Pradeep Narayan

Preoperative Glycosylated Hemoglobin: A Risk Factor for Patients Undergoing Coronary Artery Bypass

BACKGROUNDnThe prevalence of diabetes in the population of patients presenting with coronary artery disease continues to rise. The aim of this study was to assess whether high Glycosylated hemoglobin (HbA1c) was associated with adverse outcomes in patients undergoing elective coronary artery bypass grafting.nnnMETHODSnA retrospective observational study on prospectively collected data in 4,678 patients undergoing elective, isolated coronary artery bypass graft procedures in a single institution over a 4-year period was conducted. Patients were grouped into those with adequate preoperative control of hyperglycemia (HbA1c <6.5%) and those with suboptimal control (HbA1c ≥6.5%). Multivariable analysis using HbA1c as a binary independent variable was undertaken in the whole group. A subgroup analysis in diabetic patients and in nondiabetic patients was performed. The effect of HbA1c on outcomes at higher levels (HbA1c ≥8.0% and HbA1c ≥9.0%) was also assessed.nnnRESULTSnA total of 4,678 patients (mean age, 58.8; male, 4,254) were included in the study. HbA1c was less than 6.5% in 2,476 (52.93%) patients and 6.5% or higher in 2,202 (47.07%) patients. On multivariate analysis, there was no difference in mortality rates between the groups (odds ratio, 1.36; 95% confidence interval [CI], 0.95 to 1.953; pxa0=xa00.08). Overall, an HbA1c of 6.5% or higher was an independent risk factor for respiratory complications (odds ratio, 1.05; 95% CI, 1.008 to 4.631; pxa0= 0.01) and sternal dehiscence (odds ratio, 2.161; 95% CI, 1.008 to 4.63; pxa0=xa00.04). An association between HbA1c levels and adverse outcomes was not seen in nondiabetic patients. No additional adverse postoperative complications were seen with increasing HbA1c levels (HbA1c ≥8.0% and HbA1c ≥9.0%).nnnCONCLUSIONSnAn HbA1c level of 6.5% or higher in patients presenting for coronary artery bypass grafting was associated with a significant increase in the incidence of deep sternal wound infection and respiratory complications.

Benefits of Using High-Volume–Low-Pressure Tracheal Tube in Children Undergoing Congenital Cardiac Surgery: Evidence From a Prospective Randomized Study:

Background. In the past 2 decades, usage of high-volume–low-pressure microcuffed tracheal tubes in smaller children has increased. However, there is paucity of evidence of its usage in smaller children undergoing congenital cardiac surgery. The aim of this study was to assess if microcuff endotracheal tubes in neonates and younger children undergoing congenital cardiac surgery is associated with better outcomes than uncuffed tubes. Methods. We carried out this single-center, prospective, randomized study between June and November 2016. Eighty patients were randomized into those receiving microcuff tracheal tubes and conventional uncuffed tubes. Primary outcome was stridor postextubation. Secondary outcomes measured included number of tube changes, volume of anesthetic gases required, and cost incurred. Results. The 2 groups were comparable in terms of baseline characteristics and duration of intubation. Incidence of stridor was significantly higher in conventional uncuffed tubes (12 [30%] vs 4 [10%]; P = .04) and so was the number of tube changes required (17/40 [42.5%] vs 2/40 [5%]; P ≤ .001). Tube change was associated with more than 3-fold risk of stridor (odds ratio = 3.92; 95% confidence interval = 1.23-12.43). Isoflurane (29.14 ± 7.01 mL vs19.2 ± 4.81 mL; P < .0001) and oxygen flow requirement (P < .0001) and the resultant cost (7.46 ± 1.4 vs 5.77 ± 1.2 US

Artifact on postoperative chest radiograph, mimicking retained foreign body

; P < .0001) were all significantly higher in the conventional uncuffed group. Conclusion. Microcuff pediatric tracheal tube is associated with significantly lower incidence of stridor, tube changes, and anesthetic gas requirement. This leads to significant cost reduction that offsets the higher costs associated with usage of a microcuff tracheal tube.

