Regional anaesthesia via parasternal catheters inserted preoperatively and postoperative delirium after cardiac surgery: A prospective unrandomised clinical trial

VISUAL ABSTRACT

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Endovascular retrieval of a migrated contraceptive implant into the pulmonary artery : case report and review of literature

BACKGROUND

The migration of contraceptive devices into pulmonary arteries is extremely rare, reported to be 1 in 100,000.

CASE PRESENTATION

A 19-year-old female presented no sensation of a contraceptive implant in her arm which had been placed one year prior. A CT scan confirmed that the implant had migrated into the left lower segmentary pulmonary artery. After a multidisciplinary meeting, an endovascular approach was attempted. Following right femoral venous access, a 8F NeuronMax® introducer was placed into the left pulmonary artery under fluoroscopic guidance. The contraceptive device was removed using a 25-mm loop snare, with a proximal capture technique. The patient was discharged the following day, with no reported complications.

CONCLUSION

In cases of contraceptive device migration, the first medical decision involves deciding between removal or 'watching and waiting'. Previous reports describe two removal options: endovascular or surgical approaches. Fourteen reports have been published, with high technical success and low rates of complications. The loop snare technique is described as the optimal technique for an endovascular approach. Due to their invasive nature, surgical approaches should be reserved for cases of endovascular removal failure, after evaluating risks and benefits.

Factors Influencing Unfractionated Heparin Pharmacokinetics and Pharmacodynamics During a Cardiopulmonary Bypass

BACKGROUND

Unfractionated heparin (UFH) is commonly used during cardiac surgery with a cardiopulmonary bypass to prevent blood clotting. However, empirical administration of UFH leads to variable responses. Pharmacokinetic and pharmacodynamic modeling can be used to optimize UFH dosing and perform real-time individualization. In previous studies, many factors that could influence UFH pharmacokinetics/pharmacodynamics had not been taken into account such as hemodilution or the type of UFH. Few covariates were identified probably owing to a lack of statistical power. This study aims to address these limitations through a meta-analysis of individual data from two studies.

METHODS

An individual patient data meta-analysis was conducted using data from two single-center prospective observational studies, where different UFH types were used for anticoagulation. A pharmacodynamic/pharmacodynamic model of UFH was developed using a non-linear mixed-effects approach. Time-varying covariates such as hemodilution and fluid infusions during a cardiopulmonary bypass were considered.

RESULTS

Activities of UFH's anti-activated factor/anti-thrombin were best described by a two-compartment model. Unfractionated heparin clearance was influenced by body weight and the specific UFH type. Volume of distribution was influenced by body weight and pre-operative fibrinogen levels. Pharmacodynamic data followed a log-linear model, accounting for the effect of hemodilution and the pre-operative fibrinogen level. Equations were derived from the model to personalize UFH dosing based on the targeted activated clotting time level and patient covariates.

CONCLUSIONS

The population model effectively characterized UFH's pharmacokinetics/pharmacodynamics in cardiopulmonary bypass patients. This meta-analysis incorporated new covariates related to UFH's pharmacokinetics/pharmacodynamics, enabling personalized dosing regimens. The proposed model holds potential for individualization using a Bayesian estimation.

Rapid-deployment aortic valve replacement in high-risk patients: A case-control study

Introduction: Aortic valve stenosis is the most frequent cardiac valve pathology in the western world. In high-risk patients, conventional aortic valve replacement (C-AVR) carries high rates of morbidity and mortality. In the last few years, rapid-deployment valves (RDV) have been developed to reduce the surgical risks. In this work, we aimed to compare the mid-term outcomes of rapid-deployment AVR (RD-AVR) with those of the C-AVR in high-risk patients.

Methods: This retrospective case-control study identified 23 high-risk patients who underwent RD-AVR between 12/2015 to 01/2018. The study group was compared with a control group of 46 patients who were retrospectively selected from a database of 687 C-AVR patients from 2016 to 2017 which matched with the study group for age and Euro SCORE II.

Results: RD-AVR group presented more cardiovascular risk factors. Euro SCORE II was higher in the RD-AVR group (P =0.06). In the RD-AVR group, we observed significantly higher mean prosthetic size (P <0.001). In-hospital mortality was zero in RD-AVR group versus 2 deaths in C-AVR group. Hospital stay was longer in the RD-AVR group with statistical significance (P =0.03). In the group AVR with associated cardiac procedures, while comparing subgroups RD-AVR versus C-AVR, early mean gradient was lower in the first cited (P =0.02). The overall mean follow-up was 10.9 ± 4.3 months.

Conclusion: The RD-AVR technique is reliable and lead to positive outcomes. This procedure provides a much larger size with certainly better flow through the aortic root. It is an alternative to C-AVR in patients recognized to be surgically fragile.

Inaugural experience and early results of minimally invasive approach in cardiac surgery in Auvergne region, France

Introduction: Minimally invasive approach in cardiac surgery has become an established and common technique in many cardiac surgery centres throughout the world. We report how we safely introduced minimally invasive approach in cardiac surgery in our department and we aim to demonstrate that this approach is feasible in any medium-size cardiac surgical centre.

Methods: it consisted of retrospective and descriptive study on 60 patients who underwent minimally invasive mitral valve (45) or aortic valve surgery (15) from January 2017 to Februry 2018. The approach was 3 to 6-cm right thoracotomy through the 4th and 5th intercostal space. The Cor-KnotTM system was used to tie the knots of the prosthesis in case of mitral valve replacement and aortic valve replacement and the ring if mitral valve repair.

Results: There was no conversion of thoracotomy to sternotomy. The average duration in ICU was 4.3± 2.3 days and 3.3 ± 1.5 respectively for mitral and aortic valve surgery. Four mitral patients and 1 aortic patient were reoperated for bleeding. No in-hospital death was observed. The postoperative discharge echocardiogram was normal in 95.6% of the mitral valve patients the trans-aortic mean gradient for the aortic valve patients was 16.3 ± 6 mm Hg. The thirty-day mortality was zero. In the majority of the patients, the scar of the thoracotomy were almost unseen.

Conclusion: It is possible to safely implement this new approach in any mid-size cardiac centers. The use of modern technology such as 3D video and Cor Knot allows achievement of excellent short term outcomes.

