGFR in the NoCKD, ModCKD and SevCKD groups was 81.3 ± 14.2, 48.9 ± 8.10 and 25.3 ± 4.12 ml/min/1.73 m(2), respectively. NoCKD patients showed a decline in eGFR during the first month postoperatively; thereafter, eGFR remained stable over 1 year. ModCKD and SevCKD patients demonstrated an initial improvement in eGFR, which peaked at 1 week postoperatively. In ModCKD, eGFR stabilized at a slightly lower level thereafter out to 1-year follow-up. In SevCKD, eGFR declined slightly out to 6 months postoperatively. Regardlessly, eGFR in ModCKD at 1 year and in SevCKD at 6 months postoperatively demonstrated sustained improvement over baseline eGFR. Reversibility of CKD was associated with a better long-term survival in the ModCKD group (P < 0.001) and short-term survival in the SevCKD group (P = 0.018). CONCLUSIONS AVR confers a marked initial improvement in eGFR, which is sustained in patients with ModCKD and SevCKD, and is associated with a better survival. The reversible nature of CKD in certain patients warrants careful consideration during preoperative risk scoring and stratification.

Outcomes of cardiac surgery in patients less than 2.5 kg: impact of patient-dependent and patient-independent variables

OBJECTIVE A recent Society of Thoracic Surgeons database study showed that low weight (<2.5 kg) at surgery was associated with high operative mortality (16%). We sought to assess the outcomes after cardiac repair in patients weighing <2.5 kg versus 2.5 to 4.5 kg in an institution with a dedicated neonatal cardiac program and to determine the potential role played by prematurity, the Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) risk categories, uni/biventricular pathway, and surgical timing. METHODS We analyzed the outcomes (hospital mortality, early reintervention, postoperative length of stay, mortality [at the last follow-up point]) in patients weighing <2.5 kg at surgery (n = 146; group 1) and 2.5 to 4.5 kg (n = 622; group 2), who had undergone open or closed cardiac repairs from January 2006 to December 2012 at our institution. The statistical analysis was stratified by prematurity, STAT risk category, uni/biventricular pathway, and usual versus delayed surgical timing. Univariate versus multivariate risk analysis was performed. The mean follow-up was 21.6 ± 25.6 months. RESULTS Hospital mortality in group 1 was 10.9% (n = 16) versus 4.8% (n = 30) in group 2 (P = .007). The postoperative length of stay and early unplanned reintervention rate were similar between the 2 groups. Late mortality in group 1 was 0.7% (n = 1). In group 1, early outcomes were independent of the STAT risk category, uni/biventricular pathway, or surgical timing compared with group 2. A lower gestational age at birth was an independent risk factor for early mortality in group 1. CONCLUSIONS A dedicated multidisciplinary neonatal cardiac program can yield good outcomes for neonates and infants weighing <2.5 kg independently of the STAT risk category and uni/biventricular pathway. A lower gestational age at birth was an independent risk factor for hospital mortality.

Minor laparoscopic liver resection for Hepatocellular Carcinoma is safer than minor open resection, especially for less compensated cirrhotic patients: Propensity score analysis

BACKGROUND Laparoscopic liver resection (LLR) has gained significant popularity over the last 10 years. First experiences of LLR compared to open liver resection (OLR) reported a similar survival and a better safety profile for LLR. MATERIALS AND METHODS This is a retrospective analysis of prospectively collected data of all consecutive patients treated by liver resection for HCC on liver cirrhosis between January 2005 and March 2017. The choice of procedure (LLR vs OLR) was generally based on tumor localization, history of previous upper abdominal surgery and patients preference. The type of resection and indication for surgery were unrelated to the adopted technique. Based on pre-operative variables and confirmed cirrhosis, a 1:1 propensity score matching (PSM) model was developed to compare outcomes of LLR and OLR in patients with HCC. Outcomes of interest included morbidity, mortality and long-term cure potential. RESULTS After-PSM, the LLR group demonstrated better perioperative results including: lower complication rate (50.7% in OLR vs 29.3% in LLR, p = 0.0035), significantly lower intra-operative blood loss (200 ml in OLR vs 150 ml in LLR, p = 0.007) and shorter hospital length of stay (median 9 days in OLR vs 7 days in LLR, p = 0.0018). Moreover there was no significant difference between the two groups in 3-year survival (76%, CI: 60%-86% in LLR vs 68%, CI: 55%-79% in OLR, p = 0.32) or recurrence-free survival rates (44%, CI: 28%-58%, vs 44%, CI: 31%-57%, p = 0.94). CONCLUSIONS Minor LLR appeared significantly safer compared to minor OLR for HCC. LLR was associated with fewer post-operative complication, lower operative blood loss and a shorter hospital stay along with similar survival and recurrence-free survival rates.

Cardiac Function After Tetralogy of Fallot/Complete Atrioventricular Canal Repair

Background: Repair of complete atrioventricular canal (CAVC) with tetralogy of Fallot (TOF) is a challenging operation increasingly being performed as a complete, primary repair in infancy. Previous studies have focused on perioperative outcomes; however, midterm valve function, ventricular function, and residual obstruction have received little attention. Methods: We retrospectively reviewed 20 patients who underwent CAVC/TOF repair (January 2005 to December 2014). A two-patch repair was used in all patients to correct the CAVC defect. Tetralogy of Fallot repair included transannular patch in 11 (65%) patients and valve-sparing in 6 (35%) patients. Results: The average age at surgery was 72 ± 122 weeks, 40% were male, and 80% had trisomy 21. Mean echo follow-up was 3.0 ± 3.0 years. There were no in-hospital or late mortalities. The rate of reoperation was 20%. At the latest follow-up, moderate left atrioventricular valve regurgitation was present in three (15%) patients and mild stenosis present in seven (35%) patients. One (5%) patient had moderate right ventricular outflow tract (RVOT) obstruction. The valve-sparing population was smaller at the time of surgery than the non-valve-sparing cohort (body surface area: 0.28 ± 0.04 vs 0.42 ± 0.11, P = .002) and less likely to have had a previous shunt (0% vs 64%, P = .01). Among the valve-sparing patients (six), at the latest follow-up, moderate pulmonary insufficiency was present in two (33%) patients. Conclusion: Repair of CAVC concomitant with TOF can be performed with low mortality and acceptable perioperative morbidity. Management of the RVOT remains a challenge for the long term.