Adipose Derived Stromal Vascular Fraction and Mesenchymal Stem Cells Improve Angiogenesis in a Rat Hindlimb Ischaemia Model

OBJECTIVE

This study aimed to investigate the effect of human adipose tissue derived stromal vascular fraction (AD-SVF) and mesenchymal stem cells (AD-MSCs) on blood flow recovery and neovascularisation in a rat hindlimb ischaemia model.

METHODS

SVF was isolated using an automated centrifugal system, and AD-MSCs were obtained from adherent cultures of SVF cells. Rats were divided into four groups of six rats each: non-ischaemia (Group 1); saline treated ischaemia (Group 2); SVF treated ischaemia (Group 3); and AD-MSC treated ischaemia (Group 4). Unilateral hindlimb ischaemia was induced in Sprague-Dawley rats via femoral artery ligation. Saline, SVF, or AD-MSCs were injected intramuscularly into the adductor muscle intra-operatively. Cell viability was calculated as the percentage of live cells relative to total cell number. Blood flow improvement, muscle fibre injury, and angiogenic properties were validated using thermal imaging and histological assessment.

RESULTS

The viabilities of SVF and AD-MSCs were 83.3% and 96.7%, respectively. Group 1 exhibited no significant temperature difference between hindlimbs, indicating a lack of blood flow changes. The temperature gradient gradually decreased in SVF and AD-MSC treated rats compared with saline treated rats. In addition, only normal muscle fibres with peripherally located nuclei were observed in Group 1. Groups 3 and 4 exhibited significantly fewer centrally located nuclei, indicating less muscle damage compared with Group 2. Regarding angiogenic properties, CD31 staining of endothelial cells showed similar patterns among all groups, whereas expression of vascular endothelial growth factor, as a crucial angiogenesis factor, was enhanced in the SVF and AD-MSC treated groups.

CONCLUSION

SVF and AD-MSCs improved blood flow and neovascularisation in a rat hindlimb ischaemia model, suggesting their potential ability to promote angiogenesis. Further extensive research is warranted to explore their potential applications in the treatment of severe lower extremity arterial disease.

Prevention of neointimal hyperplasia after coronary artery bypass graft via local delivery of sirolimus and rosuvastatin: network pharmacology and in vivo validation

BACKGROUND

Coronary artery bypass graft (CABG) is generally used to treat complex coronary artery disease. Treatment success is affected by neointimal hyperplasia (NIH) of graft and anastomotic sites. Although sirolimus and rosuvastatin individually inhibit NIH progression, the efficacy of combination treatment remains unknown.

METHODS

We identified cross-targets associated with CABG, sirolimus, and rosuvastatin by using databases including DisGeNET and GeneCards. GO and KEGG pathway enrichment analyses were conducted using R studio, and target proteins were mapped in PPI networks using Metascape and Cytoscape. For in vivo validation, we established a balloon-injured rabbit model by inducing NIH and applied a localized perivascular drug delivery device containing sirolimus and rosuvastatin. The outcomes were evaluated at 1, 2, and 4 weeks post-surgery.

RESULTS

We identified 115 shared targets between sirolimus and CABG among databases, 23 between rosuvastatin and CABG, and 96 among all three. TNF, AKT1, and MMP9 were identified as shared targets. Network pharmacology predicted the stages of NIH progression and the corresponding signaling pathways linked to sirolimus (acute stage, IL6/STAT3 signaling) and rosuvastatin (chronic stage, Akt/MMP9 signaling). In vivo experiments demonstrated that the combination of sirolimus and rosuvastatin significantly suppressed NIH progression. This combination treatment also markedly decreased the expression of inflammation and Akt signaling pathway-related proteins, which was consistent with the predictions from network pharmacology analysis.

CONCLUSIONS

Sirolimus and rosuvastatin inhibited pro-inflammatory cytokine production during the acute stage and regulated Akt/mTOR/NF-κB/STAT3 signaling in the chronic stage of NIH progression. These potential synergistic mechanisms may optimize treatment strategies to improve long-term patency after CABG.

Sustained drug release behavior of captopril-incorporated chitosan/carboxymethyl cellulose biomaterials for antihypertensive therapy

Captopril (CTP) is an oral drug widely used to treat high blood pressure and congestive heart failure. In this study, CTP-incorporated biomaterials for antihypertensive therapy were synthesized from chitosan, carboxymethyl cellulose, and plasticizers. The physicochemical properties of the prepared biomaterials were characterized using FE-SEM, FT-IR analysis, and physical properties. CTP release experiments were carried out in buffer solutions at various pH values and temperatures. Results indicated that above 99.0 % of CTP was released within 180 min. Optimization of the experimental conditions for CTP release was analyzed by using response surface methodology (RSM). Results of CTP release through artificial skin indicated that CTP was continuously released above 95.0 % from the prepared biomaterials for 36.0 h. The CTP release mechanisms into a buffer and through artificial skin followed pseudo-Fickian diffusion mechanism and non-Fickian diffusion mechanisms, respectively. Moreover, angiotensin-converting enzyme (ACE) inhibition (related to cardiovascular disease) via the released CTP clearly reveals that the prepared biomaterials have a high potential as a transdermal drug delivery agent in antihypertensive therapy.

Effect of sequential release of sirolimus and rosuvastatin using silk fibroin microneedle to prevent intimal hyperplasia

Intimal hyperplasia (IH) is a major cause of vascular restenosis after bypass surgery, which progresses as a series of processes from the acute to chronic stage in response to endothelial damage during bypass grafting. A strategic localized drug delivery system that reflects the pathophysiology of IH and minimizes systemic side effects is necessary. In this study, the sequential release of sirolimus, a mechanistic target of rapamycin (mTOR) inhibitor, and statin, an HMG-COA inhibitor, was realized as a silk fibroin-based microneedle device in vivo. The released sirolimus in the acute stage reduced neointima (NI) and vascular fibrosis through mTOR inhibition. Furthermore, rosuvastatin, which was continuously released from the acute to chronic stage, reduced vascular stiffness and apoptosis through the inactivation of Yes-associated protein (YAP). The sequential release of sirolimus and rosuvastatin confirmed the synergistic treatment effects on vascular inflammation, VSMC proliferation, and ECM degradation remodeling through the inhibition of transforming growth factor (TGF)-beta/NF-κB pathway. These results demonstrate the therapeutic effect on preventing restenosis with sufficient vascular elasticity and significantly reduced IH in response to endothelial damage. Therefore, this study suggests a promising strategy for treating coronary artery disease through localized drug delivery of customized drug combinations.

Bilateral versus Single Internal Thoracic Artery Grafting Strategies Supplemented by Radial Artery Grafting

PURPOSE

It is unclear if a second or third arterial graft can improve clinical outcomes in coronary artery bypass graft surgery. We compared the outcomes of bilateral internal thoracic artery (BITA) plus radial artery (RA) grafting versus left internal thoracic artery (LITA) plus RA grafting after off-pump coronary artery bypass grafting.

MATERIALS AND METHODS

Between January 2009 and December 2020, a total of 3007 patients with three-vessel coronary artery disease who underwent off-pump coronary artery bypass were analyzed. Among them, 971 patients received total arterial grafting using LITA. We divided the patients into two groups [group A, BITA+RA grafting (n=227) and group B, LITA+RA grafting (n=744)], and compared the survival and major adverse cardiac and cerebrovascular event (MACCE) rates between the two groups at 10 years.

