Techniques for Robotic-Assisted Surgical Myocardial Revascularization.

The two current strategies for robotic-assisted, surgical myocardial revascularization are minimally invasive direct coronary artery bypass (MIDCAB) and totally endoscopic coronary artery bypass grafting (TECAB). We discuss the rationale underlying the benefits of robotic assistance in surgical myocardial revascularization, and detail the technical steps to safely and effectively perform these two procedures.

Minimally invasive surgical aortic valve replacement: The RALT approach.

Less-invasive techniques for cardiothoracic surgical procedures are designed to limit surgical trauma, but the technical requirements and preoperative planning are more demanding than those for conventional sternotomy. Patient selection, interdisciplinary collaboration, and surgical skills are key factors for procedural success. Aortic valve replacement is frequently performed through an upper hemisternotomy, but the right anterior minithoracotomy represents an even less traumatic, technical advancement. Preoperative assessment of the ascending aorta in relation to the sternum is mandatory to select patients and the intercostal access site. This description of the surgical technique focuses on the specific procedural details including the obligatory planning with computed tomography and our cannulation strategy. We also sought to define the anatomical ascending aorta-sternal relationship, as it is of utmost importance in preoperative computed tomographic planning.

Repeated MitraClip procedure in patients with recurrent MR after a successful first procedure: Limitations and outcome.

OBJECTIVES: The present study aimed to evaluate the outcome and potential limitations of a repeated MitraClip procedure (ReClip). BACKGROUND: The MitraClip procedure has emerged as a treatment option in high surgical risk patients suffering from severe mitral regurgitation (MR). However, despite successful initial repair a significant number of patients develops severe recurrent MR. METHODS: Patients undergoing a ReClip procedure in our institution were retrospectively identified. Baseline data and the procedural outcome were assessed to identify potential limitations of such procedures. RESULTS: Fifteen out of 234 patients undergoing a mitral-valve repair with the MitraClip device (Abbott Vascular) underwent a ReClip due to recurrent MR. In 11 patients, a MR reduction of at least one degree without causing mitral valve stenosis (trans-mitral mean gradient ≥5 mmHg) was achieved by performing a ReClip. After 1 year, two patients developed severe recurrent MR again. Pulmonary artery pressures significantly decreased after the procedure in individuals with successful repair (MR reduction of at least one degree and mitral valve mean gradient <5 mmHg). CONCLUSION: A ReClip procedure may be feasible in patients with recurrent MR but the risk benefit ratio should be carefully balanced against other treatment options.

Incidence and Predictors of Postoperative Need for High-Dose Inotropic Support in Patients Undergoing Cardiac Surgery for Infective Endocarditis.

OBJECTIVE: Patients with infective endocarditis undergoing cardiac surgery are a high-risk population. Few data on incidence and predictors of need for high-dose inotropic support in this setting are currently available. DESIGN: Retrospective study. SETTING: Tertiary-care hospital. PARTICIPANTS: Ninety consecutive patients undergoing cardiac surgery for infective endocarditis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline, intraoperative and outcome data were collected. Stepwise multiple logistic regression analysis was performed to identify preoperative predictors of postoperative hemodynamic support. High-dose postoperative inotropic support was defined as inotropic score >10 (calculated as dobutamine dose (in µg/kg/min) + dopamine dose (in µg/kg/min) + (epinephrine dose [in µg/kg/min] × 100) + (norepinephrine dose [in µg/kg/min] × 100) + (milrinone dose [in µg/kg/min] × 10) + (vasopressin dose [in U/kg/min] × 10 000) + (levosimendan dose [in µg/kg/min] × 50) or need for mechanical circulatory support at intensive care unit admission. Postoperative high-dose inotropic or mechanical circulatory support was required in 57 cases (61%). Stepwise multiple logistic regression identified 5 variables independently associated with need for postoperative circulatory support: male sex (odds ratio [OR] = 10.9), surgery duration (OR for every minute increase = 1.01), impairment of kidney function (eGFR <60 mL/min/m2 - OR = 19), preoperative new-onset heart failure (defined by clinical, imaging and laboratory parameters - OR = 5.30), and low preoperative platelet count (for every 1×103/µl increase - OR = 0.99). CONCLUSIONS: Patients undergoing cardiac surgery for infective endocarditis are at high risk for postoperative hemodynamic instability. Preoperative organ failure is an important determinant for postoperative hemodynamic instability.

Results of mitral valve repair with an adjustable annuloplasty ring 2 years after implantation.

