Ishan K. Shah

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.

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.

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)

Cardiac Transplantation After Bridged Therapy with Continuous Flow Left Ventricular Assist Devices

INTRODUCTION Cardiac transplantation is an effective surgical therapy for end-stage heart failure. Patients (pts) may need to be bridged with a continuous flow left ventricular assist device (CF-LVAD) while on the transplant list as logistic factors like organ availability are unknown. Cardiac transplantation post-LVAD can be a surgically challenging procedure and outcome in these pts is perceived to be poorer based on experience with earlier generation pulsatile flow pumps. Data from a single institution comparing these pts with those undergoing direct transplantation in the present era of continuous flow device therapy are limited. AIM Evaluate results of cardiac transplantation in pts bridged with a CF-LVAD (BTx) and compare outcomes with pts undergoing direct transplantation (Tx) in a single institution. RESULTS From June 2007 till January 2012, 106 pts underwent cardiac transplantation. Among these, 37 (35%) pts (51±11 years; 85% male) were bridged with a CF-LVAD (BTx), while 70 (65%) comprised the Tx group (53±12 years; 72% males). The median duration of LVAD support was 227 (153,327) days. During the period of LVAD support, 10/37 (27%) pts were upgraded to status 1A and all were successfully transplanted. Median hospital stay in the BTx (14 days) was slightly longer than the Tx group (12 days) but not statistically significant (p=0.21). In-hospital mortality in the BTx (5%) and Tx (1%) were comparable (p=0.25). Estimated late survival in the BTx cohort was 94±7, 90±10 and 83±16% at the end of one, two and three years, respectively which was comparable to 97±4%, 93±6% and 89±9% for the Tx group (p=0.50). CONCLUSION Cardiac transplantation after LVAD implant can be performed with excellent results. Patients can be supported on the left ventricular assist device even for periods close to a year with good outcome after cardiac transplantation.

Myocardial revascularisation in renal dysfunction: a systematic review and meta-analysis

BACKGROUND Coronary artery disease is highly prevalent in patients with end-stage renal disease. Yet randomised controlled trials are lacking, and decisions are based on retrospective cohort studies which present conflicting outcomes. Hence we conducted a systematic review and meta-analysis comparing outcomes in patients with end-stage renal disease and renal dysfunction undergoing percutaneous intervention (PCI) and coronary artery bypass grafting (CABG), with a particular focus on contemporary studies implementing drug-eluting stents. METHODS MEDLINE, EMBASE, World of Science, and the Cochrane library were searched for randomised controlled (RCT) and observational studies comparing clinical outcomes such as early mortality, myocardial infarction, need for repeat revascularisation and angina in patients undergoing PCI or CABG. We used random effect models to compare risk ratios (RR) within groups. RESULTS One RCT and 15 observational studies (7588 PCI and 9206 CABG patients) met inclusion criteria. Early mortality favoured the PCI cohort (4.2% vs 8.5%) [risk ratio=0.51(0.40, 0.64), p<0.01]. The need for repeat revascularisation was significantly lower in the CABG cohort (7.3% vs 17.8%; p<0.01). Pooled analysis of studies implementing a drug eluting stent still favoured CABG with regards to repeat revascularisation (5% vs 14%; p<0.01) and MACE (15% vs 27%; p=0.03), while early mortality was less in the DES-PCI cohort (2.4% vs 5.1%; p=0.04). CONCLUSION Compared to percutaneous intervention, coronary artery bypass grafting is associated with higher early/30-day mortality in patients with renal dysfunction or end-stage renal disease. The need for repeat revascularisation is significantly higher with percutaneous intervention, even with the use of a drug-eluting stent.

Long-term Outcomes and Prognostic Factors for Patients Requiring Renal Replacement Therapy After Cardiac Surgery

OBJECTIVE To examine long-term outcomes, including all-cause mortality, and the likelihood and timing of renal recovery among patients requiring renal replacement therapy (RRT) for acute kidney injury after cardiac surgery. PATIENTS AND METHODS This is a single-center, historical, matched cohort study of post-cardiac surgery patients who required RRT from January 1, 2007, through December 31, 2012. We matched each case with 2 controls, each of whom did not require RRT after cardiac surgery, for age, sex, and type of surgery. The patients were followed up for 1 year after the start of RRT. The main outcomes were all-cause mortality in all patients and rate of renal function recovery in patients who required RRT. RESULTS A total of 202 patients met the inclusion criteria. The unadjusted all-cause mortality among patients requiring RRT was 64% at 1 year vs 8% for matched controls. In multivariate analysis, the hazard ratio for all-cause mortality was 12.59 (95% CI, 8.24-19.68) for cases vs controls. Increased 1-year all-cause mortality was independently associated with increased age, a history of congestive heart failure, lower preoperative creatinine level, longer interval between surgery and starting RRT, and the need for mechanical ventilation or an intra-aortic balloon pump at the time of RRT. Renal recovery occurred in 34% of cases by 90 days and in 39% by 1 year. Of those who recovered renal function, 87% were within 90 days. Only 8 (4%) of the 186 patients were alive and continued to receive RRT at 1 year. CONCLUSIONS The need for RRT after cardiac surgery is an independent risk factor for mortality. In the case of survival, the chance of renal recovery is reasonable.

Coronary Artery Bypass Grafting Versus Drug‐Eluting Stents in Patients with End‐Stage Renal Disease

The optimal treatment for multivessel coronary artery disease in patients with end‐stage renal disease (ESRD) is unresolved.