Effect of red blood cell storage duration on major postoperative complications in cardiac surgery: A randomized trial.

BACKGROUND: Although observational studies suggest an association between transfusion of older red blood cell (RBC) units and increased postoperative risk, randomized trials have not supported this. The objective of this randomized trial was to test the effect of RBC storage age on outcomes after cardiac surgery. METHODS: From July 2007 to May 2016, 3835 adults undergoing coronary artery bypass grafting, cardiac valve procedures, or ascending aorta repair, either alone or in combination, were randomized to transfusion of RBCs stored for ≤14 days (younger units) or for ≥20 days (older units) intraoperatively and throughout the postoperative hospitalization. According to protocol, 2448 patients were excluded because they did not receive RBC transfusions. Among the remaining 1387 modified intent-to-treat patients, 701 were randomized to receive younger RBC units (median age, 11 days) and the remaining 686 to receive older units (median age, 25 days). The primary endpoint was composite morbidity and mortality, analyzed using a generalized estimating equation (GEE) model. The trial was discontinued midway owing to enrollment constraints. RESULTS: A total of 5470 RBC units were transfused, including 2783 in the younger RBC storage group and 2687 in the older RBC storage group. The GEE average relative-effect odds ratio was 0.77 (95% confidence interval [CI], 0.50-1.19; P = .083) for the composite morbidity and mortality endpoint. In-hospital mortality was lower for the younger RBC storage group (2.1% [n = 15] vs 3.4% [n = 23]), as was occurrence of other adverse events except for atrial fibrillation, although all CIs crossed 1.0. CONCLUSIONS: This clinical trial, which was stopped at its midpoint owing to enrollment constraints, supports neither the efficacy nor the futility of transfusing either younger or older RBC units. The effects of transfusing RBCs after even more prolonged storage (35-42 days) remains untested.

New Cardioscope-Based Platform for Minimally Invasive and Percutaneous Beating Heart Interventions.

With heart disease increasing worldwide, demand for new minimally invasive techniques and transcatheter technologies to treat structural heart disease is rising. Cardioscopy has long been considered desirable, as it allows direct tissue visualization and intervention to deliver therapy via a closed chest, with real-time fiber-optic imaging of intracardiac structures. Herein, the feasibility of the advanced cardioscopic platform, allowing both transapical and fully percutaneous access is reported. The latter technique, in particular, is believed to represent a milestone in the development of the cardioscope. Cardioscope prototypes were used in 7 bovine models (77.2-101.1 kg) for transapical or percutaneous insertion. Miniature custom-built, water-sealed cameras (diameters: Storz, 7 Fr; Medigus, 1.2 mm) were used. For percutaneous cardiopulmonary bypass, the pulmonary artery was occluded by a balloon catheter (Intraclude, 10.5 Fr, 100 cm) and perfused with a crystalloid solution. Cameras were inserted transapically (n = 4) through the left ventricular apex or percutaneously (n = 5) via the carotid artery. Insertion of the optimized cardioscope devices was feasible via either approach. Intracardiac structures (left ventricle, mitral valve opening/closure, chordal apparatus, aortic valve leaflets, and regurgitation) were visualized clearly and without deformation. Catheter tips were successfully bent >180° inside the left ventricle; rotation and navigation to view various intracardiac structures were feasible in all cases. This study showed the technical feasibility of direct cardioscopic visualization using transapical and percutaneous approaches. This advanced cardioscopic instrumentarium represents a promising platform for future interventions and surgery under direct visualization of the beating heart.

Real Age: Red Blood Cell Aging During Storage.