We aimed to investigate the safety and medium-term durability of an adjustable mitral annuloplasty ring in patients undergoing surgery for mitral valve regurgitation. Forty-five patients requiring mitral valve repair were enrolled into this prospective, multicentre study between May 2012 and May 2013 in six hospitals in Europe and Israel. Study endpoints evaluated the performance and safety of the device assessed using inter-individual comparisons. Implantation was performed through a sternotomy in ten patients and mini-thoracotomy in 35 patients. The ring was adjusted after declamping and weaning from cardio-pulmonary bypass under echocardiographic guidance if the coaptation surface was not optimal, or in cases of residual mitral regurgitation. Follow-up was performed up to 2 years post-procedure. Mean age was 61 ± 12 years. Ring adjustment was performed in 71% of patients to optimise the results of mitral valve repair. Following the procedure, 11/45 patients (24%) who had had mild residual mitral regurgitation had no mitral regurgitation following ring adjustment. Two patients with severe mitral regurgitation post-procedure had mild regurgitation following ring adjustment. Coaptation length increased significantly after adjustment. One patient died before hospital discharge due to complications unrelated to the adjustable ring. One patient had to undergo re-operation at 39 days post-procedure due to endocarditis. At 2 years of follow-up, 78% of patients had no residual mitral regurgitation and 22% had mild residual mitral regurgitation. Adjustable mitral annuloplasty ring implantation was safe in all patients. Mitral valve repair with the adjustable ring was durable in all patients who reached 2 years follow-up. CLINICAL TRIAL REGISTRATION: NCT01617720.

Mid-Term Outcomes of Minimally Invasive Direct Coronary Artery Bypass Grafting.

BACKGROUND: Minimally invasive direct coronary artery bypass grafting (MIDCAB) has gained wide acceptance for the treatment of single vessel disease of the left anterior descending artery (LAD). Here, we present our single center experience of 152 consecutive patients. MATERIALS AND METHODS: All patients underwent MIDCAB through a left anterior minithoracotomy between January 1, 2009, and December 31, 2012. Preoperative, intraoperative, postoperative, and follow-up data including major adverse cardiac and cerebrovascular events (MACCE) and need for re-intervention were collected. RESULTS: Mean age was 64.4 ± 11 years, median additive EuroSCORE 3 (0-11), 84% were male. All except one patient were successfully operated without cardiopulmonary bypass. Seven patients with unexpected severely calcified LADs were converted to sternotomy (4.6%); 91.3% were extubated in the operating room or on the day of surgery. Median stay at the intensive care unit and in hospital were 1 (0-97) and 7 (1-49) days, respectively. Thirty-day mortality was 1.9%. There was no stroke. Five patients (3.2%) had to be re-explored for bleeding and 95% received no transfusion. Median follow-up was 24 months (0-97) and complete in 93.3% with overall survival of 92.4 ± 0.2% and MACCE-free survival of 96.1 ± 1.7%. Two patients had a re-intervention of the LAD. CONCLUSION: MIDCAB is a safe procedure with low postoperative morbidity, mortality, and favorable mid-term MACCE-free survival in selected patients that should be discussed in a heart team setting to evaluate the "ideal" individual treatment option.

Repair rate and durability of video assisted minimally invasive mitral valve surgery.

BACKGROUND: Minimally invasive mitral valve surgery (MIMVS) through a right lateral thoracotomy has emerged as another option in cardiac surgery. We present our single center experience with regards to repair rate and durability of the repair in patients undergoing MIMVS. METHODS: Between January 2009 and December 2012 a total of 312 consecutive patients underwent MIMVS. Baseline characteristics, operative variables, postoperative outcomes, and follow-up information about survival, major adverse cardiac and cerebrovascular event (MACCE)-free survival, valve competence, and freedom from reoperation were collected. RESULTS: Mean age was 61 ± 13.1 years, median Euroscore 4 (0-13). The predominant valve pathology was degenerative disease (96.2%) with regurgitation (95.2%) and atrial fibrillation (23.1%). Bypass time was 147 ± 46, cross-clamp time 94 ± 32 minutes. All degenerative valves planned for repair (n = 281) were successfully repaired except for two (0.7%) resulting in a 99.3% repair rate. Eight patients (2.8%) had to be converted to sternotomy. Median ventilation time was 6.6 hours (0 to 460), ICU stay one day (0 to 96), and hospital stay eight days (3 to 61). Most of the patients did not need red blood cell transfusion (78.2%). One patient died in hospital due to acute respiratory distress syndrome (0.3%) and five suffered a permanent stroke (1.6%). In 294 patients (94.5%) follow-up was completed for a median of 22 months (0 to 53) with 95.5 ± 1.2% overall survival, 96.8 ± 1.2%, MACCE-free survival, and 94.8 ± 0.1% freedom from reoperation. CONCLUSIONS: MIMVS is a safe approach with low morbidity and mortality that allows a high and durable repair rate with low reoperation rates and favorable short-term event-free survival.

