Salah E. Altarabsheh

Bilateral Internal Thoracic Artery Harvest and Deep Sternal Wound Infection in Diabetic Patients

BACKGROUND Coronary artery bypass graft surgery is superior to percutaneous intervention in diabetic patients with multivessel disease. The use of bilateral internal thoracic arteries (BITA) may provide better long-term graft patency, but the risk of postoperative deep sternal wound infection has limited its use in diabetic patients. However, studies have reported conflicting results, and require systematic evaluation. METHODS MEDLINE, EMBASE, World of Science, and the Cochrane library were searched for randomized controlled trials and observational studies comparing the incidence of deep sternal wound infection in diabetic patients undergoing either left internal thoracic artery (LITA) or BITA harvest. We used random effect models to compare risk ratios within groups. RESULTS One randomized controlled trial and 10 observational studies (126,235 diabetic patients: 122,465 LITA, 3,770 BITA) met inclusion criteria. Deep sternal wound infection occurred in 3.1% and 1.6% for the BITA and LITA cohorts, respectively. The risk ratio for deep sternal wound infection development was 1.71 (1.37 to 2.14) for BITA compared with LITA. Patients who underwent skeletonized BITA harvest had a similar risk of deep sternal wound infection compared with LITA (0.9 [0.42 to 2.09]), although pedicled harvest demonstrated increased risk (1.77 [1.4 to 2.23]). Early mortality was comparable in the LITA cohort (2.5%) and the BITA cohort (2.3%; p = 0.8). CONCLUSIONS The risk of deep sternal wound infection can be minimized in diabetic patients undergoing coronary artery bypass graft surgery by performing ITA harvested in a skeletonized manner with meticulous attention to preserving sternal blood flow. Pedicled harvest is to be discouraged when utilizing both ITA owing to a significant increase in the risk of postoperative deep sternal wound infection.

Dual anti-platelet therapy after coronary artery bypass grafting: Is there any benefit? A systematic review and meta-analysis

Anti‐platelet therapy is an important component of medical therapy post coronary artery bypass grafting (CABG). While aspirin administration is a Class I indication after CABG, the benefit of concomitant clopidogrel is a controversial issue.

Outcome of Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy in Children and Young Adults

BACKGROUND Obstructive hypertrophic cardiomyopathy (HCM) is an important cause of heart failure in children, but there are limited data addressing outcome of myectomy in children. Our objective was to evaluate the early and late results of septal myectomy in pediatric HCM. METHODS We reviewed 127 consecutive patients (62% male) who underwent transaortic septal myectomy for obstructive HCM from January 1975 to December 2010 at 21 or less years of age. Mean age at operation was 12.9 ± 5.5 years. Preoperatively, mean maximum instantaneous gradient was 89 mm Hg and 95% had significant systolic anterior motion (SAM) with mitral regurgitation (MR). Implantable cardioverter defibrillator (ICD) and permanent pacemaker prior to surgery was present in 21 patients (17%) and 15 (11.7%), respectively. RESULTS Transaortic extended left ventricular septal myectomy was performed in all patients with no early deaths. Iatrogenic morbidity included new aortic valve regurgitation requiring repair in 7 (5.5%), mitral regurgitation needing repair in 2 (1.5%), ventricular septal defect in 1 (1%), and heart block requiring permanent pacemaker in 1 (1%). An ICD was implanted postoperatively in 8 during the same hospital admission. Mean MIG decreased from 89 to 6 mm Hg (p < 0.0001). Postoperatively, residual chordal SAM was present in 23% with mild or no MR; moderate MR was detected in 1 patient. Four patients (3%) died late during the mean follow-up period of 8.3 years (maximum, 37 years); 1 death was sudden. Overall survival was 98.6%, 94.9%, 92.4%, and 92.4% at 5, 10, 15, and 20 years, respectively. Freedom from any cardiac reoperation was 91.2%, 87.8%, 78.7%, and 72.7% at 5, 10, 15, and 20 years, respectively. Repeat septal myectomy was performed in 6 patients (5%). At late follow-up, 95% were in New York Heart Association functional class I or II and 25 patients underwent late ICD placement. CONCLUSIONS Septal myectomy is safe and effective in children with obstructive HCM, but limited exposure may increase risk of aortic or mitral valve injury. Late survival is better than the previously published untreated natural history of HCM. Patient selection and surgical expertise remain critical components of septal myectomy, especially before considering a prophylactic myectomy in a seemingly asymptomatic patient.