BACKGROUND: During cold storage, some red blood cell (RBC) units age more rapidly than others. Yet, the Food and Drug Administration has set a uniform storage limit of 42 days. Objectives of this review are to present evidence for an RBC storage lesion and suggest that functional measures of stored RBC quality-which we call real age-may be more appropriate than calendar age. METHODS: During RBC storage, biochemical substances and byproducts accumulate and RBC shape alters. Factors that influence the rate of degradation include donor characteristics, bio-preservation conditions, and vesiculation. Better understanding of markers of RBC quality may lead to standardized, quantifiable, and operationally practical measures to improve donor selection, assess quality of an RBC unit, improve storage conditions, and test efficacy of the transfused product. RESULTS: The conundrum is that clinical trials of younger versus older RBC units have not aligned with in vitro aging data; that is, the units transfused were not old enough. In vitro changes are considerable beyond 28 to 35 days, and average storage age for older transfused units was 14 to 21 days. CONCLUSIONS: RBC product real age varies by donor characteristics, storage conditions, and biological changes during storage. Metrics to measure temporal changes in quality of the stored RBC product may be more appropriate than the 42-day expiration date. Randomized trials and observational studies are focused on average effect, but, in the evolving age of precision medicine, we must acknowledge that vulnerable populations and individuals may be harmed by aging blood.

Extracorporeal Membrane Oxygenation in Pulmonary Endarterectomy Patients.

OBJECTIVES: To investigate short-term outcomes in patients with chronic thromboembolic pulmonary hypertension (CTEPH) presenting for pulmonary endarterectomy (PEA) and requiring extracorporeal membrane oxygenation (ECMO) during the perioperative period. DESIGN: Retrospective observational case series involving patients who underwent PEA for CTEPH, with focus on a subpopulation requiring perioperative ECMO support. SETTING: Single academic tertiary center. PARTICIPANTS: Patients who underwent PEA for CTEPH between January 1997 and December 2015 and required ECMO support. INTERVENTIONS: PEA for CTEPH with ECMO support at any time during the perioperative period. MEASUREMENTS AND MAIN RESULTS: A total of 150 patients underwent PEA for CEPTH during the study period. Of the 150 patients, 14 (9.3%) required ECMO support and (43%) survived, were discharged, and were alive at the time of the review. A total of 8 (57%) ECMO patients died during hospitalization. Although indications and type of support changed in some patients during their hospital course, the majority of patients required venovenous ECMO support for hypoxia (N = 9) versus venoarterial ECMO for hemodynamic support (N = 5) as initial indication. The mean length of stay among survivors was 42.2 ± 22 days. Severe RV dysfunction was present preoperatively among 6 patients in the nonsurvivors group (75%) and 2 in the survivors group (33%). The overall mean duration of ECMO support was 7.3 ± 5.3 days (8.3 ± 7.3 days among survivors and 6.5 ± 3.5 days among nonsurvivors). Four patients died while on ECMO. CONCLUSIONS: Although still associated with high morbidity and mortality, ECMO appears to be an important treatment adjunct providing additional time for healing and recovery of cardiopulmonary function in patients who develop severe hypoxemia or right ventricular failure after PEA.

Exercise capacity in asymptomatic patients with significant primary mitral regurgitation: independent effect of global longitudinal left ventricular strain.