RESULTS

After risk adjustment with inverse probability treatment weighting methods, the freedom from all-cause mortality was 93.1% and 88.3% in groups A and B, respectively (p=0.140). The freedom from MACCE rates were 68.3% and 89.0%, respectively (p<0.0001). LITA plus RA grafting [hazard ratio (HR): 1.3, 95% confidence interval (CI): 1.05-2.37, p=0.025] and incomplete revascularization (HR 1.2, 95% CI: 0.70-2.15, p=0.046) were significant risk factors for MACCEs in multivariable Cox regression analysis.

CONCLUSION

The rates of MACCEs were lower with LITA plus RA grafting than with BITA plus RA grafting in total arterial revascularization. Furthermore, complete revascularization improved long-term outcomes following total arterial grafting.

Hemostatic efficacy of a flowable collagen-thrombin matrix during coronary artery bypass grafting: a double-blind randomized controlled trial

BACKGROUND

Flowable hemostatic agents have the advantage of being able to be applied to irregular wound surfaces and difficult to reach areas. We sought to compare the effectiveness and safety of the flowable hemostatic sealants Collastat® (collagen hemostatic matrix, [CHM]) and Floseal® (gelatin hemostatic matrix, [GHM]) during off-pump coronary artery bypass (OPCAB).

METHODS

In this prospective, double-blind, randomized controlled trial, 160 patients undergoing elective OPCAB surgery were enrolled between March 2018 and February 2020. After primary suture of the aortocoronary anastomosis, an area of hemorrhage was identified, and patients received either CHM or GHM (n = 80, each). Study endpoints were the following: proportion of successful intraoperative hemostasis and time required for hemostasis overall postoperative bleeding, proportion of transfusion of blood products, and surgical revision for bleeding.

RESULTS

Of the total patients, 23% were female, and the mean age was 63 years (range 42-81 years). Successful hemostasis proportion within 5 min was achieved for 78 patients (97.5%) in the GHM group, compared to 80 patients (100%) in the CHM group (non-inferiority p = 0.006). Two patients receiving GHM required surgical revision to achieve hemostasis. There were no differences in the mean time required to obtain hemostasis [GHM vs. CHM, mean 1.49 (SD 0.94) vs. 1.35 (0.60) min, p = 0.272], as confirmed by time-to-event analysis (p = 0.605). The two groups had similar amounts of mediastinal drainage for 24 h postoperatively [538.5 (229.1) vs. 494.7 (190.0) ml, p = 0.298]. The CHM group required less packed red blood cells, fresh frozen plasma, and platelets for transfusion than the GHM group (0.5 vs. 0.7 units per patient, p = 0.047; 17.5% vs. 25.0%, p = 0.034; 7.5% vs. 15.0%, p = 0.032; respectively).

CONCLUSIONS

CHM was associated with a lower need for FFP and platelet transfusions. Thus, CHM is a safe and effective alternative to GHM.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04310150.

Effects of Residual Arch Tears on Late Outcomes After Hemiarch Replacement for DeBakey I Dissection

BACKGROUND

This study evaluated the effect of residual arch tears on late reinterventions and arch dilatation after hemiarch replacement for patients with acute DeBakey type I aortic dissection.

METHODS

Between January 1995 and October 2018, 160 consecutive patients who underwent hemiarch replacement for DeBakey type I dissection were retrospectively enrolled. They were divided into patients with (n = 73) and without (n = 87) residual arch tears. The arch tears group was subdivided into the proximal/middle arch (n = 26) and distal arch (n = 47) groups to evaluate arch growth rates according to the locations of residual arch tears. The endpoints were arch growth rate and late arch and composite events.

RESULTS

The arch diameter increased significantly over time in patients with residual arch tears (1.620 mm/y, P < .001). The increase occurred more rapidly when residual tears occurred at the distal arch than at the proximal/middle arch level (2.101 vs 1.001 mm/y). In the adjusted linear mixed model, residual arch tears or luminal communications at the distal arch level were significant factors associated with increases in the arch diameter over time. The 10-year freedom from late arch and composite event rate was significantly lower for patients with residual arch tears than for those without (82.4% vs 95.5%, P = .001; and 68.0% vs 89.3%, P = .002, respectively).

CONCLUSIONS

Residual arch tears are significant factors associated with late arch dilatation and reinterventions, especially for patients with distal arch tears. Extensive arch replacement during the initial surgery to avoid residual arch tears may improve long-term outcomes.

Clinical Validation of a Wearable Piezoelectric Blood-Pressure Sensor for Continuous Health Monitoring

Wearable blood-pressure sensors have recently attracted attention as healthcare devices for continuous non-invasive arterial pressure (CNAP) monitoring. However, the accuracy of wearable blood-pressure (BP) monitoring devices has been controversial due to the low signal quality of sensors, the absence of an accurate transfer function to convert the sensor signals into BP values, and the lack of clinical validation regarding measurement precision. Here, a wearable piezoelectric blood-pressure sensor (WPBPS) is reported, which achieves a high normalized sensitivity (0.062 kPa^-1 ), and fast response time (23 ms) for CNAP monitoring. The transfer function of a linear regression model is designed, offering a simple solution to convert the flexible piezoelectric sensor signals into BP values. In order to verify the measurement accuracy of WPBPS, clinical trials are performed on 35 subjects aged from 20 to 80 s after screening. The mean difference between the WPBPS and a commercial sphygmomanometer of 175 BP data pairs is -0.89 ± 6.19 and -0.32 ± 5.28 mmHg for systolic blood pressure (SBP) and diastolic blood pressure (DBP), respectively. By building a WPBPS-embedded wristwatch, the potentially promising use of a convenient, portable, continuous BP monitoring system for cardiovascular disease diagnosis is demonstrated.

Hemodynamic management during off-pump coronary artery bypass surgery: a narrative review of proper targets for safe execution and troubleshooting

Off-pump coronary surgery requires mechanical cardiac displacement yielding bi-ventricular systolic and diastolic dysfunction. Although transient, subsequent hemodynamic deterioration can bear dismal prognosis and at the extreme, emergent on-pump conversion may be needed, which is associated with undesirably high morbidity and mortality rates. Thus, proper decisions should be made based on objective hemodynamic targets whether surgery can be proceeded before opening the coronary artery. Hemodynamic management should prioritize the avoidance of perplexing myocardial oxygen-supply demand balance, which include maintenance of mean arterial pressure above 70 mmHg while avoiding increase in oxygen demand beyond the patient's coronary reserve. Maintenance of mixed venous oxygen saturation above 60%, which reflects the lower limit of the adequacy of global oxygen-supply demand balance, seems also important not to jeopardize the patient's prognosis. Above all, severe mechanical cardiac constraint incurring compressive syndromes that cannot by overcome by manipulating major determinants of cardiac output should be avoided. To rule out uncompromising form of cardiac constraint, central venous pressure should not equal or exceed the pulmonary artery diastolic (or occlusion) pressure, which would reflect tamponade physiology. In addition, transesophageal echocardiography should rule out mechanical cardiac displacement-induced ventricular interdependence, dyskinesia, severe mitral regurgitation, and left ventricular outflow tract obstruction with or without systolic motion of the anterior leaflet of the mitral valve, which cannot be tolerated during the period of grafting. Also, careful inspection for gas bubbles in the ascending aorta should be performed to prevent rare causes of hemodynamic collapse by massive gas embolism obstructing the right coronary ostium.

