Leonid Sternik

Accuracy of transpulmonary thermodilution versus gravimetric measurement of extravascular lung water.

Objective:Pulmonary edema is a severe and often life-threatening condition. The diagnosis of pulmonary edema and its quantification have great clinical significance and yet can be difficult. A new technique based on thermodilution measurement using a single indicator has recently been developed (PiCCO, Pulsion Medical Systems, AG Germany). This method allows the measurement of extravascular lung water and thus can quantify degree of pulmonary edema. The technique has not been compared with a gold standard, gravimetric measurement of extravascular lung water. Therefore, the objective of this study was to determine the ability of extravascular lung water measurement with the PiCCO to reflect the extravascular lung water as measured with a gravimetric technique in a dog model of pulmonary edema. Design:Prospective, randomized animal study. Setting:A university animal research laboratory. Subjects:Fifteen mongrel dogs (n = 5/group) weighing 20–30 kg. Interventions:The dogs were anesthetized and mechanically ventilated. Five dogs served as controls; in five dogs hydrostatic pulmonary edema was induced using inflation of a left atrial balloon combined with fluid administration to maintain a high pulmonary artery occlusion pressure; and in five dogs pulmonary edema was induced by intravenous injection of oleic acid. After a period of stabilization in a state of pulmonary edema, extravascular lung water was measured with the PiCCO monitor. The animals were then killed, and extravascular lung water was measured using a gravimetric technique. Measurements and Main Results:There was a very close (r = .967, p < .001) relationship between transpulmonary thermodilution and gravimetric measurements. The measurement with the PiCCO was consistently higher, by 3.01 ± 1.34 mL/kg, than the gravimetric measurement. Conclusions:Measurement of extravascular lung water using transpulmonary thermodilution with a single indicator is very closely correlated with gravimetric measurement of lung water in both increased permeability and hydrostatic pulmonary edema.

Patient Characteristics and Cell Source Determine the Number of Isolated Human Cardiac Progenitor Cells

Background— The identification and isolation of human cardiac progenitor cells (hCPCs) offer new approaches for myocardial regeneration and repair. Still, the optimal source of human cardiac progenitor cells and the influence of patient characteristics on their number remain unclear. Using a novel method to isolate human cardiac progenitor cells, we aimed to define the optimal source and association between their number and patient characteristics. Methods and Results— We developed a novel isolation method that produced viable cells (7×106±6.53×105/g) from various tissue samples obtained during heart surgery or endomyocardial biopsies (113 samples from 94 patients 23 to 80 years of age). The isolated cardiac cells were grown in culture with a stem cell expansion medium. According to fluorescence-activated cell sorting analysis, cultured cells derived from the right atrium generated higher amounts of c-kit+ (24±2.5%) and Islet-1+ cells (7%) in culture (mean of passages 1, 2, and 3) than did cultured cells from the left atrium (7.3±3.5%), right ventricle (4.1±1.6%), and left ventricle (9.7±3%; P=0.001). According to multivariable analysis, the right atrium as the cell source and female sex were associated with a higher number of c-kit+ cells. There was no overlap between c-kit+ and Islet-1 expression. In vitro assays of differentiation into osteoblasts, adipocytes, and myogenic lineage showed that the isolated human cardiac progenitor cells were multipotent. Finally, the cells were transplanted into infarcted myocardium of rats and generated myocardial grafts. Conclusion— Our results show that the right atrium is the best source for c-kit+ and Islet-1 progenitors, with higher percentages of c-kit+ cells being produced by women.

Primary coronary artery bypass grafting without cardiopulmonary bypass in impaired left ventricular function

BACKGROUND Conventional coronary artery bypass grafting using cardiopulmonary bypass carries relatively high mortality and morbidity for patients with left ventricular dysfunction. METHODS Seventy-five patients with ejection fraction less than or equal to 0.35 underwent primary coronary artery bypass grafting without cardiopulmonary bypass between December 1991 and December 1994. Thirty-two patients (43%) had congestive heart failure, 11 (15%) were referred for operation within the first 24 hours of evolving myocardial infarction, and 21 (28%) up to 1 week after acute myocardial infarction. Eighteen patients (24%), 6 of whom were in cardiogenic shock, underwent emergency operations. RESULTS Mean number of grafts/patient was 1.9 (range, 1 to 4), and internal mammary artery was used in 66 patients (85%). Only 17 patients (23%) received a graft to a circumflex marginal artery. Two patients (2.7%) died perioperatively, and 1 (1.3%) sustained stroke. At mean follow-up of 28 months, 13 patients had died, and angina had returned in 7 (10.5%). One- and four-year actuarial survival was 96% and 73%, respectively. CONCLUSIONS Coronary artery bypass grafting without cardiopulmonary bypass is a viable alternative to conventional coronary artery bypass grafting particularly for patients with extreme left ventricular dysfunction or those with coexisting risk factors, such as acute myocardial infarction and cardiogenic shock.

