Intravenous amino acid therapy for kidney protection in cardiac surgery patients: A pilot randomized controlled trial

ObjectiveTo determine whether a continuous intravenous infusion of standard amino acids could preserve kidney function after on-pump cardiac surgery.MethodsAdult patients scheduled to receive cardiac surgery lasting longer than 1 hour on-pump were randomized to standard care (n = 36) or an infusion of amino acids initiated immediately after induction of anesthesia (n = 33). The study's primary outcome measurements assessed renal function. These assessments included duration of renal dysfunction, duration and severity of acute kidney injury (AKI), estimated glomerular filtration rate (eGFR) over time, urine output, and use of renal-replacement therapy. Complications and other measures of morbidity were also assessed.ResultsSixty-nine patients (mean age 71.5 [standard deviation 9.2] years; 19 of 69 women) were enrolled and randomized. Patients received coronary artery bypass graft surgery (37/69), valve surgery (24/69), coronary artery bypass graft and valve surgery (6/69), or other procedures (2/69). Mean on-pump time was 268 [standard deviation 136] minutes. Duration of renal dysfunction did not differ between the groups (relative risk, 0.86; 95% confidence interval [CI], 0.19-3.79, P = .84). However, patients who received the amino acid infusion had a reduced duration of AKI (relative risk, 0.02; 95% CI, 0.005-0.11, P < .0001) and greater eGFR (+10.8%; 95% CI, 1.0%-20.8%, P = .033). Daily mean urine output was also significantly greater in patients who received the amino acid infusion (1.4 ± 0.5 vs 1.7 ± 0.9 L/d; P = .046).ConclusionsCommencing an infusion of standard amino acids immediately after the induction of anesthesia did not alter duration of renal dysfunction; however, other key measures of renal function (duration of AKI, eGFR and urine output) were significantly improved. These results warrant replication in multicenter clinical trials.     

Coronary artery bypass grafting after acute ST-elevation myocardial infarction

ObjectivesThe study objectives were to describe the trends and outcomes of isolated coronary artery bypass grafting after ST-elevation myocardial infarction using a nationwide database.MethodsWe queried the 2002-2016 National Inpatient Sample database for hospitalized patients with ST-elevation myocardial infarction who underwent isolated coronary artery bypass grafting. We report temporal trends, predictors, and outcomes of coronary artery bypass grafting in the early (2002-2010) and recent (2011-2016) cohorts.ResultsOf 3,347,470 patients hospitalized for ST-elevation myocardial infarction, 7.7% underwent isolated coronary artery bypass grafting. The incidence of isolated coronary artery bypass grafting after ST-elevation myocardial infarction decreased over time (9.2% in 2002 vs 5.5% in 2016, P_trend < .001), whereas perioperative crude in-hospital mortality did not change (5.1% in 2002 vs 4.2% in 2016, P_trend = .66), coinciding with an increase in the burden of comorbidities. There was an increase in performing isolated coronary artery bypass grafting on hospitalization day 3 or more, as well as an increase in the use of mechanical support devices and precoronary artery bypass grafting percutaneous coronary intervention. In the early cohort, isolated coronary artery bypass grafting on days 1 and 2 was associated with higher in-hospital mortality. In the recent cohort, coronary artery bypass grafting on day 2 had similar in-hospital mortality compared with day 3 or more and lower rates of acute kidney injury, ischemic stroke, ventricular arrhythmia, and length of hospital stay.ConclusionsIn this nationwide analysis, there has been a decline in the use of isolated coronary artery bypass grafting after ST-elevation myocardial infarction. Isolated coronary artery bypass grafting on day 1 was performed in sicker patients and was associated with higher in-hospital mortality than coronary artery bypass grafting performed on day 3 or more. In the recent cohort, isolated coronary artery bypass grafting on day 2 had similar in-hospital mortality compared with day 3 or more.     

Myeloperoxidase in the pericardial fluid improves the performance of prediction rules for postoperative atrial fibrillation