Mediastinal transposition of the greater omentum for treatment of infected prostheses of the ascending aorta and aortic arch.

OBJECTIVES: The aim of this study was to evaluate the outcomes of transposition of the omentum into the mediastinum to support the replacement of infected aortic grafts or to cover infected aortic grafts that are not amenable for surgical replacement. METHODS: All patients with thoracic aortic graft infections who underwent mediastinal transposition of the omentum at our institution between 2005 and 2023 were included in this study. Mediastinal transposition of the omentum was performed either after replacement of the infected graft ('curative concept') or solely as bailout procedure by wrapping the infected graft ('palliative concept'). The diagnosis, including computed tomography scans during follow-up, was made according to the criteria of the Management of Aortic Graft Infection Collaboration. RESULTS: The patient cohort consisted of 31 patients. Both in-hospital and 1-year mortality were 0% (n = 0) for the curative concept (n = 9) compared to 23% (n = 5) and 41% (n = 9) for the palliative concept (n = 22), respectively. There was no graft infection-associated death or recurrence of infection after 3 years in the curative group. Survival was 52% at 3 years in the palliative group, with freedom of infection in 59% of the patients (n = 13). CONCLUSIONS: Transposition of the omentum and wrapping of the infected aortic prosthetic graft is a useful bailout strategy for patients who are ineligible for replacement of an infected aortic graft. However, mortality stays high. For radical treatment of aortic graft infections, it may prove an effective supportive therapy and represents an important tool in the armamentarium of cardiac surgeons.

Mechanical Circulatory Support Strategies in Takotsubo Syndrome with Cardiogenic Shock: A Systematic Review.

BACKGROUND: Takotsubo syndrome is, by definition, a reversible form of acute heart failure. If cardiac output is severely reduced, Takotsubo syndrome can cause cardiogenic shock, and mechanical circulatory support can serve as a bridge to recovery. To date, there are no recommendations on when to use mechanical circulatory support and on which device is particularly effective in this context. Our aim was to determine the best treatment strategy. METHODS: A systematic literature research and analysis of individual patient data was performed in MEDLINE/PubMed according to PRISMA guidelines. Our research considered original works published until 31 July 2023. RESULTS: A total of 93 publications that met the inclusion criteria were identified, providing individual data from 124 patients. Of these, 62 (50%) were treated with veno-arterial extracorporeal life support (va-ECLS), and 44 (35.5%) received a microaxial left ventricular assist device (Impella). Eighteen patients received an Impella CP and twenty-one an Impella 2.5. An intra-aortic balloon pump (IABP) without other devices was used in only 13 patients (10.5%), while other devices (BiVAD or Tandem Heart) were used in 5 patients (4%). The median initial left ventricular ejection fraction was 20%, with no difference between the four device groups except for the IABP group, which was less affected by cardiac output failure (p = 0.015). The overall survival was 86.3%. Compared to the other groups, the time to cardiac recovery was shorter with Impella (p < 0.001). CONCLUSIONS: Though the Impella treatment is new, our analysis may show a significant benefit of Impella compared to other MCS strategies for cardiogenic shock in Takotsubo syndrome.

"UFO procedure" for massive aortic and mitral annular calcification involving left atrial and ventricular myocardium: a potential radical solution.

BACKGROUND: The "UFO procedure" was initially developed as a surgical option to enlarge the aortic annulus in patients requiring valve replacement. This technique can be employed to treat extensive endocarditis located in the intervalvular fibrous body (IVFB). One of the indications for a "UFO procedure" is massive aortic and mitral valve calcification. It is a challenging surgical procedure with a high risk of intraoperative complications. We present a 76-year-old male patient with massive aortic and mitral valve calcification involving the left atrium, the left ventricle and the left ventricular outflow tract. Both valves exhibited severe stenosis and moderate to severe regurgitation. The left ventricle was hypertrophic and the left ventricular ejection fraction was > 55%. The patient was prediagnosed with persistent atrial fibrillation. The risk of death following heart surgery (EuroSCORE II) was calculated as 9.21%. We successfully performed a so-called "UFO procedure" including replacement of both valves without annular decalcification to avoid atrioventricular dehiscence. We enlarged the IVFB and replaced the non-coronary sinus of Valsalva with doubled bovine pericardium. The left ventricular outflow tract was decalcified. The patient was transferred to a local hospital on the 13th postoperative day. CONCLUSION: Successful surgical treatment to this extent was demonstrated for the first time. Due to the high perioperative mortality, the surgical treatment of patients with this constellation would be refused in most cases. In our patient, the preoperative imaging showed extreme calcification of both valves and the surrounding myocardium. Excellent preoperative planning and a highly experienced surgical team is necessary.