BACKGROUND: Despite preserved left ventricular ejection fraction (LVEF), patients with significant primary mitral regurgitation (MR) often have reduced exercise capacity. In asymptomatic patients with ≥3+ primary MR undergoing rest-stress echocardiography (RSE), we sought to evaluate the incremental impact of left ventricular global longitudinal strain (LV-GLS) on exercise capacity. METHODS: A total of 660 asymptomatic patients with ≥3+ primary MR, non-dilated LV and LVEF ≥60% (mean age, 57±14 years, 66% men, body mass index or BMI 25±4 kg/m2) who underwent RSE at our center between 2001 and 2013 were included. Standard RSE data were obtained. Average resting LV-GLS was measured using Velocity Vector Imaging. RESULTS: Mean mitral effective regurgitant orifice, resting right ventricular systolic pressure (RVSP) and LV-GLS were 0.45±0.2 cm2, 31±12 mmHg and -21.7%±2%, respectively; 28% had flail mitral leaflet. Mean metabolic equivalents (METs) and post-stress RVSP were 9.9±3, and 46±15 mmHg; 28% achieved <100% age-gender predicted METs. No patient had ischemia or significant arrhythmias. On logistic regression, resting LV-GLS [odds ratio (OR), 1.40, 95% confidence interval (CI): 1.21-1.55, BMI (OR, 1.11, 95% CI: 1.06-1.17)] and resting RVSP 1.22 (1.02-1.49) were independent predictors of exercise capacity. Area under the curve for association between 100% age-gender predicted METs and various factors were as follows: (I) BMI (0.60, 95% CI: 0.55-0.65, P<0.001); (II) resting RVSP (0.57, 95% CI: 0.52-0.62, P=0.006) and LV-GLS (0.66, 95% CI: 0.61-0.70, P<0.001). CONCLUSIONS: In asymptomatic patients with ≥3+ primary MR, non-dilated LV and preserved LVEF, LV-GLS is independently associated with exercise capacity, beyond known predictors.

Simple versus complex degenerative mitral valve disease.

OBJECTIVES: At a center where surgeons favor mitral valve (MV) repair for all subsets of leaflet prolapse, we compared results of patients undergoing repair for simple versus complex degenerative MV disease. METHODS: From January 1985 to January 2016, 6153 patients underwent primary isolated MV repair for degenerative disease, 3101 patients underwent primary isolated MV repair for simple disease (posterior prolapse), and 3052 patients underwent primary isolated MV repair for complex disease (anterior or bileaflet prolapse), based on preoperative echocardiographic images. Logistic regression analysis was used to generate propensity scores for risk-adjusted comparisons (n = 2065 matched pairs). Durability was assessed by longitudinal recurrence of mitral regurgitation and reoperation. RESULTS: Compared with patients with simple disease, those undergoing repair of complex pathology were more likely to be younger and female (both P values < .0001) but with similar symptoms (P = .3). The most common repair technique was ring/band annuloplasty (3055/99% simple vs 3000/98% complex; P = .5), followed by leaflet resection (2802/90% simple vs 2249/74% complex; P < .0001). Among propensity-matched patients, recurrence of severe mitral regurgitation 10 years after repair was 6.2% for simple pathology versus 11% for complex pathology (P = .007), reoperation at 18 years was 6.3% for simple pathology versus 11% for complex pathology, and 20-year survival was 62% for simple pathology versus 61% for complex pathology (P = .6). CONCLUSIONS: Early surgical intervention has become more common in patients with degenerative MV disease, regardless of valve prolapse complexity or symptom status. Valve repair was associated with similarly low operative risk and time-related survival but less durability in complex disease. Lifelong annual echocardiographic surveillance after MV repair is recommended, particularly in patients with complex disease.

Early results of robotically assisted mitral valve surgery: Analysis of the first 1000 cases.

OBJECTIVE: The study objective was to assess the technical and process improvement and clinical outcomes of robotic mitral valve surgery by examining the first 1000 cases performed in a tertiary care center. METHODS: We reviewed the first 1000 patients (mean age, 56 ± 10 years) undergoing robotic primary mitral valve surgery, including concomitant procedures (n = 185), from January 2006 to November 2013. Mitral valve disease cause was degenerative (n = 960, 96%), endocarditis (n = 26, 2.6%), rheumatic (n = 10, 1.0%), ischemic (n = 3, 0.3%), and fibroelastoma (n = 1, 0.1%). All procedures were performed via right chest access with femoral perfusion for cardiopulmonary bypass. RESULTS: Mitral valve repair was attempted in 997 patients (2 planned replacements and 1 resection of fibroelastoma), 992 (99.5%) of whom underwent valve repair, and 5 (0.5%) of whom underwent valve replacement. Intraoperative postrepair echocardiography showed that 99.7% of patients receiving repair (989/992) left the operating room with no or mild mitral regurgitation, and predischarge echocardiography showed that mitral regurgitation remained mild or less in 97.9% of patients (915/935). There was 1 hospital death (0.1%), and 14 patients (1.4%) experienced a stroke; stroke risk declined from 2% in the first 500 patients to 0.8% in the second 500 patients. Over the course of the experience, myocardial ischemic and cardiopulmonary bypass times (P < .0001), transfusion (P = .003), and intensive care unit and postoperative lengths of stay (P < .05) decreased. CONCLUSIONS: Robotic mitral valve surgery is associated with a high likelihood of valve repair and low operative mortality and morbidity. The combination of algorithm-driven patient selection and increased experience enhanced clinical outcomes and procedural efficiency.

