Long-term results of etiology-based thoracic endovascular aortic repair: a single-center experience

The use of thoracic endovascular aortic repair (TEVAR) for thoracic aortic aneurysm (TAA) and Stanford type B aortic dissection (TBAD) has been increasing; however, in terms of etiology, the differences of long term after TEVAR outcomes remain unexplored. Thus, we investigated etiology-specific long-term results of TEVAR for TAA and TBAD. A total of 421 TEVAR procedures were performed at our institution from July 2007 to December 2021; 249 TAA cases and 172 TBAD cases were included. Traumatic aortic dissection and aortic injury cases were excluded. The mean observation duration was 5.7 years. The overall 30-day mortality rate was 1.4% (n = 6), with 1.2% (n = 3) in the TAA group and 1.7% (n = 3) in the TBAD group. The overall incidence of postoperative stroke was 0.9% (n = 4), with 1.2% (n = 3) and 0.6% (n = 1) in the TAA and TBAD groups, respectively (p = 0.90). Paraplegia developed in 1.7% (n = 7) of patients, with 2.4% (n = 6) in the TAA group and 0.6% (n = 1) in the TBAD group. Freedom from aortic-related death was not significantly different between the two etiologies; however, thoracic reintervention was more common in the TBAD group (p = 0.003), with endoleak being the most common indication for reintervention. Additionally, retrograde type A aortic dissection occurred in four TBAD cases, while migration occurred in three TAA cases. The perioperative results of TEVAR for TAA and TBAD were satisfactory. The long-term results were unfavorable owing to the occurrence of etiology-specific and common complications. In terms of the high frequency of reintervention, the long-term complications associated with TEVAR are etiology specific.

Pre-Transplant Seroprevalence, Associated Factors, and Post-Transplant Incidence of Toxoplasma gondii Infection Among Heart Transplant Recipients in Japan

BACKGROUND

Among solid organ transplant (SOT) recipients, heart transplant (HT) recipients are at a higher risk of Toxoplasma gondii infection. As Toxoplasma seroprevalence varies by geographic location, updated local epidemiology is essential to guide preventive and therapeutic strategies. However, the Toxoplasma seroprevalence and incidence of post-transplant toxoplasmosis among SOT recipients in Japan are unknown.

METHODS

We performed a single-center retrospective observational study at an HT center in Tokyo, Japan. All HT recipients aged ≥18 years between 2006 and April 2019 were included. We reviewed patient charts and conducted a questionnaire survey to investigate the risk factors for infection.

RESULTS

Among 105 recipients included in the study, 11 (10.5%) were seropositive before transplant. Ninety-five recipients (90.5%), including all pre-transplant seropositive recipients, answered the questionnaire. The recipients who had lived in Okinawa (odds ratio [OR] 7.5 [95% CI 1.42-39.61]; P = .032) and who reported raw-meat eating habits (OR 4.64 [95% CI 1.04-23.3]; P = .021) were more likely to be seropositive. None of the patients developed symptoms of toxoplasmosis. The post-transplant incidence of other major adverse outcomes was not significantly different according to the pre-transplant serostatus.

CONCLUSIONS

About 10% of HT recipients at an HT center in Tokyo were seropositive for Toxoplasma pre-transplant, and none developed symptomatic toxoplasmosis post-transplant on trimethoprim-sulfamethoxazole. The history of raw meat consumption was associated with seropositivity; therefore, avoiding it might be recommended for HT recipient candidates.

EVAHEART 2 with double cuff tipless inflow cannula is suitable for long-term support atrial switch operation in transposition of great arteries

Implantation of continuous-flow left ventricular assist device in a narrow lumen is technically challenging to secure an optimal support. We experienced a patient with the transposition of the great arteries after the Senning procedure who was initially implanted with Jarvik 2000®. She presented with worsening heart failure symptoms 2 years after implanting Jarvik 2000®. We assumed that the inflow cannula was stuck in the highly developed trabeculae on the interventricular septum, which disturbed the VAD to maintain an expected support. After converting to the EVAHEART® 2, we successfully obtained an adequate inflow. We consider that the tipless cannula of EVAHEART® 2 is the most suitable when there is no sufficient room to place a conventional inflow cannula in the systemic ventricle.

A case of colonic perforation in collagenous colitis without diarrheal symptoms.: A case report

INTRODUCTION

Collagenous colitis is an inflammatory disease characterized by hyperplasia of the collagen band beneath the colonic mucous membrane. Chronic diarrhea is a characteristic clinical symptom. The disease is often diagnosed accidentally on colonoscopy for chronic diarrhea, and patients without chronic diarrhea have few chances to suspect the disease.

