Immediate surgical coronary revascularisation in patients presenting with acute myocardial infarction

Prognostic impact of preoperative atrial fibrillation in patients undergoing heart surgery in cardiogenic shock

Surgical intervention in the setting of cardiogenic shock (CS) is burdened with high mortality. Due to acute condition, detailed diagnoses and risk assessment is often precluded. Atrial fibrillation (AF) is a risk factor for perioperative complications and worse survival but little is known about AF patients operated in CS. Current analysis aimed to determine prognostic impact of preoperative AF in patients undergoing heart surgery in CS. We analyzed data from the Polish National Registry of Cardiac Surgery (KROK) Procedures. Between 2012 and 2021, 332,109 patients underwent cardiac surgery in 37 centers; 4852 (1.5%) patients presented with CS. Of those 624 (13%) patients had AF history. Cox proportional hazards models were used for computations. Propensity score (nearest neighbor) matching for the comparison of patients with and without AF was performed. Median follow-up was 4.6 years (max.10.0), mean age was 62 (± 15) years and 68% patients were men. Thirty-day mortality was 36% (1728 patients). The origin of CS included acute myocardial infarction (1751 patients, 36%), acute aortic dissection (1075 patients, 22%) and valvular dysfunction (610 patients, 13%). In an unadjusted analysis, patients with underlying AF had almost 20% higher mortality risk (HR 1.19, 95% CIs 1.06-1.34; P = 0.004). Propensity score matching returned 597 pairs with similar baseline characteristics; AF remained a significant prognostic factor for worse survival (HR 1.19, 95% CI 1.00-1.40; P = 0.045). Among patients with CS referred for cardiac surgery, history of AF was a significant risk factor for mortality. Role of concomitant AF ablation and/or left atrial appendage occlusion or more aggressive perioperative circulatory support should be addressed in the future.

The timing of surgical revascularisation in acute myocardial infarction: when should we intervene?

INTRODUCTION

Coronary artery bypass grafting (CABG) is a crucial intervention in acute myocardial infarction (AMI), particularly when AMI is not amenable for management with primary percutaneous coronary intervention (PCI). To optimise outcome in these patients, surgical teams must consider a host of predictive factors, with the most prominent being the timing of CABG. Despite numerous studies exploring timing of CABG following AMI in the past, optimal surgical timing remains controversial. The mortality rates vary with timing of CABG, but confounding factors such as age, impaired pulmonary function, renal insufficiency, and poor left ventricular function may contribute to varied outcomes reported.

EVIDENCE ACQUISITON

An electronic literature search of articles that discussed acute myocardial presentation and urgent in-patient or elective CABG was conducted.

EVIDENCE SYNTHESIS

The evidence was synthesised based on each reported article and their outcomes.

CONCLUSIONS

Current literature suggests multiple factors can guide CABG timing including, type of AMI at initial presentation, distinctive pathological status and patient characteristics. Thus, there is a need for large, multi-centre studies to identify optimal CABG timing in complex coronary artery disease or failed PCI in patients with AMI. Future guidelines should emphasise patient cohorts by taking their risk factors into consideration. As such, a need for greater cardiac screening methods and development of scoring systems can aid in the optimisation of CABG timing.

Early and late outcomes of single versus bilateral internal thoracic artery revascularization for patients in critical condition

OBJECTIVE

The optimal surgical approach for critically ill patients with complex coronary disease remains uncertain. We compared outcomes of bilateral internal thoracic artery (BITA) versus single ITA (SITA) revascularization in critical patients.

METHODS

We evaluated 394 consecutive critical patients with multi-vessel disease who underwent CABG during 1996-2001. Outcomes measured were early mortality, strokes, myocardial-infarctions, sternal infections, revisions for bleeding, and late survival. The critical preoperative state was acknowledged concisely by one or more of the following: preoperative ventricular tachycardia/fibrillation, aborted sudden cardiac death, or the need for mechanical ventilation or for preoperative insertion of intra-aortic-balloon counter-pulsation.

