Complete Coronary Revascularization and Outcomes in Patients Who Underwent Coronary Artery Bypass Grafting: Insights from The REGROUP Trial.

There is growing evidence in support of coronary complete revascularization (CR). Nonetheless, there is no universally accepted definition of CR in patients who undergo coronary bypass grafting surgery (CABG). We sought to investigate the outcomes of CR, defined as surgical revascularization of any territory supplied by a suitable coronary artery with ≥50% stenosis. We performed a preplanned subanalysis in the Randomized Trial of Endoscopic or Open Saphenous Vein Graft Harvesting (REGROUP) clinical trial cohort. Of 1,147 patients who underwent CABG, 810 (70.6%) received CR. The primary outcome was a composite of major adverse cardiac events (MACEs), including death from any cause, nonfatal myocardial infarction, or repeat revascularization over a median 4.7 years of follow-up. MACE occurred in 175 patients (21.6%) in the CR group and 86 patients (25.5%) in the incomplete revascularization (IR) group (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.67 to 1.13, p = 0.29). A total of 97 patients (12.0%) in the CR group and 48 patients (14.2%) in the IR group died (HR 0.93, 95% CI 0.65 to 1.32, p = 0.67); nonfatal myocardial infarction occurred in 49 patients (6.0%) in the CR group and 30 patients (8.9%) in the IR group (HR 0.76, 95% CI 0.48 to 1.2, p = 0.24), and repeat revascularization occurred in 62 patients (7.7%) in the CR group and 39 patients (11.6%) in the IR group (HR 0.64; 95% CI 0.42 to 0.95, p = 0.027). In conclusion, in patients with a great burden of co-morbidities who underwent CABG in the REGROUP trial over a median follow-up period of a median 4.7 years, CR was associated with similar MACE rates but a reduced risk of repeat revascularization. Longer-term follow-up is warranted.

Postoperative Atrial Fibrillation After Surgical Aortic Valve Replacement: Amiodarone and Warfarin Use.

INTRODUCTION: The association between amiodarone treatment for postoperative atrial fibrillation (POAF) after surgical aortic valve replacement (SAVR) and both the return to normal sinus rhythm (NSR) and anticoagulation use at discharge has not been extensively studied. METHODS: We retrospectively identified all patients who underwent biological SAVR with or without concomitant coronary artery bypass grafting (CABG) at a Veterans Affairs Medical Center (2005-2015). We reviewed new-onset POAF, amiodarone use, return to NSR, and anticoagulation use with warfarin. Discharge rhythm and warfarin administration were compared among patients with POAF who were treated with amiodarone and patients who did not receive amiodarone. RESULTS: Of the 395 patients (186 AVR/coronary artery bypass grafting; 209 AVR) studied, POAF developed in 191 patients (48.0%); 80.1% (153/191) of these patients received amiodarone. Among patients treated with amiodarone, 70.6% (108/153) were in SR at the time of discharge versus 65.8% (25/38) of POAF patients who were not treated with amiodarone (P = 0.57). Among amiodarone-treated patients, 30.7% (47/153) were discharged with warfarin; among patients not treated with amiodarone, 31.6% (12/38) were discharged with warfarin (P = 0.92). Among amiodarone-treated patients discharged in NSR, 89.9% (97/108 patients) were not discharged with warfarin; among patients not treated with amiodarone who were discharged in NSR, 92% (23/25) were not discharged with warfarin (P = 0.74). CONCLUSIONS: POAF after SAVR appears common. Although amiodarone is often used for POAF patients, its use does not appear to be associated with surgeons' decision to anticoagulate patients. Surgeons' preferences for using rhythm control and antithrombotic therapy for POAF after SAVR warrant further exploration.

Analysis of Dynamic Changes in Cognitive Workload During Cardiac Surgery Perfusionists' Interactions With the Cardiopulmonary Bypass Pump.