Effect of Preoperative Administration of Intravenous Ferric Carboxymaltose in Patients with Iron Deficiency Anemia after Off-Pump Coronary Artery Bypass Grafting: A Randomized Controlled Trial

Patients scheduled for cardiac surgery often have anemia and iron deficiency. We investigated the effect of the preoperative administration of intravenous ferric carboxymaltose (IVFC) in patients with iron deficiency anemia (IDA) who were due to undergo off-pump coronary artery bypass grafting (OPCAB). Patients who were due to undergo elective OPCAB between February 2019 and March 2022 who had IDA (n = 86) were included in this single center, randomized, parallel-group controlled study. The participants were randomly assigned (1:1) to receive either IVFC or placebo treatment. Postoperative hematologic parameters [hemoglobin (Hb), hematocrit, serum iron concentration, total iron-binding capacity, transferrin saturation, transferrin concentration, and ferritin concentration] and the changes in these parameters during the follow-up period were the primary and secondary outcomes, respectively. The tertiary endpoints were early clinical outcomes, such as the volume of mediastinal drainage and the need for blood transfusions. IVFC treatment significantly reduced the need for red blood cell (RBC) and platelet transfusions. Despite receiving fewer RBC transfusions, patients in the treatment group had higher levels of Hb, hematocrit, and serum iron and ferritin concentrations during weeks 1 and 12 after surgery. No serious adverse events occurred during the study period. Preoperative IVFC treatment in patients with IDA undergoing OPCAB improved the values of the hematologic parameters and iron bioavailability. Therefore, is a useful strategy for stabilizing patients prior to OPCAB.

Sirolimus-Embedded Silk Microneedle Wrap to Prevent Neointimal Hyperplasia in Vein Graft Model

We investigated the role of a sirolimus-embedded silk microneedle (MN) wrap as an external vascular device for drug delivery efficacy, inhibition of neointimal hyperplasia, and vascular remodeling. Using dogs, a vein graft model was developed to interpose the carotid or femoral artery with the jugular or femoral vein. The control group contained four dogs with only interposed grafts; the intervention group contained four dogs with vein grafts in which sirolimus-embedded silk-MN wraps were applied. After 12-weeks post-implantation, 15 vein grafts in each group were explanted and analyzed. Vein grafts applied with the rhodamine B-embedded silk-MN wrap showed far higher fluorescent signals than those without the wrap. The diameter of vein grafts in the intervention group decreased or remained stable without dilatation; however, it increased in the control group. The intervention group had femoral vein grafts with a significantly lower mean neointima-to-media ratio, and had vein grafts with an intima layer showing a significantly lower collagen density ratio than the control group. In conclusion, sirolimus-embedded silk-MN wrap in a vein graft model successfully delivered the drug to the intimal layer of the vein grafts. It prevented vein graft dilatation, avoiding shear stress and decreasing wall tension, and it inhibited neointimal hyperplasia.

Clinical Outcomes of Endoscope-Assisted Pulmonary Endarterectomy for Chronic Thromboembolic Pulmonary Hypertension

PURPOSE

Pulmonary thromboembolism is a potentially life-threatening condition in patients with heart disease; however, limited studies discussing long-term outcomes exist. This study aimed to investigate the long-term outcomes of pulmonary endarterectomy (PEA) in patients with chronic thromboembolic pulmonary hypertension (CTEPH), focusing on the improvement of functional class and right ventricular (RV) pressure.

MATERIALS AND METHODS

Clinical data of patients with CTEPH were obtained from Yonsei Hospital between May 2012 and December 2021, and reviewed retrospectively. Twenty-six patients underwent endoscope-guided PEA during the study period, and the mean follow-up duration was 24.8±23.4 months.

RESULTS

After PEA, most patients (88.5%) were weaned from inotropes without extracorporeal membrane oxygenation support during the first few days. Two patients (7.6%) had cerebrovascular accidents without neurological deficits. On echocardiography, the RV systolic pressure and tricuspid regurgitation grades significantly improved (p<0.001). Furthermore, the mean left ventricle end-diastolic diameter was significant increased (p=0.003), and the left ventricular end-systolic diameter increased (p<0.001). The median intensive care unit stay was 3.0±9.4 days, and median hospital stay 16.0±26.5 days. The 5-year survival rate was 95.5%, and the 5-year freedom rate of cardiac death was 100%. There was a marked improvement in New York Heart Association (NYHA) status (p<0.001). Cox regression suggested that the main pulmonary artery (MPA) involvement is a significant predictor of non-improvement in functional class post-PEA.

CONCLUSION

Mortality rates are low and patients experience a marked improvement in NYHA class and health status after PEA. Moreover, MPA involvement may affect functional outcomes.

Vegetation Size, Multiplicity, and Position in Patients With Infective Endocarditis

BACKGROUND

Infective endocarditis is a life-threatening condition and is associated with embolic events. We aimed to evaluate the association of vegetation size, multiplicity, and position with cerebral embolism and late mortality in patients with infective endocarditis.

METHODS

We retrospectively reviewed patients with infective endocarditis who were admitted to a single institution between November 2005 and August 2017. A total of 419 patients with infective endocarditis were included in the study, 273 of whom had undergone surgery. The primary endpoint was all-cause mortality, and the secondary endpoint was cerebral embolism. Multivariate Cox regression and logistic regression analyses were performed to identify independent risk factors for 30-day mortality, late mortality, and cerebral embolism.

RESULTS

Age (hazard ratio [HR] 1.02; 95% confidence interval [CI], 1.00 to 1.04), renal failure (HR 4.21; 95% CI, 2.67 to 6.65), surgery (HR 0.31; 95% CI, 0.21 to 0.46), and Acute Physiology and Chronic Health Evaluation II score (HR 1.08; 95% CI, 1.01 to 1.15) were associated with late mortality. Vegetation size, multiplicity, and position were not significantly associated with late mortality, but a mitral vegetation size of greater than 10 mm (odds ratio 2.25; 95% CI, 1.32 to 3.84) was an independent risk factor for cerebral embolism.

CONCLUSIONS

A vegetation size of greater than 10 mm and the mitral position were found to be significant risk factors for cerebral embolism, and for this group, early surgery might be considered to prevent cerebral embolism.

A Randomized Trial of Clopidogrel vs Ticagrelor After Off-Pump Coronary Bypass

BACKGROUND

This study aimed to compare the outcomes of aspirin in combination with either ticagrelor or clopidogrel after off-pump coronary artery bypass (OPCAB) in patients with clopidogrel resistance.

METHODS

Between November 2014 and November 2020, 1739 patients underwent OPCAB. Aspirin and clopidogrel treatment was initiated the day after surgery. On postoperative days 7 to 9, clopidogrel resistance was evaluated using a point-of-care assay. A total of 278 (18.9%) patients had clopidogrel resistance ( platelet reaction unit >208) and were enrolled in the study. The study investigators excluded patients with coresistance to aspirin (n = 74) and divided the remaining patients (mean age, 67.4 ± 8.5 years) into 2 groups (an aspirin and ticagrelor group [AT group; n = 102] and an aspirin and clopidogrel group [AC group; n = 102]), randomly assigned using a 1:1 ratio block table. The primary end point was graft patency and major adverse cardiovascular events (MACEs; defined as the composite of cardiovascular mortality, myocardial infarction, and repeat revascularization at 1 year after OPCAB), and the coprimary end point was the graft patency rate. The data were analyzed using the intent-to-treat method.