RESULTS

During the study period, 193 of our patients who underwent SITA and 201 who underwent BITA were in critical condition. The SITA group was older (mean 68.0 vs. 63.3 years, p = 0.001) and higher proportions were females (28.5% vs. 18.9% p = 0.025), after recent-MI (69.9% vs. 57.2% p = 0.009) and with left-main disease (38.3% vs. 49.3% p = .029); the median logistic EuroSCORE was higher (0.2898 vs. 0.1597, p<0.001). No statistically significant differences were observed between the SITA and BITA groups in 30-day mortality; and in rates of early CVA, MI and sternal infections (13.0% vs. 8.5%, p = 0.148; 4.1% vs. 6.0%, p = 0.49; 6.7% vs. 4.5%, p = 0.32 and 2.1% vs. 2.5%, p>0.99, respectively). Long-term survival (median follow-up of 15 years, interquartile-range: 13.57-15) was better in the BITA group (median 14.39 vs. 9.31± 0.9 years, p = 0.001). Propensity-score matching (132 matched pairs) also yielded similar early outcomes and improved long-term survival (median follow-up of 15 years, interquartile-range: 13.56-15) for the BITA group (median 12.49±1.71 vs. 7.63±0.99 years, p = 0.002). In multivariable analysis, BITA revascularization was found to be a predictor for improved survival (hazard-ratio of 0.419, 95%CI 0.23-0.76, p = 0.004).

CONCLUSIONS

This study demonstrated long-term survival benefit for BITA revascularization in patients in a critical pre-operative state who presented for surgical revascularization.

Impact of Pre-, Intra-and Post-Operative Parameters on In-Hospital Mortality in Patients Undergoing Emergency Coronary Artery Bypass Grafting: A Scarce Single-Center Experience in Resource-Scare Setting

Background

In-hospital mortality after emergency coronary artery bypass grafting (CABG) remains an important issue that has needed considerable attention in recent years as the mortality rate is still high and prevention factors are not yet optimal. Our study presents the first largest cohort of emergency CABG from one large institution in Vietnam with the primary aim of comparing a large variety of pre-, intra-and post-operative parameters between in-hospital mortality patients and in-hospital survival patients and investigate risk factors of in-hospital mortality in patients undergoing emergency CABG.

Methods

We conducted a retrospective evaluation of prospectively collected data in patients undergoing emergency CABG at the Hanoi Heart Hospital (Hanoi, Vietnam) from January 1, 2017, to December 31, 2019. Primary outcome variable was in-hospital mortality.

Results

A total of 71 patients were included in final analysis. The mean age of the cohort was 68.68 years (± 9.28, range 38-86). The mean weight, height and body mass index were 54.35 kg (± 9.17, range 37-77), 158.96 (±7.64, range 145-179) and 21.48 kg/m² (±3.08, range 13.59-30.08), respectively. In-hospital mortality rate was 9.86%. Preoperative risk factors for in-hospital mortality included diabetes, decreased ejection fraction (EF), EF below 30%, cardiogenic shock, elevated systolic pulmonary artery pressure (PAP), elevated NT-ProBNP, and Euroscore II. Without grafting with left internal thoracic artery, and prolonged cardiopulmonary bypass (CPB) time were increased intraoperative factors for in-hospital mortality risk. In-hospital mortality's postoperative risk factors were found to be postextubation respiratory failure requiring mechanical ventilation, ventricular fibrillation, dialysis-requiring acute renal failure, pneumonia, bacterial sepsis, gastrointestinal bleeding, and prolonged mechanical ventilation time. Significant predictors determining in-hospital mortality were known as prolonged CPB time in surgery and postoperative ventricular fibrillation.

Conclusion

Our hospital mortality rate after emergency CABG was relatively high. An optimal preventive strategy in emergency CABG management should target significant factors combined with other previously identified risk factors to reduce in-hospital mortality.

