Long-term survival after surgical treatment for post-infarction mechanical complications: results from the Caution study.

BACKGROUND AND AIMS: Mechanical complications (MCs) are rare but potentially fatal sequelae of acute myocardial infarction (AMI). Surgery, though challenging, is considered the treatment of choice. The authors sought to study early and long-term results of patients undergoing surgical treatment for post-AMI MCs. METHODS: Patients undergone surgical treatment for post-infarction MCs between 2001 through 2019 in 27 centers worldwide were retrieved from the database of CAUTION study. In-hospital and long-term mortality were the primary outcomes. Cox proportional hazards regression models were used to determine independent factors associated with overall mortality. RESULTS: The study included 720 patients. The median age was 70.0 [62.0-77.0] years, with a male predominance (64.6%). The most common MC encountered was ventricular septal rupture (VSR) (59.4%). Cardiogenic shock was seen on presentation in 56.1% of patients. In-hospital mortality rate was 37.4%; in more than 50% of cases, the cause of death was low cardiac output syndrome (LCOS). Late mortality occurred in 133 patients, with a median follow-up of 4.4 [1.0-8.6] years. Overall survival at 1, 5 and 10 years was 54.0%, 48.1% and 41.0%, respectively. Older age (p < 0.001) and postoperative LCOS (p < 0.001) were independent predictors of overall mortality. For hospital survivors, 10-year survival was 65.7% and was significant higher for patients with VSR than those with papillary muscle rupture (long-rank P = 0.022). CONCLUSIONS: Contemporary data from a multicenter cohort study show that surgical treatment for post-AMI MCs continues to be associated with high in-hospital mortality rates. However, long-term survival in patients surviving the immediate postoperative period is encouraging.Trial registration number: NCT03848429.

Impact of COVID-19 on incidence and outcomes of post-infarction mechanical complications in Europe.

OBJECTIVES: Post-acute myocardial infarction mechanical complications (post-AMI MCs) represent rare but life-threatening conditions, including free-wall rupture, ventricular septal rupture and papillary muscle rupture. During the coronavirus disease-19 (COVID-19) pandemic, an overwhelming pressure on healthcare systems led to delayed and potentially suboptimal treatments for time-dependent conditions. As AMI-related hospitalizations decreased, limited information is available whether higher rates of post-AMI MCs and related deaths occurred in this setting. This study was aimed to assess how COVID-19 in Europe has impacted the incidence, treatment and outcome of MCs. METHODS: The CAUTION-COVID19 study is a multicentre retrospective study collecting 175 patients with post-AMI MCs in 18 centres from 6 European countries, aimed to compare the incidence of such events, related patients' characteristics, and outcomes, between the first year of pandemic and the 2 previous years. RESULTS: A non-significant increase in MCs was observed [odds ratio (OR) = 1.15, 95% confidence interval (CI) 0.85-1.57; P = 0.364], with stronger growth in ventricular septal rupture diagnoses (OR = 1.43, 95% CI 0.95-2.18; P = 0.090). No significant differences in treatment types and mortality were found between the 2 periods. In-hospital mortality was 50.9% and was higher for conservatively managed cases (90.9%) and lower for surgical patients (44.0%). Patients admitted during COVID-19 more frequently had late-presenting infarction (OR = 2.47, 95% CI 1.24-4.92; P = 0.010), more stable conditions (OR = 2.61, 95% CI 1.27-5.35; P = 0.009) and higher EuroSCORE II (OR = 1.04, 95% CI 1.01-1.06; P = 0.006). CONCLUSIONS: A non-significant increase in MCs incidence occurred during the first year of COVID-19, characterized by a significantly higher rate of late-presenting infarction, stable conditions and EuroSCORE-II if compared to pre-pandemic data, without affecting treatment and mortality.

Optimal metabolic strategies for microbial growth in stationary random environments.