Outcome and management of decompressive hemicraniectomy in malignant hemispheric stroke following cardiothoracic surgery.

Management of malignant hemispheric stroke (MHS) after cardiothoracic surgery (CTS) remains difficult as decision-making needs to consider severe cardiovascular comorbidities and complex coagulation management. The results of previous randomized controlled trials on decompressive surgery for MHS cannot be generally translated to this patient population and the expected outcome might be substantially worse. Here, we analyzed mortality and functional outcome in patients undergoing decompressive hemicraniectomy (DC) for MHS following CTS and assessed the impact of perioperative coagulation management on postoperative hemorrhagic and cardiovascular complications. All patients that underwent DC for MHS resulting as a complication of CTS between June 2012 and November 2021 were included in this observational cohort study. Outcome was determined according to the modified Rankin Scale (mRS) score at 1 and 3-6 months. Clinical and demographic data, anticoagulation management and postoperative hemorrhagic and thromboembolic complications were assessed. In order to evaluate a predictive association between clinical and radiological parameters and the outcome, we used a multivariate logistic regression analysis. Twenty-nine patients undergoing DC for MHS after CTS with a female-to-male ratio of 1:1.9 and a median age of 60 (IQR 49-64) years were identified out of 123 patients undergoing DC for MHS. Twenty-four patients (83%) received pre- or intraoperative substitution. At 30 days, the in-hospital mortality rate and neurological outcome corresponded to 31% and a median mRS of 5 (5-6), which remained stable at 3-6 months [Mortality: 42%, median mRS: 5 (4-6)]. Postoperatively, 15/29 patients (52%) experienced new hemorrhagic lesions and Bayesian logistic regression predicting mortality (mRS = 6) after imputing missing data demonstrated a significantly increased risk for mortality with longer aPPT (OR = 13.94, p = .038) and new or progressive hemorrhagic lesions after DC (OR = 3.03, p = .19). Notably, all but one hemorrhagic lesion occurred before discontinued anticoagulation and/or platelet inhibition was re-initiated. Despite perioperative discontinuation of anticoagulation and/or platelet inhibition, no coagulation-associated cardiovascular complications were noted. In conclusion, Cardiothoracic surgery patients suffering MHS will likely experience severe neurological disability after DC, which should remain a central aspect during counselling and decision-making. The complex coagulation situation after CTS, however, should not per se rule out the option of performing life-saving surgical decompression.

Image-based ring size prediction for mitral valve repair.

OBJECTIVES: Annuloplasty rings are routinely used in mitral valve repair (MVr). However, accurate annuloplasty ring size selection is essential to obtain a favourable outcome. Moreover, ring sizing can be challenging in some patients and is highly influenced by surgeons' experience. This study investigated the utility of three-dimensional mitral valve (3D-MV) reconstruction models to predict annuloplasty ring size for MVr. METHODS: A total of 150 patients undergoing minimally invasive MVr with annuloplasty ring due to Carpentier type II pathology and who were discharged with none/trace residual mitral regurgitation were included. 3D-MV reconstruction models were created with a semi-automated software package (4D MV Analysis) to quantitate mitral valve geometry. To predict the ring size, univariable and multivariable linear regression analyses were performed. RESULTS: Between 3D-MV reconstruction values and implanted ring sizes, the highest correlation coefficients were provided by commissural width (CW) (0.839; P < 0.001), intertrigonal distance (ITD) (0.796; P < 0.001), annulus area (0.782; P < 0.001), anterior mitral leaflet area (0.767; P < 0.001), anterior-posterior diameter (0.679; P < 0.001) and anterior mitral leaflet length (0.515; P < 0.001). In multivariable regression analysis, only CW and ITD were found to be independent predictors of annuloplasty ring size (R2 = 0.743; P < 0.001). The highest level of agreement was achieved with CW and ITD, and 76.6% of patients received a ring with no >1 ring size difference from the predicted ring sizes. CONCLUSIONS: 3D-MV reconstruction models can support surgeons in the decision-making process for annuloplasty ring sizing. The present study may be a first step towards accurate annuloplasty ring size prediction using multimodal machine learning decision support.