Robotic Mitral Valve Repair: The Learning Curve.

OBJECTIVE: Adoption of robotic mitral valve surgery has been slow, likely in part because of its perceived technical complexity and a poorly understood learning curve. We sought to correlate changes in technical performance and outcome with surgeon experience in the "learning curve" part of our series. METHODS: From 2006 to 2011, two surgeons undertook robotically assisted mitral valve repair in 458 patients (intent-to-treat); 404 procedures were completed entirely robotically (as-treated). Learning curves were constructed by modeling surgical sequence number semiparametrically with flexible penalized spline smoothing best-fit curves. RESULTS: Operative efficiency, reflecting technical performance, improved for (1) operating room time for case 1 to cases 200 (early experience) and 400 (later experience), from 414 to 364 to 321 minutes (12% and 22% decrease, respectively), (2) cardiopulmonary bypass time, from 148 to 102 to 91 minutes (31% and 39% decrease), and (3) myocardial ischemic time, from 119 to 75 to 68 minutes (37% and 43% decrease). Composite postoperative complications, reflecting safety, decreased from 17% to 6% to 2% (63% and 85% decrease). Intensive care unit stay decreased from 32 to 28 to 24 hours (13% and 25% decrease). Postoperative stay fell from 5.2 to 4.5 to 3.8 days (13% and 27% decrease). There were no in-hospital deaths. Predischarge mitral regurgitation of less than 2+, reflecting effectiveness, was achieved in 395 (97.8%), without correlation to experience; return-to-work times did not change substantially with experience. CONCLUSIONS: Technical efficiency of robotic mitral valve repair improves with experience and permits its safe and effective conduct.

Robotic mitral valve repair for degenerative posterior leaflet prolapse.

BACKGROUND: Robotic mitral valve (MV) repair is the least invasive surgical approach to the MV and provides unparalleled access to the valve. We sought to assess technical aspects and clinical outcomes of robotic MV repair for isolated posterior leaflet prolapse by examining the first 623 such cases performed in a tertiary care center. METHODS: We reviewed the first 623 patients (mean age 56±9.7 years) with isolated posterior leaflet prolapse who underwent robotic primary MV repair from 01/2006 to 11/2013. All procedures were performed via right chest access with femoral perfusion for cardiopulmonary bypass. RESULTS: MV repair was attempted in all patients; 622 (99.8%) underwent MV repair and only 1 (0.2%) converted to replacement. After an initial attempt at robotic MV repair, 8 (1.3%) patients were converted to sternotomy as a result of management of residual mitral regurgitation (n=3), bleeding (n=1), difficulties with surgical exposure (n=2), aortic valve injury (n=1), and aortic dissection (n=1). Intraoperative post-repair echocardiography confirmed that all patients left the operating room with MR graded as mild or less, and pre-discharge echocardiography confirmed mild or less MR in 573 (99.1%). There was no hospital death, sternal wound infection, or renal failure. Seven (1.1%) patients suffered a stroke, 11 (1.8%) patients underwent re-exploration for bleeding, and 111 (19%) experienced new-onset atrial fibrillation. The mean intensive care unit length of stay and hospital length of stay were 29±17 hours and 4.6±1.6 days, respectively. CONCLUSIONS: At a large tertiary care referral center, robotic MV repair for posterior prolapse is associated with zero mortality, infrequent operative morbidity, and near 100% successful repair. The combination of a patient selection algorithm and increased experience improved clinical outcomes and procedural efficiency.