A procedure to extract functional isolated mitochondria from small-sized human atrial samples. Application to obesity with a partial characterisation of the organelles

Evaluating the activity of cardiac mitochondria is probably the best way to estimate early cellular damage in chronic pathology. Early diagnosis allows rapid therapeutic intervention thus increasing patient survival rate in a number of diseases. However, data on human cardiac mitochondria are scarce in the international literature. Here, we describe a method to extract and study functional mitochondria from the small-sized right atrial aliquots (minimum of 400 mg) obtained during extracorporeal circulation and usually considered as surgical waste products. The mitochondria were purified through several mechanical processes (fine myocardial cutting, tissue grinding and potter Elvehjem homogenising), an enzymatic proteolytic action (subtilisin) and differential centrifugations. In chronic pathologies, including obesity, early disturbances of mitochondrial function can occur. The effects of obesity on the rate of mitochondrial oxygen consumption and H₂O₂ release were thus determined with three different substrates (glutamate/malate, succinate/rotenone and palmitoylcarnitine/malate). The human atrial mitochondria were of high quality from a functional viewpoint, compared to rat ventricle organelles, but the extraction yield of the human mitochondria was twice lower than that of rat mitochondria. Tests showed that glutamate/malate-related ADP-stimulated respiration was strongly increased in obese subjects, although the oxidation of the other two substrates was unaffected. Reactive oxygen species (ROS) production by the isolated mitochondria was low in comparison with that of the lean subjects. These results confirm those found in one of our previous studies in the ventricles of rats fed a high-fat diet. In conclusion, the described method is simple, reliable and sensitive. It allows for the description of the impact of obesity on the function of atrial mitochondria while using only a small patient sampling (n = 5 in both the lean and the obese groups).

Dietary EPA Increases Rat Mortality in Diabetes Mellitus, A Phenomenon Which Is Compensated by Green Tea Extract

Diabetes is characterized by a high mortality rate which is often associated with heart failure. Green tea and eicosapentaenoic acid (EPA) are known to lessen some of the harmful impacts of diabetes and to exert cardio-protection. The aim of the study was to determine the effects of EPA, green tea extract (GTE), and a combination of both on the cardiac consequences of diabetes mellitus, induced in Wistar rats by injection of a low dose of streptozotocin (33 mg/kg) combined with a high fat diet. Cardiac mechanical function, coronary reactivity, and parameters of oxidative stress, inflammation, and energy metabolism were evaluated. In the context of diabetes, GTE alone limited several diabetes-related symptoms such as inflammation. It also slightly improved coronary reactivity and considerably enhanced lipid metabolism. EPA alone caused the rapid death of the animals, but this effect was negated by the addition of GTE in the diet. EPA and GTE combined enhanced coronary reactivity considerably more than GTE alone. In a context of significant oxidative stress such as during diabetes mellitus, EPA enrichment constitutes a risk factor for animal survival. It is essential to associate it with the antioxidants contained in GTE in order to decrease mortality rate and preserve cardiac function.

Evolution of chronic kidney disease after surgical aortic valve replacement or transcatheter aortic valve implantation

BACKGROUND

Immediate improvement in kidney function has been reported after surgical aortic valve replacement or transcatheter aortic valve implantation. Long-term data, however, are not available.

AIM

To assess the evolution of kidney function in chronic kidney disease stage 3b-5, 1 year after surgical aortic valve replacement or transcatheter aortic valve implantation.

METHODS

All patients with chronic kidney disease stage 3b-5 undergoing surgical aortic valve replacement or transcatheter aortic valve implantation for aortic stenosis in a single centre were included. Kidney function was assessed 1 year postprocedure. Improvement or deterioration in estimated glomerular filtration rate was defined by an increase or decrease of 5mL/min/1.73 m², respectively.

RESULTS

Overall, 127 procedures were analysed (54 surgical aortic valve replacements and 73 transcatheter aortic valve implantations). Kidney function improved in 51% of patients at 1 year (45% of the surgical aortic valve replacement group versus 57% of the transcatheter aortic valve implantation group; P=0.21), and deteriorated in only 14% of patients at 1 year (18% of the surgical aortic valve replacement group versus 10% of the transcatheter aortic valve implantation group; P=0.22). Almost a quarter of patients (23%) had an improvement in estimated glomerular filtration rate of>15mL/min/1.73 m², and this was consistent at later follow-up. Few patients went onto chronic dialysis at 1 year (three after surgical aortic valve replacement and one after transcatheter aortic valve implantation). Acute kidney injury was an independent prognostic factor for long-term deterioration in kidney function (odds ratio 2.1, 95% confidence interval 1.4-3.6; P=0.006).

CONCLUSION

Aortic valve replacement, whether by surgical aortic valve replacement or transcatheter aortic valve implantation, improved estimated glomerular filtration rate at 1 year in more than half of patients with chronic kidney disease stage 3b-5.

Indications and perioperative outcomes of extracorporeal life support in clermont-ferrand

Objectives

To report the epidemiological profile of the patients who underwent extracorporeal life support (ECLS) and then analyze the indications and outcomes of this procedure.

Methods

It consisted of a retrospective and descriptive study based on the database from the department of cardiovascular surgery.

Setting

University hospital clinic.

Patients

One hundred and sixty-one patients have participated in the study. Included were all patients who presented with left-sided heart or biventricular failure. Those who were suffering from either isolate respiratory failure or isolate right ventricle failure were excluded.

Interventions

Participants underwent ECLS: central ECLS or peripheral ECLS.

Results

: The mean age of the patients was 54 years; there were 73% of male patients and the mean duration of ECLS was 5.3 days. There were two types of ECLS: central (71%) and peripheral (29%). Indications for support were dominated by cardiogenic shock in 69%. Bleeding was the most frequent complication (23.5%). The overall in-hospital mortality of patients who underwent ECLS was 60%.

Conclusion

The number of ECLS performed increases in proportion to mastery of surgical technique. There is a high rate of mortality and morbidity with ECLS. However, it remains a lifesaving therapy for many clinically urgent situations.

Bicuspid and tricuspid aortic valve do not have the same ascending aorta morphology

Bicuspid aortic valves are associated with histopathological abnormalities of the aorta. Their diameters have been measured in several studies, but the literature concerning changes in the overall anatomy of the ascending aorta is limited. We wanted to know whether the anatomy of the valve, bicuspid or tricuspid, is associated with anatomical differences. We prospectively included patients requiring aortic valve surgery. The protocol included a chest CT scan before the operation to determine the angulations and straight lengths of aortic segments 0 and 1. All of the patients underwent surgery to assess their aortic valve morphology. We included 107 patients, 25 (23%) with bicuspid diagnostic valves and 82 (77%) with tricuspid ones. Most angulations were similar between the groups. However, the angle between the ring and the plane of the top of the commissures of the semilunar cusps was lower in bicuspid than tricuspid aortic valves. The straight lengths in the aortic root did not differ significantly, but the lengths separating these planes from the BCAT plane were consistently greater in the bicuspid group. The angle between the ring plane and the patient's vertical axis was lower in the bicuspid, the plane of the ring being verticalized in this group. In conclusion, we were able to confirm significant morphological differences in addition to the diameters. However, this study does not establish causal relationships among valve morphology, ascending aortic morphology, histology, and possibly associated pathologies. An extremely large cohort will be required indicate such causal connections. Clin. Anat. 31:693-697, 2018. © 2018 Wiley Periodicals, Inc.

