A comprehensive deep venous thrombosis prophylaxis regimen in isolated coronary artery bypass grafting.

Objectives: Deep venous thrombosis (DVT) is a known surgical complication that can lead to pulmonary embolism with subsequent morbidity and mortality. The incidence of DVT following coronary artery bypass grafting is unclear. Prophylaxis regimens vary and some guidelines advocate against use of routine chemoprophylaxis in patients at low-moderate risk for venous thromboembolism. We utilized postoperative lower extremity venous ultrasound to determine the incidence of DVT following coronary artery bypass grafting in patients with low- to moderate-risk of venous thromboembolism receiving aggressive postoperative DVT prophylaxis. Methods: This is a single-center, retrospective study of all patients who underwent coronary artery bypass grafting between April 2022 and January 2023. All patients who completed postoperative venous ultrasound of the bilateral lower extremities were initially included. Patients who underwent concurrent valve or aortic surgery, were at high risk of venous thromboembolism, or were receiving anticoagulation therapy for nonvenous thromboembolism indications were excluded. The primary outcome was in-hospital incidence of DVT. Secondary outcomes were rates of mortality, postoperative bleeding, and thromboembolic events from discharge to 30 days postoperatively and from 30 days to 3 months postoperatively. Results: No DVTs were observed in 211 included patients. In hospital, there were 3 significant bleeding events and 1 stroke. Following discharge there were 3 additional bleeding events, 1 death, 1 transient ischemic attack, and 1 pulmonary embolism. Conclusions: We observed a 0% rate of DVT in low- to moderate-risk patients undergoing isolated coronary artery bypass grafting and receiving a comprehensive DVT prophylaxis regimen. In hospital bleeding and other thromboembolic event rates were 2.84% and 0.47% respectively.

Contemporary Outcomes of Isolated Tricuspid Valve Surgery.

INTRODUCTION: Isolated tricuspid valve (TV) surgery is uncommonly performed and has historically been associated with excessive operative mortality. We previously reported improved short-term outcomes at our center. Understanding contemporary outcomes of isolated TV surgery beyond the perioperative period is essential to properly benchmark outcomes of newer transcatheter interventions. METHODS: Patients who underwent isolated TV surgery from 2007 to 2021 at a single institution were retrospectively reviewed. Survival was estimated using the Kaplan-Meier method and multivariable Cox proportional hazards regression modeling identified independent risk factors for all-cause mortality. RESULTS: Among 173 patients undergoing isolated TV surgery, 103 (60%) underwent TV repair and 70 (40%) underwent TV replacement. Mean age was 60.3 ± 18.9 y and 55 (32%) were male. The most common etiology of TV disease was functional (46%). In-hospital mortality was 4.1% (7/173), with no difference between TV repair and replacement (P = 0.06). Overall survival at 1 y and 5 y was 78.3% (111/142) and 64.5% (53/82), respectively. After median (interquartile range) follow-up of 2.0 (0.6-4.4) y, patients undergoing TV repair experienced a higher unadjusted survival as compared to those undergoing TV replacement (log-rank P = 0.02). However, after adjusting for covariates, TV replacement was not an independent predictor of all-cause mortality (hazard ratio 1.40; 95% confidence interval, 0.71-2.76; P = 0.33). CONCLUSIONS: Isolated TV surgery can be performed with lower operative mortality than historically reported. Establishing survival benchmarks from TV surgery is important in the era of developing transcatheter interventions.

Rationale and design of a randomized trial evaluating an external support device for saphenous vein coronary grafts.

BACKGROUND: Coronary artery bypass grafting (CABG) is the most common revascularization approach for the treatment of multi-vessel coronary artery disease. While the internal mammary artery is nearly universally used to bypass the left anterior descending coronary artery, autologous saphenous vein grafts (SVGs) are still the most frequently used conduits to grafts the remaining coronary artery targets. Long-term failure of these grafts, however, continues to limit the benefits of surgery. METHODS: The Cardiothoracic Surgical Trials Network trial of the safety and effectiveness of a Venous External Support (VEST) device is a randomized, multicenter, within-patient trial comparing VEST-supported versus unsupported saphenous vein grafts in patients undergoing CABG. Key inclusion criteria are the need for CABG with a planned internal mammary artery to the left anterior descending and two or more saphenous vein grafts to other coronary arteries. The primary efficacy endpoint of the trial is SVG intimal hyperplasia (plaque + media) area assessed by intravascular ultrasound at 12 months post randomization. Occluded grafts are accounted for in the analysis of the primary endpoint. Secondary confirmatory endpoints are lumen diameter uniformity and graft failure (>50% stenosis) assessed by coronary angiography at 12 months. The safety endpoints are the occurrence of major adverse cardiac and cerebrovascular events and hospitalization within 5 years from randomization. CONCLUSIONS: The results of the VEST trial will determine whether the VEST device can safely limit SVG intimal hyperplasia in patients undergoing CABG as treatment for coronary atherosclerotic disease.