ObjectivesAfter surgery, inflammation is a prominent factor influencing postoperative atrial fibrillation. Myeloperoxidase is a major contributor to inflammatory responses after surgical tissue damage. We evaluated whether myeloperoxidase is associated with postoperative atrial fibrillation clinically and in an animal model.MethodsThis prospective cohort study included patients undergoing isolated coronary artery bypass grafting. Myeloperoxidase concentrations in blood and pericardial fluid were determined at baseline and 6, 12, and 18 hours after coronary artery bypass grafting. Myeloperoxidase activity in blood, pericardial fluid, and atrium were also evaluated in a canine coronary artery bypass grafting model. Electrophysiologic, histologic, and immunohistochemistry analyses were performed to explore underlying mechanisms.ResultsPostoperative atrial fibrillation occurred in 45 of 137 patients (32.8%). Patients with postoperative atrial fibrillation had significantly higher serum and pericardial myeloperoxidase levels. Individual clinical and surgical factors had moderate predictive value (area under the curve, 0.760) for postoperative atrial fibrillation. Discrimination improved remarkably when myeloperoxidase was combined with other parameters (area under the curve, 0.901). Pericardial myeloperoxidase at 6 hours postoperatively was the strongest independent predictor of postoperative atrial fibrillation (odds ratio, 19.215). The rate of postoperative atrial fibrillation increased exponentially across pericardial myeloperoxidase grades. Compared with controls, coronary artery bypass grafting–treated dogs showed higher atrial fibrillation vulnerability and maintenance, shorter atrial effective refractory period, attenuated connexin 43 expression, and increased myocardial and pericardial myeloperoxidase activity. Connexin 43 expression and atrial effective refractory period were strongly negatively correlated with myocardial and pericardial myeloperoxidase activity.ConclusionsMyeloperoxidase is linked to postoperative atrial fibrillation, and the ability to predict postoperative atrial fibrillation was remarkably improved by adding pericardial myeloperoxidase. Myeloperoxidase-related atrial structural and electrical remodeling is a physiologic substrate for this arrhythmia.     

A novel predictive model for poor in-hospital outcomes in patients with acute kidney injury after cardiac surgery

ObjectivePatients with cardiac surgery–associated acute kidney injury are at risk of renal replacement therapy and in-hospital death. We aimed to develop and validate a novel predictive model for poor in-hospital outcomes among patients with cardiac surgery–associated acute kidney injury.MethodsA total of 196 patients diagnosed with cardiac surgery–associated acute kidney injury were enrolled in this study as the training cohort, and 32 blood cytokines were measured. Least absolute shrinkage and selection operator regression and random forest quantile-classifier were performed to identify the key blood predictors for in-hospital composite outcomes (requiring renal replacement therapy or in-hospital death). The logistic regression model incorporating the selected predictors was validated internally using bootstrapping and externally in an independent cohort (n = 52).ResultsA change in serum creatinine (delta serum creatinine) and interleukin 16 and interleukin 8 were selected as key predictors for composite outcomes. The logistic regression model incorporating interleukin 16, interleukin 8, and delta serum creatinine yielded the optimal performance, with decent discrimination (area under the receiver operating characteristic curve: 0.947; area under the precision-recall curve: 0.809) and excellent calibration (Brier score: 0.056, Hosmer–Lemeshow test P = .651). Application of the model in the validation cohort yielded good discrimination. A nomogram was generated for clinical use, and decision curve analysis demonstrated that the new model adds more net benefit than delta serum creatinine.ConclusionsWe developed and validated a promising predictive model for in-hospital composite outcomes among patients with cardiac surgery–associated acute kidney injury and demonstrated interleukin-16 and interleukin-8 as useful predictors to improve risk stratification for poor in-hospital outcomes among those with cardiac surgery–associated acute kidney injury.     

Comparison of C-C motif chemokine ligand 14 with other biomarkers for adverse kidney events after cardiac surgery

ObjectiveOutcomes after acute kidney injury are affected by both the severity and the duration of the insult. Patients with persistent acute kidney injury have higher major adverse kidney events, including 90-day mortality, renal replacement therapy, and persistent kidney dysfunction. Methods to identify these patients are urgently needed to improve outcomes. The purpose of this study was to evaluate whether biomarkers, including C-C motif chemokine ligand 14, were able to predict persistent acute kidney injury and major adverse kidney events after cardiac surgery.MethodsThis study was a single-center, prospective, observational study. Patients who developed moderate or severe acute kidney injury (Kidney Disease Improving Global Outcomes 2 or 3) within 72 hours after cardiac surgery were enrolled with a primary end point of persistent severe acute kidney injury (Kidney Disease Improving Global Outcomes 3) lasting 72 hours or more.ResultsA total of 100 patients were available for the primary analysis, and 37 met the primary end point. C-C motif chemokine ligand 14 was the most predictive biomarker for the primary end point with an area under the curve of 0.930 (95% confidence interval, 0.881-0.979). The area under the curve of C-C motif chemokine ligand 14 was significantly higher than the area under the curve for the other biomarkers analyzed. C-C motif chemokine ligand 14 was significantly higher in end point positive patients at enrollment (4.47 ng/mL [2.35-11.5] vs 0.67 ng/mL [0.38-1.07]; P = .001). Sensitivity and specificity were 78% and 95% at a cutoff value of 2.21 ng/mL, respectively. C-C motif chemokine ligand 14 was also highly accurate for predicting renal replacement therapy within 7 days (area under the curve, 0.915; 95% confidence interval, 0.858-0.972; P < .001).ConclusionsElevated C-C motif chemokine ligand 14 levels predict persistent acute kidney injury in cardiac surgery patients with moderate or severe acute kidney injury. This new biomarker may help stratify patients destined to receive renal replacement therapy and identify patients who may benefit from novel therapeutic approaches to acute kidney injury.     