PRESENTATION OF CASE

The patient was a 75-year-old woman. The chief complaint was sudden upper abdominal pain and vomiting. There were no important findings regarding the consumed food or bowel habits (no diarrhea). Computed tomography revealed wall thickness and a small amount of free air around the descending colon. An emergency laparotomy was performed with the diagnosis of spontaneous colonic perforation. Intra-operative findings revealed a longitudinal ulcer and micro-perforation to the mesenterial side at the descending colon. Pathological findings revealed subepithelial collagenous band in the submucosal background of the ulcer, and which was diagnosed as collagenous colitis.

DISCUSSION

Intestinal perforation in collagenous colitis is extremely rare. It was considered that perforation was caused by a transient increase in intestinal pressure in the background of collagenous colitis. Further, to the best of our knowledge, this is the first report of a critical case which presented without the characteristic symptom of chronic diarrhea.

CONCLUSION

We report a rare case of colonic perforation of the collagenous colitis.

Prophylactic negative pressure wound therapy is not effective for preventing driveline infection following left ventricular assist device implantation

BACKGROUND

Driveline infection (DLI) following left ventricular assist device (LVAD) implantation remains an unresolved problem. Negative pressure wound therapy (NPWT) promotes wound healing by applying negative pressure on the surface of the wound. Recently, the prophylactic application of NPWT to closed surgical incisions has decreased surgical site infections in various postsurgical settings. Therefore, we evaluated the efficacy and safety of prophylactic NPWT for preventing DLI in patients with LVAD implantation.

METHODS

Prophylactic NPWT was provided to 50 patients who received continuous-flow LVADs as bridge-to-transplant therapy at our institution between May 2018 and October 2020 (NPWT group). The negative pressure dressing was applied immediately after surgery and retained on the driveline exit site for 7 days with a continuous application of -125 mm Hg negative pressure. The primary outcome was DLI within 1 year of LVAD implantation. We compared the rate of DLI incidence in the NPWT group with that in the historical control cohort (50 patients) treated with the standard dressing (SD) who received LVAD implantation between July 2015 and April 2018 (SD group).

RESULTS

No severe complications were associated with the NPWT. During the follow-up period, DLI was diagnosed in 16 participants (32%) in the NPWT group and 21 participants (42%) in the SD group. The rates of DLI incidence and freedom from DLI did not differ between groups (p = 0.30 and p = 0.63).

CONCLUSIONS

Prophylactic NPWT at the driveline exit site was safe following LVAD implantation. However, it did not significantly reduce the risk of DLI.

Successful Treatment with Letermovir in a Heart Transplant Recipient with UL97 Mutation Ganciclovir-Resistant Cytomegalovirus Colitis and Viremia

Currently available anti-cytomegalovirus (CMV) agents are sometimes poorly tolerated, owing to their side effects. Letermovir is a novel anti-CMV drug that is only approved for CMV prophylaxis in hematopoietic stem cell transplant recipients, with fewer side effects. We report the case of a heart transplant recipient with UL97 mutation (L595F) ganciclovir-resistant cytomegalovirus colitis who was successfully treated with off-label use of letermovir. In treating CMV infection or disease with letermovir, a transient rise or lag in the clearance of CMV-DNA polymerase chain reaction levels has been observed. Our case suggests that CMV-pp65 antigenemia can be an additional marker of treatment efficacy.

[Clinical Characteristics, Surgical Outcomes, and Optimal Approach Methods for Transverse Colon Cancers]

Surgery for transverse colon cancer is very difficult because of small number of patients, variations in the vascular system, and complexity of the mobilize hepatic and splenic flexure of colon. We analyzed the clinical characteristics and surgical outcomes in 51 cases who underwent surgery for transverse colon cancer at our hospital between January 2014 and December 2021, and examined the optimal laparoscopic approach method. The surgical procedure was right hemicolectomy in 24 cases, transverse colectomy in 22 cases, and left hemicolectomy in 5 cases, of which 37 cases had laparoscopic surgery. In laparoscopic surgery, when comparing the cranial first approach group in 21 cases and the caudal approach group in 16 cases, the operative time was almost the same between the 2 groups. In the cranial first approach group the amount of bleeding tended to be small, the number of MCA lymph node dissections tended to be large and the hospital stay tended to be short, though there was no statistically significant difference. The results suggest that the cranial first approach tends to be safer and more accurate than the caudal approach.

