New Insights into Mortality-Related Risk Factors in Infective Endocarditis: Results from the Brandenburg State Endocarditis Register.

OBJECTIVE: Endocarditis as a potentially life-threatening disease with high complication and mortality rates. In recent years, an increase in the incident of endocarditis has been reported throughout Europe. In the aging society, successful treatment is complex and challenging owing to the high rate of multimorbidity. METHODS: We initiated a statewide prospective multicenter endocarditis registry in 2020. Perioperative risk factors, comorbidities, microbiological, laboratory and imaging diagnostics, complications, and mortality including 1-year follow-up were collected. The present midterm analysis includes factors influencing mortality in the first 313 patients. RESULT: In-hospital mortality and 1-year mortality were 28.4 and 40.9%, respectively. Preoperative risk factors include age (p < 0.001), EuroSCORE II (p < 0.001), coronary artery disease (p = 0.022), pacemaker probe infection (p = 0.033), preoperative left ventricular ejection fraction (LVEF), systemic inflammatory response syndrome (SIRS), pulmonary edema, heart failure, septic emboli, acute renal failure, impaired coagulation, hypalbuminemia (p < 0.001), and N-terminal prohormone of brain natriuretic peptide (NTproBNP) (p = 0.001). The presence of peri-annular abscess, perforation, and shunt were associated with increased mortality (p = 0.004, 0.001, and 0.004, respectively). In addition, cardiopulmonary bypass time influenced mortality (p = 0.002). The main postoperative causes of death were multi-organ failure, renal failure, vasoplegia, and low-output syndrome (p < 0.001). Previous endocarditis was 7.7%, while 35.5% were prosthetic valve recipients and 33.6% were redo surgeries. CONCLUSION: Our first registry data show the complexity of endocarditis patients and the challenging treatment. Some risk factors can be treated preoperatively. For instance, hypalbuminemia and the duration of the procedure can be controlled with adequate albumin substitution and carefully planned procedures restricted to the essential requirements, that is, hybrid approaches with consecutive interventions.

Progress on a Novel, 3D-Printable Heart Valve Prosthesis.

(1) Background: Polymeric heart valves are prostheses constructed out of flexible, synthetic materials to combine the advantageous hemodynamics of biological valves with the longevity of mechanical valves. This idea from the early days of heart valve prosthetics has experienced a renaissance in recent years due to advances in polymer science. Here, we present progress on a novel, 3D-printable aortic valve prosthesis, the TIPI valve, removing the foldable metal leaflet restrictor structure in its center. Our aim is to create a competitive alternative to current valve prostheses made from flexible polymers. (2) Methods: Three-dimensional (3D) prototypes were designed and subsequently printed in silicone. Hemodynamic performance was measured with an HKP 2.0 hemodynamic testing device using an aortic valve bioprosthesis (BP), a mechanical prosthesis (MP), and the previously published prototype (TIPI 2.2) as benchmarks. (3) Results: The latest prototype (TIPI 3.4) showed improved performance in terms of regurgitation fraction (TIPI 3.4: 15.2 ± 3.7%, TIPI 2.2: 36.6 ± 5.0%, BP: 8.8 ± 0.3%, MP: 13.2 ± 0.7%), systolic pressure gradient (TIPI 3.4: 11.0 ± 2.7 mmHg, TIPI 2.2: 12.8 ± 2.2 mmHg, BP: 8.2 ± 0.9 mmHg, MP: 10.5 ± 0.6 mmHg), and effective orifice area (EOA, TIPI 3.4: 1.39 cm2, TIPI 2.2: 1.28 cm2, BP: 1.58 cm2, MP: 1.38 cm2), which was equivalent to currently used aortic valve prostheses. (4) Conclusions: Removal of the central restrictor structure alleviated previous concerns about its potential thrombogenicity and significantly increased the area of unobstructed opening. The prototypes showed unidirectional leaflet movement and very promising performance characteristics within our testing setup. The resulting simplicity of the shape compared to other approaches for polymeric heart valves could be suitable not only for 3D printing, but also for fast and easy mass production using molds and modern, highly biocompatible polymers.

Prehabilitation in older patients prior to elective cardiac procedures (PRECOVERY): study protocol of a multicenter randomized controlled trial.

