Salil V. Deo

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.

Driveline Infections in Left Ventricular Assist Devices: Implications for Destination Therapy

BACKGROUND Infection is one of the major limitations to successful long-term support after ventricular assist device implantation. There are limited data specifically examining the incidence and predictors of driveline infections (DLI), with a changing treatment paradigm toward destination therapy (DT) and longer duration of support. METHODS Between January 2007 and 2011, 143 patients underwent HeartMate II (Thoratec, Pleasanton, CA) implantation, with 87 (61%) as DT. Driveline maintenance strategy included sterile dressing changes with chlorhexidine and saline application, without prophylactic oral antibiotics. RESULTS DLI developed in 18 patients (12%) at a median of 182 days (range, 26 to 1,138 days) after implantation, among which 12 (66%) were from the DT cohort. Infections were superficial in 15 (82%) and deep in 3 (18%). Trauma was documented in 6 patients (33%). Seven patients (38%) needed readmission for DLI. Surgical debridement was needed in 3 (17%). All patients were managed successfully, without the need for device explantation or urgent cardiac transplantation. No patient required continuous antibiotic prophylaxis after the infection subsided. Risk factor analysis identified duration of support as the only independent predictor of infection (mean. 600 vs 390 days; p = 0.03). The odds of having a DLI rose by 4% for every month of support. CONCLUSIONS Longer duration of support significantly increased the risk of DLI and hence increased the risk of DLI in patients with DT. DLI may be successfully managed with antibiotics and local wound care. Most of the infections were superficial, and progression to deep pocket or pump infection is rare in our experience.

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.

The role of medical management for acute intravascular hemolysis in patients supported on axial flow LVAD.

Continuous flow left ventricular assist devices (LVADs) are used with good outcome. However, acute intravascular hemolysis due to thrombus in the pump remains a clinical challenge. We screened for LVAD-related intravascular hemolysis among 115 consecutive patients surviving HeartMateII implantation and investigated the role of medical therapy in resolving the hemolysis. Hemolytic events were identified in 7% of patients, 2–26 months after implant, manifested by peak lactate dehydrogenase (LDH) levels >6 times normal. With the institution of heparin and enhanced antiplatelet therapy, LDH levels receded rapidly reaching a stable trough level near baseline within 2 weeks with the resolution of clinical symptoms except in one patient who required additional therapy with tissue plasminogen activator (tPA). Complications included transient renal failure, one splenic infarct, and a cerebrovascular attack after tPA. The acute event of hemolysis resolved with medical therapy, and all were successfully discharged. However, recurrent hemolysis was common (6/8 patients over the next 1–7 months). At the end of follow-up, three patients were transplanted, one patient died refusing LVAD exchange for recurrent hemolysis, and 4 remained alive on LVAD support. Medical treatment with intensification of anticoagulation can be effective in resolving the acute hemolytic event. However, a definitive long-term strategy should be planned because the recurrence rate is high.

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.

De novo aortic insufficiency during long-term support on a left ventricular assist device: a systematic review and meta-analysis.

Aortic insufficiency (AI) may occur while supported on a left ventricular assist device (LVAD). We conducted a systematic review to determine the incidence, predictors, and consequences of AI during LVAD support. MEDLINE was searched for original studies presenting clinical data regarding patients who developed AI during LVAD implant. Seven observational studies (657 patients) were selected for review; 65% of patients underwent implantation with a continuous-flow device (Cf-LVAD). The incidence of AI was 25% (11–42%) (Support period: 412 ± 281 days). AI increased by 4% (1–6%) per month of support (p < 0.01). AI-positive patients were older at implant (weighted mean difference, 7.7 [4.3; 11.1]; p < 0.01). Female sex (0.002 ± 0.001; p = 0.01) and smaller body surface area (−0.003 ± 0.001 per m2; p < 0.01) correlated with progressive AI. Destination therapy patients (odds ratio [OR], 5.3 [1.2, 24]; p = 0.02) and those with Cf-LVAD pumps were likely to develop AI (hazard ratio [HR], 2.2 [1.2, 3.8]; p < 0.01). A closed aortic valve was associated with AI (OR, 4.7 [1.9, 11.8]; p < 0.01). Survival was comparable in both cohorts (HR, 1.5 [0.81, 2.8]; p = 0.2). A significant number of patients develop de novo AI during LVAD support. Advanced age, longer support duration, continuous-flow pumps, and a closed aortic valve are associated with AI. Large cohort studies would improve our understanding of this condition.

Late Outcomes for Surgical Repair of Supravalvar Aortic Stenosis

BACKGROUND We reviewed our experience with the surgical management of supravalvar aortic stenosis (SVAS) to determine long-term outcomes and factors related to late reoperation. METHODS Between August 1956 and May 2009, 78 patients (50 males) underwent surgical correction of SVAS. Median age was 10.4 years (range, 16 days to 55.2 years). Mean preoperative gradient was 57.2±21.9 mm Hg with a mean peak gradient of 99.5±34.8 mm Hg. Supravalvar aortic stenosis was discrete in 51 patients (64%) and diffuse in 27 patients (35%). Aortic valve stenosis was present in 22 patients (29%). Williams-Beuren syndrome was present in 32 patients (41%). RESULTS Surgery was either a diamond-shaped patch in 67 patients (85.9%) or a pantaloons-shaped patch in 11 patients (14.1%). Aortic valve intervention was required in 20 patients (25.64%). Mean gradient immediately after repair was 25±25 mm Hg, with 13 patients (16.7%) having a residual gradient. A high residual gradient was more likely in the diffuse group (odds ratio, 3.73; 95% confidence interval, 1.07 to 12.98). There were 2 (2.6%) early deaths, both with diffuse SVAS. Median follow-up was 19.8 years; maximum was 48.5 years. The mean gradient across the left ventricular outflow tract at late follow-up was 8.8 mm Hg (95% confidence interval, 3.7 to 14.01). Overall survival was estimated at 90%±7%, 84%±9%, and 8%2±10% at 5, 10, and 20 years, respectively. Predictors of mortality were age younger than 2 years (p=0.021), diffuse SVAS (p=0.045), aortic valve stenosis (p=0.032), and high postoperative gradient (p=0.023). Presence of Williams-Beuren syndrome did not affect survival (p=0.305). Freedom from late reoperation was 97%±4%, 93%±7%, and 86%±10% at 5, 10, and 20 years, respectively. Significant aortic valve disease (p<0.001) and diffuse SVAS (p=0.009) were risk factors for late reoperation. CONCLUSIONS Surgical repair for SVAS can be performed with a single-patch technique with good long-term outcome. Late mortality and need for reoperation are more likely with diffuse SVAS or the presence of aortic valve stenosis.

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.