Characterizing Microheterogeneity in Liquid Mixtures via Local Density Fluctuations.

We present a novel approach to characterize and quantify microheterogeneity and microphase separation in computer simulations of complex liquid mixtures. Our post-processing method is based on local density fluctuations of the different constituents in sampling spheres of varying size. It can be easily applied to both molecular dynamics (MD) and Monte Carlo (MC) simulations, including periodic boundary conditions. Multidimensional correlation of the density distributions yields a clear picture of the domain formation due to the subtle balance of different interactions. We apply our approach to the example of force field molecular dynamics simulations of imidazolium-based ionic liquids with different side chain lengths at different temperatures, namely 1-ethyl-3-methylimidazolium chloride, 1-hexyl-3-methylimidazolium chloride, and 1-decyl-3-methylimidazolium chloride, which are known to form distinct liquid domains. We put the results into the context of existing microheterogeneity analyses and demonstrate the advantages and sensitivity of our novel method. Furthermore, we show how to estimate the configuration entropy from our analysis, and we investigate voids in the system. The analysis has been implemented into our program package TRAVIS and is thus available as free software.

Device-based prevention of neurological events in coronary artery bypass patients with calcified ascending aorta.

Patients with severely calcified aorta undergoing conventional cardiac surgery are at increased risk for postoperative neurologic deficits. Implementation of cerebroprotective devices may substantially reduce or even eliminate the risk of the adverse neurologic events, thus enabling surgical therapy, especially when interventional treatment cannot be considered an alternative option.

The ALSTER-TAVI All-Comers Registry: Procedural and 1-Year Clinical Outcomes of Balloon-Expandable vs Self-Expanding Contemporary TAVI Valves.

OBJECTIVES: Both balloon-expandable and self-expanding transcatheter aortic valves are used for transcatheter aortic valve implantation (TAVI). We compared procedural and clinical outcome variables of Sapien 3 and Evolut R/Pro in an all-comers collective. METHODS: In this single-center registry, patients were consecutively treated with the Sapien 3 from November 2014 to March 2017 (n = 129) and from April 2017 to December 2018 mainly (>95%) with the Evolut R/Pro (n = 124), due to a switch in the main TAVI supplier driven by hospital management. Data were retrospectively analyzed before and after the switch. RESULTS: One-year follow-up data were available for 122 (94%) of the Sapien and 112 (90%) of the Evolut patients. Baseline characteristics were comparable (EuroSCORE: Sapien 21.8 ± 0.9% vs Evolut 22.5 ± 0.8%; P=.20). Evolut implantation was associated with a higher radiation dose (Sapien 35770 ± 2345 mGy•cm² vs Evolut 85072 ± 8202 mGy•cm²; P<.001), more postimplantation balloon dilations (Sapien 17.1% vs Evolut 37.1%; P<.001), but similar procedure time (Sapien 75.2 ± 3.8 min vs Evolut 74.6 ± 3 min; P=.30). In-hospital mortality (Sapien 3.1% vs Evolut 4.0%; P=.70), all-cause mortality (Sapien 13.2% vs Evolut 15.3%; P=.70), all-stroke rate (Sapien 1.5% vs Evolut 6.5%; P=.05), and pacemaker implantation rate (Sapien 13.2% vs Evolut 18.5%; P=.30) were similar at 1 year. Permanent pacemaker rate was numerically higher in the first 6 months with Evolut (<6 months 26.7% vs >6 months 16%; P=.62); furthermore, radiation dose and balloon dilations also suggest a learning curve with Evolut. CONCLUSIONS: Switching from Sapien 3 to Evolut R/Pro was not associated with a difference regarding periprocedural or 1-year clinical outcomes.

CP2K: An electronic structure and molecular dynamics software package - Quickstep: Efficient and accurate electronic structure calculations.