BACKGROUND: Previous studies have demonstrated the efficacy of rehabilitation after a cardiovascular procedure. Especially older and multimorbid patients benefit from rehabilitation after a cardiac procedure. Prehabilitation prior to cardiac procedures may also have positive effects on patients' pre- and postoperative outcomes. Results of a current meta-analysis show that prehabilitation prior to cardiac procedures can improve perioperative outcomes and alleviate adverse effects. Germany currently lacks a structured cardiac prehabilitation program for older patients, which is coordinated across healthcare sectors. METHODS: In a randomized, controlled, two-arm parallel group, assessor-blinded multicenter intervention trial (PRECOVERY), we will randomize 422 patients aged 75 years or older scheduled for an elective cardiac procedure (e.g., coronary artery bypass graft surgery or transcatheter aortic valve replacement). In PRECOVERY, patients randomized to the intervention group participate in a 2-week multimodal prehabilitation intervention conducted in selected cardiac-specific rehabilitation facilities. The multimodal prehabilitation includes seven modules: exercise therapy, occupational therapy, cognitive training, psychosocial intervention, disease-specific education, education with relatives, and nutritional intervention. Participants in the control group receive standard medical care. The co-primary outcomes are quality of life (QoL) and mortality after 12 months. QoL will be measured by the EuroQol 5-dimensional questionnaire (EQ-5D-5L). A health economic evaluation using health insurance data will measure cost-effectiveness. A mixed-methods process evaluation will accompany the randomized, controlled trial to evaluate dose, reach, fidelity and adaptions of the intervention. DISCUSSION: In this study, we investigate whether a tailored prehabilitation program can improve long-term survival, QoL and functional capacity. Additionally, we will analyze whether the intervention is cost-effective. This is the largest cardiac prehabilitation trial targeting the wide implementation of a new form of care for geriatric cardiac patients. TRIAL REGISTRATION: German Clinical Trials Register (DRKS; http://www.drks.de ; DRKS00030526). Registered on 30 January 2023.

The Impact of Gender and Age in Obese Patients on Sternal Instability and Deep-Sternal-Wound-Healing Disorders after Median Sternotomy.

OBJECTIVE: The aim of this study was to investigate the relationship between age and sex in regard to the development of deep sternal wound infections and sternal instability following median sternotomy. METHODS: A propensity-score-matching analysis was conducted on 4505 patients who underwent cardiac surgery between 2009 and 2021, all of whom had a BMI of ≥30 kg/m2. A total of 1297 matched pairs were determined in the sex group, and 1449 matched pairs we determined in the age group. The distributions of sex, age, diabetes mellitus, delirium, unstable sterna, wire refixation, wire removal, superficial vacuum-assisted wound closure, deep vacuum-assisted wound closure, clamp time, bypass time, logistic EuroSCORE, and BMI were determined. RESULTS: The 30-day in-hospital mortality was found to be similar in the older and younger groups (8.149% vs. 8.35%, p = 0.947), and diabetes mellitus was also equally distributed in both groups. However, postoperative delirium occurred significantly more often in the older group (29.81% vs. 17.46%, p < 0.001), and there was a significantly higher incidence in men compared with women (16.96% vs. 26.91%, p < 0.001). There were no differences found in the incidence of sternum instability, fractured sternum, superficial vacuum-assisted wound closure, and deep vacuum-assisted wound closure between the age and sex groups. CONCLUSIONS: In conclusion, this study found that sternal instability and deep-wound-healing problems occur with equal frequency in older and younger patients and in men and women following median sternotomy. However, the likelihood of postoperative delirium is significantly higher in older patients and in men. These findings suggest that a higher level of monitoring and care may be required for these high-risk patient groups to reduce the incidence of postoperative delirium and improve outcomes following median sternotomy.

Mitral Valve Repair in Advanced Age Groups: Does Cardiac Age Differ from Chronological Age?