Early sepsis does not stimulate reactive oxygen species production and does not reduce cardiac function despite an increased inflammation status

If it is sustained for several days, sepsis can trigger severe abnormalities of cardiac function which leads to death in 50% of cases. This probably occurs through activation of toll-like receptor-9 by bacterial lipopolysaccharides and overproduction of proinflammatory cytokines such as TNF-α and IL-1β In contrast, early sepsis is characterized by the development of tachycardia. This study aimed at determining the early changes in the cardiac function during sepsis and at finding the mechanism responsible for the observed changes. Sixty male Wistar rats were randomly assigned to two groups, the first one being made septic by cecal ligation and puncture (sepsis group) and the second one being subjected to the same surgery without cecal ligation and puncture (sham-operated group). The cardiac function was assessed in vivo and ex vivo in standard conditions. Several parameters involved in the oxidative stress and inflammation were determined in the plasma and heart. As evidenced by the plasma level of TNF-α and gene expression of IL-1β and TNF-α in the heart, inflammation was developed in the sepsis group. The cardiac function was also slightly stimulated by sepsis in the in vivo and ex vivo situations. This was associated with unchanged levels of oxidative stress, but several parameters indicated a lower cardiac production of reactive oxygen species in the septic group. In conclusion, despite the development of inflammation, early sepsis did not increase reactive oxygen species production and did not reduce myocardial function. The depressant effect of TNF-α and IL-1β on the cardiac function is known to occur at very high concentrations. The influence of low- to moderate-grade inflammation on the myocardial mechanical behavior must thus be revisited.

Surgical treatment of a pericardio-oesophageal fistula using a right lower lobe pulmonary tissue patch

A 58-year-old man presented with fever and chest pain 11 days after atrial fibrillation catheter ablation. The diagnosis of pericardio-oesophageal fistula was made. Aggressive surgical management was decided. The patient was managed using extracorporeal life support, aortic valve replacement and a pulmonary patch, as well as an oesophageal stent. The patient was discharged from hospital approximately 2 months later. The use of a pulmonary patch is a rare but a highly effective technique that can be used in this indication.

Valve-sparing aortic root replacement-midterm outcomes and quality of life

Background

This study evaluated the midterm outcomes, the valve related events and quality of life of patients treated by valve-sparing aortic root replacement (VSRR).

Methods

From January 2003 to December 2014, 88 consecutive patients diagnosed with an aortic root aneurysm or ascending aortic aneurysms underwent VSRR surgery. The mean age was 55±14 (range 19-77) years. A total of 84% of the patients were male; 89% were in New York Heart Association functional class I or II, 55% had aortic regurgitation (AR) grade III or IV. Twenty-four patients (27.3%) had bicuspid aortic valve. The mean left ventricular ejection fraction (LVEF) was 61%±9% (range 29-78%). Patients were yearly followed by family doctors and referent cardiologists. Doppler echocardiographic examinations were obtained annually in all patients. The midterm clinical, echocardiographic results and quality of life were analyzed. The mean follow-up was 5.3±3 (range 1-12) years.

Results

Hospital mortality was 1%. There were 10 late deaths (11%) including 5 cardiac cases. Two patients (2%) required an aortic valve or graft prosthesis reoperation. Aortic valve endocarditis occurred in two patients. Thromboembolic events were reported in three patients. None of the following morbidity has been observed: structural valve deterioration, nonstructural dysfunction, valve thrombosis, bleeding event. The 5- and 8-year survival were 92% and 88%, respectively. The 8-year survival free from cardiac death was 88%. The mean of EuroQoL visual analogue scale (EQ VAS) and EQ index were respectively 83±15 (range 30-100) and 0.94±0.12 (range 0.5-1).

Conclusions

Eight-year clinical improvement, function of the spared aortic valve and quality of life after valve sparing aortic root surgery appear excellent.

Clinical outcomes of tricuspid valve repair accompanying left-sided heart disease

AIM

To determine whether the need for additional tricuspid valve repair is an independent risk factor when surgery is required for a left-sided heart disease.

METHODS

One hundred and eighty patients (68 ± 12 years, 79 males) underwent tricuspid annuoplasty. Cox proportional-hazards regression model for multivariate analysis was performed for variables found significant in univariate analyses.

RESULTS

Tricuspid regurgitation etiology was functional in 154 cases (86%), organic in 16 cases (9%), and mixed in 10 cases (6%), respectively. Postoperative mortality at 30 days was 11.7%. Mean follow-up was 51.7 mo with survival at 5 years of 73.5%. Risk factors for mortality were acute endocarditis [hazard ratio (HR) = 9.22 (95%CI: 2.87-29.62), P < 0.001], ischemic heart disease requiring myocardial revascularization [HR = 2.79 (1.26-6.20), P = 0.012], and aortic valve stenosis [HR = 2.6 (1.15-5.85), P = 0.021]. Significant predictive factors from univariate analyses were double-valve replacement combined with tricuspid annuloplasty [HR = 2.21 (1.11-4.39), P = 0.003] and preoperatively impaired ejection fraction [HR = 1.98 (1.04-3.92), P = 0.044]. However, successful mitral valve repair showed a protective effect [HR = 0.32 (0.10-0.98), P = 0.046]. Additionally, in instances where tricuspid regurgitation required the need for concomitant tricuspid valve repair, mortality predictor scores such as Euroscore 2 could be shortened to a simple Euroscore-tricuspid comprised of only 7 inputs. The explanation may lie in the fact that significant tricuspid regurgitation following left-sided heart disease represents an independent risk factor encompassing several other factors such as pulmonary arterial hypertension and dyspnea.

CONCLUSION

Tricuspid annuloplasty should be used more often as a concomitant procedure in the presence of relevant tricuspid regurgitation, although it usually reveals an overly delayed correction of a left-sided heart disease.

The apex of the aortic arch backshifts with aging

BACKGROUND

Only a few studies, involving small numbers of patients, have globally assessed the curvature of the thoracic aorta but without any details concerning the location of the supra-aortic trunks.

OBJECTIVES

Using CT to describe normal aortic-arch morphology and its changes with age and sex.

METHODS

344 CT scans were studied. We measured the distances from the apex to the ascending and descending aorta, the curvilinear length of the entire arch, that of the segment, including bifurcations of supra-aortic vessels, and the angle, height, and shift of the arch.