CP2K is an open source electronic structure and molecular dynamics software package to perform atomistic simulations of solid-state, liquid, molecular, and biological systems. It is especially aimed at massively parallel and linear-scaling electronic structure methods and state-of-the-art ab initio molecular dynamics simulations. Excellent performance for electronic structure calculations is achieved using novel algorithms implemented for modern high-performance computing systems. This review revisits the main capabilities of CP2K to perform efficient and accurate electronic structure simulations. The emphasis is put on density functional theory and multiple post-Hartree-Fock methods using the Gaussian and plane wave approach and its augmented all-electron extension.

Ablation surgery in patients with persistent atrial fibrillation: an 8-year clinical experience.

OBJECTIVE: This analysis was undertaken to evaluate the results of persistent atrial fibrillation ablation procedures concomitant to open surgery and to identify risk factors for persistent atrial fibrillation recurrence. METHODS: Since 2001, a total of 325 consecutive patients with persistent atrial fibrillation (duration, 0.5-33 years) have undergone persistent atrial fibrillation ablation concomitant to open surgery by creating 2 encircling isolation lesions around the left and right pulmonary veins and a connecting lesion between both with the use of radiofrequency ablation procedures. Patients were restudied at discharge, 3 months, and 3 years after surgery. RESULTS: Survivals at the time of reexamination at discharge, 3 months, and 3 years were 97.8%, 96.2%, and 94.4%, respectively. Stable sinus rhythm could be documented in 72.1%, 73.9%, and 75.6% of surviving patients, respectively. Long-term persistent atrial fibrillation before surgery and a larger left atrium were predictive of postoperative persistent atrial fibrillation return (P<.001). Statistical analysis demonstrated cutoff points of 5 years for persistent atrial fibrillation and 55 mm for left atrium diameter; 89.7% of patients with persistent atrial fibrillation duration of less than 5 years and 84.5% of patients with left atrium size of 55 mm or less were in stable sinus rhythm at late follow-up. Cardiac rhythm at discharge and at 3 months was predictive of long-term rhythm prognosis (P<.001). Age, gender, concomitant diseases (eg, arterial hypertension, diabetes, renal insufficiency, or pulmonary disease), and the underlying cause of heart disease did not significantly influence the postoperative cardiac rhythm. CONCLUSIONS: The duration of persistent atrial fibrillation and the size of the left atrium are the most reliable preoperative variables to predict the success rate of ablation concomitant to open surgery. The probability of reestablishing stable sinus rhythm is excellent when persistent atrial fibrillation duration is short and left atrium size is small.

Complex surgical valve repair after failed percutaneous mitral intervention using the MitraClip device.

Catheter-based techniques of percutaneous valve intervention are recently being performed in an increasing number of patients. We finally report a case of successful, but complex surgical mitral valve repair 32 days after failed percutaneous intervention with severely aggravated mitral pathology caused by the catheter-based procedure. It is outlined that the conditions for surgery can be severely deteriorated, thereby reducing the chance for successful surgical repair after preceding mitral intervention.

Restrictive mitral valve annuloplasty for chronic ischemic mitral regurgitation: a 5-year clinical experience with the physio ring.