In order to grow in any given environment, bacteria need to collect information about the medium composition and implement suitable growth strategies by adjusting their regulatory and metabolic degrees of freedom. In the standard sense, optimal strategy selection is achieved when bacteria grow at the fastest rate possible in that medium. While this view of optimality is well suited for cells that have perfect knowledge about their surroundings (e.g. nutrient levels), things are more involved in uncertain or fluctuating conditions, especially when changes occur over timescales comparable to (or faster than) those required to organize a response. Information theory however provides recipes for how cells can choose the optimal growth strategy under uncertainty about the stress levels they will face. Here we analyse the theoretically optimal scenarios for a coarse-grained, experiment-inspired model of bacterial metabolism for growth in a medium described by the (static) probability density of a single variable (the 'stress level'). We show that heterogeneity in growth rates consistently emerges as the optimal response when the environment is sufficiently complex and/or when perfect adjustment of metabolic degrees of freedom is not possible (e.g. due to limited resources). In addition, outcomes close to those achievable with unlimited resources are often attained effectively with a modest amount of fine tuning. In other terms, heterogeneous population structures in complex media may be rather robust with respect to the resources available to probe the environment and adjust reaction rates.

Probing Single-Cell Fermentation Fluxes and Exchange Networks via pH-Sensing Hybrid Nanofibers.

The homeostatic control of their environment is an essential task of living cells. It has been hypothesized that, when microenvironmental pH inhomogeneities are induced by high cellular metabolic activity, diffusing protons act as signaling molecules, driving the establishment of exchange networks sustained by the cell-to-cell shuttling of overflow products such as lactate. Despite their fundamental role, the extent and dynamics of such networks is largely unknown due to the lack of methods in single-cell flux analysis. In this study, we provide direct experimental characterization of such exchange networks. We devise a method to quantify single-cell fermentation fluxes over time by integrating high-resolution pH microenvironment sensing via ratiometric nanofibers with constraint-based inverse modeling. We apply our method to cell cultures with mixed populations of cancer cells and fibroblasts. We find that the proton trafficking underlying bulk acidification is strongly heterogeneous, with maximal single-cell fluxes exceeding typical values by up to 3 orders of magnitude. In addition, a crossover in time from a networked phase sustained by densely connected "hubs" (corresponding to cells with high activity) to a sparse phase dominated by isolated dipolar motifs (i.e., by pairwise cell-to-cell exchanges) is uncovered, which parallels the time course of bulk acidification. Our method addresses issues ranging from the homeostatic function of proton exchange to the metabolic coupling of cells with different energetic demands, allowing for real-time noninvasive single-cell metabolic flux analysis.

Relationship between fitness and heterogeneity in exponentially growing microbial populations.

Despite major environmental and genetic differences, microbial metabolic networks are known to generate consistent physiological outcomes across vastly different organisms. This remarkable robustness suggests that, at least in bacteria, metabolic activity may be guided by universal principles. The constrained optimization of evolutionarily motivated objective functions, such as the growth rate, has emerged as the key theoretical assumption for the study of bacterial metabolism. While conceptually and practically useful in many situations, the idea that certain functions are optimized is hard to validate in data. Moreover, it is not always clear how optimality can be reconciled with the high degree of single-cell variability observed in experiments within microbial populations. To shed light on these issues, we develop an inverse modeling framework that connects the fitness of a population of cells (represented by the mean single-cell growth rate) to the underlying metabolic variability through the maximum entropy inference of the distribution of metabolic phenotypes from data. While no clear objective function emerges, we find that, as the medium gets richer, the fitness and inferred variability for Escherichia coli populations follow and slowly approach the theoretically optimal bound defined by minimal reduction of variability at given fitness. These results suggest that bacterial metabolism may be crucially shaped by a population-level trade-off between growth and heterogeneity.

The Caged-Ball Prosthesis 60 Years Later: A Historical Review of a Cardiac Surgery Milestone.

Sixty years ago, 2 cardiac operations dramatically influenced the survival of patients with valvular heart disease. The replacement of an aortic valve by Dwight Harken and of a mitral valve by Albert Starr with mechanical caged-ball valves, both in 1960, was a true milestone in the history of cardiac surgery and the beginning of a long journey toward prosthetic valve replacement full of expectations, hopes, and dreams fulfilled. Caged-ball prostheses underwent numerous modifications in design and materials to improve reliability and prevent specific mechanical and thrombogenic complications. Clinical and pathologic experience gained during the past 6 decades has enabled the development of safe, durable, and minimally thrombogenic mechanical prostheses.

Surgery and outcome of infective endocarditis in octogenarians: prospective data from the ESC EORP EURO-ENDO registry.