OBJECTIVE: Advanced age is a risk factor in cardiac surgery contributing significantly to a worse outcome. The reasons are frailty and multimorbidity. In this study, we asked: Is there an aging of the heart which differs from chronological age? METHODS: Propensity score matching was performed between 115 seniors ≥ 80 years and 345 juniors < 80 years. After the patients were found to be comparable in terms of cardiac and noncardiac disease and risk profiles, they were further analyzed for cardiac parameters. In addition, the seniors and juniors were compared in terms of cardiac health and postoperative outcome. Furthermore, the patients were subdivided into several age groups (<60 years, 60-69 years, 70-79 years, and >80 years) and compared regarding outcome. RESULTS: The seniors demonstrated significantly lower tricuspid annular plane systolic excursion (TAPSE), significantly more frequent diastolic dysfunction, significantly higher plasma levels of NT-proBNP, and significantly larger left ventricular end-diastolic and end-systolic diameters and left atrial diameters (p < 0.001, respectively). Furthermore, in-hospital mortality and most postoperative complications were significantly higher in seniors compared with juniors. While old cardiac healthy patients showed better outcome than old cardiac aged patients, the outcome from young cardiac aged patients was better than old cardiac aged patients. The outcome and survival deteriorated with increasing life decades. CONCLUSIONS: The elderly suffer significantly more from cardiac deterioration, i.e., cardiac aging, and show higher multimorbidity. Mortality risk is significantly higher and they suffer more often from a complicated postoperative course compared to younger patients. Further approaches to prevention and treatment of cardiac aging are needed to address the needs of an aging society.

How Can We Best Measure Frailty in Cardiosurgical Patients?

BACKGROUND: Frailty is gaining importance in cardiothoracic surgery and is a risk factor for adverse outcomes and mortality. Various frailty scores have since been developed, but there is no consensus which to use for cardiac surgery. METHODS: In an all-comer prospective study of patients presenting for cardiac surgery, we assessed frailty and analyzed complication rates in hospital and 1-year mortality, as well as laboratory markers before and after surgery. RESULTS: 246 included patients were analyzed. A total of 16 patients (6.5%) were frail, and 130 patients (52.85%) were pre-frail, summarized in the frail group (FRAIL) and compared to the non-frail patients (NON-FRAIL). The mean age was 66.5 ± 9.05 years, 21.14% female. The in-hospital mortality rate was 4.88% and the 1-year mortality rate was 6.1%. FRAIL patients stayed longer in hospital (FRAIL 15.53 ± 8.5 days vs. NON-FRAIL 13.71 ± 8.94 days, p = 0.004) and in intensive/intermediate care units (ITS/IMC) (FRAIL 5.4 ± 4.33 days vs. NON-FRAIL 4.86 ± 4.78 days, p = 0.014). The 6 min walk (6 MW) (317.92 ± 94.17 m vs. 387.08 ± 93.43 m, p = 0.006), mini mental status (MMS) (25.72 ± 4.36 vs. 27.71 ± 1.9, p = 0.048) and clinical frail scale (3.65 ± 1.32 vs. 2.82 ± 0.86, p = 0.005) scores differed between patients who died within the first year after surgery compared to those who survived this period. In-hospital stay correlated with timed up-and-go (TUG) (TAU: 0.094, p = 0.037), Barthel index (TAU-0.114, p = 0.032), hand grip strength (TAU-0.173, p < 0.001), and EuroSCORE II (TAU 0.119, p = 0.008). ICU/IMC stay duration correlated with TUG (TAU 0.186, p < 0.001), 6 MW (TAU-0.149, p = 0.002), and hand grip strength (TAU-0.22, p < 0.001). FRAIL patients had post-operatively altered levels of plasma-redox-biomarkers and fat-soluble micronutrients. CONCLUSIONS: frailty parameters with the highest predictive value as well as ease of use could be added to the EuroSCORE.

Gender-Related Outcomes after Surgical Resection and Level of Satisfaction in Patients with Left Atrial Tumors.