BACKGROUND: This study investigated the results of restrictive mitral annuloplasty with the semirigid Carpentier-Edwards Physio ring in patients with moderately severe to severe chronic ischemic mitral regurgitation (IMR) and advanced ischemic cardiomyopathy (ICM). METHODS: From 2003 to 2007, 100 consecutive patients (mean age +/- SD, 69 +/- 10 years) with chronic IMR of grades 3 to 4 (3.6 +/- 0.5) and a left ventricular ejection fraction (LVEF) of 31% +/- 9% (range, 12%-45%) underwent standardized restrictive prosthetic ring annuloplasty (ie, downsizing of 2.7 +/- 1.0 [range, 2-4] ring sizes) and concomitant coronary artery bypass grafting. All surviving patients were restudied 8 +/- 1 days, 3 +/- 1 months, and 2.5 +/- 1.0 years after surgery to assess survival, residual MR, New York Heart Association (NYHA) class, and LV function (end-systolic and end-diastolic dimension/volume indices and LVEF). Data were analyzed exploratatively. RESULTS: Survival rates at the postoperative reexamination times were 98%, 97%, and 94%, respectively (1 noncardiac and 5 cardiac deaths). NYHA class improved from 3.5 +/- 0.5 to 1.4 +/- 0.5 (P < .0005). The residual MR grades at discharge, early follow-up, and late follow-up were 0.4 +/- 0.5, 0.5 +/- 0.5, and 0.4 +/- 0.6, respectively (P < .0005). Post-operative recurrence of significant IMR (>grade 2) was absent in all patients. The leaflet coaptation height was 8 +/- 1 mm and did not decrease significantly over time. All LV dimension and volume indices and the LVEF (41% +/- 9% at 2.5 years) improved significantly after surgery (P < .0005), even in patients with initially severely reduced myocardial function and a preoperative LVEF of <30% (n = 42; LVEF, 22% +/- 5% versus 33% +/- 6% at late follow-up; P < .0005). CONCLUSION: Restrictive mitral valve annuloplasty using the semirigid Physio ring corrected chronic IMR in ICM patients with very low mortality and improved contractility. Surgery also prevented recurrence of significant IMR in parallel with the phenomenon of postoperative continuous reverse myocardial remodeling.

A 5-year clinical experience with bipolar radiofrequency ablation for permanent atrial fibrillation concomitant to coronary artery bypass grafting and aortic valve surgery.

This study analyses the 5-year results of permanent atrial fibrillation (pAF) bipolar radiofrequency (RF) ablation surgery concomitant to coronary artery bypass grafting (CABG) and/or aortic valve (AV) surgery. Eighty-five patients with pAF (0.5-30 years) underwent bipolar RF ablation procedure concomitant to CABG/AV surgery. All patients were restudied to assess survival, conversion rate to stable sinus rhythm (SR) and New York Heart Association (NYHA) class at 8+/-1 days and at 3+/-1 and 32+/-15 months after surgery. Survival at time of re-examination was 100%, 98% and 96%, respectively (three non-cardiac deaths), SR could be documented in 61%, 74% and 78% of patients. Long-term AF before surgery and larger size of the left atrium (LA) were predictive for postoperative AF return (P=0.005, P=0.03); 88% of patients with small preoperative LA-size (<50 mm) and 85% with pAF-duration time <5 years had stable SR at late follow-up. Cardiac rhythm at three months was predictive for long-term rhythm-prognosis (P<0.0001). NYHA-class improved significantly after surgery (P<0.0005), particularly when SR was achieved (P=0.046). Permanent AF bipolar RF ablation surgery revealed excellent results in AV/CABG patients. It could be demonstrated that established SR remained stable over time. Preoperative pAF-duration time and LA-size are useful variables to predict the success rate of ablation.

Seven-year experience with ablation of permanent atrial fibrillation concomitant to mitral valve surgery in 152 patients.

BACKGROUND: This study analyzed 7 years of results for monopolar endocardial radiofrequency (RF) ablation of permanent atrial fibrillation (pAF) concomitant to mitral valve (MV) surgery. METHODS: Between 2001 and 2007, 152 patients who had experienced pAF for a median of 4.0 years (interquartile range, 1.5-8.0 years; range, 0.5-33 years) underwent monopolar endocardial RF ablation procedures (pulmonary vein isolation plus a connecting lesion) concomitant to MV surgery. All patients were reexamined to assess survival, conversion rate to stable sinus rhythm (SR), and New York Heart Association (NYHA) class at 8 +/- 1 days after surgery and follow-ups at 3 +/- 1 months and 41 +/- 24 months postoperatively. Data were analyzed exploratatively. RESULTS: The survival rates at the 3 reexamination times were 97%, 95%, and 92%, respectively (6 cardiac and 6 noncardiac deaths), and the corresponding SR rates were 74%, 75%, and 73%. The NYHA class of the patients improved significantly after surgery (P = .006), particularly when a stable SR had been achieved (P = .039). Long-term pAF prior to surgery and a larger left atrium (LA) preoperatively were predictive of the return of postoperative AF (P = .0002, and P = .0003, respectively). Ninety-one percent of the patients with a preoperative pAF duration of <5 years and 88% of the patients with an LA size of