Minimally Invasive Extirpation of Benign Atrial Cardiac Tumors: Clinical Follow-Up and Survival.

OBJECTIVE: Evidence determining the optimal treatment for cardiac tumors is rare. We report our midterm clinical outcome and patient characteristics of our series undergoing atrial tumor removal through a right lateral minithoracotomy (RLMT). METHODS: From 2015 to 2021, 51 patients underwent RLMT for atrial tumor extirpation. Patients receiving concomitant atrioventricular valvular, cryoablation, and/or patent foramen ovale closure surgery were included. Follow-up was performed using standardized questionnaires (mean: 1,041 ± 666 days). Follow-up involved any tumor recurrence, clinical symptoms, and any recurrent arterial embolization. Survival analysis was successfully achieved in all patients. RESULTS: Successful surgical resection was achieved in all patients. Mean cardiopulmonary bypass and cross-clamping times were 75 ± 36 and 41 ± 22 min, respectively. The most common tumor location was the left atrium (n = 42, 82.4%). Mean ventilation time was 12.74 ± 17.23 h, intensive care unit stay ranged from 1 to 1.9 days (median: 1 day). Nineteen patients (37.3%) received concomitant surgery. Histopathological analysis showed 38 myxoma (74.5%), 9 papillary fibroelastoma (17.6%), and 4 thrombus (7.8%). Thirty-day mortality was observed in 1 case (2%). One patient (2%) suffered a stroke postoperatively. No patient had a relapse of cardiac tumor. Three patients (9.7%) showed arterial embolization during follow-up. Thirteen follow-up patients (25.5%) were in New York Heart Association class ≤II. Overall survival was 90.2% at 2 years. CONCLUSIONS: A minimally invasive approach for benign atrial tumor resection is effective, safe, and reproducible. Of the atrial tumors, 74.5% were myxoma and 82% were located in the left atrium. A low 30-day mortality rate with no manifestation of recurrent intracardiac tumor was observed.

Alternative minimally invasive surgical explantation techniques for failed transcatheter mitral valve repair devices.

Objective: The use of transcatheter mitral valve repair (TMVr) devices is increasing in elderly and high-risk patients. However, the increasing number of patients with recurrent mitral regurgitation (MR) has confronted surgeons with the issue of how to explant the devices and whether the mitral valve should be repaired or replaced. The aim of the study is to summarize our clinical experience with the explantation of different TMVr devices and to provide alternative surgical techniques that can be performed in different clinical scenarios. Methods: A simulator system including a dummy valve representing native valves was used to create video documentation and to develop alternative surgical methods for clip explantation. Moreover, the clip explantation techniques were shown in 2 patients undergoing minimally-invasive mitral valve repair after a failed TMVr. Results: Alternative explantation techniques were described for each TMVr device; 2 techniques for MitraClip and 3 techniques for PASCAL (Precision Transcatheter Valve Repair System), which may be adjusted for each individual according to the underlying valve pathology and the degree of device encapsulation. The patients were discharged without residual MR and remained MR free at the follow-up. Conclusions: Transcatheter edge-to-edge repair devices can be surgically explanted without damaging the MV leaflets. Removal of each device may require a different technique tailored to the degree of device encapsulation and valve pathology. Increasing experience may facilitate repair in patients with recurrent MR after TMVr.

Successful treatment of cardiogenic shock due to Takotsubo syndrome with implantation of a temporary microaxial left ventricular assist device in transaxillary approach.

OBJECTIVES: Cardiogenic shock (CS) can occur in patients with Takotsubo syndrome (TTS). As TTS has received increasing attention and has been more closely researched, several aspects of the pathogenesis have been identified, particularly that an excessive release of catecholamines plays an important role. Nevertheless, evidence on specific therapy concepts is still lacking. As a result, TTS with severe hemodynamic instability and low cardiac output creates unique challenges, and mechanical circulatory support is needed with as few inotropic drugs as possible. METHODS: We present a 77-year-old female patient who underwent minimally invasive surgical mitral valve replacement. After an uneventful course, the patient developed acute heart failure eleven days after surgery. Transthoracic echocardiography (TTE) revealed a new onset of TTS. The patient needed left ventricular venting and full haemodynamic flow. We successfully implanted a microaxial left ventricular assist device (Impella 5.5) using the transaxillary approach. The haemodynamic situation stabilised immediately. The patient was weaned and the Impella 5.5 was explanted after five days. CONCLUSION: We present the first-in-man implantation of a transaxillary Impella 5.5 in a patient with TTS. The patient benefitted from Impella 5.5 therapy with full haemodynamic support and venting of the left ventricle.