Key updates from international coronary congress 2016—a review

Following routine coronary artery bypass grafting, a radiopaque shadow was seen in the left upper zone on 2 separate chest radiographs taken 3 days apart (Figure 1). This was constant in location and was therefore thought to be a foreign body left inadvertently in the thorax. The likeliest possibility was a soft bulldog clamp seen end-on, applied to a saphenous vein graft to the circumflex. The next steps were to organize a computed tomography scan and perhaps reexplore the patient to retrieve the retained foreign body. However, discussions with radiologists revealed that this was in fact an artifact due to a damaged cassette housing the film. It was sheer coincidence that the patient had the same cassette during both chest radiographs. Absence of the shadow was confirmed by repeating the radiograph with a different cassette (Figure 2). Abnormal shadows suggesting retained foreign bodies can be misleading and have medicolegal consequences as well. Discussion with the radiologist is helpful not only to make a proper diagnosis but also to avoid inappropriate investigations.

Minimally invasive coronary artery bypass grafting

This review focuses on the key issues raised during the International Coronary Congress (ICC) 2016. The left internal thoracic artery and the drug-eluting stents in relation to the left anterior descending artery re-vascularization have been compared and the role of Heart Team stressed upon. The current role of bilateral internal thoracic artery grafting is discussed. The importance of and tools for intra-operative assessment of graft patency have been outlined. The patency and related issues of saphenous vein grafts harvested using the no-touch technique has been discussed in detail. Following the discussion at ICC 2016 and review of literature, we conclude that left internal thoracic artery remains the best option for left anterior descending artery lesions and for left main and ostial or proximal left anterior descending artery lesions. The Heart Team should be approached for decision making. Bilateral internal thoracic artery usage should be encouraged especially in the Indian population which includes a higher proportion of younger patients with a particularly high prevalence of diabetes. Transit time flowmetry is a useful tool to confirm and assess whether intra-operative graft flow and saphenous vein grafts harvested with a no-touch technique have better patency than conventionally harvested vein grafts.

Myocardial protection following del Nido cardioplegia in pediatric cardiac surgery

Minimally invasive cardiac surgery (MICS)-CABG is a technique that at its core has patient comfort, early return to routine activities, meeting patient expectations for less invasive options, and maintaining the highest possible standards of care and outcomes. The technique requires not only surgical dexterity but also integration of significant technological advancements in patient care. At a time when percutaneous interventions are often prescribed on the pretext of increased patient comfort and demand, minimally invasive myocardial revascularization becomes even more relevant. Minimally invasive myocardial revascularization is ever evolving and encompasses both small-incision open techniques as well as endoscopic-assisted procedures. The success of the procedure depends not only on the learning curve and familiarity with the technology but also on appropriate patient selection. Mere feasibility of the technique is not sufficient, and the results have to be comparable with the long-established techniques of conventional coronary artery bypass grafting both in terms of early morbidity and mortality as well as long-term outcomes. In this review, we discuss patient selection and technical aspects of minimally invasive coronary artery bypass grafting. We also provide an evidence-based comparison to early and long-term outcomes with conventional coronary artery bypass grafting. Finally, we review the uptake and outcomes of minimally invasive revascularization in the Indian subcontinent.