Downsizing of the mitral valve and coronary revascularization in severe ischemic mitral regurgitation results in reverse left ventricular and left atrial remodeling.

OBJECTIVE: Data of combined mitral downsizing by restrictive prosthetic ring annuloplasty and coronary artery bypass grafting (CABG) in patients with ischemic cardiomyopathy and moderately severe to severe mitral regurgitation (MR) are rare, and little is known about the effect on reverse left ventricular (LV) and left atrial (LA) remodeling. METHODS: Thirty-eight patients (70.6+/-8.3 years) with coronary artery disease, ischemic cardiomyopathy (LV ejection fraction [LVEF] 31+/-8%) and moderately severe to severe MR (grade 3.6+/-0.5) underwent CABG and mitral downsizing by 2-4 ring sizes. Clinical follow-up and serial transthoracic echocardiographic studies were performed after surgery (discharge, 3+/-0.5 months, 13+/-7 months) to assess survival, NYHA class, MR, leaflet coaptation height, LA and LV dimensions/volumes, fractional shortening (FS) and LVEF. RESULTS: Early mortality (<30 days) was 2.6%, survival at follow-up was 92 and 85%, respectively. NYHA class improved from 3.3+/-0.6 to 1.5+/-0.6 (P<0.001). Residual MR at discharge and at follow-up was grade 0.5 and 0.6, respectively (P<0.001). Leaflet coaptation height was 8+/-1 mm and did not change over time. LV end-diastolic, end-systolic and LA dimensions decreased from 60+/-7 to 57+/-8 mm, from 47+/-9 to 42+/-9 mm and from 51+/-5 to 45+/-4 mm, FS increased from 23+/-9 to 28+/-10% (P<0.001); LV end-diastolic and end-systolic volumes decreased from 188+/-33 to 171+/-30 ml and from 129+/-35 to 105+/-33 ml, LVEF increased from 31+/-8 to 39+/-10% (P<0.001). CONCLUSIONS: Combined mitral downsizing and CABG surgery was performed with excellent clinical results: only minimal residual MR, a significant reduction of LA dimension and an increase of LV contractility due to reverse remodeling were observed.

Three years experience with monopolar and bipolar radiofrequency ablation surgery in patients with permanent atrial fibrillation.

OBJECTIVE: In our population permanent atrial fibrillation (pAF) is a frequent concomitant problem in patients undergoing open heart surgery. A 3-year experience with a treatment strategy using mono- and bipolar radiofrequency (RF) ablation procedures in a heterogeneous group of patients is reported. METHODS: In a prospective analysis the incidence of pAF among all patients undergoing open heart surgery in our department between February 2001 and July 2004 was evaluated. In a second step a selective group of 106 patients with pAF (primary mitral: n=63; aortic: n=24; CABG: n=16; aortic+mitral: n=3) underwent either monopolar (n=86) or bipolar (n=20) RF ablation procedures creating two encircling isolation lesions around the left and the right pulmonary veins (PVs) and a connection line between both. In addition amiodarone was given for 3 months after surgery. Regular follow-ups were performed 3, 6, 9, 12, 18, 24 and 36 months after surgery. RESULTS: The incidence of pAF in the total group of 4.110 patients was 3.6%. While the rate was low in cases without severe heart valve disease (1.1%), a significantly higher presence of pAF in patients scheduled for heart valve surgery (10.3%) was observed (P<0.0001). The incidence was 30-39% in patients with degenerative and rheumatic mitral valve (MV) disease, and further particularly high in the older aged compared to younger patients (4.2-8.3% at 70-99 years; P<0.001). Hospital mortality after combined open heart and RF ablation surgery was 1.9%. Whereas patients with small left atrial size (LA-diameters <56 mm; n=59) had SR in almost 90% at follow-up, LA enlargement (LA-diameter > or =56 mm; n=47) was associated with a significant risk of persisting pAF after surgery (P=0.033, 0.002 and 0.006 at 3, 6 and 9 months follow-up). CONCLUSION: The use of RF ablation procedures in combination with amiodarone therapy represents a safe and efficient option to cure pAF during open heart surgery in a selective group of patients. The preoperative LA size was of significant importance for the outcome in this investigation.