RESULTS

The graft occlusion rates in the AT and AC groups were 3.9% and 5.9%, respectively (P = .52). Neither death from cardiovascular causes (1.0% vs 2.9%; P = .32) nor myocardial infarction showed significant differences (1.0% vs 3.9%; P = .18). No significant difference in the rates of major bleeding were found between the 2 groups (P = .75). However, the AT group was associated with a lower rate of MACEs after OPCAB (hazard ratio, 0.77; 95% CI, 0.684-0.891; P = .01).

CONCLUSIONS

These results suggest that ticagrelor may be associated with reducing MACEs in patients with clopidogrel resistance after OPCAB.

Long-Term Outcomes of Preoperative Atrial Fibrillation in Cardiac Surgery

Background

Methods

Results

Conclusion

Time-dependent pathobiological and physiological changes of implanted vein grafts in a canine model

Although autologous vein grafting is essential, the high vein failure rate and specific clinical interventions are not clear, so a potential treatment is critically needed; thus, complex analyses of the relationship between pathobiological and physiological processes in preclinical are essential. The interposition of the femoral vein was performed in a canine model. Maximized expansion and velocity were measured at 8 weeks post-implantation, and a relative decrease was observed at 12 weeks. However, NI formation and NI/Media ratio significantly increased time dependently, and differences between the mechanical properties were observed. Additionally, RhoA-mediated TNF-α induced by rapid structural changes and high shear stress was confirmed. After adaptation to the arterial environment, vascular remodeling occurred by SMC proliferation and differentiation, apoptosis and autophagy were induced through YAP activity without vasodilation and RhoA activity. Our results show that understanding pathobiological processes in which time-dependent physiological changes contribute to vein failure can lead to a potential strategy. The implanted vein graft within the arterial environment undergoes pathobiological processes through RhoA and YAP activity, leading to pathophysiological changes.

Human Tissue Analysis of Left Atrial Adipose Tissue and Atrial Fibrillation after Cox Maze Procedure

Cardiac adipose tissue is a well-known risk factor for the recurrence of atrial fibrillation (AF) after radiofrequency catheter ablation, but its correlation with maze surgery remains unknown. The aim of this study was to investigate the correlation between the recurrence of AF and the adipose component of the left atrium (LA) in patients who underwent a modified Cox maze (CM) III procedure. We reviewed the pathology data of resected LA tissues from 115 patients, including the adipose tissue from CM-III procedures. The mean follow-up duration was 30.05 ± 23.96 months. The mean adipose tissue component in the AF recurrence group was 16.17% ± 14.32%, while in the non-recurrence group, it was 9.48% ± 10.79% (p = 0.021), and the cut-off value for the adipose component for AF recurrence was 10% (p = 0.010). The rates of freedom from AF recurrence at 1, 3, and 5 years were 84.8%, 68.8%, and 38.6%, respectively, in the high-adipose group (≥10%), and 96.3%, 89.7%, and 80.3%, respectively, in the low-adipose group (<10%; p = 0.002). A high adipose component (≥10%) in the LA is a significant risk factor for AF recurrence after CM-III procedures. Thus, it may be necessary to attempt to reduce the perioperative adipose portion of the cardiac tissue using a statin in a randomized study.

Highly flexible and porous silk fibroin microneedle wraps for perivascular drug delivery

Various perivascular drug delivery techniques have been demonstrated for localized post-treatment of intimal hyperplasia: a vascular inflammatory response caused by endothelial damages. Although most perivascular devices have focused on controlling the delivery duration of anti-proliferation drug, the confined and unidirectional delivery of the drug to the target tissue has become increasingly important. In addition, careful attention should also be paid to the luminal stability and the adequate exchange of vascular protein or cell between the blood vessel and extravascular tissue to avoid any side effect from the long-term application of any perivascular device. Here, a highly flexible and porous silk fibroin microneedle wrap (Silk MN wrap) is proposed to directly inject antiproliferative drug to the anastomosis sites while ensuring sufficient vascular exchanges. Drug-embedded silk MNs were transfer-molded on a highly flexible and porous silk wrap. The enhanced cell compatibility, molecular permeability, and flexibility of silk MN wrap guaranteed the structural integrity of blood vessels. Silk wrap successfully supported the silk MNs and induced multiple MN penetration to the target tissue. Over 28 days, silk MN wrap significantly inhibited intimal hyperplasia with a 62.1% reduction in neointimal formation.

Global patterns in genomic diversity underpinning the evolution of insecticide resistance in the aphid crop pest Myzus persicae

The aphid Myzus persicae is a destructive agricultural pest that displays an exceptional ability to develop resistance to both natural and synthetic insecticides. To investigate the evolution of resistance in this species we generated a chromosome-scale genome assembly and living panel of >110 fully sequenced globally sampled clonal lines. Our analyses reveal a remarkable diversity of resistance mutations segregating in global populations of M. persicae. We show that the emergence and spread of these mechanisms is influenced by host-plant associations, uncovering the widespread co-option of a host-plant adaptation that also offers resistance against synthetic insecticides. We identify both the repeated evolution of independent resistance mutations at the same locus, and multiple instances of the evolution of novel resistance mechanisms against key insecticides. Our findings provide fundamental insights into the genomic responses of global insect populations to strong selective forces, and hold practical relevance for the control of pests and parasites.

Clinical and Hemodynamic Outcomes in 121 Patients Who Underwent Perceval Sutureless Aortic Valve Implantation - Early Results From a Single Korean Institution

BACKGROUND

This study aimed to evaluate the early outcomes of Perceval sutureless valves in the Korean population and to introduce a modified technique of guiding suture placement during valve deployment.Methods and Results:From December 2014 to April 2019, 121 patients (mean age: 74.7±6.2 years; 53.7% female) received a Perceval sutureless aortic valve replacement. To prevent conduction system injury, the depth of guiding suture placement (1 mm below the nadir of the annulus) was modified. All patients underwent echocardiographic evaluation at discharge and 6-12 months postoperatively, with a mean follow up of 13.7±11.2 months. Concomitant surgeries, such as coronary artery bypass grafting, and other valvular surgeries, were performed in 45.5% of cases. The mean aortic cross-clamp times for isolated and minimal procedures were 32.8±7.9, and 41.2±8.0 min, respectively. The overall transvalvular mean gradients were 13.1±3.8 mmHg at discharge and 11.5±4.7 mmHg at the last follow up. After modifying the guiding suture placement, permanent pacemaker implantation risk decreased from 9.9% to 2.5%. Cardiac-related mortality was 0.8%, with no patient developing valvular or paravalvular aortic regurgitation, valve thrombosis, or endocarditis.

CONCLUSIONS

Perceval valve implantation provided a significant cardiac-related survival benefit with excellent early hemodynamic and clinical outcomes. Further research is needed to determine whether adjusting the implantation depth, such as modification of the guiding suture technique, can reduce the risk of permanent pacemaker implantation.

Outcome of Extracorporeal Ventricular Assist Device for Cardiogenic Shock as a Bridge to Transplantation

Background

The extracorporeal ventricular assist device (e-VAD) system is designed for left ventricular support using a permanent life support console. This study aimed to determine the impact of temporary e-VAD implantation bridging on posttransplant outcomes.