OBJECTIVE: This novel preliminary study sought to capture dynamic changes in heart rate variability (HRV) as a proxy for cognitive workload among perfusionists while operating the cardiopulmonary bypass (CPB) pump during real-life cardiac surgery. BACKGROUND: Estimations of operators' cognitive workload states in naturalistic settings have been derived using noninvasive psychophysiological measures. Effective CPB pump operation by perfusionists is critical in maintaining the patient's homeostasis during open-heart surgery. Investigation into dynamic cognitive workload fluctuations, and their relationship with performance, is lacking in the literature. METHOD: HRV and self-reported cognitive workload were collected from three Board-certified cardiac perfusionists (N = 23 cases). Five HRV components were analyzed in consecutive nonoverlapping 1-min windows from skin incision through sternal closure. Cases were annotated according to predetermined phases: prebypass, three phases during bypass, and postbypass. Values from all 1min time windows within each phase were averaged. RESULTS: Cognitive workload was at its highest during the time between initiating bypass and clamping the aorta (preclamp phase during bypass), and decreased over the course of the bypass period. CONCLUSION: We identified dynamic, temporal fluctuations in HRV among perfusionists during cardiac surgery corresponding to subjective reports of cognitive workload. Not only does cognitive workload differ for perfusionists during bypass compared with pre- and postbypass phases, but differences in HRV were also detected within the three bypass phases. APPLICATION: These preliminary findings suggest the preclamp phase of CPB pump interaction corresponds to higher cognitive workload, which may point to an area warranting further exploration using passive measurement.

Epiaortic Ultrasound for Assessment of Intraluminal Atheroma; Insights from the REGROUP Trial.

OBJECTIVES: To assess the use of epiaortic ultrasound in contemporary cardiac surgery, as well as its impact on surgical cannulation strategy and cerebrovascular events. DESIGN: Epiaortic ultrasound data was prospectively collected in the Randomized Endovein Graft Prospective (REGROUP) trial (VA Cooperative Studies Program #588, ClinicalTrials.gov, NCT01850082), which randomized 1,150 coronary artery bypass graft patients between 2014 and 2017 to endoscopic or open-vein graft harvest. SETTING: Sixteen cardiac surgery programs within the Veterans Affairs Healthcare System with expertise at performing endoscopic vein-graft harvesting. PARTICIPANTS: Veterans Affairs patients, greater than 18 years of age, undergoing elective or urgent coronary artery bypass grafting with cardiopulmonary bypass and cardioplegic arrest with at least one planned saphenous vein graft were eligible for enrollment. INTERVENTIONS: Epiaortic ultrasound was performed by the surgeon using a high frequency (>7 MHz) ultrasound transducer. Two-dimensional images of the ascending aorta in multiple planes were acquired before aortic cannulation and cross-clamping. MEASUREMENTS AND MAIN RESULTS: Epiaortic ultrasound was performed in 34.1% (269 of 790) of patients in REGROUP. Among these patients, simple intraluminal atheroma was observed in 21.9% (59 269), and complex intraluminal atheroma comprised 2.2% (6 of 269). The aortic cannulation or cross-clamp strategy was modified based on these findings in 7.1% of cases (19 of 269). There was no difference in stroke between patients who underwent epiaortic ultrasound and those who did not (1.9% v 1.2% p = 0.523). CONCLUSIONS: Despite current guidelines recommending routine use of epiaortic ultrasound (IIa/B) to reduce the risk of stroke in cardiac surgery, in this contemporary trial, use remains infrequent, with significant site-to-site variability.

Randomized Trial of Endoscopic or Open Vein-Graft Harvesting for Coronary-Artery Bypass.

