Temporal Trends in Predictors of Early and Late Mortality After Emergency Coronary Artery Bypass Grafting for Cardiogenic Shock Complicating Acute Myocardial Infarction.

BACKGROUND: Cardiogenic shock after acute myocardial infarction is an indication for emergent coronary artery bypass grafting in patients not amenable to percutaneous coronary intervention. Our study aimed to evaluate and identify risk factors for early and long-term outcomes in such patients. METHODS: A total of 508 patients who underwent coronary artery bypass grafting for cardiogenic shock complicating acute myocardial infarction between January 2000 and June 2014 were divided into 3 time cohorts: 2000 to 2004 (n=204), 2005 to 2009 (n=166), and 2010 to 2014 (n=138). Predictors of in-hospital mortality for each time cohort and long-term mortality for all patients were identified by logistic and Cox regression analyses, respectively. RESULTS: Mean age was 68.3±9.8 years. Of the 508 patients, 78.5% had 3-vessel and 47.1% had left main disease. Left ventricular function <30% was observed in 44.1% of patients, with 30.4%, 37.9%, 52.9%, and 3.1% requiring preoperative resuscitation, ventilation, intra-aortic balloon pump, and extracorporeal membrane oxygenation support, respectively. Overall in-hospital mortality was 33.7%; declined from 42.2% to 30.7% to 24.6%, respectively, for the 3 time cohorts (P=0.02); and was independently predicted by serum lactate >4 mmol/L (odds ratio [OR], 4.78; 95% confidence interval, 2.88-7.95; P<0.0001), ST-segment-elevation myocardial infarction (OR, 2.10; 95% confidence interval, 1.36-3.26; P=0.001), age >75 years (OR, 2.01; 95% confidence interval, 1.06-3.85; P=0.03), and left ventricular ejection fraction <30% (OR, 1.83; 95% confidence interval, 1.15-2.91; P=0.01). Cumulative survival was 42.6±2.0% and 33.4±2.0% at 5 and 10 years, respectively, and correspondingly improved to 64.3±3.0% and 49.8±3.0% in hospital survivors. Serum lactate >4 mmol/L (OR, 2.2; P<0.0001), incremental age (OR, 1.05; P<0.0001), New York Heart Association class IV (OR, 1.33; P=0.02), diabetes mellitus (OR, 1.39; P=0.005), and preoperative inotropic (OR, 2.61; P=0.001) and extracorporeal membrane oxygenation (OR, 1.68; P=0.05) support predicted late mortality. CONCLUSIONS: Emergency coronary artery bypass grafting in patients with acute myocardial infarction complicated by cardiogenic shock is associated with a high in-hospital mortality, which showed a significant decline with time. Hospital survivors have good long-term outcomes, which demonstrate the beneficial effect of surgical revascularization. Preoperative serum lactate >4 mmol/L is a strong predictor of both early and late mortality.

Early and late outcomes of 517 consecutive adult patients treated with extracorporeal membrane oxygenation for refractory postcardiotomy cardiogenic shock.

OBJECTIVE: Adult postcardiotomy cardiogenic shock potentially requiring mechanical circulatory support occurs in 0.5% to 1.5% of cases. Risk factors influencing early or long-term outcome after extracorporeal membrane oxygenation implantation are not well described. METHODS: Between May 1996 and May 2008, 517 adult patients received extracorporeal membrane oxygenation support for postcardiotomy cardiogenic shock. Procedures were isolated coronary artery bypass grafting (37.4%), isolated valve surgery (14.3%), coronary artery bypass grafting plus valve surgery (16.8%), thoracic organ transplantation (6.5%), and other combinations (25.0%). Fifty-four preoperative and 42 procedural risk factors concerning in-hospital mortality were evaluated by logistic regression analyses. RESULTS: Mean age was 63.5 years, 71.5% were male, ejection fraction was 45.9% +/- 17.6%, logistic EuroSCORE was 21.6% +/- 20.7%. Extracorporeal membrane oxygenation was established through thoracic (60.8%) or extrathoracic (39.2%) cannulation. Extracorporeal membrane oxygenation support was 3.28 +/- 2.85 days. Intra-aortic balloon pumps were implanted in 74.1%. Weaning from extracorporeal membrane oxygenation was successful for 63.3%, and 24.8% were discharged. Cerebrovascular events occurred in 17.4%, gastrointestinal complications in 18.8%, and renal replacement therapy in 65.0%. Risk factors for hospital mortality were age older than 70 years (odds ratio, 1.6), diabetes (odds ratio, 2.5), preoperative renal insufficiency (odds ratio, 2.1), obesity (odds ratio, 1.8), logistic EuroSCORE greater than 20% (odds ratio, 1.8), operative lactate greater than 4 mmol/L (odds ratio, 2.2). Isolated coronary artery bypass grafting (odds ratio, 0.44) was protective. Cumulative survivals were 17.6% after 6 months, 16.5% after 1 year, and 13.7% after 5 years. CONCLUSIONS: Extracorporeal membrane oxygenation support is an acceptable option for patients with postcardiotomy cardiogenic shock who otherwise would die and is justified by good long-term outcome of hospital survivors. Because of high morbidity and mortality, extracorporeal membrane oxygenation must be decided by individual risk profile.

Assessing learning progress and quality of teaching in large groups of students.

The classic tool of assessing learning progress are written tests and assignments. In large groups of students the workload often does not allow in depth evaluation during the course. Thus our aim was to modify the course to include active learning methods and student centered teaching. We changed the course structure only slightly and established new assessment methods like minute papers, short tests, mini-projects and a group project at the end of the semester. The focus was to monitor the learning progress during the course so that problematic issues could be addressed immediately. The year before the changes 26.76 % of the class failed the course with a grade average of 3.66 (Pass grade is 4.0/30 % of achievable marks). After introducing student centered teaching, only 14 % of students failed the course and the average grade was 3.01. Grades were also distributed more evenly with more students achieving better results. We have shown that even in large groups of students with > 100 participants student centered and active learning is possible. Although it requires a great work overhead on the behalf of the teaching staff, the quality of teaching and the motivation of the students is increased leading to a better learning environment.

The use of methods involving semi-empirical molecular orbital theory to study the structure and reactivity of transition metal complexes.

The electronic structure of molecular systems containing transition metal atoms is traditionally studied using methods based on density functional theory (DFT). Although such an approach has been quite successful, the treatment of large systems, be they transition metal complexes, bioinorganic molecules or the solid state, is still extremely computationally demanding at this level, and may not be practical for many systems of interest. In this paper we describe how semi-empirical MO methods can be used to overcome these computational bottlenecks, yet still provide predictions of the necessary accuracy. We describe strategies to achieve this by focussing on: (i) obtaining appropriate parameters for transition metal atoms via a genetic algorithm, to be used within a parallelised implementation of neglect of differential diatomic overlap (NDDO) methods, and (ii) the use of multilevel treatments which involve DFT and semi-empirical methods to describe different regions of the molecule. Here we show by reference to histidine and porphyrin complexes, the importance of a correct partitioning of the organic substrate. We illustrate the potential of such a dual level approach by reporting preliminary results showing the catalytic role of the enzyme, dimethyl sulfoxide reductase.