Mid-term outcomes of surgical aortic valve replacement using a mosaic porcine bioprosthesis with concomitant mitral valve repair.

This study retrospectively evaluated the mid-term outcomes of surgical aortic valve replacement (SAVR) using a stented porcine aortic valve bioprosthesis (Mosaic; Medtronic Inc., Minneapolis, MN, USA) with concomitant mitral valve (MV) repair. From 1999 to 2014, 157 patients (median [interquartile range] age, 75 [70-79] years; 47% women) underwent SAVR with concomitant MV repair (SAVR + MV repair), and 1045 patients (median [interquartile range] age, 76 [70-80] years; 54% women) underwent SAVR only at 10 centers in Japan as part of the long-term multicenter Japan Mosaic valve (J-MOVE) study. The 5-year overall survival rate was 81.5% ± 4.1% in the SAVR + MV repair group and 85.1% ± 1.4% in the SAVR only group, and the 8-year overall survival rates were 75.2% ± 5.7% and 78.1% ± 2.1%, respectively. Cox proportional hazards analysis showed no significant difference in the survival rates between the two groups (hazard ratio, 0.87; 95% confidence interval, 0.54-1.40; P = 0.576). Among women with mild or moderate mitral regurgitation who were not receiving dialysis, those who underwent SAVR + MV repair, were aged > 75 years, and had a preoperative left ventricular ejection fraction of 30-75% tended to have a lower mortality risk. In conclusion, this subgroup analysis of the J-MOVE cohort showed relevant mid-term outcomes after SAVR + MV repair.

[Cooperation between the Department of Cardiovascular Surgery in University of Tsukuba and Cho-Ray Hospital, Ho-Chi-Minh City, Vietnam--for an attractive collaboration in international medical education].

The Department of Cardiac Surgery in Cho-Ray Hospital, Ho-Chi-Minh city stands for a representative high volume center in the south of Vietnam. In the department about 1,200 cases of open-heart surgery are performed in a year. In next era, they wish to improve their surgical quality, focusing on complex and low-weight congenital cases, mitral repair, maze operation and off-pump CABG. Since 2008, University of Tsukuba has started to collaborate with many departments in Cho-Ray Hospital as a project of international medical educations in Global 30, and has been establishing meaningful activities in the Department of Cardiac Surgery as well. We keep providing opportunities for education, research and training for young Vietnamese doctors and investigators as much as possible both in Cho-Ray Hospital and University of Tsukuba with some financial support. We believe that our steady collaboration with Cho-Ray Hospital will bring certain developments not only for Vietnamese but for ourselves.

Identification of human placenta-derived mesenchymal stem cells involved in re-endothelialization.

Human placenta is an attractive source of mesenchymal stem cells (MSC) for regenerative medicine. The cell surface markers expressed on MSC have been proposed as useful tools for the isolation of MSC from other cell populations. However, the correlation between the expression of MSC markers and the ability to support tissue regeneration in vivo has not been well examined. Here, we established several MSC lines from human placenta and examined the expression of their cell surface markers and their ability to differentiate toward mesenchymal cell lineages. We found that the expression of CD349/frizzled-9, a receptor for Wnt ligands, was positive in placenta-derived MSC. So, we isolated CD349-negative and -positive fractions from an MSC line and examined how successfully cell engraftment repaired fractured bone and recovered blood flow in ischemic regions using mouse models. CD349-negative and -positive cells displayed a similar expression pattern of cell surface markers and facilitated the repair of fractured bone in transplantation experiments in mice. Interestingly, CD349-negative, but not CD349-positive cells, showed significant effects on recovering blood flow following vascular occlusion. We found that induction of PDGFß and bFGF mRNAs by hypoxia was greater in CD349-negative cells than in CD349-positive cells while the expression of VEGF was not significantly different in CD349-negative and CD349-positive cells. These findings suggest the possibility that CD349 could be utilized as a specialized marker for MSC isolation for re-endothelialization.

Coronary sinus atrial septal defects in adults over the past 20 years at new Tokyo hospital: case series.