Association between coronary artery bypass graft center volume and year-to-year outcome variability: New York and California statewide analysis

ObjectiveWe evaluated whether volume-based, rather than time-based, annual reporting of center outcomes for coronary artery bypass grafting may improve inference of quality, assuming that large center-level year-to-year outcome variability is related to statistical noise.MethodsWe analyzed 2012 to 2016 data on isolated coronary artery bypass grafting using statewide outcome reports from New York and California. Annual changes in center-level observed-to-expected mortality ratio represented stability of year-to-year outcomes. Cubic spline fit related the annual observed-to-expected ratio change and center volume. Volume above the inflection point of the spline curve indicated centers with low year-to-year change in outcome. We compared observed-to-expected ratio changes between centers below and above the volume threshold and observed-to-expected ratio changes between consecutive annual and biennial measurements.ResultsThere were 155 centers with median annual volume of 89 (interquartile range, 55-160) for isolated coronary artery bypass grafting. The inflection point of observed-to-expected ratio variability was observed at 111 cases/year. Median year-to-year observed-to-expected ratio change for centers performing less than 111 cases (62 centers) was greater at 0.83 (0.26-1.59) compared with centers performing 111 cases or more (93 centers) at 0.49 (022-0.87) (P < .001). By aggregating the outcome over 2 years, centers above the 111-case threshold increased from 93 centers (60%) to 118 centers (76%), but the median observed-to-expected change for all centers was similar between annual aggregates at 0.70 (0.26-1.22) compared with observed-to-expected change between biennial aggregates at 0.54 (0.23-1.02) (P = .095).ConclusionsCenter-level, risk-adjusted coronary artery bypass grafting mortality varies significantly from one year to the next. Reporting outcomes by specific case volume may complement annual reports.     

Relation between functional coronary artery stenosis and graft occlusion after coronary artery bypass grafting

ObjectivesThis study was conducted to evaluate graft patency rates during the 5 years after coronary artery bypass grafting according to the functional significance of the coronary artery stenosis, as determined by myocardial single-photon-emission computed tomography.MethodsTwo hundred ninety-five patients who underwent coronary artery bypass grafting using Y-composite grafts based on the in situ left internal thoracic artery, and in whom preoperative stress/rest myocardial single-photon-emission computed tomography and 1-year angiographies were available were enrolled. Seven hundred sixty-nine and 262 distal anastomoses were constructed to ischemic and nonischemic areas, respectively. One-year and 5-year angiographic occlusion rates were evaluated in all and 80.3% of study patients, respectively. Factors associated with graft occlusion were evaluated using generalized linear mixed-effects models.ResultsOverall 1- and 5-year graft occlusion rates were 4.3% (44 of 1031 distal anastomoses) and 5.5% (45 out of 820), respectively. The occlusion rates of grafts bypassed to vessels with functionally significant and insignificant stenosis were 2.7% (21 out of 769) and 8.8% (23 out of 262) at 1 year and were 4.0% (25 out of 618) and 9.9% (20 out of 202) at 5 years, respectively. Graft occlusion during the 5 years after coronary artery bypass grafting was associated with the functional significance of coronary artery stenosis (odds ratio, 0.50; 95% confidence interval, 0.28-0.92). The odds ratio of the graft occlusion according to functional ischemia was lower and significant in grafts to arteries with intermediate stenosis (stenosis ≥70% but <90%; odds ratio, 0.34; 95% confidence interval, 0.13-0.93) whereas it was higher and insignificant in grafts to arteries with severe stenosis (≥90% stenosis; odds ratio, 0.76; 95% confidence interval, 0.33-1.72).ConclusionsGraft occlusion during the 5 years after coronary artery bypass grafting was associated with the functional significance of coronary artery stenosis, particularly when the stenosis degree was not severe.     