The Effects of Preoperative Volume Replacement in Diabetic Patients Undergoing Coronary Artery Bypass Grafting Surgery: Protocol for a Randomized Controlled Trial (VeRDiCT Trial)

Background This study was designed to compare myocardial protection with del Nido cardioplegia and conventional blood cardioplegia in children undergoing cardiac surgery in Risk Adjustment for Congenital Heart Surgery categories 1 and 2. Methods Sixty patients were randomized into 2 groups receiving del Nido cardioplegia solution or conventional blood cardioplegia. Myocardial injury was assessed using biochemical markers (troponin I and creatine kinase-MB). Vasoactive-inotropic scores were calculated to compare inotropic requirements. Results Demographic characteristics, cardiopulmonary bypass time, and aortic crossclamp time were comparable in the 2 groups. Time-related changes in troponin I and creatine kinase-MB were similar in both groups. Statistically significant differences were seen in total cardioplegia volume requirement (pu2009<u20090.0001), number of cardioplegia doses given (pu2009<u20090.0001), packed red cell volume usage during cardiopulmonary bypass (pu2009<u20090.02), and time taken to restore spontaneous regular rhythm (pu2009<u20090.0001). Vasoactive-inotropic scores on transfer to the intensive care unit (pu2009<u20090.040) and at 24u2009h (pu2009<u20090.030) were significantly lower in the del Nido group. Duration of mechanical ventilation, intensive care unit stay, and hospital stay were comparable in the 2 groups. Conclusions Our results show that del Nido cardioplegia solution is as safe as conventional blood cardioplegia. Moreover, it provides the benefits of reduced dose requirement, lower consumption of allogenic blood on cardiopulmonary bypass, quicker resumption of spontaneous regular cardiac rhythm, and less inotropic support requirement on transfer to the intensive care unit and at 24u2009h, compared to conventional blood cardioplegia.

Bilateral internal mammary arteries—are they really enough?

Background Diabetes mellitus is a major risk factor for prolonged hospital stays, renal failure, and mortality in patients having coronary artery bypass grafting (CABG). Complications pose a serious threat to patients and prolong intensive care and hospital stays. Low glomerular filtration rate (GFR) due to existing renal impairment or volume depletion may exacerbate acute renal impairment/failure in these patients. Preoperative volume replacement therapy (VRT) is reported to increase the GFR and we hypothesize that VRT will reduce renal impairment and related complications in diabetic patients. Objective The objective of this study is to establish the efficacy of preoperative VRT in reducing postoperative complications in diabetic patients undergoing CABG surgery. Time to “fit for discharge”, incidence of postoperative renal failure, cardiac injury, inflammation, and other health outcomes will be investigated. Methods In this open parallel group randomized controlled trial, 170 diabetic patients undergoing elective or urgent CABG surgery received 1 mL/kg/hour of Hartmann’s solution for 12 consecutive hours prior to surgery, versus routine care. The primary outcome was time until participants were “fit for discharge”, which is defined as presence of: normal temperature, pulse, and respiration; normal oxygen saturation on air; normal bowel function; and physical mobility. Secondary outcomes included: incidence of renal failure; markers of renal function, inflammation, and cardiac damage; operative morbidity; intensive care stay; patient-assessed outcome, including the Coronary Revascularization Outcome Questionnaire; and use of hospital resources. Results Recruitment started in July 2010. Enrolment for the study was completed in July 2014. Data analysis commenced in December 2016. Study results will be submitted for publication in the summer of 2017. Conclusions VRT is a relatively easy treatment to administer in patients undergoing surgical procedures who are at risk of renal failure. This experimental protocol will increase scientific and clinical knowledge of VRT in diabetic patients undergoing elective or urgent CABG surgery. Findings supporting the efficacy of this intervention could easily be implemented in the health care system. Trial Registration International Standard Randomized Controlled Trial Number (ISRCTN): 02159606; http://www.controlled-trials.com/ISRCTN02159606 (Archived by WebCite at http://www.webcitation.org/6rDkSSkkK)

Prosthetic valve thrombosis—should thrombolysis be considered as first line of management?