Permanent atrial fibrillation ablation surgery in patients with advanced age.

BACKGROUND: Even if permanent atrial fibrillation (pAF) is a frequent concomitant problem in patients undergoing open heart surgery and particularly in those with advanced age, data of pAF ablation surgery in older aged patients are scarce. This study was performed to assess early and late results of combined open heart surgery and pAF ablation procedures in patients with advanced aged, compared to young patients. MATERIAL AND METHODS: A selective group of 126 patients (Group A: age =70 [76.4+/-4.8] years, n=70; Group B: age <70 [62.0+/-6.2] years: n=56) with pAF (=6 months) underwent either monopolar (Group A, B: n=51 vs. n=44) or bipolar (Group A, B: n=19 vs. n=12) radiofrequency (RF) ablation procedures concomitant to open heart surgery. Regular follow-up was performed 3 to 36 months after surgery to assess survival, New York Heart Association (NYHA) class and conversion rate to stable sinus rhythm (SR). RESULTS: Early mortality (<30 days) was 2.9% in Group A (Group B: 0%), cumulative survival at long-term follow up was 0.78 vs. 0.98 (p=0.03) and NYHA-class improved significantly in both groups, particularly in cases with stable SR. At 12-months follow-up 73% of Group A patients were in stable SR (Group B 78%). CONCLUSION: Concomitant mono- and bipolar RF ablation surgery represents a safe option to cure pAF during open heart surgery with a very low risk, even in patients with advanced age.

Monopolar and bipolar radiofrequency ablation surgery: 3-year experience in 90 patients with permanent atrial fibrillation.

OBJECTIVE: In our population, permanent atrial fibrillation (pAF) is a serious concomitant problem in patients scheduled for open heart surgery. The high incidence necessitates reliable methods of treating pAF efficiently. We report our 3-year experience with a safe concept of using monopolar and bipolar radiofrequency (RF) ablation procedures. METHODS: Ninety patients (mitral, n = 56; aortic, n = 22; aortic and mitral, n = 1; coronary artery bypass grafting, n = 11) underwent either monopolar (n = 77) or, recently, bipolar (n = 13) RF ablation procedures that produced encircling isolation lesions around the left and the right pulmonary veins (PVs) and a connection line between the two. Amiodarone was given for 3 months after surgery. RESULTS: Hospital mortality was 2.2%. At follow-up, 75% of the patients were in stable sinus rhythm (SR). Preoperative pAF duration, etiology of heart disease, and type of RF energy application were not predictive of the risk of persisting pAF after surgery. Whereas patients (50 of 90) with small preoperative left atrial (LA) diameters (<56 mm) had SR in almost 90% of cases, large preoperative LA diameters (>or=56 mm; 40 of 90 patients) were associated with a significant risk of persisting pAF (P < .05). CONCLUSION: Particularly in cases of small preoperative LA diameters, isolation of the PVs using either monopolar or bipolar RF ablation procedures in combination with amiodarone therapy represents a safe and efficient option for curing pAF in patients undergoing open heart surgery.