Coronary artery bypass with single versus multiple arterial grafts in women: A meta-analysis

ObjectiveThe study objective was to investigate the impact of multiple arterial grafting on long-term all-cause mortality in women undergoing isolated coronary artery bypass grafting.MethodsA comprehensive search was performed to identify observational studies reporting outcomes after coronary artery bypass grafting reported by sex and stratified into multiple arterial grafting versus single arterial grafting strategies. Articles were considered for inclusion if they were written in English and were propensity-matched observational studies. Included studies were then pooled in a meta-analysis performed using the generic inverse variance method. The primary outcome was long-term all-cause mortality. Secondary outcomes were operative mortality and spontaneous myocardial infarction. Meta-regression was used to explore the effects of preoperative and intraoperative variables on the primary outcome.ResultsA total of 6 studies with 32,793 women (25,714 single arterial grafting and 7079 multiple arterial grafting) were included. Women who received multiple arterial grafting had lower long-term mortality (incidence rate ratio, 0.86; 95% confidence interval, 0.76-0.96; P = .007) and spontaneous myocardial infarction (incidence rate ratio, 0.80; 95% confidence interval, 0.68-0.93; P = .003) compared with women who received single arterial grafting, but the difference in mortality disappeared when including only the 3 largest studies. There was no difference between groups in operative mortality (odds ratio, 0.99; 95% confidence interval, 0.84-1.17; P = .91). Meta-regression did not identify any associations with the incidence rate ratio for long-term mortality.ConclusionsThe use of multiple arterial grafting in women undergoing coronary artery bypass grafting is associated with lower long-term mortality, although the difference is mostly driven by small series. Further studies, including randomized trials, are needed to evaluate the efficacy of multiple arterial grafting in women undergoing coronary artery bypass grafting.     

Postoperative kidney oxygen saturation as a novel marker for acute kidney injury after adult cardiac surgery

ObjectiveAcute kidney injury is a severe complication and one of the stronger risk factors for death in patients undergoing cardiac surgery. The relationship between postoperative brain oxygen saturation and kidney oxygen saturation with acute kidney injury in adults undergoing cardiac surgery has not been determined. We designed a single-center prospective study to determine if the continuous monitoring of postoperative brain oxygen saturation and kidney oxygen saturation could predict postoperative acute kidney injury.MethodsWe conducted a prospective open cohort study from January to September 2017. The primary outcome was postoperative acute kidney injury using the Kidney Disease: Improving Global Outcomes criteria. Brain oxygen saturation and kidney oxygen saturation, the metrics of which were area measurements (%-min), were recorded during the surgery and the first 48 hours after the cardiac procedure. Receiver operating characteristic curve analysis was used to evaluate the predictive power of kidney oxygen saturation for acute kidney injury.ResultsA total of 121 consecutive patients were enrolled. Thirty-five patients (28.9%) developed acute kidney injury. Brain oxygen saturation showed no statistical difference in both groups; however, kidney oxygen saturation was related to acute kidney injury (P = .001). Receiver operating characteristic curve analysis showed that kidney oxygen saturation could predict the risk of acute kidney injury. Kidney oxygen saturation less than 65% (area under the curve-receiver operating characteristic, 0.679 ± 0.054, 95% confidence interval, 0.573-0.785, P = .002) and 20% decrease from baseline (area under the curve-receiver operating characteristic, 0.639 ± 0.059, 95% confidence interval, 0.523-0.755, P = .019) showed the better performance, respectively.ConclusionsPostoperative kidney oxygen saturation is related to the development of cardiac surgery–associated acute kidney injury. Continuous kidney saturation monitoring might be a promising, noninvasive tool for predicting acute kidney injury during the postoperative period for adult patients after cardiac surgery.     

Hospital variability in modifiable factors driving coronary artery bypass charges

ObjectiveCoronary artery bypass grafting is associated with significant interhospital variability in charges. Drivers of hospital charge variability remain elusive. We identified modifiable factors associated with statewide interhospital variability in hospital charges for coronary artery bypass grafting.MethodsCharge data were used as a surrogate for cost. Society of Thoracic Surgeons data from Maryland institutions and charge data from the Maryland Health Care Commission were linked to characterize interhospital charge variability for coronary artery bypass grafting. Multivariable linear regression was used to identify perioperative factors independently related to coronary artery bypass grafting charges. Of the factors independently associated with charges, we analyzed which factors varied between hospitals.ResultsA total of 10,337 patients underwent isolated coronary artery bypass grafting at 9 Maryland hospitals from 2012 to 2016, of whom 7532 patients were available for analyses. Mean normalized charges for isolated coronary artery bypass grafting varied significantly among hospitals, ranging from $30,000 to $57,000 (P < .001). Longer preoperative length of stay, operating room time, and major postoperative morbidity including stroke, renal failure, prolonged ventilation, reoperation, and deep sternal wound infection were associated with greater hospital charges. Incidence of major postoperative events, except stroke and deep sternal wound infection, was variable between hospitals. In a univariate linear regression model, patient risk profile only accounted for approximately 10% of statistical variance in charges.ConclusionsThere is significant charge variability for coronary artery bypass grafting among hospitals within the same state. By targeting variation in preoperative length of stay, operating room time, postoperative renal failure, prolonged ventilation, and reoperation, cardiac surgery programs can realize cost savings while improving quality of care for this resource-intense patient population.     