The Potential of Intertwining Gene Diagnostics and Surgery for Mitral Valve Prolapse.

Mitral valve prolapse (MVP) is common among heart valve disease patients, causing severe mitral regurgitation (MR). Although complications such as cardiac arrhythmias and sudden cardiac death are rare, the high prevalence of the condition leads to a significant number of such events. Through next-generation gene sequencing approaches, predisposing genetic components have been shown to play a crucial role in the development of MVP. After the discovery of the X-linked inheritance of filamin A, autosomal inherited genes were identified. In addition, the study of sporadic MVP identified several genes, including DZIP1, TNS1, LMCD1, GLIS1, PTPRJ, FLYWCH, and MMP2. The early screening of these genetic predispositions may help to determine the patient population at risk for severe complications of MVP and impact the timing of reconstructive surgery. Surgical mitral valve repair is an effective treatment option for MVP, resulting in excellent short- and long-term outcomes. Repair rates in excess of 95% and low complication rates have been consistently reported for minimally invasive mitral valve repair performed in high-volume centers. We therefore conceptualize a potential preventive surgical strategy for the treatment of MVP in patients with genetic predisposition, which is currently not considered in guideline recommendations. Further genetic studies on MVP pathology and large prospective clinical trials will be required to support such an approach.

Off-pump surgery for the poor ventricle?

Severely decreased ejection-fraction is an established risk-factor for worse outcome after cardiac surgery. We compare outcomes of off-pump coronary artery bypass grafting (OPCAB) and on-pump CABG (ONCABG) in patients with severely compromised EF. From 2004 to 2009, 478 patients with a decreased EF ≤35% underwent myocardial-revascularization. Patients received either OPCAB (n = 256) or ONCABG (n = 222). Propensity score (PS), including 50 preoperative risk-factors, was used to balance characteristics between groups. PS adjusted logistic regression analysis was performed to assess mortality and major adverse cardiac and cerebrovascular events (MACCE). A composite endpoint for major non-cardiac complications such as respiratory failure, renal failure, rethoracotomy was applied. Complete revascularization (CR) was assumed when the number of distal anastomoses was larger than that of diseased vessels. There was no difference for mortality (2.3 vs. 4.1%; PS-adjusted odds ratio (PS-OR) = 1.05; p = 0.93) and MACCE (13.7 vs. 17.6%; PS-OR = 1.22; p = 0.50) including myocardial-infarction (1.4 vs. 4.9%; PS-OR = 0.39; p = 0.26), low cardiac output (2.3 vs. 4.7%; PS-OR = 0.75; p = 0.72) and stroke (2.3 vs. 2.7%; PS-OR = 0.69; p = 0.66). OPCAB patients presented with a trend to less frequent occurrence of the non-cardiac composite (12.1 vs. 22.1%; PS-OR = 0.54; p = 0.059) including renal dysfunction (PAOR = 0.77; 95% CI 0.31-1.9; p = 0.57), bleeding (PAOR = 0.42; 95% CI 0.14-1.20; p = 0.10) and respiratory failure (PAOR = 0.39; 95% CI 0.05-3.29; p = 0.39). The rate of complete revascularization was similar (92.2 vs. 92.8%; PS-OR = 0.75; p = 0.50). OPCAB in patients with severely decreased EF is safe and feasible. It may even benefit these patients in regard to non-cardiac complications and does not come at cost of less complete revascularization.

The three ghosts of medical AI: Can the black-box present deliver?

Our title alludes to the three Christmas ghosts encountered by Ebenezer Scrooge in A Christmas Carol, who guide Ebenezer through the past, present, and future of Christmas holiday events. Similarly, our article takes readers through a journey of the past, present, and future of medical AI. In doing so, we focus on the crux of modern machine learning: the reliance on powerful but intrinsically opaque models. When applied to the healthcare domain, these models fail to meet the needs for transparency that their clinician and patient end-users require. We review the implications of this failure, and argue that opaque models (1) lack quality assurance, (2) fail to elicit trust, and (3) restrict physician-patient dialogue. We then discuss how upholding transparency in all aspects of model design and model validation can help ensure the reliability and success of medical AI.