Early surgical myocardial revascularization in non-ST-segment elevation acute coronary syndrome

BACKGROUND

In non-ST-elevation myocardial infarction (NSTEMI) there is no consensus regarding optimal time point for coronary artery bypass grafting (CABG). Recent findings suggest that long-term outcomes are improved in early-revascularized NSTEMI patients. However, it has been stated that early surgery is associated to increased operative risk. In this study, we wanted to elucidate if early CABG in non-ST-elevation acute coronary syndrome can be performed safely.

METHODS

We performed a monocentric-prospective observational study within a 2-year interval. A total of 217 consecutive patients (41 female, age 68.9±10.2, ES II 6.62±8.56) developed NSTEMI and underwent CABG. Patients were divided into two groups according to the time point of coronary artery bypass after symptom onset (group A: <72 h; group B: >72 h). Endpoints included 6-month mortality and incidence of MACE (death, stroke or re-infarction).

RESULTS

There were no differences regarding mortality between both groups (30 days: group A 2.4% vs. group B 3.7%; P=0.592; 6 months: 8.4% vs. 6.0%; P=0.487). Incidence of MACE in the 6-month follow-up was also similar in both groups (group A: 9.6% vs. 9.7%, P=0.982). Regression analysis revealed as independent risk factors for mortality in the entire cohort ES II OR 1.045 (95% CI: 1.004-1.088). ES II remained an independent prognostic factor in group A OR 1.043 (95% CI: 1.003-1.086) and group B OR 1.032 (95% CI: 1.001-1.063).

CONCLUSIONS

Early revascularized patients showed a higher level of illness. However, results of early CABG were comparable to those following delayed revascularization. Moreover, EuroSCORE II was determined as independent risk factors for mortality.

Outcome of Stable Patients With Acute Myocardial Infarction and Coronary Artery Bypass Surgery Within 48 Hours: A Single-Center, Retrospective Experience

BACKGROUND

The optimal timing of coronary artery bypass grafting (CABG) in clinically stable patients with acute myocardial infarction who are unsuitable for percutaneous coronary intervention is unclear. We report our experience with early CABG in these patients.

METHODS AND RESULTS

Between January 2001 and May 2015, 766 patients with ST-segment-elevation myocardial infarction (STEMI, n=305) or non-STEMI (NSTEMI, n=461) not including cardiogenic shock underwent CABG within 48 hours at our department. STEMI patients were younger than non-STEMI patients (age 65 years [range: 58-72] versus 70 years [range: 62-75], P<0.001) with a lower EuroSCORE II (4.12 [range: 2.75-5.81] versus 4.58 [range: 2.80-7.74], P=0.009). STEMI patients had undergone preoperative percutaneous coronary intervention more often (20.3% versus 7.8%, P<0.001). Time to surgery was shorter in STEMI compared with non-STEMI patients (5.0 hours [range: 3.2-8.8] versus 11.7 hours [range: 6.4-22.0], P<0.001). No significant differences concerning arterial graft use (93.8% versus 94.8%, P=0.540) or complete revascularization (87.5% versus 83.4%, P=0.121) were observed. The rate of strokes did not differ between the groups (2.0% versus 3.9%, P=0.134). Thirty-day mortality was lower in STEMI patients (2.7% versus 6.6% P=0.018), especially when CABG was performed within 6 hours (1.8% versus 7.1%, P=0.041). Survival of STEMI and non-STEMI patients was 94% versus 88% after 1 year (P<0.001), 87% versus 73% after 5 years (P<0.001), and 74% versus 57% after 10 years (P<0.001). Independent predictors of 30-day and long-term mortality included preoperatively increased lactate values, age, atrial fibrillation, and reduced left ventricular function.

CONCLUSIONS

Stable STEMI patients showed a lower rate of perioperative complications and better survival compared with non-STEMI patients when CABG was performed within 48 hours.

Optimal Timing of Surgical Revascularization for Myocardial Infarction and Left Ventricular Dysfunction

Background:

The optimal timing of surgical revascularization for patients presenting with ST-segment elevation myocardial infarction (STEMI) and impaired left ventricular function is not well established. This study aimed to examine the timing of surgical revascularization after STEMI in patients with ischemic heart disease and left ventricular dysfunction (LVD) by comparing early and late results.