BACKGROUND: An isolated coronary sinus (CS) atrial septal defect (ASD) is defined as a CS unroofed in the terminal portion without a persistent left superior vena cava or other anomalies. This defect is rare and part of the wide spectrum of unroofed CS syndrome (URCS). Recently, several reports have described this finding. The database of New Tokyo Hospital was searched to determine the incidence of this defect. Additionally, to raise awareness of this condition, the findings from five patients with CS ASD who underwent surgical repair at New Tokyo Hospital are discussed. CASE PRESENTATION: The patients were three women and two men with an age range of 63-77 years. All patients underwent transthoracic echocardiography and computed tomography, and one underwent magnetic resonance imaging. In two patients, the defect was found unexpectedly intraoperatively; left-to-right shunting was apparent in the other three patients preoperatively. The pulmonary-to-systemic blood flow ratio ranged from 1.42 to 3.1 following cardiac catheterization, and oxygen saturation step-up was seen on the right side of the heart. Valvular regurgitation was seen in 4/5 patients with different combinations and degrees of mitral, tricuspid, and aortic valve involvement. Right atrial and ventricular dilation were seen in 4/5 patients; three patients had left atrial dilation. Three patients experienced atrial fibrillation, and one of these also experienced paroxysmal ventricular contractions. All patients underwent surgical repair, and some underwent multiple procedures. One patient who had previously undergone kidney transplantation died approximately 1 year postoperatively; the remaining four patients are currently experiencing good activities of daily living without symptoms. CONCLUSIONS: CS ASD (Kirklin and Barratt-Boyes type IV URCS) comprised 1.3% of adult congenital heart surgeries and 0.07% of adult open-heart surgeries at New Tokyo Hospital from 1999 to 2019. At New Tokyo Hospital, cardiac surgery is performed mainly for patients with acquired cardiac disease, and CS ASD is rare. Early diagnosis is important, as well as early surgical repair in symptomatic patients, especially those with blood access shunts, which may overload the heart. The case of a poor prognosis in this series is noteworthy, as similar cases have not been reported previously.

Experimental validation of left ventricular transmural strain gradient with echocardiographic two-dimensional speckle tracking imaging.

AIMS: To validate intramural strain measured by a speckle tracking imaging (STI) system against that measured by sonomicrometry crystals. METHODS AND RESULTS: In 11 anaesthetized sheep, six sets of three sonomicrometry crystals were implanted in endo-, mid-wall, and epimyocardium on the anterior and lateral walls. Circumferential strain (CS) was calculated at three layers from endo-, mid-wall, and epicardial speckle. Radial strain (RS) was assessed for inner and outer halves of the myocardium. We compared ultrasound-derived strain measurements against those by sonomicrometry at baseline and during pharmacological stress and coronary occlusion. Intraclass correlation coefficients at baseline and during coronary occlusion were as follows: endocardial CS 0.80, 0.97; mid-wall CS 0.58, 0.89; epicardial CS 0.71, 0.81; endocardial RS 0.50, 0.78; epicardial RS 0.35, 0.83; and total RS 0.33, 0.71; respectively. At baseline, endocardial strains were higher than mid-wall and epicardial strains, resulting in an inner/outer wall RS gradient and inner/mid/outer wall CS gradients. Ischaemia caused significant reduction in all strains and disappearance of the strain gradient. CONCLUSION: A newly developed STI system can accurately assess the intramural heterogeneity of CS distribution in normal and ischaemic myocardial segments and has the potential to become a non-invasive bedside tool for characterizing myocardial strain gradient.

A modification of extended aortic arch anastomosis augmented with subclavian flap aortoplasty for interrupted or hypoplastic aortic arch.

BACKGROUND: Surgical repair for hypoplastic aortic arch in neonates carries a substantial risk of recurrent obstruction. Simple arch anastomosis is not always a solution in cases of extended arch hypoplasia. We present our modified technique of extended aortic arch anastomosis augmented with subclavian flap aortoplasty. METHOD: We describe two neonates: interrupted aortic arch and transverse arch hypoplasia associated with aortic coarctation, who underwent a modification of extended aortic arch anastomosis augmented with subclavian flap aortoplasty. RESULTS: The patients recovered without any pressure gradient at the anastomotic site. Postoperative aortography showed no arch obstruction and they successfully underwent second stage repair. CONCLUSION: Our technique provides extensive augmentation of the aortic arch with a tension-free, wide and non-circumferential suture line which preserves potential for growth. The technique described may avoid persistent or repeat arch obstruction.