Minimally invasive mitral valve surgery after previous sternotomy: A propensity-matched analysis.

BACKGROUND: Although the incidence of mitral valve (MV) surgery after previous open-heart surgery is increasing, there is no consensus regarding the optimal surgical approach. Reoperative MV surgery is most commonly performed via sternotomy (ST). We sought to determine whether minimally-invasive (MIS) reoperative MV surgery is safe and feasible. METHODS: All patients with a history of ST undergoing MV surgery with or without concomitant tricuspid or atrial fibrillation surgery at a single institution from 2007 to 2018 were retrospectively reviewed. ST and MIS approaches were compared using propensity-matched analysis. The coprimary endpoints were operative mortality and 1-year survival, and secondary endpoints were operative complications and length of stay. RESULTS: A total of 305 isolated MV reoperations were performed: 199 (65%) MIS and 106 (35%) ST. MIS patients were older than ST patients (71 [63, 76.5] vs. 66 [56, 72] years, p < .01), more likely to have undergone prior coronary artery bypass grafting (57% vs. 27%, p < .01), and less likely to have had prior valve surgery (55% vs. 78%, p < .01). In unmatched comparisons, operative mortality was significantly lower among MIS patients (3.0% vs. 8.5%, p = .04), but 1-year mortality was similar (14.4% vs. 15.6%, p = .8). After propensity matching, 88 pairs had excellent balance across baseline characteristics. Mortality was similar among MIS and ST patients at 30 days (3.4% vs. 8%, p = .19) and 1 year (15.9% vs. 16.5%, p = .9). RBC and fresh frozen plasma transfusions were significantly lower in the MIS group (p < .01). CONCLUSIONS: A minimally invasive approach is a safe alternative in patients with prior ST undergoing MV surgery.

Outcomes of Isolated Tricuspid Valve Surgery Have Improved in the Modern Era.

BACKGROUND: Surgery for isolated tricuspid valve (TV) disease remains relatively infrequent because of significant patient comorbidities and poor surgical outcomes. This study reviewed the experience with isolated TV surgery in the current era to determine whether outcomes have improved. METHODS: From 2007 through 2017, 685 TV operations were performed in a single institution, of which 95 (13.9%) operations were isolated TV surgery. Patients were analyzed for disease origin, risk factors, operative mortality and morbidity, and long-term survival. RESULTS: A total of 95 patients underwent isolated TV surgery, an average of 9 patients per year increasing from an average of 5 per year to 15 per year during the study period. Surgery was reoperative in 41% (38 of 95) of patients, including 11.6% (11 of 95) with prior coronary artery bypass grafting and 29.4% (28 of 95) with prior valve surgery (9 TV, 11 mitral, 2 aortic, 5 mitral and aortic, and 1 mitral and TV). Repair was performed in 71.6% (68 of 95) of patients, and replacement was performed in 28.4% (27 of 95). Operative mortality was 3.2% (3 of 95), with no mortality in the most recent 73 patients over the last 6 years. Stroke occurred in 2.1% (2 of 95) of patients, acute kidney injury requiring dialysis in 5.3% (5 of 95), and the need for new permanent pacemaker in 16.8% (16 of 95). CONCLUSIONS: In the current era with careful patient selection and periprocedural management, isolated TV surgery can be performed with lower morbidity and mortality than has traditionally been reported with good long-term survival. These outcomes can also serve as a benchmark for catheter-based TV intervention outcomes.

Does method of sternal repair influence long-term outcome of postoperative mediastinitis?

BACKGROUND: Post-sternotomy mediastinitis reduces survival after cardiac surgery, potentially further affected by details of mediastinal vascularized flap reconstruction. The aim of this study was to evaluate survival after different methods for sternal reconstruction in mediastinitis. METHODS: Two hundred twenty-two adult cardiac surgery patients with post-sternotomy mediastinitis were reviewed. After controlling infection, often augmented by negative pressure therapy, muscle flap, omental flap, or secondary closure was performed. Outcomes were reviewed and survival analysis was performed. RESULTS: Baseline characteristics were similar. In-hospital mortality (15.7%) did not differ between groups. Secondary closure was correlated with negative pressure therapy and reduced length hospital of stay. Recurrent wound complications were more common with muscle flap repair. Survival was unaffected by sternal repair technique. By multivariate analysis, heart failure, sepsis, age, and vascular disease independently predicted mortality, while negative pressure therapy was associated with survival. CONCLUSIONS: Choice of sternal repair was unrelated to survival, but mediastinal treatment with negative pressure therapy promotes favorable early and late outcomes.

Cellular and molecular regulation of skeletal muscle side population cells.