RESULTS

In men, the arch was significantly longer (146.2 vs 122.8 mm; p < 0.001), higher (49.3 vs 40.1 mm, p < 0.001), and wider transversely (83.6 vs 73.3 mm; p < 0.001) than in women. The average men's arch also had a more acute angle at the apex (79.7° vs 83.7° p < 0.001). Neither morphology nor age influenced the winding angle around the mediastinum. Aging was accompanied by deflection and extension of the aortic arch, which grew more anteroposteriorly (6.1 mm/10 years in men) than vertically (2.5 mm/10 years in men), while the apex moved towards the rear of the arch. The ascending aorta was the only curvilinear length unaffected by age, whereas the supra-aortic trunks parted from each other.

CONCLUSION

We believe that all these original observations could lead to a better assessment of normal aging of the aorta and guide technical choices during surgical or hybrid procedures.

Sutureless aortic bioprosthesis valve implantation and bicuspid valve anatomy: an unsolved dilemma?

Interest is growing in the clinical use of sutureless (SU) valves. However, indications in some anatomical sub-settings, like bicuspid aortic valves (BAV), have been so far limited. We discuss herein our initial experience with the implantation of the 3f Enable SU bioprosthesis in patients with a BAV. Patients with a BAV were selected in our unit between March 2011 and September 2014 for a SU 3f Enable valve implantation. Twenty of the 198 patients who underwent a 3f Enable valve implantation in our unit had a BAV. Procedural success was 100 %, but reclamping was necessary in one (5 %) case. Median size of implanted bioprosthesis was 23 mm. After a mean follow-up of 13.8 ± 10.7 months, survival was 100 %. Two patients (10 %) showed an immediate grade 1 paravalvular leak (PVL) that progressed to grade 2 and 3+ (moderate/severe), respectively, during follow-up. Type of bicuspidy (Sievers classification) in these two patients was 0 and intraoperatively aortic annuli admitted the 25 mm calibrator. Among the 18 patients without PVL, no one had a type 0 large BAV. At 1 year, implantation of the 3f Enable SU bioprosthesis appears to be safe in patients with BAV type I and II, while in type 0 use of the SU valve seems to be safe only if the annular diameter is <25 mm. Larger studies are necessary to confirm our findings in order to clarify the indications for SU technology in the subset of bicuspid patients.

Are all heparins safe for on-pump heart surgery?

BACKGROUND

Intravenous Panpharma heparin(®) was used in all on-pump cardiac surgery in our heart-surgery department for a short period. This brand of heparin replaced the previous Choay heparin(®) heparin supplied by the Sanofi-Aventis Laboratory. Unusual postoperative bleedings over this period prompted us to evaluate postoperative hemostasis by comparing these two heparins.

METHODS

We compared data from patients who had undergone on-pump cardiac surgery during Panpharma heparin(®) period (group P, 257 patients) to those how received Choay heparin(®) (group C, 194 patients).

RESULTS

Despite group P receiving a significantly lower dose of heparin (mean dose 21,000 IU/CEC) compared to group C (mean dose 22,000 IU/CEC) (p = 0.05), the number of surgical re-explorations needed to perfect postoperative hemostasis was significantly higher for group P (3.5% vs. 0) (p = 0.01). Heparin anti-Xa activity after surgery was higher in group P at postoperative h1 and h12 compared to group C, which explained reoperations for hemostasis.

CONCLUSION

Despite standardization, variations remain regarding anticoagulant activity between different manufacturing processes and heparin preparations. Surgical teams need to be aware that the biological effects of different brands of heparin may not be as expected and could endanger a usually safe procedure, such as cardiac surgery.

Long-term abdominal adiposity activates several parameters of cardiac energy function

Abdominal obesity increases the incidence of cardiac events but reduces mortality when one of these events occurs. The phenomenon called obesity paradox might be related to myocardial energetics. This study was aimed at determining whether long-term abdominal adiposity alters cardiac energy function. Two groups of male Wistar rats were fed a standard or a Western-type (WD) diet for 8 months. The ex vivo coronary reactivity and mechanical function as well as the mitochondrial oxidative phosphorylation (mOxPhos) and hydrogen peroxide release (mH2O2r) were determined. Abdominal adiposity was augmented by the WD. This was also the case for the coronary reactivity to acetylcholine, but the rate pressure product remained roughly stable despite a reduction of the left ventricle-developed pressure partly compensated by a slight increase in heart rate. The prolonged WD administration resulted in an improvement of mOxPhos, but the mH2O2r was exaggerated which was confirmed in the whole cell by a reduced aconitase to fumarase ratio. This did not modify the plasma oxidative stress due to an increased plasma antioxidant status. In conclusion, long-term WD administration improved the cardiac fitness and might predispose the organism to the obesity paradox. Conversely, the increased mitochondrial mH2O2r can precipitate the heart toward cardiomyopathy if the WD is maintained for a longer duration.

Coronary bifurcation lesions: Present status and future perspectives

Coronary bifurcation lesions (CBLs) are challenging and associated with a higher rate of adverse events than non-bifurcation lesions. In the era of drug-eluting stents, 2 primary interventional strategies for treating CBL include the complex strategy the main vessel (MV) and side-branch (SB) stenting, and the simple strategy MV stenting combined with provisional SB stenting. The meta-analysis of the simple vs. complex strategies demonstrated an increased incidence of myocardial infarction in the complex strategy. Likewise, the Tryton dedicated bifurcation stents, as compared with the simple strategy, increased the rate of myocardial infarction. In contrast, the Nordic-Baltic Bifurcation Study IV demonstrated that event rates were not significantly different comparing the simple vs. complex strategies in true bifurcation lesions involving a large SB. Fractional flow reserve (FFR) has emerged as a powerful catheter based tool for the functional assessment of a stenosis, but the role of FFR on the long-term outcomes of patients with CBL has not been studied. Given the recent evidence that Tryton stents (a dedicated bifurcation stent) increased event rates, and the lack of benefit from using 2-stent techniques (the Nordic Baltic Bifurcation Study IV) in true CBL, assessing the FFR of the SB seems now of outmost importance, but randomized data are lacking. An intravascular study showed that kissing balloon inflation (KBI) significantly reduced SB stenosis, restored stent lumen at the carina, and expanded stent in the proximal segment. However, a recent randomized study showed no significant benefit of routine KBI. This review highlights current concepts and future perspectives in patients with CBL.

[Impact of transcatheter aortic valve implantation in the treatment of aortic valve disease after previous coronary artery bypass]

INTRODUCTION

Patients with a history of coronary artery bypass and aortic valve disease constitute a high-risk group for conventional redo surgery. The transcatheter aortic valve implantation (TAVI) may be an alternative for high-risk patients. The purpose of this study is to evaluate the impact of TAVI in the treatment of aortic valve disease after previous surgical coronary artery revascularization.

PATIENTS AND METHODS

This is a single-center retrospective, observational study, including 87 patients undergoing surgery for surgical heart valve replacement or TAVI from January 2007 to December 2013.