Oxygen delivery-guided perfusion for the prevention of acute kidney injury: A randomized controlled trial

ObjectivesThe reduction of postoperative acute kidney injury in patients undergoing cardiopulmonary bypass surgery using an oxygen delivery-guided perfusion strategy (oxygen delivery strategy) for cardiopulmonary bypass management compared with a fixed flow perfusion (conventional strategy) remains controversial. The purpose of this study was to determine whether a oxygen delivery strategy would reduce the incidence of postoperative acute kidney injury in patients undergoing cardiopulmonary bypass surgery.MethodsWe randomly enrolled 300 patients undergoing cardiopulmonary bypass surgery. Patients were randomly assigned to a oxygen delivery strategy (maintaining a oxygen delivery index value >300 mL/min/m² through pump flow adjustments during cardiopulmonary bypass) or a conventional strategy (a target pump flow was determined on the basis of the body surface area). The primary end point was the development of acute kidney injury. Secondary end points were the red blood cell transfusion rate and number of red blood cell units, intubation time, postoperative length of stay in the intensive care unit and the hospital, predischarge estimated glomerular filtration rate, and hospital mortality.ResultsAcute kidney injury occurred in 20 patients (14.6%) receiving the oxygen delivery strategy and in 42 patients (30.4%) receiving the conventional strategy (relative risk, 0.48; 95% confidence interval, 0.30-0.77; P = .002). The secondary end points were not significantly different between strategies. In a prespecified subgroup analysis of patients who had nadir hematocrit less than 23% or body surface area less than 1.40 m², the oxygen delivery strategy seemed to be superior to the conventional strategy and the existence of quantitative interactions was suggested.ConclusionsAn oxygen delivery strategy for cardiopulmonary bypass management was superior to a conventional strategy with respect to preventing the development of acute kidney injury.     

Interhospital failure to rescue after coronary artery bypass grafting

ObjectiveWe evaluated whether interhospital variation in mortality rates for coronary artery bypass grafting was driven by complications and failure to rescue.MethodsAn observational study was conducted among 83,747 patients undergoing isolated coronary artery bypass grafting between July 2011 and June 2017 across 90 hospitals. Failure to rescue was defined as operative mortality among patients developing complications. Complications included the Society of Thoracic Surgeons 5 major complications (stroke, surgical reexploration, deep sternal wound infection, renal failure, prolonged intubation) and a broader set of 19 overall complications. After creating terciles of hospital performance (based on observed:expected mortality), each tercile was compared on the basis of crude rates of (1) major and overall complications, (2) operative mortality, and (3) failure to rescue (among major and overall complications). The correlation between hospital observed and expected (to address confounding) failure to rescue rates was assessed.ResultsMedian Society of Thoracic Surgeons predicted mortality risk was similar across hospital observed:expected mortality terciles (P = .831). Mortality rates significantly increased across terciles (low tercile: 1.4%, high tercile: 2.8%). Although small in magnitude, rates of major (low tercile: 11.1%, high tercile: 12.2%) and overall (low tercile: 36.6%, high tercile: 35.3%) complications significantly differed across terciles. Nonetheless, failure to rescue rates increased substantially across terciles among patients with major (low tercile: 9.1%, high tercile: 14.3%) and overall (low tercile: 3.3%, high tercile: 6.8%) complications. Hospital observed and expected failure to rescue rates were positively correlated among patients with major (R² = 0.14) and overall (R² = 0.51) complications.ConclusionsThe reported interhospital variability in successful rescue after coronary artery bypass grafting supports the importance of identifying best practices at high-performing hospitals, including early recognition and management of complications.     

Twenty-year outcomes of minimally invasive direct coronary artery bypass surgery: The Leipzig experience

ObjectiveMinimally invasive direct coronary artery bypass (MIDCAB) surgery involving left anterior descending coronary artery grafting with the left internal thoracic artery through a left anterior small thoracotomy is being routinely performed in some specified centers for patients with isolated complex left anterior descending coronary artery disease, but very few reports regarding long-term outcomes exist in literature. Our study was aimed at assessing and analyzing the early and long-term outcomes of a large cohort of patients who underwent MIDCAB procedures and identifying the effects of changing trends in patient characteristics on early mortality.MethodsA total of 2667 patients, who underwent MIDCAB procedures between 1996 and 2018, were divided into 3 groups on the basis of the year of surgery: group A, 1996-2003 (n = 1333); group B, 2004-2010 (n = 627) and group C, 2011-2018 (n = 707). Groupwise characteristics and early postoperative outcomes were compared. Long-term survival for all patients was analyzed and predictors for late mortality were identified using Cox proportional hazards methods.ResultsThe mean age was 64.5 ± 10.9 years and 691 (25.9%) patients were female. Group C patients (log EuroSCORE I = 4.9 ± 6.9) were older with more cardiac risk factors and comorbidities than groups A (log EuroSCORE I = 3.1 ± 4.5) and B (log EuroSCORE I = 3.5 ± 4.7). Overall and groupwise in-hospital mortality was 0.9%, 1.0%, 0.6%, and 1.0% (P = .7), respectively. Overall 10-, 15-, and 20-year survival estimates for all patients were 77.7 ± 0.9%, 66.1 ± 1.2%, and 55.6 ± 1.6%, respectively.ConclusionsMIDCAB can be safely performed with very good early and long-term outcomes. In-hospital mortality remained constant over the 22-year period of the study despite worsening demographic profile of patients.     