Methods

We reviewed the clinical records of 6 patients with the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile 1, awaiting heart transplantation, who were provided with temporary e-VAD from 2018 to 2019. The circuit comprised a single centrifugal pump without an oxygenator. The e-VAD inflow cannula was inserted into the apex of the left ventricle, and the outflow cannula was positioned in the ascending aorta. The median follow-up duration was 8.4±6.9 months.

Results

After e-VAD implantation, lactate dehydrogenase levels significantly decreased, and Sequential Organ Failure Assessment scores significantly improved. Bedside rehabilitation was possible in 5 patients. After a mean e-VAD support duration of 14.5±17.3 days, all patients were successfully bridged to transplantation. After transplantation, 5 patients survived for at least 6 months.

Conclusion

e-VAD may reverse end-organ dysfunction and improve outcomes in INTERMACS I heart transplant patients.

Long-term Fate of Dilated Ascending Aorta after Aortic Valve Replacement for Bicuspid Versus Tricuspid Aortic Valve Disease

We compared the long-term outcomes and difference in dilatation rates of the ascending aorta after aortic valve (AV) replacement (AVR) between bicuspid and tricuspid AV patients, and evaluated risk factors associated with ascending aorta dilatation and aortic events during the follow-up. Of 1,127 patients who underwent AVR from 1995 to 2015, 259 patients with a dilated ascending aorta (≥40 mm in diameter) were included. The patients were divided into those with bicuspid (group bicuspid aortic valve [BAV], n = 105) and with tricuspid (group tricuspid aortic valve [TAV], n = 154) AV, and a propensity score-matched analysis was performed to match 98 patients in each group. The differences in the dilation rate of the ascending aorta and long-term outcomes were analyzed. Risk factors for ascending aorta dilatation, mortality, and aortic events were identified. Follow-up was completed in 100% of patients with a median follow-up duration of 106.1 [68.8, 163.0] months. The early clinical outcomes and dilation rate of the ascending aorta were similar between the groups. Overall survivals up to 15 years postoperatively were similar between groups BAV and TAV (p = 0.223). Aortic events occurred in 6 patients (groups BAV vs TAV, 2 vs 4;p = 0.678). Preoperative ascending aorta diameter showed a linear relationship with the dilatation rate of ascending aorta (p <0.001) and was related to progressive aortic dilatation and aortic events (odds ratio: 1.25, p <0.001 and hazard ratio = 1.56, p <0.001, respectively). In conclusion, the long-term outcomes and ascending aorta dilatation rate were similar between the BAV and TAV patients up to 15 years after AVR. Bicuspid AV was not a risk factor of mortality or aortic events.

The fate of residual aortic regurgitation after ascending aorta replacement in type A aortic dissection

OBJECTIVE

This study aimed to evaluate the changes in postoperative aortic regurgitation (AR) and determine the predictors of significant AR and root reoperation after ascending aortic replacement (AAR) in patients with acute type A aortic dissection.

METHODS

From January 1995 to December 2017, 271 consecutive patients underwent valve/root-preserving AAR (n = 225) and root replacement (n = 46). AR grade trend over time was analyzed by the ordinal mixed-effects model. Significant AR was defined as AR grade ≥3+ during the follow-up period. Predischarge and follow-up echocardiograms were obtained in 95.6% and 88.8% of enrolled patients, respectively.

RESULTS

At predischarge, postoperative ≥2+ AR was present in 20 (9.3%) and 1 (2.3%) patients in the AAR and root replacement groups, respectively. With increasing time after surgery, the grade of AR increased. At 10 years, 4.6% of patients had developed 3+ or 4+ AR. Considering death as the competing risk, the 10-year cumulative incidence of significant AR was significantly higher in the AAR than in the root replacement group (12.3% vs 2.2%; P = .047). The risk of root reoperation at 10 years was not different between the groups (P = .118). On Cox analysis, preoperative ≥3+ AR (P = .002), postoperative ≥2+ AR (P = .040), and false to true lumen ratio (P = .005) were associated predictors of significant AR.

CONCLUSIONS

Although valve/root-preserving AAR demonstrated reasonable long-term outcomes when compared with root replacement, preoperative ≥3+ AR, postoperative ≥2+ AR, and high false to true lumen ratio significantly increased the risk of significant AR. Therefore, careful echocardiographic surveillance may be warranted in patients with postoperative ≥2+ AR and small true lumen.

The Impact of a Reentry Tear After Open Repair of Nonsyndromic Acute Type I Aortic Dissection

BACKGROUND

The role of a reentry tear in the descending thoracic aorta (DTA) after repair of acute aortic dissection is not well known. We therefore investigated the impact of reentry tear location on late aorta reintervention and the aortic expansion rate after open repair of acute type I aortic dissection.

METHODS

We analyzed 309 nonsyndromic acute type I aortic dissection patients who were treated with a repair to the proximal aorta between 1994 and 2017. The locations of reentry tears, identified with predischarge computed tomography, were the proximal DTA in 119 patients (38.5%), distal DTA in 78 (25.2%), and abdominal aorta in 129 (41.7%). Patients who had a proximal DTA reentry tear were defined as the PDR group (119 [38.5%]), and the others were defined as the non-PDR group (190 [61.5%]).

RESULTS

The 15-year freedom from aorta reintervention was significantly lower in the PDR group (51.5% ± 0.7% vs 90.4% ± 4.4%, P < .001). The aortic expansion rates of the proximal DTA (7.6 ± 16.1 mm/y vs 0.1 ± 2.5 mm/y, P < .001) and distal DTA (6.8 ± 15.5 mm/y vs 0.3 ± 3.1 mm/y, P < .001) were significantly higher in the PDR group. The 15-year freedom from significant aortic expansion was significantly lower in the PDR group (34.6% ± 6.9% vs 83.6% ± 7.9%, P < .001). Multivariate analysis showed that a proximal DTA reentry tear was an independent risk factor for aorta reintervention (hazard ratio, 4.955; 95% confidence interval, 1.691-14.523; P = .004) and significant aortic expansion (HR, 4.214; 95% CI, 1.691-10.498; P = .002).

CONCLUSIONS

A proximally located DTA reentry tear was associated with an increased risk of late aorta reintervention and distal aortic dilatation.

Statins Reduce Thoracic Aortic Aneurysm Growth in Marfan Syndrome Mice via Inhibition of the Ras-Induced ERK (Extracellular Signal-Regulated Kinase) Signaling Pathway

Background

Statins reduce aneurysm growth in mouse models of Marfan syndrome, although the mechanism is unknown. In addition to reducing cholesterol, statins block farnesylation and geranylgeranylation, which participate in membrane‐bound G‐protein signaling, including Ras. We dissected the prenylation pathway to define the effect of statins on aneurysm reduction.

Methods and Results

Fbn1^C1039G/+ mice were treated with (1) pravastatin (HMG‐CoA [3‐hydroxy‐3‐methylglutaryl coenzyme A] reductase inhibitor), (2) manumycin A (MA; FPT inhibitor), (3) perillyl alcohol (GGPT1 and ‐2 inhibitor), or (4) vehicle control from age 4 to 8 weeks and euthanized at 12 weeks. Histological characterization was performed. Protein analysis was completed on aortic specimens to measure ERK (extracellular signal‐regulated kinase) signaling. In vitro Fbn1^C1039G/+ aortic smooth muscle cells were utilized to measure Ras‐dependent ERK signaling and MMP (matrix metalloproteinase) activity. Pravastatin and MA significantly reduced aneurysm growth compared with vehicle control (n=8 per group). In contrast, PA did not significantly decrease aneurysm size. Histology illustrated reduced elastin breakdown in MA‐treated mice compared with vehicle control (n=5 per group). Although elevated in control Marfan mice, both phosphorylated c‐Raf and phosphorylated ERK1/2 were significantly reduced in MA‐treated mice (4–5 per group). In vitro smooth muscle cell studies confirmed phosphorylated cRaf and phosphorylated ERK1/2 signaling was elevated in Fbn1^C1039G/+ smooth muscle cells (n=5 per group). Fbn1^C1039G/+ smooth muscle cell Ras‐dependent ERK signaling and MMP activity were reduced following MA treatment (n=5 per group). Corroborating in vitro findings, MMP activity was also decreased in pravastatin‐treated mice.