Global surgical experience with the Acorn cardiac support device.

OBJECTIVE: Surgical intervention is an option for treating the remodeled and dilated left ventricles of patients with heart failure. Providing end-diastolic support with an innovative mesh-like cardiac support device reduces mechanical stress, improves function, and reverses cardiac remodeling in animal models without safety issues. The objective of this study was to review the global clinical safety and feasibility experience of this device. METHODS: The Acorn CorCap cardiac support device (Acorn Cardiovascular, Inc, St Paul, Minn) has been implanted worldwide in more than 130 patients with dilated cardiomyopathy with or without concomitant cardiac surgery. The device is positioned around the ventricles and given a custom fit. A series of 48 patients were implanted with the device in initial safety and feasibility studies, of whom 33 also received concomitant cardiac surgery. RESULTS: At implantation, 11 patients were in New York Heart Association class II, 33 were in class III, and 4 were in class IV. The average CorCap implantation time was 27 minutes. The mean intraoperative reduction in left ventricular end-diastolic dimension was 4.6% +/- 1%. There were no device-related intraoperative complications. Eight early and 9 late deaths occurred during follow-up extending to 24 months. Actuarial survival was 73% at 12 months and 68% at 24 months. There were no device-related adverse events or evidence of constrictive disease, and coronary artery flow reserve was maintained. Ventricular chamber dimensions decreased, whereas ejection fraction and New York Heart Association class were improved in patients overall and in those patients implanted with the CorCap device without concomitant operations. CONCLUSIONS: The CorCap device appears safe for patients with dilated cardiomyopathy. Randomized clinical trials are underway in Europe, Australia, and North America.

Surgical treatment of permanent atrial fibrillation during cardiac surgery using monopolar and bipolar radiofrequency ablation.

OBJECTIVE: Permanent atrial fibrillation (pAF) is a serious problem in cardiac surgery: An incidence of 3.5% among all patients scheduled for open heart surgery, 9.8% in heart valve cases and 45.6% among patients with severe rheumatic mitral valve (MV) disease was observed in our institution. Our experience with radiofrequency (RF) ablation procedures to treat pAF in these cases is reported. METHODS: Since February 2001 monopolar endocardial RF ablation procedures creating two encircling isolation lesions around the left and the right pulmonary veins (LPVs, RPVs) and a connection line between both were performed in patients with pAF concomitant to heart valve surgery. Since March 2003 bipolar RF ablation was used as an adjunct to CABG surgery. Amiodarone was given for 3 months after surgery. RESULTS: Sixty-two patients with pAF underwent surgical ablation procedures and primary valve (mitral: n=45; aortic: n=13; aortic+mitral: n=1; LA-diameter 55.6+/-7.3 mm) or CABG surgery (n=3). Follow-up was performed at 3, 6, 9, 12, 18 and 24 months; 75% had stable sinus rhythm (SR) at late follow-up. Almost 90% of the patients with a preoperative LA-diameter of <56 mm had SR. CONCLUSION: Isolation of the PVs using RF ablation procedures in combination with amiodarone therapy represents a safe and efficient option to cure pAF in patients undergoing open heart surgery.

Surgical treatment of permanent atrial fibrillation during heart valve surgery.

A simple strategy to abolish permanent atrial fibrillation (AF) in patients undergoing heart valve surgery is described. The concept includes: (1) endocardial radiofrequency (RF) ablation creating two encircling isolation lesions around the left and the right pulmonary veins (LPV, RPV) and a connection line between both; (2) antiarrhythmic protection with amiodarone for 3 months. Between 02/01 and 02/02 29 patients underwent surgical AF ablation procedures associated with primary valve operations (mitral, n=22; aortic, n=6; aortic+mitral, n=1). Six months after surgery 87.5% (14 of 16) were in sinus rhythm (SR), particularly all patients with an LA diameter of <56 mm had SR.