Endocardial surface area tracking for assessment of regional LV wall deformation with 3D speckle tracking imaging.

OBJECTIVES: The aim of this experimental study was to validate area tracking by 3-dimensional (3D) speckle tracking imaging (STI) as a method to measure changes in regional left ventricular (LV) endocardial surface area with sonomicrometry and to assess the usefulness as a wall motion evaluation method compared with 1-dimensional strain parameters. BACKGROUND: A 3D-STI allows for tracking a regional endocardial surface area during a cardiac cycle. Area tracking is a new concept that regional wall motion is quantified through the magnitude of deformation in an endocardial surface area. METHODS: In each of 8 anesthetized sheep, sonomicrometry crystals were implanted on the endocardium at the LV mid and apical anterior walls. Area change ratio (ACR) that was a novel parameter obtained by area tracking was measured as percentage change in a segmental area during systole. Segmental longitudinal (LS) and circumferential strain (CS) also were measured by 3D-STI. The ACR, LS, and CS were compared with those by sonomicrometry at baseline and during pharmacological stress tests (dobutamine and propranolol infusion) and acute myocardial ischemia induced by occlusion of mid-left ascending artery. RESULTS: The strong correlation was observed between ACR measurements by 3D-STI and those by sonomicrometry (Y = -4.20 + 0.84X, r = 0.87, p < 0.001). The ACR showed significant relations with both LS and CS (LS: Y = -15.1 + 1.73X, r = 0.73, p < 0.001; CS: Y = -5.85 + 1.06X, r = 0.79, p < 0.001). ACR showed significant differences among baseline, pharmacological stress, and acute myocardial ischemia. In contrast, LS and CS were reduced significantly during acute ischemia studies compared with those during the other studies; no differences were observed among baseline, propranolol infusion, and dobutamine infusion studies. CONCLUSIONS: Area tracking by 3D-STI can estimate changes in LV regional area and might be promising for regional wall motion evaluations.

Validation of 3-dimensional speckle tracking imaging to quantify regional myocardial deformation.

BACKGROUND: Three-dimensional speckle tracking imaging (3D-STI) has been introduced to assess regional left ventricular (LV) myocardial function. This study was designed to validate LV strain measurements by 3D-STI against data obtained by sonomicrometry. METHODS AND RESULTS: In each of 10 anesthetized sheep, sonomicrometry crystals were implanted on the endocardium and epicardium at the LV basal, mid, and apical anterior and lateral walls. LV 3D-STI data sets were obtained from the apical approach at a frame rate of approximately 30 frames/s. Segmental longitudinal (LS), radial (RS), and circumferential strain (CS) measurements by 3D-STI were compared with those by sonomicrometry at baseline and during pharmacological stress tests (dobutamine and propranolol infusion) and acute myocardial ischemia induced by coronary artery occlusion. Data were available from 136 LS, 108 CS, and 175 RS measurements. Good correlations were observed between strain measurements by 3D-STI and those by sonomicrometry (LS: r=0.89, P<0.001; RS: r=0.84, P<0.001; CS: r=0.90, P<0.001). In each segmental study, significant correlations of the 3 strain components were observed (LS: r=0.65 to 0.68, P<0.001; RS: r=0.59 to 0.70, P<0.001; CS: r=0.71 to 0.78, P<0.001). CONCLUSIONS: The newly developed 3D-STI technique can estimate LV regional circumferential, longitudinal, and radial strain components with reasonable correlation to sonomicrometry data. This methodology could be applied clinically to assess alteration of myocardial function by accurately measuring strain in basal, mid, and apical LV segments, even during pharmacological and ischemic interventions. Therefore, 3D-STI appears to be a reliable tool to assess LV regional wall function.

Heart failure due to severe supravalvular aortic stenosis in painless type A aortic dissection.

Severe supravalvular aortic stenosis is a rare complication of aortic dissection. Painless aortic dissection is also relatively rare. We report the case of a 67-year-old man who had New York Heart Association class III heart failure without chest pain and was found to have supravalvular aortic stenosis secondary to chronic type A aortic dissection. The patient underwent ascending aorta and hemiarch replacement with selective antegrade cerebral perfusion under deep hypothermic circulatory arrest. The patient was discharged to home with complete resolution of heart failure and has been carefully followed up for 1 year, during which he has experienced no symptoms.