RESULTS

The introduction of transcatheter aortic valve implantation techniques has doubled the number of redo patients treated for aortic valve disease. From 2010 to 2013, the patients treated by conventional surgery diminished by 30%, with improved postoperative outcomes. This study allowed us to notice differences in patient's in terms of operative risk factors. For the same reasons no comparison was possible between 2 subgroup of patients. Hospital mortality was 6.4% for conventional aortic surgery and 20% for transcatheter aortic valve treatment.

CONCLUSION

Surgery remains the standard treatment for aortic valve disease even in redo patients, but TAVI becomes a very interesting tool as it may represent a tailored approach for our patients.

Severe non-traumatic bleeding events detected by computed tomography: do anticoagulants and antiplatelet agents have a role?

Purpose

Bleeding is the most common and most serious complication of anticoagulant (AC) and antiplatelet agents (APA) which are increasingly used in every day practice. The aim of this study was to enlist and analyze the most severe bleeding events revealed during computed tomography scanner (CT scan) examinations over a 1-year period at our University Hospital and to evaluate the role of ACs and APAs in their occurrence.

Methods

This descriptive monocentric retrospective study included all patients who benefited from an emergency CT scan with a diagnosis of severe non-traumatic bleeding. Patients were divided into two groups: those treated with ACs and/or APAs, and those not treated with ACs or APAs.

Results

After applying the inclusion criteria, 93 patients were enrolled. Sixty-one patients received an anticoagulant or antiplatelet treatment, and 32 did not receive any AC or APA therapy. Seventy nine percent presented with an intracranial hemorrhage, 17% with a rectus sheath or iliopsoas bleeding or hematoma, and 4% with a quadriceps hematoma. Only patients who received ACs or APAs suffered a muscular hematoma (p <0.0001). Among patients treated with vitamin K antagonists, 6/43 (14%), had an international normalized ratio (INR) higher than the therapeutic range (INR >3).

Conclusions

In our series, intracranial hemorrhage was preponderant and muscular hematomas occurred exclusively in patients treated with ACs and/or APAs. This study needs to be extended to evaluate the impact of new anticoagulant and antiplatelet agents.

Electronic supplementary material

The online version of this article (doi:10.1186/s13019-014-0166-9) contains supplementary material, which is available to authorized users.

Functional changes of the coronary microvasculature with aging regarding glucose tolerance, energy metabolism, and oxidative stress

This study was aimed at characterizing the functional progression of the endothelial (ECs) and smooth muscle cells (SMCs) of the coronary microvasculature between youth and old age, as well as at determining the mechanisms of the observed changes on the basis of the glucose tolerance, mitochondrial energy metabolism, and oxidative stress. Male rats were divided into four age groups (3, 6, 11, and 17 months for the young (Y), young adult (YA), middle-aged (MA), and old (O) animals). The cardiac mechanical function, endothelial-dependent dilatation (EDD) and endothelial-independent dilatation (EID) of the coronary microvasculature were determined in a Langendorff preparation. The mitochondrial respiration and H2O2 production were evaluated and completed by ex vivo measurements of oxidative stress. EDD progressively decreased from youth to old age. The relaxation properties of the SMCs, although high in the Y rats, decreased drastically between youth and young adulthood and stabilized thereafter, paralleling the reduction of mitochondrial oxidative phosphorylation. The ECs dilatation activity, low at youth, was stimulated in YA animals and returned to their initial level at middle age. That parameter followed faithfully the progression of the amount of active cardiac endothelial nitric oxide synthase and whole body glucose intolerance. In conclusion, the progressive decrease in EDD occurring with aging is due to different functional behaviors of the ECs and SMCs, which appear to be associated with the systemic glucose intolerance and cardiac energy metabolism.

Body adiposity dictates different mechanisms of increased coronary reactivity related to improved in vivo cardiac function

BACKGROUND

Saturated fatty acid-rich high fat (HF) diets trigger abdominal adiposity, insulin resistance, type 2 diabetes and cardiac dysfunction. This study was aimed at evaluating the effects of nascent obesity on the cardiac function of animals fed a high-fat diet and at analyzing the mechanisms by which these alterations occurred at the level of coronary reserve.

MATERIALS AND METHODS

Rats were fed a control (C) or a HF diet containing high proportions of saturated fatty acids for 3 months. Thereafter, their cardiac function was evaluated in vivo using a pressure probe inserted into the cavity of the left ventricle. Their heart was isolated, perfused iso-volumetrically according to the Langendorff mode and the coronary reserve was evaluated by determining the endothelial-dependent (EDV) and endothelial-independent (EIV) vasodilatations in the absence and presence of endothelial nitric oxide synthase and cyclooxygenase inhibitors (L-NAME and indomethacin). The fatty acid composition of cardiac phospholipids was then evaluated.

RESULTS

Although all the HF-fed rats increased their abdominal adiposity, some of them did not gain body weight (HF- group) compared to the C group whereas other ones had a higher body weight (HF+). All HF rats displayed a higher in vivo cardiac activity associated with an increased EDV. In the HF- group, the improved EDV was due to an increase in the endothelial cell vasodilatation activity whereas in the HF+ group, the enhanced EDV resulted from an improved sensitivity of coronary smooth muscle cells to nitric oxide. Furthermore, in the HF- group the main pathway implicated in the EDV was the NOS pathway while in the HF+ group the COX pathway.

CONCLUSIONS

Nascent obesity-induced improvement of cardiac function may be supported by an enhanced coronary reserve occurring via different mechanisms. These mechanisms implicate either the endothelial cells activity or the smooth muscle cells sensitivity depending on the body adiposity of the animals.

Mitochondrial protein synthesis is increased in oxidative skeletal muscles of rats with cardiac cachexia

Since cardiac cachexia could be associated with alterations in muscular mitochondrial metabolism, we hypothesized that the expected alterations in the activities of mitochondrial oxidative enzymes could be associated with changes in mitochondrial protein synthesis in oxidative skeletal muscles. Cardiac cachexia was provoked in male rats by the ligation of the left coronary artery. Six cachectic and 6 control rats were age-paired, and their food intake was observed. The synthesis of mitochondrial proteins was measured by [1-13C]-valine infusion in soleus, tibilais, myocardium, and liver. Muscles (soleus, gastrocnemius, and tibialis anterior), heart, kidneys, liver, and visceral adipose tissue were weighed. Mitochondrial cytochrome c oxydase IV as well as citrate synthase and myosin ATPase activities were measured. As expected, decreased food intake was observed in the cachectic group. Heart, kidney, and liver weights were higher in the cachectic group, while the visceral adipose tissue weight was lower (P < .01). No changes in muscle weights were observed. Soleus mitochondrial proteins fractional synthesis rate was higher in the cachectic group (P = .054). Cytochrome c oxydase IV activity was reduced (P = .009) and increased (P = .038) in the soleus and liver of the cachectic rats, respectively. No change in citrate synthase activity was observed. Myosin ATPase activity was reduced in the gastrocnemius of the cachectic group (P < .01). Mitochondrial protein synthesis is increased in the soleus of rats with cardiac cachexia, suggesting a compensatory mechanism of the impaired oxidative mitochondrial function. Further work should assess whether the mitochondrial protein synthesis is altered in chronic heart failure patients with cardiac cachexia, and whether this is the cause or the consequence of cachexia.