Degenerative mitral valve disease-contemporary surgical approaches and repair techniques.

Given the increasing age of the US population and the accompanying rise in cardiovascular disease, we expect to see an increasing number of patients affected by degenerative mitral valve disease in a more complex patient population. Therefore, increasing the overall rate of mitral valve repair will become even more important than it is today, and the capability to provide a universally and uniformly accepted quality of repair will have important medical, economic, and societal implications. This article will describe preoperative and intraoperative considerations and the currently practiced mitral valve repair approaches and techniques. The aim of the article is to present our contemporary approach to mitral valve repair in the hope that it can be adopted at other institutions that may have low repair rates. Adoption of simple and reproducible mitral valve repair techniques is of paramount importance if we as a profession are to accomplish overall higher rates of mitral valve repair with optimal outcomes.

Valve Repair Is Superior to Replacement in Most Patients With Coexisting Degenerative Mitral Valve and Coronary Artery Diseases.

BACKGROUND: For mitral regurgitation (MR) from degenerative mitral disease in patients with coexisting coronary artery disease, the appropriate surgical strategy remains controversial. METHODS: From 1985 to 2011, 1,071 adults (age 70 ± 9.3 years, 77% men) underwent combined coronary artery bypass grafting and either mitral valve repair (n = 872, 81%) or replacement (n=199, 19%) for degenerative MR. Propensity matching (177 patient pairs, 89% of possible matches) was used to compare early outcomes and time-related recurrence of MR after mitral valve repair, mitral valve reoperation, and mortality. Risk factors for death were identified with multivariable, multiphase hazard-function analysis. RESULTS: Patients undergoing valve replacement were older, with more valve calcification and a higher prevalence of preoperative atrial fibrillation and heart failure (all p < .0001). Among matched pairs, mitral replacement versus repair was associated with higher hospital mortality (5.0% vs 1.0%, p = .0001) and more postoperative renal failure (7.0% vs 3.2%, p = .01), reexplorations for bleeding (6.0% vs 3.1%, p = .05), and respiratory failure (14% vs 4.7%, p < .0001). Of matched patients undergoing repair, 18% had MR above 3+ by 5 years. Mitral valve durability was similar between matched groups, but survival at 15 years was 18% after replacement versus 52% after repair. Nomograms from the multivariable equation revealed that in 94% of cases, 10-year survival was calculated to be higher after repair than after replacement. CONCLUSIONS: In patients with coexisting degenerative mitral valve and coronary artery diseases, mitral valve repair is expected to confer a long-term survival advantage over replacement despite some recurrence of MR. When feasible, it is the procedure of choice for these patients.

Long-term results after robotically assisted coronary bypass surgery.

BACKGROUND: Robotically-assisted coronary bypass grafting (CABG) was introduced in 1998 and dedicated centers have continuously applied and developed this minimally invasive method of coronary bypass surgery. While short-term results are relatively well published, data on long-term outcome are limited. In this literature review, we assessed the outcomes after robotic CABG following the first postoperative year. METHODS: We searched PubMed for articles containing the terms "robotic" or "robotically assisted" and "coronary bypass". A total of 11 papers contained long-term results. We specifically investigated survival, graft patency, freedom from angina and re-intervention, as well as freedom from major adverse cardiac and cerebrovascular events (MACCE). RESULTS: Five-year survival after robotic CABG was consistently consistently greater than 90% and graft patency between 3 and 5 years was reported to be above 90%. Fifteen percent to 26% of patients re-experienced angina at 3 to 5 years postoperatively. Long-term freedom from re-intervention reached the range and the 5-year freedom from MACCE rate was approximately 75%. CONCLUSIONS: According to data in the literature, long-term results after CABG carried out with the assistance of a surgical robot appear to be in line with results achieved after conventional CABG.

