Christoph T. Starck

Epicardial left atrial appendage clip occlusion also provides the electrical isolation of the left atrial appendage.

OBJECTIVES The exclusion of the left atrial appendage (LAA) has been used to reduce the risk of stroke associated with atrial fibrillation (AF). While LAA exclusion has been associated with a reduced risk of stroke, the effect on the electrical activity of the LAA (a potential source of AF) remains unknown. As such, we sought to demonstrate whether surgical epicardial clip occlusion leads to the electrical isolation of the LAA. METHODS From December 2010 until August 2011, 10 patients with paroxysmal AF underwent off-pump coronary artery bypass surgery with bilateral pulmonary vein isolation and an LAA clip occlusion with a new epicardial clip. Before and after the clip was placed, pacing manoeuvres were performed to assess the electrical exit and entry blocks from the LAA. RESULTS All clips were applied successfully. The mean procedure time for the clip application was 4 ± 1 min. No complications occurred related to clip application. Prior to the pericardial closure, 18 ± 3 min after the clip placement, the LAA stimulation and pacing manoeuvres demonstrated complete electrical isolation of the LAA in all cases. CONCLUSIONS Epicardial LAA clip occlusion leads to the acute electrical isolation of the LAA and may not only provide stroke prevention but also reduce the recurrence of AF.

Frailty is a predictor of short- and mid-term mortality after elective cardiac surgery independently of age†

OBJECTIVES Assessment of perioperative risk of elderly patients in cardiac surgery is difficult, and most of the common risk scores show over- or underestimation. Two frailty scores, the comprehensive assessment of frailty (CAF) score and the Frailty predicts death One yeaR after CArdiac Surgery Test (FORECAST), were developed as additional tools to estimate the preoperative mortality risk, taking into consideration the frailty status of elderly patients. METHODS Four hundred and fifty patients who were referred for elective cardiac surgery were included. All the patients were assessed with the CAF test and the FORECAST. Thirty-day and 1-year mortality were evaluated by telephone interview. Univariate and bivariate logistic regression were performed to test the predictive power of the tests on mortality. Correlation of the scores with age was calculated with Spearman ranks. Three commensurate groups were built for each of the frailty scores and the outcome was compared between the groups. All analyses were performed for Society of Thoracic Surgeons (STS) and European System for Cardiac Operative Risk Evaluation (EuroSCORE) accordingly. RESULTS A total of 227 male and 223 female patients were included. Thirty-day mortality was 6.1%, and 1-year mortality was 13.3%. Logistic regression showed that both scores are able to predict 30-day as well as 1-year mortality. Bivariate logistic regression showed that both frailty scores give relevant additional information to the STS and EuroSCORE for the prediction of 1-year mortality. The frailty scores were only weakly correlated with age in contrast to STS and EuroSCORE and therefore can be used as indicator of the biological age of patients besides the numerical age. Survival up to 1 year was relevantly reduced in the group of patients with the higher frailty scores. CONCLUSIONS CAF and FORECAST are additional tools to evaluate elderly patients adequately before elective cardiac surgery, and showed an association with short- and mid-term mortality independently of age.

Toward a Rational Design of Surface Textures Promoting Endothelialization

The safe integration of cardiovascular devices requires the sustainable coverage of their luminal surface by endothelial cells (ECs). The engineering of active surface textures has the potential to coordinate cellular adhesion and migration under the action of hemodynamic forces. We define a paradigm to rationally design textures maximizing EC activities as a function of the applied stresses. This is based on harnessing the adhesions established by ECs through fine-tuning of the vertical extend of the underlying surface nanotopography.