Mid-term results of self-testing of the international normalized ratio in adults with a mechanical heart valve

BACKGROUND

Commonly the frequency of international normalized ratio (INR) monitoring with a conventional laboratory test in stable patients is once a month. When using a dedicated personal device for INR assessment, the frequency may be increased to two or more times a month.

OBJECTIVE

To show that INR assessed by self-measurement at home is reliable and feasible in the mid-term and improves medical care.

PATIENTS AND METHODS

All patients in the study on INR self-measurement (clinical trial.gov: NCT00925197), conducted between 2004 and 2007, were re-contacted for mid-term follow-up. One hundred and seventy eight out of 192 patients who participated in the study answered a questionnaire. The average follow-up time was 4.2 years (±1) for the self-measurement group and 4.9 years (±1) for the laboratory-analyzed control group.

RESULTS

Only 26 patients (group A) continued to use INR self-measurement to monitor treatment with vitamin K antagonists (VKA). The main reasons to stop INR self-measurement were its high cost and difficulty in obtaining strips. There were significantly fewer bleeding complications (p=0.04) and complications related to VKA (p=0.01) in self-measured patients compared to the control group. Feelings of security and quality of life were also significantly better (p=0.002) for self-measured patients.

CONCLUSION

Many patients with a mechanical heart valve, who self-measured INR, continue to use this method for their follow-up because of its positive effects on their health and quality of life.

Advantages of 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography in detecting post cardiac surgery infections

The 18F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) offers an excellent negative predictive value. Consequently, it is a reliable tool for excluding an infectious phenomenon in case of negativity. In case of persistent fever of unknown origin after cardiac surgery and in combination with other bacteriological examinations and medical imaging, we can rely on FDG-PET/CT to confirm or eliminate deep infections and prosthetic endocarditis. For this reason, FDG-PET/CT should be considered among the examinations to be performed in case of suspected infection after cardiac surgery. We have reported the case of a 76-year-old man who presented with a fever of unknown origin and recurrent septic shocks after a biological Bentall procedure combined with left anterior descending (LAD) coronary artery revascularization by the left internal thoracic artery. We performed a FDG-PET/CT which showed external iliac vein and right common femoral vein hyperfixation with infiltration of adjacent soft tissues, highly suspected to be an infectious process.

LEARNING OBJECTIVE

The aim of this case report is to show that FDG-PET/CT, in combination with other bacteriological examinations and medical imaging, can be extremely helpful in detecting deep infectious sources, even during the early postoperative period.

[Contribution of magnetic resonance imaging in diagnosis of pericardial mesothelioma: a case report]

Pericardial mesothelioma is a rare form of pericardial tumor. The invasive investigations such as biopsy make the diagnosis. Non-invasive imaging techniques provide valuable information about its diagnosis and its clinical impact. We report here the results of magnetic resonance imaging of pericardial mesothelioma in a 65-year-old woman. The originality and purpose of this case is to illustrate the additional value of magnetic resonance imaging that should be systematically performed when assessing this pathology.

[Pseudo-aneurysm of mitro-aortic continuity: a rare complication after aortic valve replacement]

Pseudo-aneurysm of the fibrous continuity zone between the aortic and mitral valves, the so-called "mitral-aortic intervalvular fibrosa" is a rare complication of acute infective endocarditis, rarely after an aortic valve replacement. We report the case of a large pseudo-aneurysm occurred in a 70-year-old man, who had a history of surgical aortic valve replacement 3 years before. There were no biological or clinical evidence for infective acute endocarditis. The originality of this observation can be summarized in three points: the late onset after surgery, the absence of any infectious context and the chronic nature of pseudo-aneurysm, without any complication during a follow-up of 12 months. Transesophageal echocardiography remains the best diagnostic tool.

Results of the first randomized French study evaluating self-testing of the International Normalized Ratio

BACKGROUND AND AIM OF THE STUDY

In this single-center French study, the conventional management of patients receiving vitamin K antagonists (VKAs) was compared with an International Normalized Ratio (INR) self-testing program. The aim was to determine the reliability of self-testing devices, and to estimate the variability of the self-measured INR within the therapeutic and target range.

METHODS

A total of 206 patients who had undergone valve replacement with a mechanical prosthesis, with or without myocardial revascularization, between May 2004 and September 2007 was randomized into two groups. Group 1 patients (n = 103) underwent INR monitoring at a laboratory, while Group 2 patients (n = 103) underwent self-testing INR using either the CoaguChek (Roche) (Group 2A; n = 55) or INRatio (Hemosense) (Group 2B; n = 48) system. Patients in Group 1 underwent at least once-monthly INR measurement, while those in Group 2 carried out once-weekly self-testing, and also underwent once-monthly INR measurement at the laboratory. The large majority of patients (97.9%) were treated with fluindione.

RESULTS

The mean follow up period was 49.0 +/- 10.3 weeks. Self-testing was reliable, with a correlation coefficient between device- and laboratory-measured INRs of 0.80 [CI: 0.78, 0.82] (p < 0.0001). The proportion of time spent within the INR target range was significantly higher for Group 2 (61.5 +/- 19.3% versus 55.5 +/- 19.9%; p < 0.05), while the absolute mean deviation of INR from the target range was higher in Group 1 (60.1 +/- 70.2% versus 47.4 +/- 51.5%). Adverse events were reported by seven patients in Group 1, but by no patients in Group 2 (p < 0.01).

CONCLUSION

INR self-testing devices are reliable and beneficial. Moreover, INR self-monitoring allows an enhanced stability within a target range, and also helps to prevent serious postoperative complications.

Comparison of INR stability between self-monitoring and standard laboratory method: preliminary results of a prospective study in 67 mechanical heart valve patients

INTRODUCTION

Thromboembolic accidents and haemorrhage are the main complications observed during long-term follow-up of mechanical heart valve patients. Several suggestions for improving anticoagulation quality have been made, including international normalised ratio (INR) self-monitoring.

OBJECTIVES

We report the preliminary results of a single-centre, open, randomised study (scheduled population of 200 patients), which compares monthly laboratory monitoring (group A) versus weekly self-monitoring of INR (group B). The primary aim is INR stability improvement within the target range, and the secondary aim is adverse events reduction.