Long-Term Benefit of Mechanical Thrombectomy for Acute Ischemic Stroke in Patients with a Left Ventricular Assist Device: A Single-Center Retrospective Study

OBJECTIVE

Left ventricular assist devices (LVADs) are an epoch-making treatment option for patients with severe heart failure; however, the patients occasionally experience severe acute ischemic strokes (AISs). Although mechanical thrombectomy is considered as an effective treatment for severe AIS in patients with LVADs, there remains a paucity of data on the long-term outcomes. This study aimed to investigate the acute-phase efficacy and long-term outcomes of mechanical thrombectomy for AIS patients with LVADs.

METHODS

We retrospectively reviewed 9 cases in 8 patients with LVADs who developed AIS and underwent mechanical thrombectomy from July 2014 to November 2021 at our hospital. Clinical information, including the National Institutes of Health Stroke Scale score and modified Rankin Scale score before and after thrombectomy, the details of procedures, and the long-term outcomes after thrombectomy, was retrospectively reviewed and statistically analyzed.

RESULTS

Effective recanalization was achieved in 89% of the 9 cases. The median National Institutes of Health Stroke Scale score improved from 12 (range, 8-29) to 5 (range, 0-29) after mechanical thrombectomy. The median total follow-up duration was 1327 (range, 78-2659) days. Of the 8 patients, 3 patients underwent heart transplantation, and the LVAD was removed after recovery of the patient's heart function. One patient awaited heart transplantation.

CONCLUSIONS

This study revealed the long-term benefit of mechanical thrombectomy for AIS in patients with LVADs, eventually achieving 50% of independence from LVADs.

Klebsiella invasive liver abscess syndrome presenting with a central nervous system manifestation secondary to latent cholecystitis: a case report

Background

Brain abscess is a life-threatening event. Moreover, when Klebsiella pneumoniae is the cause, rapid diagnosis and appropriate treatment are required. Klebsiella invasive liver abscess syndrome, a bloodstream metastatic infection of potentially aggressive nature, has been recognized to cause infection in the central nervous system, and concern for Klebsiella liver abscess syndrome is increasing globally.

Case presentation

A 73-year-old Japanese woman was admitted to the institution complaining of aggravated dysarthria and weakness in the right upper extremities with onset 5 days earlier. Magnetic resonance imaging revealed a brain abscess in the left basal ganglia, and abdominal computed tomography revealed a liver abscess in liver segment 7. The patient’s dysarthria symptoms became increasingly worse over the next few days, so surgical drainage via frontotemporal craniotomy was performed on admission day 3, and subsequent culture from the brain abscess showed growth of Klebsiella pneumoniae. On admission day 9, percutaneous transhepatic drainage of the liver segment 7 abscess was undertaken. The pus culture also showed growth of Klebsiella pneumoniae, thus associating the liver abscess with the brain abscess. Following long-term conservative treatment with antibiotics and abscess drainage, the liver abscess disappeared. However, the patient continuously presented with right upper quadrant pain, and abdominal computed tomography showed swelling of the gallbladder. Consequently, percutaneous transhepatic gallbladder drainage was initially administered, and the bile culture was also positive for Klebsiella pneumoniae. For radical treatment, a laparoscopic cholecystectomy was performed on admission day 99. The postoperative period was complicated by an intraabdominal abscess; however, conservative therapy was successful. She was subsequently discharged, and 12-month follow-up revealed no further sequelae.

Conclusions

We describe a rare case of Klebsiella liver abscess syndrome, which first presented with a central nervous system manifestation. Our patient was successfully treated via an early surgical intervention and subsequent antibiotic therapy. Although surgical drainage remains the cornerstone treatment for brain abscess, when a brain abscess is found, and there is a high index of suspicion for the existence of a liver abscess, Klebsiella liver abscess syndrome should be considered as a possible diagnosis.

Residual Pulmonary Vascular Resistance Increase Under Left Ventricular Assist Device Support Predicts Long-Term Cardiac Function After Heart Transplantation

Aims

We compared hemodynamics and clinical events after heart transplantation (HTx) in patients stratified by the severity of residual pulmonary vascular resistance (PVR) after left ventricular assist device (LVAD) implantation for bridge to transplantation.

Methods

We retrospectively analyzed patients who had undergone HTx at the University of Tokyo Hospital. We defined the high PVR group as patients with PVR of >3 Wood Units (WU) as measured by right heart catheterization performed 1 month after LVAD implantation.