Methods:

From January 2003 to December 2013, there were 2276 patients undergoing isolated coronary artery bypass grafting (CABG) in our institution. Two hundred and sixty-four (223 male, 41 females) patients with a history of STEMI and LVD were divided into early revascularization (ER, <3 weeks), mid-term revascularization (MR, 3 weeks to 3 months), and late revascularization (LR, >3 months) groups according to the time interval from STEMI to CABG. Mortality and complication rates were compared among the groups by Fisher's exact test. Cox regression analyses were performed to examine the effect of the time interval of surgery on long-term survival.

Results:

No significant differences in 30-day mortality, long-term survival, freedom from all-cause death, and rehospitalization for heart failure existed among the groups (P > 0.05). More patients in the ER group (12.90%) had low cardiac output syndrome than those in the MR (2.89%) and LR (3.05%) groups (P = 0.035). The mean follow-up times were 46.72 ± 30.65, 48.70 ± 32.74, and 43.75 ± 32.43 months, respectively (P = 0.716). Cox regression analyses showed a severe preoperative condition (odds ratio = 7.13, 95% confidence interval 2.05–24.74, P = 0.002) rather than the time interval of CABG (P > 0.05) after myocardial infarction was a risk factor of long-term survival.

Conclusions:

Surgical revascularization for patients with STEMI and LVD can be performed at different times after STEMI with comparable operative mortality and long-term survival. However, ER (<3 weeks) has a higher incidence of postoperative low cardiac output syndrome. A severe preoperative condition rather than the time interval of CABG after STEMI is a risk factor of long-term survival.

[Perioperative risk and mortality after major surgery]

Although anesthesia-associated mortality has been significantly reduced down to 0.00068-0.00082% over the last decades, recent studies have revealed a high perioperative mortality of 0.8- 4%. Apart from anesthesia and surgery-induced major complications, perioperative mortality is primarily negatively influenced by individual patient comorbidities. These risk factors predispose for acute critical incidents (e.g., myocardial infarction); however, the majority of fatal complications are a result of slowly progressing conditions, particularly infections or the sequelae of systemic inflammation. This implicates a broad window of opportunity for the detection and treatment of slow-onset complications to improve the perioperative outcome. The term "failure to rescue" (FTR), i.e., the proportion of patients who die from major complications compared to the number of all patients with complications, has been introduced as a valid indicator for the quality of perioperative care. Growing evidence has already shown that FTR is an underestimated factor in perioperative medicine accounting for or at least being involved in the development of postoperative mortality. While the incidence of severe postoperative complications amazingly does not show much variation between hospitals, FTR shows significant differences implying a major potential for improvement. With 14 million surgical procedures per year in Germany, a postoperative mortality of approximately 1% and an avoidable FTR rate of 40% mean that there are an estimated 60,000 preventable deaths per year. Hence, in the future it will be imperative to (1) identify patients at risk, (2) to prevent the development of postoperative complications with the use of adequate adjunctive therapeutic strategies, (3) to establish surveillance and monitoring systems for the early detection of postoperative complications and (4) to treat postoperative complications efficiently and in time when they arise.

Emergency Coronary Artery Bypass Grafting: Indications and Outcomes from 2003 through 2013

Emergency coronary artery bypass grafting (CABG) is associated with increased in-hospital mortality rates and adverse events. This study retrospectively evaluated indications and outcomes in patients who underwent emergency CABG. The Society of Thoracic Surgeons database for a single center (Jewish Hospital) was queried to identify patients undergoing isolated CABG. Univariate analysis was performed. From January 2003 through December 2013, 5,940 patients underwent CABG; 212 presented with emergency status. A high proportion of female patients (28.2%) underwent emergency surgery. Emergency CABG patients experienced high rates of intra-aortic balloon pump support, bleeding, dialysis, in-hospital death, and prolonged length of stay. The proportion of emergency coronary artery bypass grafting declined during years 2008-2013 compared with 2003-2007 (2.2% vs. 4.5%, P < 0.001), but the incidence of angiographic accident (5.3% vs. 29.2%) increased as an indication. Ongoing ischemia remains the most frequent indication for emergency CABG, yet the incidence of angiographic accident has greatly increased. In-hospital mortality rates and adverse events remain high. If we look specifically at emergency CABG cases arising from angiographic accident, we find that 14 (15%) of all 93 emergency CABG deaths occurred in that subset of patients. Efforts to improve outcomes should therefore be focused on this high-risk group.