Levosimendan Reduces Mortality in Adults with Left Ventricular Dysfunction Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis.

Levosimendan is implemented in patients with low cardiac output after cardiac surgery. However, the strength of evidence is limited by randomized controlled trials enrolling a small number of patients. Hence we have conducted a systematic review to determine the role of levosimendan in adult cardiac surgery.

Hepatic and Renal Function with Successful Long-term Support on a Continuous Flow Left Ventricular Assist Device

INTRODUCTION Data regarding the long-term clinical effects of a continuous flow left ventricular assist device (CF-LVAD) on hepato-renal function is limited. Hence our aim was to assess changes in hepato-renal function over a one-year period in patients supported on a CF-LVAD. METHODS During the study period 126 patients underwent CF-LVAD implant. Changes in hepato-renal laboratory parameters were studied in 61/126 patients successfully supported on a CF-LVAD for period of one year. A separate cohort of a high-risk group (HCrB) of patients (56/126) with a serum creat>1.9 mg/dL (168 μmol/L) (75th percentile) or a serum bil>1.5 mg/dL (25.65 μmol/L) (75th percentile) was created. Changes in serum creatinine and bilirubin were analysed at regular intervals for this group along with the need for renal replacement therapy. RESULTS Baseline creatinine and blood urea nitrogen (BUN) for the entire cohort was 1.4[1.2,1.9 mg/dL] [123.7(106,168) μmol/L) and 27[20,39.5 mg/dL] [9.6(7.1,14.1) mmol/L] respectively. After an initial reduction at the end of one month [1(0.8,1.2) mg/dL; 88(70,105) μmol/L] (p<0.0001), a gradual increase was noted over the study period to reach (1.25[1.1,1.5] mg/dL; 106(97.2,132.6) μmol/L] (p=0.0003). The serum bilirubin normalised from a [1(0.7,1.55) mg/dL] [17(18.8,25.7) μmol/L) to 0.9(0.6,1.2)mg/dL [15.4(10.2,20.5) μmol/L] (p=0.0005) and continued to decline over one year. Improvement in the synthetic function of the liver was demonstrated by a rise in the serum albumin levels to reach 4.3[4.1,4.5] [43(41,45) gm/L] at the end of one year (p<0.0001). The baseline serum creatinine and bilirubin for the high-risk cohort (HCrB) was 1.9(1.3,2.4) mg/dL [168(115,212) μmol/L] and 1.7(1.00,2.4) mg/dL [29(17.1,68.4) μmol/L] respectively. The high-risk cohort (HCrB) demonstrated a trend towards higher 30-day mortality (p=0.06). While the need for temporary renal replacement therapy was higher in this cohort (16% vs. 4%; p=0.03), only 3% need it permanently. A significant reduction in creatinine was apparent at the end of one month [1.1(0.8,1.4) mg/dL; 97(70.7,123.7) μmol/L] (p<0.0001) and then remained stable at [1.3(1.1,1.5) mg/dL; 115(97,132.6) μmol/L]. Bilirubin demonstrated a 30% decline over one month and then remained low at [0.7(0.5,0.8) mg/dL; 62(44,70) μmol/L] p=0.0005 compared to the pre-operative baseline. CONCLUSION Hepato-renal function demonstrates early improvement and then remains stable in the majority of patients on continuous flow left ventricular assist device support for one year. High-risk patients demonstrate a higher 30-day mortality and temporary need for renal replacement therapy. Yet even in this cohort, improvement is present over a period of one year on the device, with a minimal need for permanent haemodialysis.

Off-Pump Coronary Artery Bypass Reduces Early Stroke in Octogenarians: A Meta-Analysis of 18,000 Patients