Are racial differences in hospital mortality after coronary artery bypass graft surgery real? A risk-adjusted meta-analysis

BackgroundDespite several reports, there are still conflicting data on the influence of ethnicity on mortality rates associated with coronary artery bypass grafting (CABG). We aimed to get further insights into the effect of race on mortality following CABG by performing a risk adjusted meta-analysis.MethodsRelevant studies were searched on PubMed, Embase, BioMed Central, and the Cochrane Central register. Pairwise meta-analysis was used to estimate the relative risk of hospital death of black, Hispanic, and Asian patients using white patients as reference. Risk adjusted meta-analytic estimates were obtained using generic inverse variance methods with random effect model.ResultsA total of 28 studies were selected for analysis. A total of 21 studies reported on hospital mortality in black (n = 222,892) versus white (n = 3,884,043) patients, 7 studies reported on Hispanic (n = 91,256) versus white (n = 1,458,524) and 9 studies reported on Asian (n = 27,820) versus white (n = 1,081,642). When compared with white patients, adjusted risk of hospital death was significantly greater for black patients (adjusted odds ratio [OR], 1.25; 95% confidence interval [CI], 1.13-1.39; P < .001), and not statistically different for Asian (OR, 1.33; 95% CI, 0.99-1.77; P = .05) and Hispanic patients (adjusted OR, 1.08; 95% CI, 0.94-1.23; P = .26). Meta-regression showed a significant trend toward lower mortality rates in most recent series in both black (P = .02) and white (P = .0007) and Asian (P = .01) but not for Hispanic (P = .41). However, as mortality rates were lower across the different races, the relative disadvantage between the study groups persisted, which may explain the lack of interaction between study period and race effect on mortality for black (adjusted P = .09), Asian (adjusted P = .63), and Hispanic (adjusted P = .97) patients.ConclusionsThe present meta-analysis showed that despite progress is being made in lowering in-hospital mortality rates among the major racial/ethnic groups, ethnical disparities in hospital mortality after CABG remain.     

Mortality after tricuspid valve procedures: A 27-year,single-center experience

ObjectiveTo assess mortality after tricuspid valve (TV) surgery in a large single-center patient cohort.MethodsData from 392 TV procedures performed between 1989 and 2015 in 388 adult patients were retrospectively reviewed. The patients were divided into groups according to the type of concomitant procedure, ie, coronary artery bypass grafting (CABG) (TV + CABG group; n = 87), other valve surgery (TV + valve group; n = 240), or an isolated TV procedure with or without another minor procedure (isolated TV group; n = 65), and the era of the operation, ie, 1989-2005 (n = 173) or 2006-2015 (n = 219). Control groups of patients who underwent other valve procedures and/or CABG during the same time periods were used for comparison.ResultsDuring the most recent era, the annual number of TV procedures increased 2.4-fold, mainly for TV + valve procedures (2.8-fold). Within the TV + valve group, a larger proportion of patients had mild-to-moderate tricuspid regurgitation (grade ≤2) compared with the first-time period (P = .001). The TV + CABG group had significantly greater mortality than both the other groups during both time periods, whereas isolated TV procedure had the lowest mortality rates with the exception of the TV + valve group during the most recent era (P = .41). Survival for patients undergoing TV + valve procedures has improved significantly during the last decade (P = .001) and was comparable with that for other valve operations during this period.ConclusionsIn the last decade, TV repair has been performed more frequently and at lower grades of tricuspid regurgitation compared with previously, and mortality after TV procedures has decreased.     