Left Atrial Contractile Function Following a Successful Modified Maze Procedure at Surgery and the Risk for Subsequent Thromboembolic Stroke

OBJECTIVES The aim of this study was to evaluate whether certain post-Maze left atrial (LA) contractile profiles may pose a risk for ischemic stroke. BACKGROUND The mechanical contraction of the left atrium may be modified after the Maze procedure. Whether this imposes a risk for stroke, even in the presence of sinus rhythm and after removal of the LA appendage, is not known. METHODS Clinical, surgery-related, and echocardiographic data from 150 patients who underwent radiofrequency and cryoablation Maze procedures without the use of atrial incisions between 2004 and 2009 and were in sustained sinus rhythm were collected and analyzed. The occurrence of stroke was evaluated by reviewing clinical records. All stroke events were adjudicated by a neurologist. RESULTS At a mean follow-up time of 24.5 months, 15 patients (10%) had experienced ischemic strokes. Forty-seven patients (31%) had no evidence of LA mechanical contraction at 3 months after surgery (baseline assessment) and on follow-up echocardiography. Multivariate analysis showed that a lack of LA mechanical contraction at baseline was associated with a 5-fold increase in the risk for stroke (p = 0.02) during follow-up. Larger atria imposed a significant risk as well; LA volume index ≥33 ml/m(2) was associated with a 3-fold risk increase (p = 0.03). These effects were maintained regardless of the lack of mechanical valve implantation and anticoagulation treatment. CONCLUSIONS Absence of LA contraction and LA volume index ≥33 ml/m(2) result in a significant increase in the risk for thromboembolic stroke after the Maze procedure for patients in sinus rhythm.

Comparison of myocardial revascularization without cardiopulmonary bypass to standard open heart technique in patients with left ventricular dysfunction.

OBJECTIVE To compare myocardial revascularization without cardiopulmonary bypass to standard open heart technique in patients with left ventricular (LV) dysfunction. METHODS 117 patients with LV dysfunction (ejection fraction (EF) < 35%) underwent coronary artery bypass surgery between January 1991 and July 1994. Sixty-four (group A) were operated on without a cardiopulmonary bypass, and 53 (group B) with one. Prevalence of EF < 20% (17 vs. 6%) and emergency operations (22 vs. 7%, P = 0.03) was higher in group A. The average number of grafts was 1.9 +/- 0.8/pt in group A and 3.5 +/- 0.9/pt in group B (P < 0.01), and the internal mammary artery was used in 54 (84%) and 42 (79%) patients, respectively. Only 16 patients (25%) in group A received a graft to a circumflex marginal artery compared to 51 (96%) in group B (P < 0.0001). RESULTS Two patients (3.1%) died perioperatively in group A compared to 7 (13%) in group B (P = NS). In two patients from group A (3.1%) and in four (7.5%) from group B intra-aortic balloon pump was inserted postoperatively (P = NS). One year actuarial survival was 91 and 79% (P = 0.03) and 2-year survival was 86 and 65% (P = 0.04), respectively. Return of angina occurred in five (8%) and three (6%) patients (P = NS). CONCLUSIONS These results show a trend for lower operative risk resulting in better overall survival in selected patients with LV dysfunction undergoing coronary artery bypass surgery without cardiopulmonary bypass.

Quality of mitral valve repair: Median sternotomy versus port-access approach

OBJECTIVES We sought to compare early and late clinical and echocardiographic outcomes of patients undergoing minimally invasive mitral valve repair by means of the port-access and median sternotomy approaches. METHODS Between 2000 and 2009, 503 patients had mitral valve repair, of whom 143 underwent surgical intervention for isolated posterior leaflet pathology: 61 through port access and 82 through median sternotomy. The port-access group had better preoperative New York Heart Association functional class (P = .007) and a higher rate of elective cases (97% vs 87%, P = .037). Other preoperative characteristics were similar between the groups, including mitral valve pathology and repair techniques. RESULTS Operative, bypass, and clamp times were significantly longer in the port-access group. Mean hospital stay was 5.3 +/- 2.5 days in the port-access group versus 5.7 +/- 2.5 days in the median sternotomy group (P = .4). Early postoperative echocardiographic analysis showed that most patients in both groups had none or trivial mitral regurgitation and none of the patients had greater than grade 2 mitral regurgitation. Follow-up extended for up to 100 months (mean, 34 +/- 24 months). New York Heart Association class improved in both groups (P = .394). Freedom from reoperation was 97% and 95% in the port-access and median sternotomy groups, respectively. Late echocardiographic analysis revealed that 82% (49/60) in the port-access group and 91% (73/80) in the median sternotomy group were free from moderate or severe mitral regurgitation (P = .11). CONCLUSIONS In isolated posterior mitral valve pathology, quality of mitral valve repair with the port-access approach can compare with that with the conventional median sternotomy approach.

Late clinical outcome of transient intraoperative systolic anterior motion post mitral valve repair.