PATIENTS AND METHODS

Between May 2004 and June 2005, 67 patients with an average age of 56.6 years (+/-9.6), were enrolled in the study (group A: 34 patients, group B: 33 patients). The mean follow-up was 47 weeks (+/-11.5). The two groups differed only in the sex ratio (44.1 and 21.2% of women in groups A and B respectively, p=0.0459). Mechanical heart valves were aortic in 73% of patients, mitral in 13.5%, and multiple in 13.5%. Sixty-five patients (97%) were treated with fluindione, the others with acenocoumarol. The intraclass correlation coefficient between the self- and laboratory-monitored INR was 0.75.

RESULTS

The time spent in the INR target range (group A: 53+/-19%, group B: 57+/--19%, p=0.45) and the time spent in the INR therapeutic range, between 2 and 4.5, (group A: 86+/-14%, group B: 91+/-7%, p=0.07) are longer in group B, but not significantly so. For patients outside the range, the absolute mean deviation of INR from the target or therapeutic range (range standardized between 0 and 100) is lower for the self-monitoring group (41.1+/-39.3 and 11.27+/-11.2) than for the control group (62.4+/-72.6 and 39.2+/-52.8). This difference is significant (p=0.0004 and p=0.0005). Eighteen adverse events were reported: 17 haemorrhages, 13 in group A (9 mild, 4 serious) and four in group B (all mild), and one sudden death in group B, two days after the patient's discharge. No thromboembolic events were reported. Six patients (8.8 %), 3 in each group, dropped out of the study.

CONCLUSION

This first study evaluating INR self-monitoring in France shows that this method leads to better stability of the INR within the target range. On the basis of these preliminary data, this appears to be related to a decrease in serious haemorrhages (11.8% serious haemorrhage cases in group A versus 0% in group B, p=0.06, NS).

Improving cardiac function after cardiac surgery by biventricular pacing in patient selected by three-dimensional echocardiography

We present the case of a 57-year-old woman with severe aortic regurgitation and ventricular dysfunction (ejection fraction 34%) requiring surgical intervention. In pre-operative period, no left ventricular (LV) asynchrony was detected by QRS duration and current echocardiographic techniques, including tissue Doppler imaging. A new echocardiographic technology, the timing of regional volumetric changes by three-dimensional echocardiography (3DEcho), demonstrated an intraventricular mechanical asynchrony. Indeed, during surgery, epicardial leads were attached to the right atrium and the right ventricle as part of the standard management. Two additional epicardial leads were attached to the left ventricle on the most delayed wall localized precisely by 3DEcho on the inferolateral wall. In post-operative period, biventricular (BiV) pacing showed improvement in the LV mechanical synchronization, resulting in improvement in the LV systolic function compared with right ventricular pacing or no pacing. This case shows the potential utility of 3DEcho in prediction of favourable response of the BiV pacing in patients with depressed LV systolic function ongoing cardiac surgery.

[Type III endoleaks at follow-up of covered descending thoracic aortic stent-grafts: report of 3 patients]

PURPOSE

To describe the imaging work-up and management of type III endoleaks detected after covered stent-graft treatment of descending thoracic aortic aneurysms.

PATIENTS AND METHODS

Retrospective study of circumstances surrounding the diagnosis, management and outcome type III endoleaks occuring in 3 of 18 patients following covered stent-graft treatment of descending thoracic aortic aneurysms between April 1998 and July 2005. The endoleaks were detected at a mean follow-up of 22 months (19-24 months) after stent-graft placement.

RESULTS

The type III endoleaks were detected on scheduled follow-up CT examinations in asymptomatic patients. Endovascular management was proposed at a mean interval time of 4.4 months (1 week - 11 months) after diagnosis of the endoleak, and was successful in all 3 cases. One patient died 1 month after endovascular repeai of the leak, 1 patient required surgical management at 14 months for new recurrence, and 1 patient had a favorable outcome at 2 months.

CONCLUSION

Follow-up of patients after covered stent-graft treatment of descending thoracic aortic aneurysms is required. Prompt endovascular repair of delayed complications may be possible, but surgical management may become necessary.

An in-use microbiological comparison of two surgical hand disinfection techniques in cardiothoracic surgery: hand rubbing versus hand scrubbing

Surgical site infection after heart surgery increases morbidity and mortality. The method of presurgical hand disinfection could influence the infection risk. From February to April 2003, we compared the microbiological efficacy of hand-rubbing (R) and hand-scrubbing (S) procedures. The surgical team alternately used hand-scrubbing or hand-rubbing techniques every two weeks. Fingertip impressions were taken before and immediately after hand disinfection, every 2h and at the end of the operation. Acceptability of hand rubbing was assessed by a questionnaire. Mean durations of surgical procedures were 259+/-68 and 244+/-69min for groups S and R respectively (P=0.43). Bacterial counts immediately after hand disinfection were comparable with the two techniques, but significantly lower in group R at the end of surgery. No differences were observed between the percentages of negative samples taken after 2h, 4h and at the end of surgery between the two groups. Bacterial skin flora reduction immediately after hand disinfection, after 2h and 4h of operating time and at the end of surgery was better in group R, but the difference was not statistically significant. Before surgery, the hand-rubbing method with alcohol solution preceded by hand washing with mild neutral soap is as effective as hand scrubbing to reduce bacterial counts on hands. It decreased the bacterial counts both immediately after hand disinfection and at the end of long cardiothoracic surgical procedures. The acceptability of hand rubbing was excellent and it can be considered to be a valid alternative to the conventional hand-scrubbing protocol.

Can erythropoietin improve skeletal myoblast engraftment in infarcted myocardium?

The benefits of skeletal myoblast transplantation are limited by the high rate of early cell death which is partly of ischemic origin. We, therefore, assessed whether graft survival could be improved by the additional use of the angiogenic cytokine erythropoietin (EPO). Thirty-five Lewis rats underwent coronary artery ligation and, two weeks later, were randomized to receive in-scar injections of control medium, skeletal myoblasts (5x10(6)) or skeletal myoblasts with EPO started the day before transplantation and continued for two weeks (500 U/kg three times a week). A fourth group was treated by EPO alone without injections. Function was assessed by 2D echocardiography before transplantation and one month thereafter. Compared with controls and hearts treated by EPO-alone, those transplanted with myoblasts yielded a significantly better recovery of LV ejection fraction, irrespective of whether they had received EPO or not. Neither the area of myoblast engraftment, nor angiogenesis differed between the myoblast-alone and the myoblast+EPO groups. Apoptosis was hardly detectable and, therefore, unaffected by EPO therapy. In this model, EPO failed to improve myoblast engraftment and postinfarction LV function. These negative findings justify to pursue the search for alternate cell survival-enhancing strategies.