New-onset postoperative atrial fibrillation impact on 5-year clinical outcomes and costs

ObjectiveThe impact of new-onset postoperative atrial fibrillation (POAF) following coronary artery bypass grafting (CABG) surgery on long-term clinical outcomes and costs is not known. This subanalysis of the Veterans Affairs “Randomized On/Off Bypass Follow-up Study” compared 5-year outcomes and costs between patients with and without POAF.MethodsOf the 2203 veterans in the study, 100 with pre-CABG atrial fibrillation (93) or missing data (7) were excluded (4.8%). Unadjusted and risk-adjusted outcomes were compared between new-onset POAF (n = 551) and patients without POAF (n = 1552). Five-year clinical outcomes included mortality, major adverse cardiovascular events (MACE, comprising mortality, repeat revascularization, and myocardial infarction), MACE subcomponents, stroke, and costs. A stringent P value of ≤.01 was required to identify statistical significance.ResultsPatients with POAF were older and had more complex comorbidities. Unadjusted 5-year all-cause mortality was 16.3% POAF versus 11.9% no-POAF, P = .008. Unadjusted cardiac-mortality was 7.4% versus 4.8%, P = .022. There were no differences between groups in any other unadjusted outcomes including MACE or stroke. After risk adjustment, there were no significant differences between groups in 5-year all-cause mortality (POAF odds ratio, 1.19; 99% confidence interval, 0.81-1.75) or cardiac mortality (odds ratio, 1.51, 99% confidence interval, 0.88-2.60). Adjusted first-year post-CABG costs were $15,300 greater for patients with POAF, but 2- through 5-year costs were similar.ConclusionsNo 5-year risk-adjusted outcome differences were found between patients with and without POAF after CABG. Although first-year costs were greater in patients with POAF, this difference did not persist in subsequent years.     

Should concomitant surgical ablation for atrial fibrillation be performed in elderly patients?

ObjectiveThe incidence of atrial fibrillation increases with age, and therefore many elderly patients presenting for cardiac surgery have atrial fibrillation. In recent publications, increasing age has been recognized as a predictor for ablation failure. Furthermore, many surgeons are reluctant to perform a surgical ablation in elderly patients. We investigated the safety and efficacy of concomitant surgical atrial fibrillation ablation in elderly patients.MethodsBetween 2003 and 2013, 556 patients underwent concomitant surgical atrial fibrillation ablation at the University Heart Center Hamburg and served as our primary study cohort. During follow-up, rhythm monitoring was established by 24-hour Holter electrocardiogram (70.5%) or an implantable loop recorder (29.5%) at 3, 6, and 12 months postoperatively. The primary end point of the study was freedom from atrial fibrillation at 12 months follow-up and the detection of deviations from a linear association between age and risk of atrial fibrillation recurrence. A multiple logistic regression model including age as a linear term was used to identify predictors for rhythm outcome.ResultsMean patients’ age was 68.4 ± 9.07 years, and 67.3% of the patients were male. Mean duration of atrial fibrillation was 3.5 ± 3.3 years, and mean left atrium diameters were enlarged with 50.5 ± 8.8 mm. There were no major ablation-related complications. The 30-day and 1-year survivals were 97.7% and 95.8%, respectively. The overall rate of freedom from atrial fibrillation ranged from 62% to 72% and was independent of age. The age-dependent risk of atrial fibrillation at 12 months was significantly increased in elderly patients undergoing a concomitant coronary artery bypass grafting surgery. Multiple logistic regression model revealed double valve procedures (odds ratio, 3.48; P = .020), preoperative persistent atrial fibrillation (odds ratio, 2.43; P = .001), and coronary artery bypass grafting surgery in elderly patients (odds ratio, 2.03; P = .009) as risk factors for recurrence of atrial fibrillation. Sinus rhythm at discharge (odds ratio, 0.39; P < .001) and bipolar ablation (odds ratio, 0.32; P < .001) were significant predictors for successful ablation.ConclusionsSurgical atrial fibrillation ablation was safe and effective independently of age. Sinus rhythm at discharge and bipolar ablation were significant predictors for successful ablation, whereas double valve procedures, preoperative persistent atrial fibrillation, and coronary artery bypass grafting surgery in elderly patients were risk factors for recurrence of atrial fibrillation.     

Is anterior mitral valve leaflet length important in outcome of septal myectomy for obstructive hypertrophic cardiomyopathy?