Conclusions

Aneurysm reduction in Fbn1^C1039G/+ mice following pravastatin and MA treatment was associated with a decrease in Ras‐dependent ERK signaling. MMP activity can be reduced by diminishing Ras signaling.

Effect of Pulmonary Hypertension on Clinical Outcomes in Patients With Rheumatic Mitral Stenosis

BACKGROUND

Long-term outcomes of mitral valve replacement (MVR) recipients with pulmonary hypertension (PH) remain unclear. We determined the effect of concomitant PH on the clinical outcomes and late-onset progression of tricuspid regurgitation (TR) after MVR for rheumatic mitral stenosis.

METHODS

We retrospectively reviewed 394 patients who underwent MVR between January 2000 and December 2013. PH was defined as systolic pulmonary arterial pressure (sPAP) >50 mm Hg. Changes in echocardiographic parameters (preoperative to postoperative), TR progression (grade ≥ II), and long-term survival were evaluated according to the presence of PH at MVR (non-PH, n = 322; PH, n = 72).

RESULTS

The 10-year overall survival rate was significantly lower in the PH group (79.7% vs 90.7%, P = .04), whereas the rate of freedom from TR progression was similar between groups (76.9% vs 80.5%, P = .373). High preoperative sPAP and right ventricular systolic pressure (RVSP) did not affect TR progression. However, substantial postoperative reductions in sPAP and RVSP protected against TR progression (hazard ratio [95% confidence interval], 0.966 [0.942-0.991], P = .008, and 0.973 [0.960-0.986], P < .001, respectively). The 10-year rate of freedom from TR progression was significantly higher in patients with substantial sPAP and RVSP reductions (sPAP, 84.2% vs 70.6%, P = .003; RVSP, 84.9% vs 71.0%, P < .001).

CONCLUSIONS

Although concomitant PH at MVR is associated with poor long-term survival, adequate sPAP and RVSP reduction can prevent TR progression even in patients with severe PH preoperatively. Therefore, we suggest careful monitoring of PAP and RVSP after MVR and should make an effort to reduce postoperative PAP.

Effect of the proximal anastomosis site on mid-term radial artery patency in off-pump coronary artery bypass

OBJECTIVES

The purpose of this study was to evaluate mid-term patency and clinical outcomes according to the proximal anastomosis site after off-pump coronary artery bypass using the radial artery (RA).

METHODS

From January 2001 to December 2015, 1124 patients who underwent isolated off-pump coronary artery bypass using the RA were reviewed and divided into 2 groups: the composite Y-graft (n = 1014, Y group) and aortocoronary graft (n = 110, Aorta group). Graft patency was assessed by computed tomography or coronary angiography.

RESULTS

Patients receiving Y-grafts had a greater number of RA anastomoses (1.79 ± 0.68 per patient vs 1.40 ± 0.51 per patient, P < 0.001), more sequential grafts (55.6% vs 37.3%, P < 0.001) and a higher incidence of total arterial revascularization (77.9% vs 54.5%, P < 0.001). Postoperative graft patency at a mean of 3.1 ± 3.5 years was assessed in 1944 distal RA anastomoses (Y group: 1811, Aorta group: 133). No significant differences were observed in RA graft patency rate (P = 0.705), overall survival (P = 0.987) and major cardiac event-free survival (P = 0.830) between groups. Multivariable analysis demonstrated that the independent predictors of graft occlusion were age [hazard ratio (HR) 1.025, confidence interval (CI) 1.007-1.044; P = 0.007], female gender (HR 1.391, CI 1.007-1.924; P = 0.047), target of the right coronary artery territory (HR 2.135, CI 1.347-3.382; P = 0.001) and target vessel stenosis ≥90% (HR 0.478, CI 0.291-0.785; P = 0.004). The proximal anastomosis site was not significantly associated with graft occlusion (P = 0.705).

CONCLUSIONS

When target vessel territory and stenosis are appropriately considered, the RA as a secondary conduit can be effectively used for myocardial revascularization, regardless of the proximal anastomosis site.

Late complications after hybrid aortic arch repair

OBJECTIVE

Although hybrid arch repair has gained widespread application as an alternative option for high-risk patients, concerns about its long-term durability remain an important issue. The aim of this study was to investigate late complications after hybrid arch repair.

METHODS

From January 2002 to December 2017, hybrid arch repair was performed in 65 patients with aortic arch disease (median age, 66.1 years; range, 41-86 years). Hybrid arch repair was defined as debranching involving at least one supra-aortic vessel bypass and simultaneous or staged endovascular thoracic stent grafting. We retrospectively analyzed late complications including reintervention, open conversion, and aortic-related death. The median follow-up period was 60.1 months (range, 1-170 months).

RESULTS

The in-hospital mortality rate was 6% (4/65). Except for early death (n = 4) and early open conversion (n = 2), late complications were observed in 25 patients (25/59 [42%]). The median time interval between the initial procedure and late complication was 36.6 months (range, 1-92 months). Late complications included delayed type I endoleak (n = 8), distal stent-induced new entry (n = 3), stent migration (n = 3), retrograde type A dissection (n = 2), aortopulmonary fistula (n = 2), aortoesophageal fistula (n = 1), stent fracture (n = 1), infection (n = 1), and sudden death (n = 4). Six of these patients (10%) underwent late open conversion. The overall survival rates at 3 years and 6 years were 71.1 ± 7.4% and 57.2 ± 11.3%, respectively. The aortic event-free rates at 3 years and 6 years were 52.1 ± 7.3% and 39.4 ± 10.3%, respectively.

CONCLUSIONS

Late complications in hybrid arch repair occurred in a substantial proportion of patients during midterm follow-up. Regardless of zone type, the incidence of late complications was relatively high. This study suggests that timely reintervention and open conversion are important for rescuing patients, but repeated reinterventions and conservative strategies are not recommended. Aggressive management and life-long surveillance after hybrid arch repair are mandatory for better outcomes.

Experimental Tracheal Replacement Using 3-dimensional Bioprinted Artificial Trachea with Autologous Epithelial Cells and Chondrocytes

Various treatment methods for tracheal defects have been attempted, such as artificial implants, allografts, autogenous grafts, and tissue engineering; however, no perfect method has been established. We attempted to create an effective artificial trachea via a tissue engineering method using 3D bio-printing. A multi-layered scaffold was fabricated using a 3D printer. Polycaprolactone (PCL) and hydrogel were used with nasal epithelial and auricular cartilage cells in the printing process. An artificial trachea was transplanted into 15 rabbits and a PCL scaffold without the addition of cells was transplanted into 6 rabbits (controls). All animals were followed up with radiography, CT, and endoscopy at 3, 6, and 12 months. In the control group, 3 out of 6 rabbits died from respiratory symptoms. Surviving rabbits in control group had narrowed tracheas due to the formation of granulation tissue and absence of epithelium regeneration. In the experimental group, 13 of 15 animals survived, and the histologic examination confirmed the regeneration of epithelial cells. Neonatal cartilage was also confirmed at 6 and 12 months. Our artificial trachea was effective in the regeneration of respiratory epithelium, but not in cartilage regeneration. Additional studies are needed to promote cartilage regeneration and improve implant stability.