Can bone marrow-derived multipotent adult progenitor cells regenerate infarcted myocardium?

OBJECTIVES

To assess the functional effects of multipotent adult progenitor cells (MAPCs) transplanted in a rat model of chronic myocardial infarction.

METHODS

Forty-four rats underwent coronary ligation and, 14 days later, were randomly allocated to receive in-scar injections (5 x 10(6) cells/150 microL) of green fluorescent protein (eGFP)-transduced allogeneic MAPCs (n = 25) or culture medium (controls, n = 19). Nine of the MAPC-treated hearts were employed for functional studies while the remaining 16 received cells co-labeled with Resovist and were only used for serial histological assessments. Left ventricular (LV) function was assessed echocardiographically before transplantation and 1 month thereafter in a blinded manner. Immunohistochemistry, electron microscopy and PCR were used to detect grafted cells. All data were compared by nonparametric tests.

RESULTS

Baseline ejection fractions (EF, median;[interquartile range]) did not differ significantly among the groups: 30% [0.23;0.37] and 37% [0.32;0.38] in control and rMAPC-transplanted hearts, respectively. One month later, LV function of control hearts was found to have deteriorated, as reflected by a decline in EF to 24% [0.21;0.30], and although EF tended to remain more stable after cell transplantation (37% [0.27;0.41]), the difference between the two groups failed to achieve statistical significance (p = 0.06). While MAPCs could be identified early post-transplant, no evidence of engraftment was further observed at 1 month by immunohistochemistry, electron microscopy or PCR.

CONCLUSIONS

In this model, MAPCs did not improve global pump function, and although some of these cells expressed endothelial markers during the early post-transplant period, we could not detect any evidence for differentiation into cardiomyocytes and no engraftment was further identified beyond 2 weeks after cell injections.

[Long-term MRI follow-up of aortic dissection in 56 patients: therapeutic impact]

PURPOSE

To retrospectively assess the value of MRI in long-term follow-up of aortic dissection (AD) and its impact on therapy.

MATERIALS AND METHODS

Comparison of clinical progression and analysis of 215 MRI examinations performed on 56 patients in our center from 1991 to 2002.

RESULTS

Twenty-six patients (46%) had AD complications: 14 (54%) were asymptomatic and eight (31%) had subsequent surgical repair (native aorta upstream prosthesis disease in three patients and aneurismal dilatation of false lumen in five cases). Of the eight patients with secondary surgery, five (63%) were clinically asymptomatic. The delay between initial dissection and secondary surgery was less than 5 years in five patients and exceeded 10 years in three cases. The remaining 30 patients (54%) had unmodified radiological findings after a mean follow-up of 3.5 years (6 months to 9 years).

CONCLUSION

MRI depicted AD complications in long-term follow-up of sometimes asymptomatic patients, allowing for adaptation of surgical treatment in 26 cases (46%).

Can cold or heat shock improve skeletal myoblast engraftment in infarcted myocardium?

OBJECTIVE

Cell death remains a major limitation of skeletal myoblast (SM) transplantation but the patterns of cell survival and proliferation in heart and their potential modulation by thermic stresses like heat shock (HS) and cryopreservation (Cryo) are still incompletely characterized.

METHODS

To track SMs in situ, we developed a dual-marker system based on the semiconservative expression of the foreign soluble protein, beta-Galactosidase (beta-Gal) and the constitutive expression of the Y chromosome in a myocardial infarction model. Control medium or Lewis male rat SMs (fresh or subjected to Cryo or HS) were injected in Lewis female rats.

RESULTS

There was a massive cell loss early after transplantation in the fresh group, which was only partially compensated for by a subsequent proliferation. Conversely, both Cryo and HS significantly improved early cell survival but blunted subsequent proliferation so that, at 15 days posttransplantation, the total number of engrafted donor-derived Y-positive cells did not differ significantly between the three groups. Most of them expressed a skeletal muscle phenotype.

CONCLUSIONS

These data confirm the high death rate of in-scar transplanted myoblasts, demonstrate the ability of those that survive to proliferate and differentiate along the myogenic pathway but do not support the efficacy of either Cryo or HS for increasing the ultimate magnitude of myoblast engraftment.

Enhancement of the functional benefits of skeletal myoblast transplantation by means of coadministration of hypoxia-inducible factor 1α

OBJECTIVE

Early cell death remains a major limitation of skeletal myoblast transplantation. Because the poor vascularization of the target scars contributes to cell loss, we assessed the effects of combining skeletal myoblast transplantation with administration of hypoxia-inducible factor 1alpha, a master gene that controls the expression of a wide array of angiogenic factors.

METHODS

A myocardial infarction was created in 56 rats by means of coronary artery ligation. Eight days later, rats were randomly allocated to receive in-scar injections of culture medium (control animals, n = 11), skeletal myoblasts (5 x 10(6) , n = 13), adenovirus-encoded hypoxia-inducible factor 1alpha (1.0 x 10(10) pfu/mL, n = 7), or skeletal myoblasts (5 x 10(6)) in combination with an empty vector (n = 3) or active hypoxia-inducible factor 1alpha (1.0 x 10(10) pfu/mL, n = 13). A fifth group (n = 9) underwent a staged approach in which hypoxia-inducible factor 1alpha (1.0 x 10(10) pfu/mL) was injected at the time of infarction, followed 8 days later by skeletal myoblasts (5 x 10(6)). Left ventricular function was assessed echocardiographically before transplantation and 1 month thereafter. Explanted hearts were then processed for the immunohistochemical detection of myotubes, quantification of angiogenesis, myoblast engraftment, and cell survival.

RESULTS

Baseline ejection fractions were not significantly different among groups (35%-40%). One month later, ejection fraction had decreased from baseline in control hearts and in those injected with hypoxia-inducible factor 1alpha. In contrast, it did not deteriorate after injections of skeletal myoblasts alone or combined with either the empty vector or active hypoxia-inducible factor 1alpha administered sequentially. The most striking change occurred in the skeletal myoblast plus hypoxia-inducible factor 1alpha combined group in which ejection fraction increased dramatically (by 27%) above baseline levels and was thus markedly higher than in all other groups ( P = .0001 and P = .001 vs control animals and animals receiving hypoxia-inducible factor 1alpha, respectively). Compared with skeletal myoblasts alone, the coadministration of hypoxia-inducible factor 1alpha resulted in a significantly greater degree of angiogenesis, cell engraftment, and cell survival.

CONCLUSION

Induction of angiogenesis is an effective means of potentiating the functional benefits of myoblast transplantation, and hypoxia-inducible factor 1alpha can successfully achieve this goal.