OBJECTIVE Systolic anterior motion (SAM) after mitral valve repair with significant mitral regurgitation requires immediate reintervention. Transient SAM immediately after repair is usually managed by hemodynamic maneuvers. We investigated the late clinical and echocardiographic significance of postoperative transient SAM. METHODS Between 2004 and 2013, mitral valve repair was performed on 549 consecutive patients with degenerative mitral valve disease. Of the 45 patients (8.2%) identified with postrepair SAM, 5 needed immediate reintervention. Hemodynamic maneuvers, such as preload and afterload augmentation and rate control, effectively abolished SAM in 40 patients (SAM). They were followed and compared with the remaining 509 patients (non-SAM). RESULTS Mean clinical follow-up was 54 ± 28 and 31 ± 26 months and was available in 100% and 95% (SAM and non-SAM) patients, respectively. One hospital death occurred in each group (P = .14). At follow-up, 2 patients (0.3%) showed significant SAM with left ventricular outflow tract obstruction, which resolved in 1 patient after beta-blocker therapy. SAM patients underwent exercise stress echocardiography: 1 patient showed left ventricular outflow tract obstruction that worsened after exercise. At 5 years, freedom from moderate or severe mitral regurgitation and New York Heart Association functional class III-IV was 85% versus 92% (P = .27) and 81% versus 92% (P = .15), and freedom from reoperation was 100% and 96% (P = .4), in SAM and non-SAM patients, respectively. CONCLUSIONS Late postoperative exercise stress echocardiogram revealed low incidence of SAM in patients with immediate postrepair transient SAM. All other late clinical outcomes were similar to those of non-SAM repair patients. Conservative management of intraoperative transient SAM is both successful and reliable.

Adult Respiratory Distress Syndrome Following Cardiac Surgery

Severe lung injury with the development of acute respiratory distress syndrome (ARDS) is a serious complication of cardiac surgery. The aim of this study was to determine the incidence, risk factors, and mortality of ARDS following cardiac surgery.

Midterm Results of Mitral Valve Repair: Closed Versus Open Annuloplasty Ring

BACKGROUND Closed and open annuloplasty rings are both used for mitral valve repair. This study compared the clinical and echocardiographic results in patients with degenerative mitral disease undergoing MV repair with closed semirigid rings vs open bands. METHODS Between 2004 and 2008, 377 patients (mean age, 59 + or - 12 years) underwent mitral valve repair. Valve pathology was degenerative in 273 (72%). Closed rings were used in 163 (60%) and open rings in 110 (40%). Patients had similar characteristics and comorbidities. In addition to annuloplasty, repair techniques included leaflet resection (48% and 77%, p < 0.01), artificial chordal (55% and 36%, p < 0.01), and edge-to-edge repair (4% and 4%, p = 0.79), in closed and open groups, respectively. RESULTS One patient in each group died (0.7%). Mean follow-up was 19 + or - 14 (closed group) and 34 + or - 15 months (open group; p < 0.01). Freedom from reoperation was 97.5% (closed group) vs 96.5% (open group). At follow-up, New York Heart Association functional class was similar between groups, and 91% in the closed group and 84% in the open group were free from moderate or severe mitral regurgitation (p = 0.05). Closed group patients had a longer line of leaflet coaptation (9.1 + or - 2.7 mm) vs the open group (7.1 + or - 1.9 mm; p < 0.01). CONCLUSIONS Patients with closed semirigid annuloplasty rings demonstrated significantly longer lines of leaflet coaptation and tendency toward better echocardiographic midterm results than patients with open bands and may, therefore, benefit from improved repair durability.

Evaluation of the impact of a quality improvement program and intensivist-directed ICU team on mortality after cardiac surgery.

OBJECTIVE Quality improvement is an important pursuit for critical care teams. DESIGN The authors performed an observational cohort study with historic control. SETTING Eight-bed cardiac surgery ICU in a tertiary university hospital. PARTICIPANTS A total of 4,866 patients undergoing cardiac surgery over a 6-year period between January 2005 and December 2010. INTERVENTIONS In this study, the influence of the introduction of a quality improvement program under the supervision of a newly appointed intensivist on patient outcomes after cardiac surgery was evaluated. Patients were further divided into three 2-year periods: Period I, 2005-2006, before appointment of an intensivist; Period II, 2007-2008, after appointment of an intensivist and initial introduction of a quality improvement program; and Period III, 2009-2010, after implementation of the program and introduction of Critical Care Information Systems. MEASUREMENTS AND MAIN RESULTS There were 1,633, 1,690, and 1,543 patients in each period, respectively. There was no significant difference in the severity of patient illness between the groups. Unadjusted in-hospital mortality decreased from 6.37% (104 patients) in Period I to 4.32% (73 patients) and 3.3% (51 patients) in Periods II and III, respectively (p< 0.01). CONCLUSIONS Appointment of an intensivist-directed team model and introduction of quality improvement interventions were associated with decreased mortality after cardiac surgery.