BACKGROUND: Cardiac tumors are rare, with a low incidence of between 0.0017 and 0.19%. The majority of cardiac tumors are benign and predominantly occur in females. The aim of our study was to examine how outcomes differ between men and women. METHODS: From 2015 to 2022, 80 patients diagnosed with suspected myxoma were operated on. In all patients, preoperative, perioperative, and postoperative data were recorded. Such patients were identified and included in a retrospective analysis focused on gender-related differences. RESULTS: Patients were predominantly female (n = 64; 80%). The mean age was 62.76 ± 13.42 years in female patients and 59.65 ± 15.84 years in male patients (p = 0.438). The body mass index (BMI) was comparable in both groups: between 27.36 ± 6.16 in male and 27.09 ± 5.75 (p = 0.945) in female patients. Logistic EuroSCORE (LogES) (female: 5.89 ± 4.6; male: 3.95 ± 3.06; p = 0.017) and EuroSCORE II (ES II) (female: 2.07 ± 2.1; male: 0.94 ± 0.45; p = 0.043), both scores to predict the mortality in cardiac surgery, were significantly higher in female patients. Two patients died early, within 30 days after surgery: one male and one female patient. Late mortality was defined as the 5-year survival rate, which was 94.8%, and 15-year survival rate, which was 85.3% in our cohort. Causes of death were not related to the primary tumor operation. The follow up showed that satisfaction with surgery and long-term outcome was high. CONCLUSION: Predominately female patients presented with left atrial tumors over a 17-year period. Relevant gender differences aside from that were not evident. Surgery could be performed with excellent early (within 30 days after surgery) and late results (follow up after discharge).

Simple and Safe: Inverse Plication of the Posterior Mitral Leaflet in Everyday Mitral Valve Reconstruction with and without Concomitant Procedures.

Objective: Cardiosurgical mitral valve repair (MVR) cannot be easily replaced by other interventional procedures due to the complexity of mitral valve regurgitation as well as physiologic and anatomic repair techniques. A wide variety of techniques have been adopted for proper reconstruction of posterior leaflet prolapse. We investigated the long-term results of quadrangular resections and compared them with a simplified reconstruction maneuver, the inverse plication. Methods: We retrospectively collected data from 1977 patients after mitral valve repair between 2004 and 2022. After considering inclusion and exclusion criteria, we analyzed data from 180 patients after MVR with and without concomitant procedures such as CABG and/or aortic valve replacement (AVR). All MVRs were performed with a semi-rigid annuloplasty ring. A total of 180 patients received quadrangular resection (QuadRes, N = 120)) or inverse plication (InvPlic, N = 60) of the posterior leaflet, among other measures. Demographic data, risk factors, procedure times, hospitalization time, early and long-term mortality as well as Kaplan-Meier survival were analyzed. Results: Age (65.3 vs. 63.1 years) and sex (28.8% female vs. 337.5% female) did not differ significantly, and the EuroSCORE was significantly higher in the InvPlic group (6.46 ± 2.75) than in the QuadRes group (5.68 ± 3.1). Procedural times did not differ for cardiopulmonary bypass, and were as follows: InvPlic 136 ± 44 min; QuadRes 140 ± 48 min; X-Clamp: InvPlic 91 ± 31 min; QuadRes 90 ± 32 min. Hospitalization time was slightly but insignificantly lower in the InvPlic group (15.5 days) than in the QuadRes group (16.1 days). Early mortality (5.08% vs. 8.33%) and re-do procedures (1.69% InvPlic; 6.67% QuadRes) did not differ significantly. However, long-term mortality was significantly lower in the InvPlic group (15.25% vs. 32.32%, p = 0.029). Conclusions: Among the surgical measures for the posterior leaflet, inverse plication appears to be non-inferior to quadrangular resection in unselected all-comer patients. Long-term results and absence of re-do procedures indicate very good stability. Thus, inverse plication not only allows correction of PML, but is also completely safe in the long term and can replace quadrangular resection, especially in patients where a reduction in technical challenges and procedure duration is desired.

Does Age Influence the Preoperative Condition and, Thus, the Outcome in Endocarditis Patients?