Clinical Characteristics and Outcomes of Patients With Myocardial Infarction and Cardiogenic Shock Undergoing Coronary Artery Bypass Surgery: Data From The Society of Thoracic Surgeons National Database

BACKGROUND

Acute myocardial infarction complicated by cardiogenic shock (AMI-CS) is associated with substantial mortality. We evaluated outcomes of patients in The Society of Thoracic Surgeons Adult Cardiac Surgery Database who underwent coronary artery bypass graft surgery (CABG) in the setting of AMI-CS.

METHODS

All patients with AMI-CS who underwent nonelective CABG or CABG with ventricular assist device implantation within 7 days after myocardial infarction were enrolled. The primary analysis sample consisted of patients who underwent surgery between June 2011 and December 2013. Baseline characteristics, operative findings, outcomes, and the utilization of mechanical circulatory support (MCS) were assessed in detail in this population. We also evaluated trends in unadjusted mortality for all patients undergoing CABG or CABG with ventricular assist device for AMI-CS from January 2005 to December 2013.

RESULTS

A total of 5,496 patients met study criteria, comprising 1.5% of all patients undergoing CABG during the study period. Overall operative mortality was 18.7%, decreasing from 19.3% in 2005 to 18.1% in 2013 (p < 0.001). Use of MCS increased from 5.8% in 2011 to 8.8% in 2013 (p = 0.008). Patients receiving MCS had a high proportion of cardiovascular risk factors or high clinical acuity. Patients requiring preoperative and patients requiring intraoperative or postoperative MCS had operative mortality of 37.2% and 58.4%, respectively. Patients undergoing CABG as a salvage procedure had an operative mortality of 53.3%, and a high incidence of reoperation (21.8%), postoperative respiratory failure requiring prolonged ventilation (59.7%), and renal failure (18.5%).

CONCLUSIONS

Most patients undergoing CABG for AMI-CS have a sizeable but not prohibitive risk. Patients who require MCS and those undergoing operation as a salvage procedure reflect higher risk populations.

Impact of prasugrel pretreatment and timing of coronary artery bypass grafting on clinical outcomes of patients with non-ST-segment elevation myocardial infarction: From the A Comparison of Prasugrel at PCI or Time of Diagnosis of Non-ST-Elevation Myocardial Infarction (ACCOAST) study

OBJECTIVES

We evaluated impact of timing of coronary artery bypass grafting (CABG) and prasugrel pretreatment in patients with non-ST-segment elevation myocardial infarction undergoing CABG in the ACCOAST study.

METHODS

Of 4033 enrolled patients, 314 (7.8%) underwent isolated CABG through 30 days. Primary efficacy end point for this analysis was any cardiovascular death, myocardial infarction, stroke, urgent revascularization, or glycoprotein IIb/IIIa inhibitor bailout through 30 days.

RESULTS

More CABG versus percutaneous coronary intervention or medically managed patients were men, diabetic, or had peripheral arterial disease. Per randomization, 157 of 314 patients received a 30-mg prasugrel loading dose before CABG, and 157 of 314 received placebo. Patients were stratified by tertile of time from randomization to CABG: <2.98 days (n = 104), ≥2.98 and <6.95 days (n = 106), and ≥6.95 days (n = 104). Primary end point occurred in 12.5%, 4.7%, and 4.8%, respectively (<2.98 days vs other tertiles, hazard ratio [HR] = 2.80; P = .011). Similarly, the rate of all TIMI major bleeding was highest in the lowest tertile (26.0% vs 10.4% and 4.8%; P < .001), but no difference in all-cause death was observed through 30 days (3.9% vs 1.9% and 1.9%; P = .30). Time from randomization to CABG (HR = 0.84 for each day delay), left main disease (HR = 1.76), region of enrollment (Non-Eastern Europe vs Eastern Europe; HR = 3.83), but not prasugrel pretreatment and baseline troponin ≥3× upper limit of normal, were independent predictors of combined 30-day end point of all-cause death/myocardial infarction/stroke/TIMI major bleeding.