BACKGROUND Data comparing results of off-pump and conventional operations in octogenarians is very limited. Thus we chose to compare early adverse events between off-pump coronary artery bypass grafting (OPCABG) and on-pump CABG (ONCABG) in patients older than 80 years. METHODS Systematic review of multiple databases was performed to obtain original studies fulfilling search criteria. End points--early mortality, stroke, respiratory failure, atrial fibrillation, and myocardial infarction--were compared between these cohorts. A random-effects weighted analysis was performed using the trim-fill adjustment when necessary. Results are presented as risk ratios (RRs) with 95% confidence intervals (CIs); p < 0.05 is considered statistically significant. RESULTS Sixteen retrospective studies (9,744 ONCABG and 8,566 OPCABG patients) were included in the systematic review. OPCAGB patients received significantly fewer grafts (2.54 ± 0.16) compared with ONCABG patients (3.22 ± 0.41). Early mortality was comparable at 4.6% and 5.2% in the OPCABG and ONCABG cohorts, respectively (risk ratio [RR], 0.91; 95% CI, 0.64-1.28; p = 0.598). Stroke rates were higher in the ONCABG cohort (RR, 0.65; 95% CI, 0.49- 0.87; p < 0.01). Respiratory failure was higher with ONCABG (RR, 0.74; 95% CI, 0.57-0.97; p = 0.03). New-onset renal failure (p = 0.99), atrial fibrillation (p = 0.27), and myocardial infarction (p = 0.99) were comparable. CONCLUSIONS Coronary artery bypass in octogenarians can be performed safely with low early mortality. Although off-pump operations reduce the risk of early stroke, all other adverse events are comparable in on- and off-pump coronary artery bypass operations. Data regarding late mortality is at present limited; however, both on- and off-pump procedures appear to produce comparable survival.

Predictive Value of the Model for End-Stage Liver Disease Score in Patients Undergoing Left Ventricular Assist Device Implantation

Axial flow left ventricular assist device (LVAD) implantation is an effective therapy for patients with advanced heart failure. As the preoperative hepatic and renal function play a critical role in determining adverse events after LVAD implantation, we analyzed the predictive role of the model for end-stage liver disease (MELD) score in determining in-hospital mortality after surgery. One hundred twenty-six patients underwent implant of an LVAD at our institution. Their individual preoperative MELD scores and perioperative total blood product usage (TBPU) were calculated. As LVAD implant as a reoperation is known to influence postoperative bleeding and mortality independently, the patients were divided into group I (first cardiac surgery) and group II (reoperative surgery). Group I: LVAD implantation was performed in 68/126 (54%) patients as their first cardiac surgery. The mean MELD score was 16.3 ± 6. Median TBPU for this group was 20.7 (0, 135) units. Inhospital mortality/30-day mortality was 4/68 (5.8%). Increasing MELD score (c-statistic = 0.88) and TBPU were found to be predictors of early mortality. An increasing MELD score was associated with more TBPU (p < 0.01) with a 10.9 ± 3 TBPU increase per a 10 unit rise in the MELD score. Group II: Of the 126 patients, 58 (46%) underwent LVAD implantation as a reoperation. Mean MELD score for these patients was 16 ± 5. Inhospital mortality/30-day mortality in this group was 12% and median TBPU was 30 (4,153) units. The MELD score was not predictive of inhospital mortality in these patients (p = 0.97). The MELD score is predictive of early mortality in patients undergoing LVAD implantation as their first cardiac surgery. Use of this score to select patients for LVAD implantation may be appropriate.

Concomitant Tricuspid Valve Repair or Replacement During Left Ventricular Assist Device Implant Demonstrates Comparable Outcomes in the Long Term

Abstract  Introduction: Severe tricuspid regurgitation (TR) is present in nearly half the patients undergoing implant of a left ventricular assist device (LVAD) and its correction confers better long‐term outcome. Aim: To compare the early and late results of tricuspid valve repair (TVrpr) or replacement (TVR) with LVAD implant. Patient and Methods: Sixty‐four from a cohort of 126 patients had a concomitant tricuspid valve procedure; 48 (75%) underwent a TVrpr whereas 16 (25%) had TVR. All preoperative hemodynamic parameters including the mean TR grade (TVrpr; 3.6 vs. TVR; 3.7) were comparable (p = 0.7). The mean TR grade was 1.6 ± 1.5 for the remaining 62 patients who did not have a concomitant tricuspid valve procedure, with 4/62 (6%) having severe TR (p < 0.0001). Results: Cardiopulmonary bypass time was longer for patients undergoing TVR (p = 0.01). There was a significant reduction in right atrial pressure for the entire cohort (p < 0.01) and the postoperative right atrial pressure was not statistically different between TVrpr (13.6 ± 4.6) and TVR (11.6 ± 4.3; p = 0.6. Postoperative intensive care unit stay was comparable as was the duration of inotropic support (p = 0.5) or need for temporary right ventricular mechanical support. In‐hospital mortality (12%) was not different between groups. The mean time for LVAD support was 12.3 ± 9.71 months and the last transthoracic echocardiographic examination was performed at mean intervals of 13.8 ± 10.8 months (TVrpr) and 11.8 ± 7.6 months (TVR; p = 0.47). Reduction in TR grade was similar between groups (p = 0.27). Late mortality (p = 1.00) was comparable in both groups. Using log‐rank analysis, there was no significant difference in the estimated survival between TVrpr and TVR (p = 0.88). Conclusion: TVrpr repair at the time of LVAD implant is effective in correcting TR even at the end of one year of follow‐up. The choice to repair or replace does not affect the clinical outcome. (J Card Surg 2012;27:760‐766)