Background: Demographic changes have led to an increase in the proportion of older patients undergoing heart surgery. The number of endocarditis cases is also steadily increasing. Given the sharp increase in patients who have received valve prostheses or electrophysiological implants, who are on chronic dialysis or taking immunosuppressants, the interdependence of these two developments is quite obvious. We have studied the situation of older patients suffering from endocarditis compared to younger ones. Are they more susceptible, and are there differences in outcomes? Patients and Methods: A total of 162 patients was studied from our database, enrolled from 2020 to 2022. Fifty-four of them were older than 75 years of age (mean age 79.9 ± 3.8 years). The remaining 108 patients had a mean age of 61.6 ± 10.1 years. EuroSCORE II (ES II) was higher in the older patients (19.3 ± 19.7) than in the younger ones (13.2 ± 16.84). The BMI was almost identical. The preoperative NYHA proportions did not differ. A statistical analysis was performed using R. Results: Older patients had a lower left ventricular ejection fraction (LVEF), a higher proportion of coronary heart disease (CHD), a higher amount of N-terminal probrain natriuretic peptides (NT-proBNPs), worse coagulation function, worse renal function than younger patients, and were more often valve prosthesis carriers compared to the younger patients. The diagnostic interval was 66.85 ± 49.53 days in the younger cohort, whereas it was only 50.98 ± 30.55 in the elderly (p = 0.081). Significantly fewer septic emboli were observed in the older patients than in the younger patients, but postoperative delirium and critical illness polyneuropathy and critical illness myopathy (CIP/CIM) were observed significantly more frequently compared to younger patients. In-hospital mortality was higher in older patients than in younger patients, but did not reach statistical significance (29.91% vs. 40.38%; p = 0.256). The postoperative clinical status was worse in older patients than in the younger ones (NYHA-stage, p = 0.022). Conclusions: Age did have an impact on the outcome, probably due to causing a higher number of cumulative preoperative risk factors. However, an interesting phenomenon was that older patients had fewer septic emboli than younger patients. It can only be speculated whether this was due to a shorter diagnostic interval or lower mobility, i.e., physical exertion. Older patients suffered more frequently than younger ones from typical age-related postoperative complications, such as delirium and CIP/CIM. In-hospital mortality was high, but not significantly higher compared to the younger patients. Considering the acceptable mortality risks, and in light of the lack of alternatives, older patients should not be denied surgery. However, individual consideration is necessary.

What Exactly Makes Age a Risk Factor for an Unfavorable Outcome after Mitral Valve Surgery?

Objective: Age has an undeniable impact on perioperative mortality. However, it is not necessarily a predictor of frailty per se, as older patients have different outcomes. To verify specific conditions underlying frailty, we examined demographics, comorbidities, frequency, and distribution of postoperative complications influencing outcomes in a challenging cohort of patients undergoing mitral valve surgery. Methods: The study enrolled 1627 patients who underwent mitral valve surgery. Patients younger than 40 years who had been diagnosed with endocarditis were excluded. Patients were divided into three groups with ages ranging from 40−59 (n = 319), 60−74 (n = 795), and >75 years (n = 513). Baseline, comorbidities, postoperative complications, and mortality were recorded. Results: The older the patients were, the more frequently they suffered from pre- and postoperative renal insufficiency (p < 0.001). The likelihood of postoperative renal failure requiring dialysis was significantly higher with pre-existing renal failure. There was a significant association between postoperative renal insufficiency and the development of postoperative pleural or pericardial effusion (p < 0.001, p = 0.016). A significant decrease in BMI was observed in patients >75 years of age compared to the 60−74 years group (27.3 vs. 28.2 kg/m2, p = 0.007). The development of critical illnesses such as myopathy and neuropathy (CIP/CIM) was age-dependent and increased significantly with age (p = 0.04). Hospitalization duration and mortality also increased significantly with age (p = 0.013, p < 0.001). Conclusions: It appears that elderly patients with advanced renal failure have a significantly higher risk of mortality, postoperative renal failure, need for dialysis, and possibly the development of pleural and pericardial effusions in mitral valve surgery. In addition, more frequent CIP/CIM with concomitant decrease in BMI in the most advanced age group indicate sarcopenia and thus an additional feature of frailty besides renal failure.

Do Not Withhold Mitral Surgery from Patients with Poor Left Ventricular Function.