In a retrospective study titled Bilateral internal mamary arteries (BIMA) are enough for total coronary revascularization published later in this issue [1], the authors have presented their experience of multiple arterial grafting and proposed that bilateral internal mammary arteries alone are adequate to revascularize the myocardium. In the study, 4571 out of 4952 (92.3%) patients received a single internal mammary artery (SIMA). Of the remaining, 191 (3.8%) received BIMAalongwith a third graft whichwas either a vein or another artery, and another 190 (3.8%) received only BIMA. Using the EuroSCORE, the authors selected a similar number of patients (n = 190) from the SIMA group and compared the three groups for short-term outcomes. Themain conclusion the authors draw is BIMA usage, with or without an additional conduit, is associated with significantly reduced neurological events. They have also shown that it is possible to bypass comparable number of targets using BIMA alone and have therefore suggested that a third conduit is not really necessary. Their findings have indeed been substantiated by evidence from other researchers. Studies in the past [2] and in more recent times [3–5] have demonstrated the superiority of BIMA over SIMA. It has also been shown that coronary artery operations exclusively with BIMA grafting using composite grafts may be associated with better long-term survival than grafting with SIMA plus other types of conduits [6]. However, their final assertion which is also the title of their work BBilateral internal mammary arteries are enough for total coronary revascularization^ needs further discussion. The authors have reported no difference in outcome between patients receiving only BIMA grafts and those who received an additional graft, at times arterial, along with BIMA. However, they have only reported short-term outcomes, and it is well-known that the main advantage of using arterial grafts lies in improved long-term outcomes, and probably, this was one of the reasons why the 5-year data of the ART trial failed to demonstrate the superiority of BIMA over SIMA [7]. Since the authors have not reported any follow-up data in their paper, do they feel they can be certain that the patient population which received a third arterial conduit in addition to BIMAwill not have better long-term outcome? In fact, there are some single center reports that provide evidence to the contrary [8, 9]. Also, a recently published meta-analysis that evaluated pooled data from 10,287 matched patients receiving two versus three arterial conduits reported that the use of a third arterial graft is associatedwith a 24% survival benefit at a mean follow-up of 77.9 months, and this survival advantage is independent of the patient’s sex and diabetic status [10]. The other concern is methodological. The authors have used EuroSCORE to select matched patients from their SIMA cohort. Even though the three groups the authors have thus created appear reasonably well-matched, there are some significant intergroup differences in terms of age, left main stem stenosis, and presence of diffuse coronary artery disease. In view of these, why did the authors choose EuroSCORE to select their patients and not propensity score matching which would have allowed them to control for these intergroup differences and provide a more accurate comparison? Lastly, the authors have shown that in the short-term, there is a reduction in early neurological events in the BIMA group. However, the authors in this study have not detailed the prevalence of carotid artery disease in the three groups and thus * Pradeep Narayan pradeepdoc@gmail.com

Dramatic regression of coronary artery stenosis three years after diagnosis

BackgroundTraditionally prosthetic valve thrombosis has been managed with emergency surgery. However, there is growing evidence that thrombolysis is a suitable alternative. In this study, we aim to examine the safety and efficacy of thrombolysis in the management of prosthetic valve thrombosis (PVT).Material and methodsThis retrospective study was carried out at a single center between June 2010 and June 2014. All patients presenting with PVT were included in the study. All patients were treated with thrombolysis using our institutional protocol.ResultsNineteen patients presented with 24 episodes of PVT. Overall, 73.6xa0% (14/19) of the patients were successfully treated with thrombolysis leading to clinical as well as haemodynamic improvement. Four (21xa0%) patients were taken directly for an operative intervention. The remaining 15 patients had a trial of thrombolysis which was successful in all cases. However, four of these patients had a recurrence within 2xa0weeks and were offered a second trial of thrombolysis. Three of these patients had a satisfactory outcome, and one patient was taken for surgery. Overall, 73.6xa0% (14/19) of the patients were successfully treated with thrombolysis. There was one incidence of intracerebral bleed leading to death. Mitral valve was the commonest valve involved in our study.ConclusionsThrombolysis is safe and may be considered as primary treatment strategy for first episode of prosthetic valve thrombosis. In recurrent thrombosis as well, a trial of thrombolysis can be given.