PURPOSE: High mortality and a limited performance of valvular surgery are typical features of infective endocarditis (IE) in octogenarians, even though surgical treatment is a major determinant of a successful outcome in IE. METHODS: Data from the prospective multicentre ESC EORP EURO-ENDO registry were used to assess the prognostic role of valvular surgery depending on age. RESULTS: As compared to < 80 yo patients, ≥ 80 yo had lower rates of theoretical indication for valvular surgery (49.1% vs. 60.3%, p < 0.001), of surgery performed (37.0% vs. 75.5%, p < 0.001), and a higher in-hospital (25.9% vs. 15.8%, p < 0.001) and 1-year mortality (41.3% vs. 22.2%, p < 0.001). By multivariable analysis, age per se was not predictive of 1-year mortality, but lack of surgical procedures when indicated was strongly predictive (HR 2.98 [2.43-3.66]). By propensity analysis, 304 ≥ 80 yo were matched to 608 < 80 yo patients. Propensity analysis confirmed the lower rate of indication for valvular surgery (51.3% vs. 57.2%, p = 0.031) and of surgery performed (35.3% vs. 68.4%, p < 0.0001) in ≥ 80 yo. Overall mortality remained higher in ≥ 80 yo (in-hospital: HR 1.50[1.06-2.13], p = 0.0210; 1-yr: HR 1.58[1.21-2.05], p = 0.0006), but was not different from that of < 80 yo among those who had surgery (in-hospital: 19.7% vs. 20.0%, p = 0.4236; 1-year: 27.3% vs. 25.5%, p = 0.7176). CONCLUSION: Although mortality rates are consistently higher in ≥ 80 yo patients than in < 80 yo patients in the general population, mortality of surgery in ≥ 80 yo is similar to < 80 yo after matching patients. These results confirm the importance of a better recognition of surgical indication and of an increased performance of surgery in ≥ 80 yo patients.

Surgical revascularization for stable coronary syndrome: the ISCHEMIA trial versus a single-centre matched population-a real-world analysis of patients undergoing surgical revascularization.

OBJECTIVES: The aim of this study was to test if the current general practice of surgical revascularization is comparable to the setting of International Study of Comparative Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial and to evaluate the comparative risk of cardiovascular events or death after coronary artery bypass grafting. METHODS: We selected patients undergoing surgical revascularization and matching ISCHEMIA inclusion criteria. Chronic coronary syndrome patients were included if diagnosis of myocardial ischaemia by functional testing and coronary artery disease at angiography were detected. The primary end point was a composite of cardiovascular death, myocardial infarction, rehospitalization for unstable angina, heart failure and resuscitated cardiac arrest. Secondary end points were death by any cause, cardiovascular death, myocardial infarction and rehospitalization. RESULTS: Among 353 patients, the primary outcome occurred in 62 (17.6%) patients. At 6 months, cumulative event-free survival was 97%, at 1 year 96%, at 5 years 89% and at 10 years 80%. Cumulative risk of the primary composite outcome at 5 years was 11%, 18% in the conservative arm of ISCHEMIA and 16% in the revascularization arm of ISCHEMIA (P < 0.001). Risk of myocardial infarction at 5 years was 7% in surgical patients and 12% and 10% in the conservative and invasive arms of the trial, respectively (P < 0.001). CONCLUSIONS: Long-term results in surgical patients treated for chronic coronary syndromes showed that ISCHEMIA trial findings are not transferable in a 'real-world' scenario and have not changed previous medical practice. A patient-tailored approach, especially with diabetes and reduced left ventricle function, offers the best results in patients with stable coronary artery disease.

Endothelial Progenitor Cells: An Appraisal of Relevant Data from Bench to Bedside.

The mobilization of endothelial progenitor cells (EPCs) into circulation from bone marrow is well known to be present in several clinical settings, including acute coronary syndrome, heart failure, diabetes and peripheral vascular disease. The aim of this review was to explore the current literature focusing on the great opportunity that EPCs can have in terms of regenerative medicine.

Path-integral solution of MacArthur's resource-competition model for large ecosystems with random species-resources couplings.

We solve MacArthur's resource-competition model with random species-resource couplings in the "thermodynamic" limit of infinitely many species and resources using dynamical path integrals à la De Domincis. We analyze how the steady state picture changes upon modifying several parameters, including the degree of heterogeneity of metabolic strategies (encoding the preferences of species) and of maximal resource levels (carrying capacities), and discuss its stability. Ultimately, the scenario obtained by other approaches is recovered by analyzing an effective one-species-one-resource ecosystem that is fully equivalent to the original multi-species one. The technique used here can be applied for the analysis of other model ecosystems related to the version of MacArthur's model considered here.