ObjectivesElongation of mitral valve leaflets is a phenotypic feature of hypertrophic cardiomyopathy, and some surgeons advocate plication of the anterior leaflet at the time of septal myectomy. The present study investigates mitral valve leaflet length and outcomes of patients undergoing septal myectomy for obstructive hypertrophic cardiomyopathy.MethodsWe reviewed the records and echocardiograms of 564 patients who underwent transaortic septal myectomy for obstructive hypertrophic cardiomyopathy between February 2015 and April 2018. Extended septal myectomy without plication of the anterior leaflet was the standard procedure. From intraoperative prebypass transesophageal echocardiograms, we measured anterior and posterior mitral valve leaflets and their coaptation length. For comparison, we performed these mitral valve leaflet measurements in 90 patients who underwent isolated coronary artery bypass grafting and 92 patients undergoing aortic valve replacement in the same period. Among patients with hypertrophic cardiomyopathy undergoing septal myectomy, we assessed left ventricular outflow tract gradient relief and 1-year survival in relation to leaflet length.ResultsMedian patient age (interquartile range) was 60.3 (50.2-67.7) years, and 54.1% were male. Concomitant mitral valve repair was performed in 36 patients (6.4%), and mitral valve replacement was performed in 8 patients (1.4%), primarily for intrinsic mitral valve disease. Patients in the hypertrophic cardiomyopathy cohort had significantly longer mitral valve leaflet measurements compared with patients undergoing coronary artery bypass grafting or aortic valve replacement (P < .001 for all 3 measurements). Preoperative resting left ventricular outflow tract gradients were not related to leaflet length (<30 mm, median 49 [21, 81.5] mm Hg vs ≥30 mm, 50.5 [21, 77] mm Hg; P = .76). Further, gradient reduction after myectomy was not related to leaflet length; patients with less than 30 mm anterior leaflet length had a median gradient reduction of 33 (69, 6) mm Hg compared with 36.5 (62, 6) mm Hg for patients with leaflet length 30 mm or more (P = .36). Anterior mitral valve leaflet length was not associated with increased 1-year mortality (P = .758).ConclusionsOur study confirms previous findings that patients with hypertrophic cardiomyopathy have slight (5 mm) elongation of mitral valve leaflets. In contrast to other reports, increased anterior mitral valve leaflet length was not associated with higher left ventricular outflow tract gradients. Importantly, we found no significant relationship between anterior mitral valve leaflet length and postoperative left ventricular outflow tract resting gradients or gradient relief. Thus, in the absence of intrinsic mitral valve disease, transaortic septal myectomy with focus on extending the excision beyond the point of septal contact is sufficient for almost all patients.     

Application of the descending branch of the lateral circumflex femoral artery in coronary artery bypass grafting

ObjectiveTo investigate a technical method for harvesting and using the descending branch of the lateral circumflex femoral artery (DLCFA) in coronary artery bypass grafting (CABG).MethodsBetween January 2017 and January 2019, 40 patients (36 in the planed selection group and 4 in the temporary decision group) with mean age of 49.1 ± 7.5 years received DLCFA as an arterial conduit in CABG. In all patients, the DLCFA was successfully harvested via an anterior thigh incision. Depending on the location of the target vessel, the DLCFA was used as a free graft or a composite graft.ResultsOf the 44 patients in the planned selection group, DLCFA harvesting was abandoned in 8 patients because computed tomographic angiography revealed anatomical variation or stenosis of the superficial femoral artery. Of the 5 patients in the temporary decision group, harvesting was abandoned in 1 because of short length and thin caliber. On an average, 3.7 ± 0.9 distal anastomoses were created during CABG, with no adverse effects. The length of the harvested DLCFA was 9.9 ± 1.7 cm, with an average proximal lumen diameter of 3.4 ± 0.7 mm. The DLCFA was used as a free graft in 26 patients and as a “Y”-shape composite graft in 14 patients. Total arterial CABG was performed in 75% of the patients.ConclusionsThe DLCFA is an alternative conduit for CABG. It can be harvested easily and safely. However, preoperative computed tomographic angiography examination is necessary for the smooth application of the DLCFA, and an appropriate strategy for graft establishment should be considered.     

Conduit selection and early graft failure in coronary artery bypass surgery: A post hoc analysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) coronary artery bypass grafting study

ObjectivesRelative rates of early graft failure and conduit selection in coronary artery bypass grafting (CABG) surgery remain controversial. Therefore, we sought to determine the incidence and determinants of graft failure of the left internal mammary artery (LIMA), radial artery, saphenous vein, and right internal mammary artery (RIMA) 1 year after CABG surgery.MethodsA post hoc analysis of the Cardiovascular Outcomes for People Using Anticoagulation Strategies (COMPASS) CABG study, involving patients from 83 centers in 22 countries. We completed an analysis of 3480 grafts from 1068 patients who underwent CABG surgery with complete computed tomography angiography data. The primary outcome was graft failure as diagnosed by computed tomography angiography 1 year after surgery.ResultsGraft failure occurred in 6.4% (68/1068) for LIMA, 9.9% (9/91) for radial artery, 10.4% (232/2239) for saphenous vein, and 26.8% (22/82) for RIMA grafts. The RIMA had a greater rate of graft failure (26.8%) than radial artery (9.9%) and veins (10.4%) (adjusted odds ratio, 2.69; 95% confidence interval, 1.30-5.57; P = .008 and adjusted odds ratio, 2.07; 95% confidence interval, 1.33-3.21; P = .001, respectively).ConclusionsIn this international trial dataset, LIMA and radial artery performed as expected, whereas vein grafts performed better. However, high rates of RIMA failure are worrisome and highlight the need for a thorough evaluation of the patency and safety of the RIMA in CABG surgery.