Rosuvastatin attenuates bioprosthetic heart valve calcification

OBJECTIVE

There are pathophysiologic similarities between calcification and atherosclerosis because both are the product of an active inflammatory process. The aim of the study was to examine the effects of statin treatment on calcification in commercially available bioprosthetic heart valves.

METHODS

Twenty Sprague-Dawley rats were fed a high-fat diet to induce hypercholesterolemia during 4 weeks. They were randomly divided into 2 groups according to statin intake (control, n = 10: high-fat diet/statin; n = 10: high-fat diet with statin). Four commercially available tissue valve (Magna Perimount, Carpentier-Edwards, Irvine, Calif; Hancock, Medtronic, Minneapolis, Minn; Mitroflow, LivaNova, London, England; and Trifecta, St Jude Medical, St Paul, Minn) cusp samples (total 320) were implanted in rat dorsal subcutis at 4 weeks. After implantation, rosuvastatin was administered daily to the statin group. The cusps were explanted at 12 weeks, and calcium levels were determined by atomic absorption spectroscopy. Western blotting, histologic, and immunohistochemical analyses were conducted to identify the anticalcification mechanism of the statin.

RESULTS

The mean calcium level in the control group was significantly higher than in the statin group (P < .01) for all tissue valves (Magna Perimount: 2.67 ± 0.26 mg/g vs 1.31 ± 0.40 mg/g; Hancock: 2.70 ± 0.57 mg/g vs 1.53 ± 0.34 mg/g; Mitroflow: 2.39 ± 0.71 mg/g vs 1.26 ± 0.38 mg/g; Trifecta: 2.54 ± 0.42 mg/g vs 1.63 ± 0.72 mg/g). Inflammatory cell infiltration and interleukin-6 and bone morphogenetic protein 2 expressions were significantly reduced in the statin group.

CONCLUSIONS

Statin treatment significantly attenuated bioprosthetic heart valve calcification associated with decreasing the levels of interleukin-6 and bone morphogenetic protein 2. Thus, statin treatment might be helpful for the longevity of bioprosthetic heart valves.

Surgical Repair of Distal Aortic Arch Aneurysm With Distal Extension: Sternotomy Versus Thoracotomy

BACKGROUND

There is no consensus as to whether a median approach or a lateral approach is better for distal aortic arch aneurysms with distal extensions. The aim of this study was to compare clinical outcomes of these two approaches for distal aortic arch aneurysms with distal extensions.

METHODS

From January 2001 to December 2017, 212 consecutive patients with distal aortic arch aneurysms with distal extensions underwent surgery using different approaches: hemiarch and descending thoracic aneurysm replacement through thoracotomy (group 1, n = 91); and total arch and descending thoracic aneurysm replacement through sternotomy (group 2, n = 121). Early and late outcomes were compared using scores and inverse probability of treatment adjustments to reduce treatment selection bias.

RESULTS

The in-hospital mortality was 9.89% (9 of 91) in the thoracotomy group and 2.48% (3 of 121) in the sternotomy group (p = 0.02). The sternotomy group had a lower incidence of permanent stroke (2.48%, 3 of 121) compared with the thoracotomy group (10.99%, 10 of 91, p = 0.01). After adjustment, patients who underwent thoracotomy were at a greater risk of hospital mortality (odds ratio 5.0, p = 0.01), permanent stroke (odds ratio 6.83, p < 0.01), and pneumonia (odds ratio 2.99, p = 0.04), compared with patients who underwent sternotomy. The overall survival at 10 years was 69.8% ± 7.0% for the thoracotomy group and 83.0% ± 5.0% for the sternotomy group (unadjusted p = 0.049, adjusted p = 0.034).

CONCLUSIONS

The sternotomy approach showed better outcomes in terms of operative mortality, stroke, and pneumonia, as well as long-term survival compared with the thoracotomy approach. These results suggested that the sternotomy approach was more appropriate for patients with distal aortic arch aneurysms with distal extensions.

Comparison of open surgical versus hybrid endovascular repair for descending thoracic aortic aneurysms with distal arch involvement

Background

Our aim was to compare the efficacies of conventional open thoracotomy and hybrid endovascular technique in patients with descending thoracic aortic aneurysms involving the distal arch.

Methods

Between January 2005 and December 2015, 125 consecutive patients with descending aneurysms involving distal arch underwent open repair via thoracotomy (n=79) or zone 1/2 hybrid endovascular repair (n=46). Surgeries entailing total arch replacement by elephant trunk technique (with sternotomy) and Zone 0 hybrid arch repairs were excluded. Early and late outcomes were compared using propensity scores and inverse-probability-of-treatment weighting (IPTW).

Results

In-hospital mortality rates for open repair (10.1%) and hybrid repair (6.5%) did not differ significantly (P=0.49). Major adverse outcomes included stroke (11.4% vs. 8.7%), paraplegia (2.5% vs. 0.0%) and lung complications (19.0% vs. 6.5%). Once adjusted by IPTW, hospital mortality risk for conventional open repair (OR =4.396; P=0.086) tended to be higher, and there was significant risk of lung complications (OR =4.372; P=0.025). However, both techniques were similar in terms of 30-day mortality (OR =2.745; P=0.257), stroke (OR =2.134; P=0.217), paraplegia (OR =3.639; P=0.407), and midterm survival (OR =1.05; P=0.90). Freedom from reintervention at 10 years was significantly better for open repair (85.2%±7.1%) compared with the hybrid approach (46.3%±11.0%; OR =0.13; P<0.01).

Conclusions

Hybrid arch repair conferred a significantly lower incidence of pulmonary complications, without benefitting perioperative mortality and stroke. However, open repair proved more reliable, showing greater durability. Long-term investigations are needed to confirm the viability and safety of hybrid repair as an alternative treatment in this setting.

The feasibility and safety of off-pump coronary bypass surgery in emergency revascularization

Background

The efficacy and safety of off-pump coronary artery bypass grafting (OPCAB) in emergency revascularization remains controversial despite its widespread use. The aim of our study was to examine the applicability and safety of OPCAB in patients who were indicated for emergency surgery.

Methods

This single-center study reviewed the indication, operative data, and early and long-term outcomes of 113 patients (mean age, 67.2±9.0 years; logistic EuroSCORE, 14.3±13.5) who underwent emergency OPCAB from January 2003 to December 2014 and were followed up (94.6% completion rate) for a mean 51.1±40.3 (range, 1-135) months.

Results

Emergency OPCAB was associated with favorable surgical outcomes (number of distal anastomoses per patient, 3.04±0.87; internal thoracic artery (IMA) use, 98.2%; complete revascularization, 79.6%) and in-hospital outcomes (mortality, 5.3%; low cardiac output syndrome, 5.3%; stroke, 2.7%; pulmonary complications, 8.8%; renal failure, 11.5%). Only five patients (4.4%) required on-pump conversion. The 10-year outcomes were also acceptable (survival, 75.4%±5.6%; major cerebral and cardiovascular events, 52.1%±1.8%). The multivariate risk factors for late mortality were peripheral vascular disease (HR 2.95, 95% CI: 1.11-11.83), cardiogenic shock (HR 3.67, 95% CI: 1.35-9.96), and incomplete revascularization (HR 3.41, 95% CI: 1.06-14.26). When patients were separated by whether the procedure was performed early (<2010) or late (≥2010) in the study period, the late period cohort had better outcomes despite containing higher-risk patients.