BACKGROUND: The saphenous-vein graft is the most common conduit for coronary-artery bypass grafting (CABG). The influence of the vein-graft harvesting technique on long-term clinical outcomes has not been well characterized. METHODS: We randomly assigned patients undergoing CABG at 16 Veterans Affairs cardiac surgery centers to either open or endoscopic vein-graft harvesting. The primary outcome was a composite of major adverse cardiac events, including death from any cause, nonfatal myocardial infarction, and repeat revascularization. Leg-wound complications were also evaluated. RESULTS: A total of 1150 patients underwent randomization. Over a median follow-up of 2.78 years, the primary outcome occurred in 89 patients (15.5%) in the open-harvest group and 80 patients (13.9%) in the endoscopic-harvest group (hazard ratio, 1.12; 95% confidence interval [CI], 0.83 to 1.51; P=0.47). A total of 46 patients (8.0%) in the open-harvest group and 37 patients (6.4%) in the endoscopic-harvest group died (hazard ratio, 1.25; 95% CI, 0.81 to 1.92); myocardial infarctions occurred in 34 patients (5.9%) in the open-harvest group and 27 patients (4.7%) in the endoscopic-harvest group (hazard ratio, 1.27; 95% CI, 0.77 to 2.11), and revascularization occurred in 35 patients (6.1%) in the open-harvest group and 31 patients (5.4%) in the endoscopic-harvest group (hazard ratio, 1.14; 95% CI, 0.70 to 1.85). Leg-wound infections occurred in 18 patients (3.1%) in the open-harvest group and in 8 patients (1.4%) in the endoscopic-harvest group (relative risk, 2.26; 95% CI, 0.99 to 5.15). CONCLUSIONS: Among patients undergoing CABG, we did not find a significant difference between open vein-graft harvesting and endoscopic vein-graft harvesting in the risk of major adverse cardiac events. (Funded by the Cooperative Studies Program, Office of Research and Development, Department of Veterans Affairs; REGROUP ClinicalTrials.gov number, NCT01850082 .).

Relationship between intra-operative vein graft treatment with DuraGraft® or saline and clinical outcomes after coronary artery bypass grafting.

BACKGROUND: Saphenous vein grafts (SVGs) remain the most often used conduits for coronary bypass grafting (CABG). Progressive intimal hyperplasia contributes to vein-graft disease and vein-graft failure (VGF). We compared the impact of intraoperative preservation of SVGs in a storage solution (DuraGraft®) versus heparinized saline on VGF-related outcomes after CABG. METHODS: From 1996 to 2004, 2436 patients underwent isolated CABG with ≥ 1 SVG. SVGs were consecutively treated with DuraGraft in 1036 patients (2001-2004) and heparinized saline in 1400 patients (1996-1999). Short- (< 30 days) and long-term (≥ 1000 days) outcomes were assessed using repeat revascularization (primary end point), and major adverse cardiac events (MACE) consisting of the composite of death, nonfatal myocardial infarction, or repeat revascularization. RESULTS: Mean follow-up in the DuraGraft group was 8.5 ± 4.2 years and 9.9 ± 5.6 years in controls. Short-term event rates were low and generally did not differ between groups. DuraGraft was associated with a 45% lower occurrence of nonfatal myocardial infarction after 1000 days (hazard ratio 0.55, 95% CI 0.41-0.74; P < 0.0001). There was 35% and 19% lower long-term risk for revascularization (HR 0.65, 95% CI 0.44-0.97; P = 0.037) and MACE (HR 0.81, 95% CI 0.70-0.94; P = 0.0051), respectively, after DuraGraft. Mortality was comparable between both groups at 1, 5, and 10 years. There was no statistically significant association between DuraGraft exposure and time to death starting at 30 or 1000 days (HR 0.91, 95% CI 0.76-1.09; P = 0.29). CONCLUSION: In this study, intraoperative treatment of SVGs with DuraGraft was associated with a lower risk of long-term adverse events suggesting that efficient intraoperative SVG treatment may reduce VGF-related complications post-CABG. These data warrant randomized clinical trials to validate these findings.

Topical vancomycin in combination with perioperative antibiotics and tight glycemic control helps to eliminate sternal wound infections.