Background and Objectives: Increasing reluctance to perform surgical mitral valve repair or replacement particularly in high-risk patients with poor left-ventricular function is trending. These patients are increasingly treated interventionally, e.g., by MitraClip, but often show only low to moderate improvement. The primary objective of the study was to investigate whether left ventricular ejection fraction (LVEF) influences postoperative mortality. Materials and Methods: The study included 903 patients undergoing mitral valve repair or replacement between 2009 and 2021. Statistical comparison was performed between patients with LVEF ≤ 30% and LVEF > 30%. Finally, statistical analysis was performed according to propensity score matching (1:3 PS matching). Results: No significant difference in in-hospital mortality was found before and after matching regarding LVEF ≤ 30% and LVEF > 30% (Pre: 10.8% vs. 15.1%, p = 0.241, after: 11.6% vs. 18.1%, p = 0.142). After PS matching, the 112 patients with LVEF ≤ 30% compared with 336 patients with LVEF > 30% showed a significantly higher preoperative NT-proBNP (p < 0.001), larger diameters at preoperative left ventricle and atrium (p < 0.001), lower preoperative TAPSE (p = 0.003) and PAP (p = 0.003), and more dilated cardiomyopathy and chronic kidney disease (p < 0.001, p = 0.045). Conclusions: The results of this study demonstrate that poor preoperative LVEF alone does not play a significant role in postoperative outcome and long-term mortality. Prognosis appears to be multifactorial. Poor preoperative LVEF is not a contraindication for surgery and does not justify primary interventional treatment accepting inferior hemodynamic results impeding outcome.

Liver cirrhosis: Still an elusive risk factor in the current EuroSCORE system.

OBJECTIVES: Liver cirrhosis increases the risk of death in patients having cardiac surgery, and the risk is markedly dependent on the actual stage. The EuroSCORE II, however, does not specifically address the risk of death of patients with liver cirrhosis. We investigated the predictive power of EuroSCORE II in patients with liver cirrhosis. METHODS: Between 2000 and 2020, a total of 218 patients with liver cirrhosis underwent cardiac surgery. To improve the predictive value of the EuroSCORE II, we calculated additional ß-coefficients to include liver cirrhosis in the EuroSCORE IIb. The control group included 5,764 patients without liver cirrhosis from the same period. RESULTS: Of the 5,764 patients without cirrhosis, 8.9% died early. Of those with cirrhosis, 8.9% of 146 patients with Child A stage, 52.9% of 51 patients with Child B stage and 100% of 21 patients with Child C stage died. Moreover, the EuroSCORE II showed a poor predictive value for patients in Child B and C stages. The resulting values of calculated ß using the area under the curve of the receiver operating characteristic and bootstrapping for Child stages as predictors of mortality were as follows: ßA = 0.1640205, ßB= 2.9911625 and ßC= 6.2501248. By calculating the updated EuroSCORE IIb and regenerating the receiver operating characteristic curves, we were able to demonstrate an improvement in area under the curve values. Postoperative complications, need for extracorporeal membrane oxygenation or intra-aortic balloon pump implants, intensive care unit stays and hospital stays were significantly higher in cirrhotic patients with cirrhosis compared with patients without cirrhosis. The most common cause of liver cirrhosis was alcohol abuse (55.5%). CONCLUSIONS: Although patients with liver cirrhosis represent only a small proportion of cardiac surgical cases, the poor outcomes are particularly relevant in patients with advanced stages of the disease. Our study results show that Child class A patients show outcomes similar to those of patients without liver disease whereas Child class C patients appear to be nearly inoperable, i.e. can only be operated on with exceptional risks. Including these patients in the EuroSCORE II calculation would thus represent an improvement in preoperative mortality risk assessment.

MitraClip: a word of caution regarding an all too liberal indication and delayed referral to surgery in case of failure.

OBJECTIVES: Although indications for the MitraClip are becoming increasingly liberal, the number of patients requiring valve surgery after an insufficient outcome of the procedure is growing. Referral to surgery is, however, frequently delayed. During this time, the patients often deteriorate. We retrospectively analysed patients before MitraClip implantation and after mitral valve surgery. METHODS: A total of 49 patients who received a mitral valve replacement (average 8 ± 12 months after MitraClip implantation) were assessed. Of these, 53% had 2-4 clips inserted. The mean age was 73 years, and the mean log EuroSCORE was 20.79 ± 14.42%. Echocardiographic data obtained prior to MitraClip implantation and preoperatively, 10 days and 6 and 12 months after cardiac surgery were reviewed. Survival analysis, risk profile and postoperative complications were analysed. RESULTS: The 30-day and 1-year mortality was 26.5% and 59.2%, respectively. Prior to MitraClip implantation, 42.8% of patients had mild tricuspid insufficiency and 6.1% had moderate tricuspid insufficiency. Prior to surgery, 26.5% showed mild, 32.7% moderate and 38.8% severe tricuspid insufficiency (P < 0.001). Furthermore, right heart function assessed by tricuspid annular plane systolic excursion deteriorated significantly after Implantation of the MitraClip (P < 0.001). In patients with a MitraClip, the pulmonary artery pressure was significantly higher at the time of mitral replacement than it was before the MitraClip was implanted (P < 0.001). CONCLUSIONS: A subgroup of patients does not benefit from a MitraClip and shows progressive deterioration in cardiac function, making valve replacement under difficult circumstances inevitable. The earlier these patients are operated on, the better it is. It can be assumed that some patients would be better off with primary surgery, especially if mitral reconstruction is then still feasible. Therefore, the indications for MitraClip implantation should be carefully considered and caution should be exercised during monitoring.