Older patients fare better with the Ross operation

BACKGROUND The Ross operation has an established position in young patients. We address the question of whether any age group profits most from the Ross operation, and we compare the results in various ages. METHODS From February 1995 to August 2001 we performed 250 Ross operations. Group 1 consisted of 46 patients, ages 2 to 25 years (median age, 15 years). Group 2 consisted of 123 patients, ages 26 to 49 years (median age, 39 years). Group 3 consisted of 81 patients, ages 50 to 67 years (median age, 55 years). Echocardiography was performed perioperatively, at 2 to 6 months, and then yearly. RESULTS Mean follow-up for the three groups was 32, 31, and 28 months, respectively (p = 0.36). One patient from group 2 died after 25 months caused by suppurative pneumonia and 3 patients from group 3 died (1 from suspected acute thoracic aorta dissection at 40 months, 1 from ventricular fibrillation after 25 months, and 1 from an undiagnosed sudden death at 5 months). Autograft replacement was necessary for 3 patients from group 2 and 1 from group 3. Autograft repair was necessary for 1 patient from group 2, and pulmonary homograft reoperation was necessary for 1 patient from group 1. All other autografts currently have physiologic gradients and clinically insignificant regurgitation. Median peak gradient across the right ventricular outflow tract was 23.6 +/- 18 mm Hg for group 1, 14.6 +/- 8 mm Hg for group 2, and 11.5 +/- 7 mm Hg, which was significantly lower for group 3 patients (p < 0.001). Eleven patients are under close follow-up for right ventricular outflow tract gradients > or = 40 mm Hg; eight of these patients are from group 1, 3 are from group 2, and there are none from group 3. CONCLUSIONS Although the Ross operation provides excellent results in all age groups, the problem of right ventricular outflow tract stenosis has not been seen in patients older than 50 years, which implies that it offers superior results for aortic valve disease in middle aged and older patients.

Treatment with higher dosages of heart failure medication is associated with improved outcome following cardiac resynchronization therapy

BACKGROUND Cardiac resynchronization therapy (CRT) is associated with improved morbidity and mortality in patients with chronic heart failure (CHF) on optimal medical therapy. The impact of CHF medication optimization following CRT, however, has never been comprehensively evaluated. In the current study, we therefore investigated the effect of CHF medication dosage on morbidity and mortality in CHF patients after CRT implantation. METHODS AND RESULTS Chronic heart failure medication was assessed in 185 patients after CRT implantation. During an overall mean follow-up of 44.6 months, 83 patients experienced a primary endpoint (death, heart transplantation, assist device implantation, or hospitalization for CHF). Treatment with higher dosages of angiotensin-converting enzyme inhibitor (ACE-I) or angiotensin receptor blockers (ARBs) (P = 0.001) and beta-blockers (P < 0.001) as well as with lower dosages of loop diuretics (P < 0.001) was associated with a reduced risk for the primary combined endpoint as well as for all-cause mortality. Echocardiographic super-responders to CRT were treated with higher average dosages of ACE-I/ARBs (68.1 vs. 52.4%, P < 0.01) and beta-blockers (59 vs. 42.2%, P < 0.01). During follow-up, the average dosage of loop diuretics was decreased by 20% in super-responders, but increased by 30% in non-super-responders (P < 0.03). CONCLUSION The use of higher dosages of neurohormonal blockers and lower dosages of diuretics is associated with reduced morbidity and mortality following CRT implantation. Our data imply a beneficial effect of increasing neurohormonal blockade whenever possible following CRT implantation.

Transvenous lead extractions: comparison of laser vs. mechanical approach.

AIMS In this retrospective study we compared different lead extraction techniques. METHODS AND RESULTS Between January 2009 and December 2012 we performed transvenous lead extraction procedures on 206 leads in 122 patients. Mean implant duration (MID) was 69.6 months (1-384 months). Leads with lead implant duration ≥ 12 months were assigned to groups according to the extraction technique: Group A: no extraction tool; Group B: laser approach; and Group C: mechanical approach. Overall clinical success was 93.3%. Group A showed a significantly lower MID [38.1 (19-122) months] compared with Groups B and C [83.1 (13-168) months; P < 0.0001 vs. 95.4 (12-384) months; P < 0.0001]. Mean implant duration between Groups B and C did not differ significantly (P = 0.28). Clinical and complete procedural success was 100% in Group A. Clinical success rate was higher in Group C than in Group B (97.0 vs. 76.9%, P = 0.018). Complete procedural success did not differ significantly between Groups B and C (88.9 vs. 76.9%; P = 0.132). In Groups B and C, absence of complete procedural success occurred in long implanted leads (MID 107.8 ± 36.4 and 137.6 ± 89.2 months). Relative costs per extracted lead were 49% higher in Group B than in Group C. CONCLUSION In case of long implanted leads a laser and a mechanical approach are comparable in complete procedural success and safety. Clinical success and cost effectiveness analysis favours the mechanical approach. Regardless of the extraction technique efficacy and safety optimization has to focus on long implanted leads.