OBJECTIVE: This study was undertaken to determine whether topical vancomycin would further reduce the incidence of sternal infections in the presence of perioperative antibiotics and tight glycemic control. METHODS: A total of 1075 consecutive patients undergoing cardiac surgery from December 2007 to August 2013 receiving topical vancomycin (2.5 g in 2 mL of normal saline) applied as a slurry to the cut edges of the sternum were compared with 2190 patients from December 2003 to November 2007 who did not receive topical vancomycin. All patients received perioperative antibiotics (cefazolin 2 g intravenously every 8 hours and vancomycin 1 g intravenously every 12 hours) on induction of anesthetic and continuing for 48 hours; and intravenous insulin infusions to maintain serum blood glucose level between 120 and 180 mg/dL. RESULTS: Patients receiving topical vancomycin had less superficial sternal infections (0% vs 1.6%; P < .0001), deep sternal infections (0% vs 0.7%; P = .005), any type of sternal infection (0% vs 2.2%; P < .0001) and significantly less sternal infections of any type in patients with diabetes mellitus (0% vs 3.3%; P = .0004). CONCLUSIONS: Topical vancomycin applied to the sternal edges, in conjunction with perioperative antibiotics and tight glycemic control, helps to eliminate wound infections in cardiac surgical patients.

Aortic valve endocarditis from Staphylococcus lugdunensis.

This is a case of aortic valve endocarditis and leaflet perforation caused by Staphylococcus lugdunensis successfully treated with aortic valve replacement and antibiotics. We believe that the patient's endocarditis may be related to the vasectomy he underwent two months prior to presentation, as S. lugdunensis is an integral component of normal skin flora of the lower abdomen and groin. We also suggest that whenever this organism is found in patients with endocarditis, early surgical treatment of the infected valve should be considered, as S. lugdunensis is an aggressive and virulent coagulase-negative staphylococcus.

Atrial fibrillation at discharge in older cardiac surgery patients: A prospective study of prevalence and associated medication utilization.

BACKGROUND: Although postoperative atrial fibrillation (AF) is prevalent after cardiac surgery, the corresponding medication burden associated with this postoperative arrhythmia is unknown. METHODS: We conducted a prospective study of 204 patients aged 60 or older (median age 73) undergoing cardiac surgery at two academic medical centers. We defined "AF at discharge" as AF that developed after surgery and was present on the day of discharge. We evaluated the prevalence of anticoagulant and antiarrhythmic use at discharge, and out to 1 year post-discharge. We investigated the association between age and prescription of both classes of medications at discharge. RESULTS: Ninety-one (45%) patients developed new postoperative AF, which persisted at discharge in 28 (14%) patients. Thirty-four percent of patients with postoperative AF were discharged on warfarin, 62% were discharged on antiarrhythmic medication, and 25% were discharged on both. Eighty-two percent of those discharged on both were older than 72 years of age. Patients with AF present at discharge were more likely to be discharged on anticoagulant agents than patients whose AF resolved prior to discharge (54% versus 26%, p=0.01), and more likely to be discharged on antiarrhythmic agents than patients whose AF resolved prior to discharge, though not significantly so (73% versus 57%, p=0.2). At 12 months, the proportion of patients on antiarrhythmic and anticoagulant medications had still not returned to preoperative rates. CONCLUSIONS: AF persists at hospital discharge in nearly one-third of affected patients. Cardiac surgery results in the initiation of anticoagulant and antiarrhythmic medications in many older patients annually, often concurrently. Our findings underscore the need for additional studies on the natural history of this arrhythmia and clinical trials investigating different management strategies after discharge. Such research will help to inform development of guidelines addressing duration of use for these medications, to aid physicians in these complicated post-discharge management decisions.

Radial artery grafts vs saphenous vein grafts in coronary artery bypass surgery: a randomized trial.