Effects of tubing degradation and pump position on extracorporeal circulation performance.

Extracorporeal circulation (ECC) is an integral part of cardiac surgery. Yet, the contact with artificial surfaces, mechanical stress, shear, and suction forces within the ECC pose a pronounced risk for damaging the corpuscular components of the blood. These suction forces may be reduced by a repositioning of the roller pumps employed below the reservoir. Furthermore, the repeated compression of the involved silicone tubing is likely to cause degradation. We present our observations regarding changes in the ECC performance following this degradation process. In vitro experiments were performed in a standard as well as a simplified ECC setup and included measurements of pressure, effective flow, and tubing restoring force over a time frame of 12 hours with two different pump positions utilizing transit time flow measurement. Suction forces within the tubing could be significantly reduced by shifting the pump position below the reservoir. Regardless of the setup, the tubing showed significant loss of restoring force as well as effective flow over time. A shift of the pump position within the ECC setup can be recommended to prevent blood damaging negative pressures. Further research is necessary to evaluate the exact cause of the reduction of restoring force overtime as well as its risks for the patients. Finally, our results underline the importance of transit time flow measurements to collect reliable flow data.

Q-PULS, a new quasi-physiological pulsatile extracorporeal model to simulate heart function.

OBJECTIVES: The invention of new surgical procedures requires testing at different stages including animal models. To facilitate this process, we have developed a computer-controlled extracorporeal circulation system for testing of an explanted porcine heart simulating a variety of physiological parameters. Mitral valve function can be assessed before and after induced valve insufficiency and after valve repair. Accordingly, techniques and instruments can be modified at early stages of prototype development. METHODS: In the diastole, the left atrium is passively filled through the reservoir. The loading pressure of the atrium and flow rates can be widely adjusted. To simulate the systole, a linear motor-driven piston pump promotes volume into the left ventricle and the aorta. An additional circulatory pump compensates for undesired total emptying of the heart chambers. The processor control of the linear pump allows for various settings of flow rate, velocity and even irregular rhythm. Twenty-one isolated porcine hearts were used. The leaflet movement was filmed using a universal serial bus (USB)-probe camera. RESULTS: With 80 mm stroke and 1 m/s speed, a volume of 150 ml can be pumped at a heart rate of up to 73 bpm. Cardiac outputs of up to 10.9 l/min can be achieved. Constant visualization and continuous measurements of the pressure gradients before and after the induction of mitral insufficiency and after repair allowed quantitative verification of repair quality under beating-heart conditions. CONCLUSIONS: This model allows a controllable pulsation, loading and unloading of a porcine heart in a wide range. Thus, the function of the leaflets and repair results can be qualitatively and quantitatively evaluated under quasiphysiological conditions.

Double-Wire versus Single-Wire Sternal Closure in Obese Patients: a Randomized Prospective Study.

Background Sternal instability after coronary artery bypass grafting (CABG) is a serious complication. Obese patients are at high risk for sternal instability after CABG. This study was conducted to assess the positive impact of double-wire sternal closure on sternal instability. Methods A total of 200 obese patients with a body mass index ≥ 30 kg/m2 undergoing isolated CABG with left internal mammary artery (LIMA) graft were randomly assigned to sternal closure either by eight single wires (n = 100) or by a combination of four double wires and four single wires. Results There was a total of 21 cases with sternal instability: 5 cases (i.e., 5%) in the double-wire group versus 16 cases (16%) in the single-wire group (p = 0.019). Logistic regression analysis showed sternal closure via double wires as an independent protection factor (odds ratio [OR]: 0.276; p = 0.029). Smoking (OR: 5.5; p = 0.006) and postoperative delirium (OR: 3.5; p = 0.033) turned out to be independent risk factors for the development of sternal instability. Conclusion Double-wire sternal closure significantly reduces postoperative sternal instability in obese patients undergoing isolated CABG with LIMA graft.