Results

We included 85 consecutive HTx recipients, 20 of whom were classified in the high PVR group and 65 in the low PVR group. The difference in PVR between the two groups became apparent at 2 years after HTx (the high PVR group: 1.77 ± 0.41 WU, the low PVR group: 1.24 ± 0.59 WU, p = 0.0009). The differences in mean pulmonary artery pressure (mPAP), mean right arterial pressure (mRAP), and mean pulmonary capillary wedge pressure (mPCWP) tended to increase from the first year after HTx, and were all significantly higher in the high PVR group at 3 years after HTx (mPAP: 22.7 ± 9.0 mm Hg vs. 15.4 ± 4.3 mm Hg, p = 0.0009, mRAP: 7.2 ± 3.6 mm Hg vs. 4.1 ± 2.1 mm Hg, p = 0.0042, and mPCWP: 13.4 ± 4.5 mm Hg, 8.8 ± 3.3 mm Hg, p = 0.0040). In addition, pulmonary artery pulsatility index was significantly lower in the high PVR group than in the low PVR group at 3 years after HTx (2.51 ± 1.00 vs. 5.21 ± 3.23, p = 0.0033). The composite event including hospitalization for heart failure, diuretic use, and elevated intracardiac pressure (mRAP ≥ 12 mm Hg or mPCWP ≥ 18 mm Hg) between the two groups was significantly more common in the high PVR group. Residual high PVR was still an important predictor (hazard ratio 6.5, 95% confidence interval 2.0–21.6, and p = 0.0023) after multivariate Cox regression analysis.

Conclusion

Our study demonstrates that patients with residual high PVR under LVAD implantation showed the increase of right and left atrial pressure in the chronic phase after HTx.

Myocardial recovery evaluation from ventricular assist device in patients with dilated cardiomyopathy

AIMS

The removal of left ventricular assist device (LVAD) after myocardial recovery can provide survival benefits with freedom from LVAD-associated complications. However, in the absence of standardization, the weaning evaluation and surgical strategy differ widely among centres. Therefore, we analysed the experiences of LVAD explantation with our protocol in dilated cardiomyopathy (DCM) patients and investigated the validity of our weaning evaluation and surgical strategy from the perspective of optimal long-term survival.

METHODS AND RESULTS

All LVAD explantation patients in our institution between May 2012 and May 2020 were enrolled. All patients were evaluated by our three-phase weaning assessment: (i) clinical stability with improved cardiac function under LVAD support; (ii) haemodynamic stability shown by ramp-loading and saline-loading test; (iii) intraoperative pump-off test. Explant surgery involved removal of the whole system including driveline, pump, sewing ring and outflow-graft, and closure of an apical hole. Intra-operative, peri-operative, and post-operative outcomes, including all-cause mortality and LVAD associated major complications, were retrospectively analysed. A total of 12 DCM patients (DuraHeart, n = 2; EVAHEART, n = 2; HeartMate II, n = 6; HeartMate 3, n = 2) had myocardial recovery after a median 10 months [interquartile range (IQR); 6.3-15 months] support and qualified for our LVAD explantation study protocol [median age: 37 y, IQR; 34-41 years; 83% men]. The median left ventricular ejection fraction was 20% (IQR; 12-23%) at LVAD-implantation and 54% (IQR: 45-55%) before LVAD explantation (P < 0.001). There were no perioperative complications and median ICU stay was 4 days (IQR; 2-4 days). All patients were discharged after a median of 24 days (IQR: 17-28 days) postoperatively. No patient suffered from any cardiac event (heart failure hospitalization, re-implantation of LVAD, or heart transplantation) at a median of 40 months (IQR: 17-58 months) follow up. All patients are alive with NYHA functional class 1 with preserved left ventricular function.

CONCLUSIONS

The evaluation of LVAD explant candidates by our weaning protocol was safe and effective. In the patients completing our protocol successfully, LVAD explantation is feasible and an excellent long-term cardiac event free-survival seems to be achieved.

Sarcopenia and risk of infection in adult heart transplant recipients in Japan

AIMS

Heart transplantation (HT) is an effective therapeutic option for end-stage heart failure. Infection is a major cause of morbidity and mortality after HT. Sarcopenia, defined as the loss of muscle mass and strength, is a common comorbidity in HT candidates with end-stage heart failure. However, the effects of sarcopenia on the occurrence of post-HT infections are not well understood. Therefore, we explored the association between the skeletal muscle mass and post-transplant infections in adult HT recipients.