CONCLUSIONS

In ACCOAST, early (<2.98 days) surgical revascularization carried increased risk of bleeding and ischemic complications without affecting all-cause mortality through 30 days. Baseline troponin and prasugrel pretreatment did not impact ischemic clinical outcomes.

Admission hyperglycemia is associated with poor outcome after emergent coronary bypass grafting surgery

PURPOSE

Hyperglycemia during or after cardiac surgery is a common finding that is associated with poor outcome. Very few data, however, are available regarding a correlation between admission blood glucose and outcomes after coronary artery bypass grafting (CABG). Thus, the goal of the current study was to examine the relationship between admission blood glucose and outcome after emergency CABG surgery.

MATERIALS AND METHODS

A retrospective analysis to evaluate whether admission hyperglycemia associated with increased morbidity or mortality was performed in patients after emergency CABG surgery. The records of all the patients undergoing emergency CABG surgery between January 1999 and December 2010 at the University of Virginia Health System were reviewed. Postoperative in-hospital mortality and complications were considered as study end points.

RESULTS

A total of 240 patients met the final inclusion criteria. Overall mortality was 14.1%. The median admission blood glucose in patients who died 7.4 (interquartile range, 5.9-10.1) mmol/L was significantly higher compared with survivors 6.1 (interquartile range, 5.4-7.2; P<.01). Furthermore, 59% of the patients who died had admission blood glucose levels higher than 6.6 mmol/L, whereas only 35% of the patients who survived had similar blood glucose levels (P=.01). On multivariable analysis, admission blood glucose was identified as an independent risk factor for death after emergency CABG (P=.01; odds ratio, 1.16; 95% confidence interval, 1.04-1.29). Admission blood glucose was further identified as independently associated with increased risk for a composite outcome of death, postoperative renal failure or stroke (P=.01; odds ratio, 1.14; 95% confidence interval, 1.03-1.27).

CONCLUSIONS

Our study shows for the first time that admission blood glucose is correlated with increased morbidity and mortality among patients undergoing emergency CABG surgery.

An experimental model of myocardial infarction and controlled reperfusion using a miniaturized cardiopulmonary bypass in rats

OBJECTIVES

Different revascularization strategies for patients with acute myocardial infarction (AMI) exist. It remains unclear whether ventricular unloading using cardiopulmonary bypass (CPB) or extracorporeal life support (ECLS) has an impact on early postischaemic ventricular function. Here, we report on the results of an approach using a miniaturized CPB in a well-established animal model of AMI.

METHODS

In a randomized fashion, 30 male Wistar rats were assigned to temporary left anterior descending (LAD) ligation (30 min) followed by 180 min of reperfusion either with or without 60 min of CPB (70 ml/min, 36°C). The CPB circuit consisted of a venous reservoir, a peristaltic roller pump and a membrane oxygenator with heat exchanger. Cardiac function was measured at 60 and 120 min after reperfusion (F60, F120) using a conductance catheter.

RESULTS

The mortality rate was 37% (11/30). Thus, 19 animals could be included into the analysis (8 CPB). The mean cardiac output did not differ between the groups at F60 [63 ± 29 vs 54 ± 25 ml/min (CPB), P = 0.56] and F120 [73 ± 27 vs 53 ± 24 ml/min (CPB), P = 0.21]. During reperfusion, the mean left ventricular ejection fraction (LVEF) was stable in both the control (F60 37 ± 5% vs F120 33 ± 8%, P = 0.42) and the CPB groups (F60 52 ± 11% vs F120 51 ± 13%, P = 0.71). CPB animals had a significantly better LVEF after reperfusion (F60 P = 0.007, F120 P = 0.01).