Robotic mitral valve surgery: current limitations and future directions.

Use of the surgical robot facilitates less invasive mitral valve surgery. Although multiple single center studies confirmed excellent results with robotically-assisted mitral valve surgery, both real and perceived limitations have slowed adoption of this technology. Some still question the safety and efficacy of robotically-assisted mitral valve surgery. However, present data suggests that robotic operations can be performed by specialized surgeons in appropriately selected patients without compromising results. That said, the robot does introduce additional procedural complexity related to management of cardiopulmonary bypass and myocardial protection. A direct approach to these challenges combined with careful patient selection enables the surgeon to obtain excellent results with robotically-assisted mitral valve surgery.

Technical aspects of robotic posterior mitral valve leaflet repair.

Posterior mitral valve leaflet repair is safe, effective and durable and can be performed through conventional sternotomy or by using minimally invasive thoracoscopic or robotic-assisted approaches. Triangular resection with ventricularization, quadrangular resection with sliding or folding leaflet reconstruction, neochordae implantation and edge-to-edge leaflet repair are different techniques for eliminating the prolapsing mitral leaflet segment and restoring normal leaflet coaptation. Recent studies have demonstrated that minimally invasive approaches are associated with a reduced risk of postoperative complications, shorter hospital stay and improved cosmetic outcomes when compared to conventional sternotomy. In this review, we sought to describe technical aspects of robotic posterior mitral valve repair.

Strain Echocardiography and Functional Capacity in Asymptomatic Primary Mitral Regurgitation With Preserved Ejection Fraction.

BACKGROUND: The potential additive utility of baseline resting left ventricular global longitudinal strain (LV-GLS) and exercise stress testing in risk stratification of patients with significant mitral regurgitation (MR) has not been studied. OBJECTIVES: The goal of this study was to determine whether resting LV-GLS and exercise testing provide incremental prognostic utility in asymptomatic patients with ≥3+ primary MR and preserved left ventricular ejection fraction. METHODS: Between 2000 and 2011, resting and exercise echocardiography data, Society of Thoracic Surgeons (STS) scores, and death were recorded in 737 patients (mean age 58 ± 13 years; 68% men). RESULTS: Coronary artery disease and flail leaflet were seen in 10% and 28% of patients, respectively. STS score, resting left ventricular ejection fraction, mitral effective regurgitant orifice, resting right ventricular systolic pressure (RVSP), exercise metabolic equivalents (METs), and percentage of age-/sex-predicted METs were 1.5 ± 1%, 62 ± 2%, 0.45 ± 0.2 cm2, 31 ± 12 mm Hg, 9.8 ± 3, and 115 ± 27, respectively. Median LV-GLS was -21.7%. Within 3 months (interquartile range: 1 to 15 months), 65% underwent mitral valve surgery. At 8.3 ± 3 years, 64 (9%) patients died (0% 30-day post-operative deaths). On multivariable Cox survival analysis, higher STS score (hazard ratio [HR]: 1.14), more abnormal resting LV-GLS (HR: 1.60), higher baseline RVSP (HR: 1.35), and lower percentage of age-/sex-predicted METs (HR: 1.13) were associated with higher mortality, whereas mitral valve surgery (HR: 0.82) was associated with improved survival (all p < 0.01). Addition of predicted METs and resting LV-GLS to STS, resting RVSP, left ventricular end-systolic dimension, and mitral effective regurgitant orifice increased the C-statistic for longer-term mortality from 0.61 to 0.69 and 0.78, respectively (all p < 0.01). On quadratic spline analysis, the risk of death progressively increased as resting LV-GLS worsened below -21%. CONCLUSIONS: Reduced exercise capacity and worsening resting LV-GLS were associated with mortality, providing additive prognostic utility.