Model for end-stage liver disease excluding international normalized ratio (MELD-XI) score predicts heart transplant outcomes: Evidence from the registry of the United Network for Organ Sharing

BACKGROUND Hepato-renal function is a valuable predictor of success after left ventricular assist device therapy and heart transplantation. Hence, we analyzed the importance of the Model for End-stage Liver Disease excluding international normalized ratio (MELD-XI) score to outcomes after heart transplant. METHODS Adults undergoing heart transplant from the United Network for Organ Sharing (UNOS) database were identified (1994 to 2014). Individual MELD-XI scores were calculated; patients were stratified by MELD-XI quartiles (Q1 to Q4). Multivariate logistic regression and the Cox proportional hazard model were implemented to determine any association between MELD-XI scores, survival and other outcomes. RESULTS From 39,711 patients undergoing OHT during the study period, MELD-XI score [median 10.7 (interquartile range 7.0 to 14.4)] was calculated for 36,005 patients (76% male and 75% white, 34% Status 1A). Higher MELD-XI scores had higher rates of pre-transplant extracorporeal membrane oxygenation, intra-aortic balloon pump, inotrope use and mechanical ventilation (p < 0.001 for all). Adjusted long-term mortality (median follow-up 8.1 years) was associated with MELD-XI score (hazard ratio [HR] 1.021 [1.016 to 1.026], p < 0.001). The highest MELD-XI quartile was associated with an HR 1.364 [1.255 to 1.482] risk of mortality compared with Q1. MELD-XI score was also associated with increased post-transplant infections (adjusted HR Q4 vs Q1: 1.364 [1.153 to 1.614], p < 0.001), stroke (adjusted HR Q4 vs Q1: 1.410 [1.074 to 1.852], p = 0.013), dialysis (adjusted HR Q4 vs Q1: 3.982 [3.386 to 4.683], p < 0.001), rejection (adjusted HR Q4 vs Q1: 1.519 [1.286 to 1.795], p = 0.003) and prolonged hospitalization (adjusted HR Q4 vs Q1: 1.635 [1.429 to 1.871], p < 0.001). CONCLUSION Hepato-renal dysfunction, measured with MELD-XI score, predicts morbidity and mortality in patients undergoing orthotopic heart transplantation. Etiology of hepato-renal dysfunction should be sought and treated before heart transplantation.

Compartmentalization Role of A-Kinase Anchoring Proteins (AKAPs) in Mediating Protein Kinase A (PKA) Signaling and Cardiomyocyte Hypertrophy

The Beta-adrenergic receptors (β-ARs) stimulation enhances contractility through protein kinase-A (PKA) substrate phosphorylation. This PKA signaling is conferred in part by PKA binding to A-kinase anchoring proteins (AKAPs). AKAPs coordinate multi-protein signaling networks that are targeted to specific intracellular locations, resulting in the localization of enzyme activity and transmitting intracellular actions of neurotransmitters and hormones to its target substrates. In particular, mAKAP (muscle-selective AKAP) has been shown to be present on the nuclear envelope of cardiomyocytes with various proteins including: PKA-regulatory subunit (RIIα), phosphodiesterase-4D3, protein phosphatase-2A, and ryanodine receptor (RyR2). Therefore, through the coordination of spatial-temporal signaling of proteins and enzymes, mAKAP controls cyclic-adenosine monophosphate (cAMP) levels very tightly and functions as a regulator of PKA-mediated substrate phosphorylation leading to changes in calcium availability and myofilament calcium sensitivity. The goal of this review is to elucidate the critical compartmentalization role of mAKAP in mediating PKA signaling and regulating cardiomyocyte hypertrophy by acting as a scaffolding protein. Based on our literature search and studying the structure–function relationship between AKAP scaffolding protein and its binding partners, we propose possible explanations for the mechanism by which mAKAP promotes cardiac hypertrophy.