CONCLUSIONS

In this animal model of AMI, the establishment of CPB resulted in a significantly better LVEF in comparison with conventional reperfusion only. This beneficial effect may have an impact on revascularization strategies and timing in patients presenting with AMI in the future.

Directed cardiomyogenesis of autologous human induced pluripotent stem cells recruited to infarcted myocardium with bioengineered antibodies

OBJECTIVE

Myocardial infarctions constitute a major factor contributing to non-natural mortality world-wide. Clinical trials of myocardial regenerative therapy, currently pursued by cardiac surgeons, involve administration of stem cells into the hearts of patients suffering from myocardial infarctions. Unfortunately, surgical acquisition of these cells from bone marrow or heart is traumatic, retention of these cells to sites of therapeutic interventions is low, and directed differentiation of these cells in situ into cardiomyocytes is difficult. The specific aims of this work were: (1) to generate autologous, human, pluripotent, induced stem cells (ahiPSCs) from the peripheral blood of the patients suffering myocardial infarctions; (2) to bioengineer heterospecific antibodies (htAbs) and use them for recruitment of the ahiPSCs to infarcted myocardium; (3) to initiate in situ directed cardiomyogenesis of the ahiPSCs retained to infarcted myocardium.

METHODS

Peripheral blood was drawn from six patients scheduled for heart transplants. Mononuclear cells were isolated and reprogrammed, with plasmids carrying six genes (NANOG, POU5F1, SOX2, KLF4, LIN28A, MYC), to yield the ahiPSCs. Cardiac tissues were excised from the injured hearts of the patients, who received transplants during orthotopic surgery. These tissues were used to prepare in vitro models of stem cell therapy of infarcted myocardium. The htAbs were bioengineered, which simultaneously targeted receptors displayed on pluripotent stem cells (SSEA-4, SSEA-3, TRA-1-60, TRA-1-81) and proteins of myocardial sarcomeres (myosin, α-actinin, actin, titin). They were used to bridge the ahiPSCs to the infarcted myocardium. The retained ahiPSCs were directed with bone morphogenetic proteins and nicotinamides to differentiate towards myocardial lineage.

RESULTS

The patients' mononuclear cells were efficiently reprogrammed into the ahiPSCs. These ahiPSCs were administered to infarcted myocardium in in vitro models. They were recruited to and retained at the treated myocardium with higher efficacy and specificity, if were preceded with the htAbs, than with isotype antibodies or plain buffers. The retained cells differentiated into cardiomyocytes.

CONCLUSIONS

The proof of concept has been attained, for reprogramming the patients' blood mononuclear cells (PBMCs) into the ahiPSCs, recruiting these cells to infarcted myocardium, and initiating their cardiomyogenesis. This novel strategy is ready to support the ongoing clinical trials aimed at regeneration of infarcted myocardium.

Directed cardiomyogenesis of autologous human induced pluripotent stem cells recruited to infarcted myocardium with bioengineered antibodies

Objective

Myocardial infarctions constitute a major factor contributing to non-natural mortality world-wide. Clinical trials ofmyocardial regenerative therapy, currently pursued by cardiac surgeons, involve administration of stem cells into the hearts of patients suffering from myocardial infarctions. Unfortunately, surgical acquisition of these cells from bone marrow or heart is traumatic, retention of these cells to sites of therapeutic interventions is low, and directed differentiation of these cells in situ into cardiomyocytes is difficult. The specific aims of this work were: (1) to generate autologous, human, pluripotent, induced stem cells (ahiPSCs) from the peripheral blood of the patients suffering myocardial infarctions; (2) to bioengineer heterospecific tetravalent antibodies (htAbs) and use them for recruitment of the ahiPSCs to infarcted myocardium; (3) to initiate in situ directed cardiomyogenesis of the ahiPSCs retained to infarcted myocardium.