Initial cell density encodes proliferative potential in cancer cell populations.

Individual cells exhibit specific proliferative responses to changes in microenvironmental conditions. Whether such potential is constrained by the cell density throughout the growth process is however unclear. Here, we identify a theoretical framework that captures how the information encoded in the initial density of cancer cell populations impacts their growth profile. By following the growth of hundreds of populations of cancer cells, we found that the time they need to adapt to the environment decreases as the initial cell density increases. Moreover, the population growth rate shows a maximum at intermediate initial densities. With the support of a mathematical model, we show that the observed interdependence of adaptation time and growth rate is significantly at odds both with standard logistic growth models and with the Monod-like function that governs the dependence of the growth rate on nutrient levels. Our results (i) uncover and quantify a previously unnoticed heterogeneity in the growth dynamics of cancer cell populations; (ii) unveil how population growth may be affected by single-cell adaptation times; (iii) contribute to our understanding of the clinically-observed dependence of the primary and metastatic tumor take rates on the initial density of implanted cancer cells.

Surgical Treatment of Post-Infarction Left Ventricular Free-Wall Rupture: A Multicenter Study.

BACKGROUND: Left ventricular free-wall rupture (LVFWR) is an uncommon but serious mechanical complication of acute myocardial infarction. Surgical repair, though challenging, is the only definitive treatment. Given the rarity of this condition, however, results after surgery are still not well established. The aim of this study was to review a multicenter experience with the surgical management of post-infarction LVFWR and analyze the associated early outcomes. METHODS: Using the CAUTION (Mechanical Complications of Acute Myocardial Infarction: an International Multicenter Cohort Study) database, we identified 140 patients who were surgically treated for post-acute myocardial infarction LVFWR in 15 different centers from 2001 to 2018. The main outcome measured was operative mortality. Multivariate analysis was carried out by constructing a logistic regression model to identify predictors of postoperative mortality. RESULTS: The mean age of patients was 69.4 years. The oozing type of LVFWR was observed in 79 patients (56.4%), and the blowout type in 61 (43.6%). Sutured repair was used in the 61.4% of cases. The operative mortality rate was 36.4%. Low cardiac output syndrome was the main cause of perioperative death. Myocardial rerupture after surgery occurred in 10 patients (7.1%). Multivariable analysis revealed that preoperative left ventricular ejection fraction (P < .001), cardiac arrest at presentation (P = .011), female sex (P = .044), and the need for preoperative extracorporeal life support (P = .003) were independent predictors for operative mortality. CONCLUSIONS: Surgical repair of post-infarction LVFWR carries a high operative mortality. Female sex, preoperative left ventricular ejection fraction, cardiac arrest, and extracorporeal life support are predictors of early mortality.

Use of Pericardium for Cardiac Reconstruction Procedures in Acquired Heart Diseases-A Comprehensive Review.

BACKGROUND: Reconstruction of cardiac structures has been the goal of many surgeons even before the advent of open-heart procedures with cardiopulmonary bypass. Unsatisfactory results with synthetic materials has switched the attention to biological tissues, among which pericardium, either autologous or of animal origin, has been widely used as patch material. METHODS: We have reviewed the literature to assess the effective role of pericardial tissue in the correction of various acquired cardiac lesions. Particularly, special attention was given not only to established techniques but also to detect any peculiar and unusual application of pericardium. RESULTS: Autologous pericardium is frequently used as patch material particularly when limited valvular lesions must be corrected, while xenograft pericardium appears particularly useful in patients with endocarditis and extensive destruction of the intracardiac structures by infection and abscesses. Pericardium is an extremely versatile material owing to its pliability and strength; however, it tends to calcify in the long term when in contact with blood, although stability of the repair is maintained in most cases. CONCLUSIONS: Pericardium plays an important role in various cardiac and aortic pathologies. Tissues resistant to fibrosis and calcification to be used as patch material are the ideal solution for more successful cardiac reconstruction procedures and will hopefully be provided by the ongoing research.

Aortic valve-sparing procedure-a durable choice in liver transplantation recipient.

A 44-year old man with aortic regurgitation and aneurysm of the ascending aorta underwent an aortic valve-sparing procedure as a durable treatment before liver transplantation. Since patients with chronic liver failure are at high risk of hemorrhagic complications at time of major surgery, while management of warfarin administration may still represent a concern, the choice of a cardiac procedure which avoids any anticoagulant treatment appeared justified.