Bypass surgery with psychological and spiritual support (the BY.PASS Study): results of a pragmatic trial based on patients' preference.

BACKGROUND: Some general hospitals within the German health system provide supportive interventions, psychological as well as spiritual, to their patients. It remains to be proven if these interventions are effective when used in routine clinical practice. AIM: To evaluate the effectiveness of psychological and spiritual interventions on improving recovery following bypass surgery. METHODS: The BY.PASS study is a pragmatic, patient preference trial (ISRCTN 07297983). Adult patients scheduled for elective coronary bypass surgery were enrolled. Patients were assigned to study conditions according to their personal preference: preference for psychological interventions, for spiritual interventions or for no intervention. Patients who were open for any kind of intervention were randomly assigned either to psychological or spiritual interventions. During a control period, patients were asked about their preference, but did not receive any interventions. Primary outcomes of the study were in-hospital morbidity and early mortality. Psychological measures served as secondary outcomes. RESULTS: A total of 847 patients were enrolled. Patients of the control (n = 260) and the intervention group (n = 269) who explicitly wanted to have interventions were compared. No significant treatment effects either for morbidity (d = 0.08, 95% CI -0.09 to 0.25), or for mortality (OR = 1.81; 95% CI 0.50-6.57) could be found. A reduction of negative mood resulted from both interventions. CONCLUSIONS: Although the effects observed were small, the study can serve as a basis to discuss methodological as well as theoretical aspects of a pragmatic trial, based upon patients' preferences.

Bypass surgery with psychological and spiritual support (the By.pass study): study design and research methods.

Effects of psychological as well as spiritual interventions on outcome in cardiac surgery have mostly been studied with a focus on presurgical interventions. Systematically controlled analyses of the effects of psychological and spiritual interventions depending on the patients' preference have not been performed so far, although these studies would help to assign patients to an adequate support. The By.pass study is a bi-center, controlled trial of patients undergoing coronary bypass surgery and coronary bypass surgery combined with valve replacement surgery in 2 different German hospitals. Patients are assigned to 1 of 5 conditions, mainly according to their personal therapeutic preference: preference for psychological interventions (group 1), preference for spiritual interventions (group 2), or preference for no intervention (group 5). Patients who are open for any kind of intervention are randomly assigned either to psychological (group 3) or spiritual interventions (group 4). Six months before the start and 6 months after the end of the treatment phase, patients were assigned to the control groups. These were asked about their subjective preference (psychological, spiritual, no intervention, or no specific preference) as well but received no interventions. Patients will be enrolled from October 2006 to December 2009. The 6-month follow-up will be completed in July 2010.

Numerical simulation techniques to study the structural response of the human chest following median sternotomy.

BACKGROUND: The optimal closure technique of median sternotomy remains controversial. The objective of this study was to analyze the structural response of the separated sternum using computer-based numerical discretization techniques, such as finite element methods. METHODS: Thoracic computer tomographic scans (2.5-mm slices) were segmented, analyzed by image processing techniques, and transferred into a three-dimensional finite element model. In a first approach a linear elastic material model was used; neglecting nonlinear and damage effects of the bones. The influence of muscles and tendons was disregarded. Nonlinear contact conditions were applied between the two sternal parts and between fixation wires and sternum. The structural response of this model was investigated under normal breathing and asymmetric leaning on one side of the chest. Displacement and stress response of the segmented sternum were compared regarding two different closure techniques (single loop, figure-of-eight). RESULTS: The obtained results revealed that for the normal breathing load case the single loop technique is capable of clamping the sternum sufficiently, assuming that the wires are prestressed. For asymmetric loading conditions, such as leaning on one side of the chest, the figure-of-eight loop can substantially reduce the relative longitudinal displacement between the two parts compared with the single loop. CONCLUSIONS: The application of numerical simulation techniques using complex computer models enabled the determination of structural behavior of the chest regarding the influence of different closure techniques. They allowed easy and fast modifications and therefore, in contrast to a real physical model, in-depth parameter studies.