Muscle progenitor cells (satellite cells) function in the maintenance and repair of adult skeletal muscle. Side population (SP) cells are enriched in repopulating activity and also reside in adult skeletal muscle. In this study, we observed that Abcg2 is a determinant of the SP cell phenotype. Using reverse transcription polymerase chain reaction and immunohistochemical techniques, we localized Abcg2-expressing cells in the interstitium and in close approximation to the vasculature of adult skeletal muscle. Muscle SP cells are able to differentiate into myotubes and increase in number after cardiotoxin-induced muscle injury. Similar to myogenic progenitor cells, muscle SP cells express Foxk1 and are decreased in number in Foxk1 mutant skeletal muscle. Using emerging technologies, we examine the molecular signature of muscle SP cells from normal, injured, and Foxk1 mutant skeletal muscle to define common and distinct molecular programs. We propose that muscle SP cells are progenitor cells that participate in repair and regeneration of adult skeletal muscle.

Reducing hospital morbidity and mortality following esophagectomy.

BACKGROUND: Esophagogastrectomy (EG) is a formidable operation with significant morbidity and mortality rates. Risk factor analyses have been performed, but few studies have produced strategies that have improved operative results. This study was performed in order to identify prognostic variables that might be used to develop a strategy for optimizing outcomes after EG. METHODS: The records of all patients (n = 379) who underwent EG patients at a tertiary medical center between 1996 and 2002 were retrospectively reviewed. Thirty-day morbidity and mortality were determined, and multivariable logistical regression analysis assessed the effect of preoperative and postoperative variables on early mortality. RESULTS: Operations included Ivor Lewis (n = 179), transhiatal (n = 130), and other approaches (n = 70). Operative mortality was 5.8%; 64% experienced complications, including respiratory complications (28.5%), anastamotic strictures (25%), and leak (14%). Increasing age, anastomotic leak, Charlson comorbidity index 3, worse swallowing scores, and pneumonia were associated with increased risk of mortality by univariate analysis. However, only age (p = 0.002) and pneumonia (p = 0.0008) were independently associated with mortality by multivariable analysis. Pneumonia was associated with a 20% incidence of death. Patients with pneumonia had significantly worse deglutition and anastomotic integrity on barium esophagogram compared with patients without pneumonia (p < 0.001, Mann-Whitney rank sum test). CONCLUSIONS: Morbidity and mortality of EG are significant, but most complications, including anastomotic leak, are not independent predictors of mortality. The most important complication after EG is pneumonia. Strategies to decrease postoperative mortality should include careful assessment of swallowing abnormalities and predisposition to aspiration by cineradiography or fiberoptic endoscopy. After EG, acceptable pharyngeal function and airway protection should be verified before resuming oral intake.

TRPC3 channels confer cellular memory of recent neuromuscular activity.

Skeletal muscle adapts to different patterns of motor nerve activity by alterations in gene expression that match specialized properties of contraction, metabolism, and muscle mass to changing work demands (muscle plasticity). Calcineurin, a calcium/calmodulin-dependent, serine-threonine protein phosphatase, has been shown to control programs of gene expression in skeletal muscles, as in other cell types, through the transcription factor nuclear factor of activated T cells (NFAT). This study provides evidence that the function of NFAT as a transcriptional activator is regulated by neuromuscular stimulation in muscles of intact animals and that calcium influx from the transient receptor potential (TRPC3) channel is an important determinant of NFAT activity. Expression of TRPC3 channels in skeletal myocytes is up-regulated by neuromuscular activity in a calcineurin-dependent manner. These data suggest a mechanism for cellular memory in skeletal muscles whereby repeated bouts of contractile activity drive progressively greater remodeling events.

Real-time three-dimensional echocardiography to construct clinically ready, load-independent indices of myocardial contractile performance.

BACKGROUND: Real-time 3-dimensional echocardiography (RT3DE) reliably determines intracardiac chamber volumes without left ventricular (LV) geometric assumptions, yet clinical assessment of contractile performance is often on the basis of potentially inaccurate, load-dependent indices such as ejection fraction. METHODS: In 6 chronically instrumented dogs, RT3DE estimated LV volumes at various loading conditions. Preload recruitable stroke work and end-systolic pressure-volume relationships were constructed. RT3DE-derived indices were compared with similar relationships determined by sonomicrometry. RESULTS: Highly linear preload recruitable stroke work and end-systolic pressure-volume relationships were constructed by RT3DE and sonomicrometry. Mean preload recruitable stroke work slopes correlated between methods, but volume intercepts differed as a result of geometric assumptions of sonomicrometry. Conversely, RT3DE-derived end-systolic pressure-volume relationships did not correlate well with sonomicrometry. CONCLUSIONS: These data are unique in reporting load-independent measures of LV performance using RT3DE. These techniques would strengthen evaluation of LV function after myocardial ischemia or cardiac operation, in which frequent changes in ventricular geometry or loading conditions confound functional assessment by more traditional methods.