Interhospital transfer of seriously sick ARDS patients using veno-venous Extracorporeal Membrane Oxygenation (ECMO): Concept of an ECMO transport team

Background: Extracorporeal membrane oxygenation (ECMO) therapy constitutes the last option for patients with acute respiratory distress syndrome (ARDS) refractory to conservative treatment. Since primary care centers are unable to provide this therapy, such patients need a transfer to a tertiary care center, which may be life-threatening without extracorporeal support. Methods: An ECMO transport team implanted an ECMO at the site of the primary care center with subsequent transport of the patient to the tertiary care center. Between September 2009 and March 2011, six patients with ARDS were treated by our ECMO transport team. Mean age was 39.5±12.0 years. All implantations were done percutaneously in a veno-venous configuration. Results: No complications occurred during the implant procedure and the subsequent transport. Four patients (67%) were successfully weaned from ECMO-therapy, and discharged from hospital. Conclusion: With a specialized ECMO transport team, ECMO-implantation can be achieved successfully in a peripheral hospital, and patients can be transported safely.

The influence of surface micro-structure on endothelialization under supraphysiological wall shear stress

Interaction between platelets and artificial materials within cardiovascular devices triggers blood coagulation and represents a frequent adverse response to implant deployment. Avoidance of this interaction is obtained through the generation and sustenance under flow of a confluent and stable endothelial monolayer covering the luminal device surface, altogether defined as the process of endothelialization. Supraphysiological wall shear stress (WSS) levels generated within vascular assist devices (VADs) constitute a major challenge toward endothelialization. Here we report the experimental demonstration that stable endothelialization can be achieved at supraphysiological WSS levels by pure means of appropriate surface micro-structuring. Using a custom-designed flow bioreactor we exposed endothelial monolayers to physiological and supraphysiological WSS levels and investigated the resulting integrity of cell-to-cell junctions, the cell density and the cell polarization. At physiological WSS levels, optimal endothelialization was obtained independently from surface topography. However, at higher WSS levels, only monolayers grown on appropriately micro-structured surfaces preserved optimal integrity. Under these flow conditions, endothelial cells polarized by the contact with the micro-structure and, interestingly, oriented themselves in the direction perpendicular to flow. Such endothelial layers withstood WSS levels exceeding of 100% or more the thresholds detected on flat substrates.

Retrospective analysis of outcome data with regards to the use of Phisio®-, Bioline®- or Softline®-coated cardiopulmonary bypass circuits in cardiac surgery.

Background: Numerous cardiopulmonary bypass circuits with various coatings designed to reduce the inflammatory response and to provide better hemocompatibility are available. The aim of this study was to compare the effect of phosphorylcholine-coated, albumin-heparin-coated and synthetic polymer-coated perfusion tubing systems on patient outcome. Methods: We performed a retrospective database review of elective patients between January 1st 2010 and December 31st 2010. Demographics, preoperative, operative, postoperative data and follow-up were collected and statistically analysed. Results: We identified 201 patients and formed three groups: Group 1 with phosphorylcholine coating (n=133), Group 2 with albumin-heparin coating (n=32) and Group 3 synthetic polymer coating (n=36). Mean age was 68±11years, additive Euroscore 5.8±2.7. In-hospital outcomes were comparable between the groups without statistically significant differences. The overall 30-day and 1-year late survival were 98.5% and 96.7±1.9%, respectively. Conclusions: Our findings suggest that in-hospital and follow-up outcomes are comparable in cardiac surgery patients after using either phosphorylcholine-coated, albumin-heparin-coated or synthetic polymer-coated circuits during cardiopulmonary bypass.

Tricuspid valve interventions: surgical techniques and outcomes.

The surgical treatment of isolated and concomitant tricuspid valve disease, especially functional tricuspid valve regurgitation, remains controversial. Functional tricuspid regurgitation may be classified into defined stages, and surgical treatment may be tailored to the extent of the disease. This report describes current surgical techniques for tricuspid valve surgery and their results.