CONTEXT: Arterial grafts are thought to be better conduits than saphenous vein grafts for coronary artery bypass grafting (CABG) based on experience with using the left internal mammary artery to bypass the left anterior descending coronary artery. The efficacy of the radial artery graft is less clear. OBJECTIVE: To compare 1-year angiographic patency of radial artery grafts vs saphenous vein grafts in patients undergoing elective CABG. DESIGN, SETTING, AND PARTICIPANTS: Multicenter, randomized controlled trial conducted from February 2003 to February 2009 at 11 Veterans Affairs medical centers among 757 participants (99% men) undergoing first-time elective CABG. INTERVENTIONS: The left internal mammary artery was used to preferentially graft the left anterior descending coronary artery whenever possible; the best remaining recipient vessel was randomized to radial artery vs saphenous vein graft. MAIN OUTCOME MEASURES: The primary end point was angiographic graft patency at 1 year after CABG. Secondary end points included angiographic graft patency at 1 week after CABG, myocardial infarction, stroke, repeat revascularization, and death. RESULTS: Analysis included 733 patients (366 in the radial artery group, 367 in the saphenous vein group). There was no significant difference in study graft patency at 1 year after CABG (radial artery, 238/266; 89%; 95% confidence interval [CI], 86%-93%; saphenous vein, 239/269; 89%; 95% CI, 85%-93%; adjusted OR, 0.99; 95% CI, 0.56-1.74; P = .98). There were no significant differences in the secondary end points. CONCLUSION: Among Veterans Affairs patients undergoing first-time elective CABG, the use of a radial artery graft compared with saphenous vein graft did not result in greater 1-year patency. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00054847.

Cerebral hemodynamics during coronary artery bypass graft surgery: the effect of carotid stenosis.

Carotid stenosis is a frequent coexisting condition in patients undergoing coronary artery bypass graft (CABG) surgery. The impact of carotid stenosis on cerebral perfusion is not fully understood. The purpose of this study was to determine the impact of carotid stenosis on cerebral blood flow velocity in patients undergoing CABG. Seventy-three patients undergoing CABG were prospectively recruited and underwent preoperative Duplex carotid ultrasound to evaluate the degree of carotid stenosis. Intraoperatively, transcranial Doppler ultrasound was used to record the mean flow velocity (MFV) within the bilateral middle cerebral arteries. In addition, during the period of cardiopulmonary bypass, regulators of cerebral hemodynamics such as hematocrit, partial pressure of carbon dioxide and temperature were recorded. The ipsilateral middle cerebral artery mean flow velocity was compared in arteries with and without carotid stenosis using a repeated measures analysis. Seventy-three patients underwent intraoperative monitoring during CABG and 30% (n=22) had carotid stenosis. Overall, MFV rose throughout the duration of CABG including when the patient was on cardiopulmonary bypass. However, there was no significant MFV difference between those arteries with and without stenosis (F=1.2, p=.21). Further analysis during cardiopulmonary bypass, demonstrated that hemodilution and partial pressure of carbon dioxide may play a role in cerebral autoregulation during CABG. Carotid stenosis did not impact mean cerebral blood flow velocity during CABG. The cerebrovascular regulatory process appears to be largely intact during CABG.

Troponin I after cardiac surgery and its implications on myocardial protection, outcomes, and cost.

BACKGROUND: Myocardial acidosis during cardiac surgery and postoperative troponin I are markers of myocardial damage that have been shown to predict adverse outcomes. We investigated the relationship between troponin I and myocardial tissue pH, patient outcomes, and cost. METHODS: Data were prospectively collected on 205 cardiac surgery patients. Troponin I was sampled upon arrival to the intensive care unit (ICU) and every 6 hours thereafter for 24 hours. The lowest pH encountered during aortic cross clamp (LpH) was related to postoperative troponin I on the multivariate level. Multivariate models were constructed to predict adverse events (AE) and cost. RESULTS: LpH was an independent inverse determinant of postoperative troponin I (P = .0067). Troponin I and its interaction with LpH were multivariate predictors of AE (P = .0012; .0001;odds ratio = 6.9, 10.2, respectively). Troponin I independently predicts surgical ICU (SICU) cost (P = .0256). CONCLUSION: Postoperative troponin I elevation reflects intraoperative myocardial acidosis and damage. The strong relationship between troponin I, AE, and cost indicates the damage incurred is clinically and economically relevant. Strategies to ameliorate intraoperative myocardial tissue acidosis will decrease troponin I release, subsequent AE, and associated costs.