Conclusions

Our study suggests that emergency OPCAB can be performed safely and effectively with good hospital outcomes and adequate long-term results. OPCAB strategy can be considered as a good option in emergency revascularization.

Clinical outcomes of different surgical approaches for proximal descending thoracic aneurysm involving the distal arch

BACKGROUND

The aim of this study was to evaluate clinical outcomes of different approaches to patients with proximal descending thoracic aneurysm (DTA) involving the distal arch.

METHODS

From January 2002 to December 2016, 229 consecutive patients with proximal descending aorta aneurysm involving the distal arch underwent surgery using different approaches: total arch and DTA replacement via sternotomy (TAR group; n = 98), hemiarch and DTA replacement via thoracotomy (DTR group; n = 84), or hybrid arch repair (HAR group; n = 47). We retrospectively evaluated the outcomes of the 3 groups with a mean follow-up duration of 60.2 months.

RESULTS

The in-hospital mortality rate was 3.1% (3/98) in the TAR group, 11.9% (10/84) in the DTR group, and 4.3% (2/47) in the HAR group (P = .04). The TAR group had a lower incidence of stroke (3.1%, 3/98) compared with the DTR (13.1%, 11/84) and HAR (10.6%, 5/47) groups (P = .03). The overall survival rate at 10 years was 82.8% ± 5.6% for the TAR group, 61.0% ± 8.6% for the DTR group, and 55.9% ± 9.0% for the HAR group (vs DTR [P = .03] and HAR [P < .01]). The freedom from composite of aortic events at 10 years was 75.6% ± 8.1% in the TAR group, 43.6% ± 14.9% in the DTR group, and 31.1% ± 11.5% in the HAR group (P < .01).

CONCLUSIONS

The sternotomy approach showed better outcomes in terms of operative mortality, stroke, and long-term survival compared with the thoracotomy or hybrid approaches. This study suggests that the sternotomy approach is the superior option for patients with proximal descending aneurysm involving the distal arch.

Transfer-molded wrappable microneedle meshes for perivascular drug delivery

After surgical procedures such as coronary/peripheral bypass grafting or endarterectomy for the treatment of organ ischemia derived from atherosclerosis, intimal hyperplasia (IH) which leads to restenosis or occlusion at the site of graft anastomosis frequently occurs. In order to inhibit IH caused by abnormal growth of smooth muscle cells (SMCs) in tunica media, various perivascular drug delivery devices are reported for delivery of anti-proliferation drugs into vascular tissue. However, there still remain conflicting requirements such as local and unidirectional delivery vs device porosity, and conformal tight device installation vs pulsatile expansion and constriction of blood vessels. In this study, a biodegradable microneedle (MN) array is developed on a flexible woven surgical mesh using a transfer molding method. Mechanical properties of 'wrappable' MN meshes are investigated and compared to the properties of blood vessels. Ex vivo and in vivo animal studies demonstrate enhanced drug delivery efficiency, efficacy for IH reduction, and safety of MN mesh. In particular, MN mesh showed significantly reduced neointiamal formation (11.1%) compared to other competitive groups (23.7 and 22.2%) after 4-week in vivo animal study. Additionally, wrappable MN meshes effectively suppressed side effects such as IH due to mechanical constriction, loss of toxic drug to the surroundings, and cell death that were frequently observed with other previous perivascular drug delivery devices.

Impact of prosthesis-patient mismatch after mitral valve replacement in rheumatic population: Does mitral position prosthesis-patient mismatch really exist?

Background

Prosthesis-patient mismatch (PPM) is characterised by the effects of inadequate prosthesis size relative to body surface area (BSA).The purpose of this study was to determine the impact of PPM on late clinical outcomes after mitral valve replacement (MVR) in rheumatic population.

Methods

From 2000 to 2013, a total of 445 patients (mean age 54.2 ± 11.7 years) underwent isolated MVR (±tricuspid annuloplasty) for rheumatic disease were investigated. Effective orifice area (EOA) was determined by the continuity equation and PPM was defined as indexed EOA (EOA/BSA) ≤ 1.2 cm²/m². Clinical and echocardiographic follow-up (mean follow up 8.7 ± 4.0 years) results were compared.

Results

37% of patients (n = 165) had PPM. There were no significant differences in baseline and operative characteristics between patients with and without PPM except age and IEOA. A significant decrease in mean trans-valvular pressure gradient (MPG) over time following MVR, however the change of MPG showed no differences between groups (No PPM vs. PPM: 8.9 ± 4.7 mmHg → 3.6 ± 1.2 mmHg vs. 8.7 ± 4.5 mmHg → 3.8 ± 1.4 mmHg, p-value = 0.28). In all patients, there was a reduction of left atrium dimension (58.6 ± 12.0 mm → 53.2 ± 12.0 mm vs. 57.9 ± 8.9 mm → 52.2 ± 8.9 mm, p-value = 0.68) and left ventricular end diastolic diameter (49.9 ± 5.7 mm → 48.9 ± 5.7 mm vs. 49.7 ± 6.0 mm → 48.3 ± 5.0 mm, p = 0.24) without statistical significance. Freedom from TR progression rates at 3 and 5 years (99% vs.98%, 99% vs. 98%, p-value = 0.1), and overall survival rates at 3 and 5 years (97% vs. 96%, 94% vs. 94%, p-value = 0.7) were similar.

Conclusion

This study shows that mitral PPM is not associated with atrial /ventricular remodeling and might not influence late clinical outcome including late TR progression, survival in rheumatic population.

Effect of Recurrent Mitral Regurgitation After Mitral Valve Repair in Patients With Degenerative Mitral Regurgitation

BACKGROUND

This study investigated the consequences of recurrent mitral regurgitation (MR) after mitral valve (MV) repair in patients with degenerative MR and risk factors for recurrence.Methods and Results:From January 1990 to December 2015, 792 patients underwent MV repair due to degenerative MR. Recurrent MR was defined as moderate-to-severe MR on follow-up echocardiography. Mean follow-up duration was 8.71±5.58 years. During the follow-up period, MR recurred in 133 (16.8%) patients, and the MR recurrence-free rate at 20 years was 77.5±2.0%. In the recurrence group, the degree of MR decreased in 8 (6.0%) patients and was aggravated in 46 (34.6%) patients. Recurrent MR was associated with increased mortality and adverse left ventricular (LV) remodeling. Independent risk factors for MR recurrence were MV repair performed before 2000, preoperative atrial fibrillation, high LV end-diastolic dimension (LVEDD), prolapse of the isolated anterior leaflet or multiple segments, and absence of ring annuloplasty. Predictors of MR progression were high LVEDD and repair without artificial chordae implantation.

CONCLUSIONS

Recurrent MR after MV repair in patients with degenerative MR showed a tendency to progress and was associated with increased mortality and adverse LV remodeling. Early referral for MV repair before development of atrial fibrillation and LV enlargement may reduce the risk of MR recurrence. Moreover, artificial chordae implantation and ring annuloplasty may assure the long-term durability of MV repair.