Methods

Peripheral blood was drawn from six patients scheduled for heart transplants. Mononuclear cells were isolated and reprogrammed, with plasmids carrying six genes (NANOG, POU5F1, SOX2, KLF4, LIN28A, MYC), to yield the ahiPSCs. Cardiac tissues were excised from the injured hearts of the patients, who received transplants during orthotopic surgery. These tissues were used to prepare in vitro model of stem cell therapy of infarcted myocardium. The htAbs were bioengineered, which simultaneously targeted receptors displayed on pluripotent stem cells (SSEA-4, SSEA-3, TRA-1-60, TRA-1-81) and proteins of myocardial sarcomeres (myosin, α-actinin, actin, titin). They were used to bridge the ahiPSCs to the infarcted myocardium. The retained ahiPSCs were directed with bone morphogenetic proteins and nicotinamides to differentiate towards myocardial lineage.

Results

The patients’ mononuclear cells were efficiently reprogrammed into the ahiPSCs. These ahiPSCs were administered to infarcted myocardium in in vitro models. They were recruited to and retained at the treated myocardium with higher efficacy and specificity, if were preceded the htAbs, than with isotype antibodies or plain buffers. The retained cells differentiated into cardiomyocytes.

Conclusions

The proof of concept has been attained, for reprogramming the patients’ blood mononuclear cells (PBMCs) into the ahiPSCs, recruiting these cells to infarcted myocardium, and initiating their cardiomyogenesis. This novel strategy is ready to support the ongoing clinical trials aimed at regeneration of infarcted myocardium.

Percutaneous extracorporeal life support for patients in therapy refractory cardiogenic shock: initial results of an interdisciplinary team

OBJECTIVES

Therapy refractory cardiogenic shock is associated with dismal outcome. Percutaneous implantation of an extracorporeal life support (ECLS) system achieves immediate cardiopulmonary stabilization, sufficient end-organ perfusion and reduction of subsequent multiorgan failure (MOF).

METHODS

Forty-one patients undergoing percutaneous ECLS implantation for cardiogenic shock from February 2012 until August 2013 were retrospectively analysed. Mean age was 52 ± 13 years, 6 (15%) were female. Mean pH values obtained before ECLS implantation were 7.15 ± 0.24, mean lactate concentration was 11.7 ± 6.4 mmol/l. Levels obtained 6 h after ECLS implantation were 7.30 ± 0.14 and 8.7 ± 5.0 mmol/l, respectively. In 23 patients (56%) cardiogenic shock resulted from an acute coronary syndrome in 13 (32%) from cardiomyopathy, in 5 (12%) from other causes. Twenty-seven (66%) had been resuscitated, in 14 (34%) implantation was performed under ongoing cardiopulmonary resuscitation (CPR). Of note, 97% of the acute coronary syndrome patients underwent percutaneous coronary intervention (PCI) either before ECLS implantation or under ECLS support. Extracorporeal life support implantation was performed on scene (Emergency Department, Cath Lab, Intensive Care Unit) by a senior cardiac surgeon and a trained perfusionist, in 8 cases (20%) in the referring hospital.

RESULTS

Thirty-day mortality was 51% [21 patients, due to MOF (n = 14), cerebral complications (n = 6) and heart failure (n = 1)]. Logistic regression analysis identified 6-h pH values as an independent risk factor of 30-day mortality (P < 0.001, OR = 0.000, 95% CI 0.000-0.042). Neither CPR nor implantation under ongoing CPR resulted in significant differences. In 26 cases (63%), the ECLS system could be explanted, after mean support of 169 ± 67 h. Seven of these patients received cardiac surgery [ventricular assist device implantation (n = 4), heart transplantation (n = 1), other procedures (n = 2)].

CONCLUSIONS

Due to the evolution of transportable ECLS systems and percutaneous techniques implantation on scene is feasible. Extracorporeal life support may serve as a bridge-to-decision and bridge-to-treatment device. Neurological evaluation before ventricular assist device implantation and PCI under stable conditions are possible. Despite substantial mortality, ECLS implantation in selected patients by an experienced team offers additional support to conventional therapy as well as CPR and allows survival in patients that otherwise most likely would have died. This concept has to be implemented in cardiac survival networks in the future.