METHODS AND RESULTS

We retrospectively examined the records of 135 patients who underwent HT between August 2007 and November 2019 at our institution. Pre-transplant computed tomography was used to calculate the skeletal muscle index (SMI) at the level of the third lumbar vertebra. Muscle wasting was defined as the SMI of the lowest sex-based tertiles. The primary endpoint was infections within 6 months of HT. The study included 109 patients (80 men, mean age: 41.6 ± 12.0 years): 37 patients in the muscle wasting group and 72 patients in the non-muscle wasting group. The mean SMI values in the muscle wasting and non-muscle wasting groups were 29.9 ± 4.8 cm² /m² and 40.7 ± 6.7 cm² /m² , respectively. Prior to HT, 108 (99.1%) patients were on left ventricular assist device support, and during that support, the rate of late right heart failure was significantly higher in the muscle wasting group than non-muscle wasting group (P = 0.012). Sixteen infections occurred within 6 months of HT. The most common infection sites included the respiratory tract (n = 5) and the upper gastrointestinal tract (n = 5), followed by the urinary tract (n = 4). Overall, 10 patients experienced infections in the muscle wasting group (27.0%) and 6 in the non-muscle wasting group (8.3%) (P = 0.009). Two patients in the muscle wasting group required intensive care unit admission, compared to none in the non-muscle wasting group. Low skeletal muscle mass was associated with infections in the univariate and multivariate logistic regression models (hazard ratio: 3.68, 95% confidence interval: 1.19-11.3; P = 0.023). However, the duration of all-cause mortality within 3 years did not differ between the groups (P = 0.56).

CONCLUSIONS

Low skeletal muscle mass is a predictor of post-HT infections within 6 months of HT.

Late-onset right ventricular failure after continuous-flow left ventricular assist device implantation: case presentation and review of the literature

With the widespread use of implantable left ventricular assist device (LVAD), right ventricular failure (RVF) has become a serious problem that becomes apparent several weeks or later after LVAD implantation. However, there are no marked preoperative signs of RVF. This is called late-onset RVF and is currently a major problem leading to long-term complications following implantable LVAD use. Pathogenically, this could be the result of left ventricular suction by LVAD that causes the septum shift to the left ventricular side. This causes a change in morphology of the right ventricle, resulting in impaired right ventricular function. Aortic insufficiency and ventricular arrhythmia, which are also important as long-term complications after LVAD implantation, are considered to be closely involved in the onset and progression of RVF. Once late-onset RVF develops, exercise capacity declines and inotrope administration may be required. Late-onset RVF was also reported to be significantly associated with increased mortality. Several predictors of RVF have been proposed such as preoperative left ventricular diastolic dimension <64 mm, tricuspid valve annulus diameter ≥41 mm, and so on. However, some reports identified no predictors. The basic treatment strategy for late-onset RVF is to optimize volume status by administering diuretics and ensuring inotrope as needed. β-blockers and antiarrhythmic agents often need to be reduced in terms of dosage or even discontinued because these might reduce right ventricular function. Although their efficacy is unclear, pulmonary vasodilators may be used to reduce right ventricular afterload. It is better to decrease the rotation speed of LVAD to minimize the displacement of the septum; however, this is often difficult because the required flow rate cannot be secured. Progress in the prevention and management of late-onset RVF is required because the number of patients who require longer-term LVAD support will increase with the spread of LVAD use as destination therapy.

[Surgical Outcomes and Clinicopathological Analysis of Non-Ampullary Duodenal Tumors]

Non-ampullary duodenal tumors are relatively rare; however, in recent years, they have been encountered more frequently. We analyzed the surgical outcomes and clinicopathological findings in 20 patients who underwent surgery based on preoperative diagnoses of non-ampullary duodenal tumors at our hospital between January 2011 and April 2021. We performed surgery for 3 cases of GIST, 4 cases of adenoma, and 13 cases of adenocarcinoma. The average age of the patients was 64.3 years and the male-to-female ratio was 17:3. The location of the tumor was the blub in 5 cases, the superior duodenal angle in 2 cases, the descending portion in 9 cases, the horizontal portion in 3 cases, and the ascending portion in 1 case. The histological type of adenocarcinoma was tub1 in all cases of early cancer, whereas in advanced cancer, there were many cases with histological types other than tub1. Various surgical procedures from duodenal local resection to pancreatoduodenectomy can be performed for treating non-ampullary duodenal tumors depending on the tumor location and the necessity of lymph node dissection. It is important to establish a treatment policy that considers both curability and invasiveness.

[Penrose Method Independent of the Rib Arch for Retraction of the Liver in Laparoscopic Gastrectomy y-Shape+1 Method]

We report the y-shape+1 method, which is a retraction of the liver method, independent of the position of the costal arch. Additionally, we report changes in liver enzymes induced by different methods of liver retraction. Three Penrose No. 6 drains were cut into 6 cm pieces. Penrose 1 was fixed with a thread attached to the end and Penrose 2 in a y-shape. A knitting thread with needles was prepared, and a loop was made at the end of the thread. The needle thread was passed over the abdominal wall and through the Penrose 2. The needle thread was passed over the diaphragmatic leg and through the Penrose 3. The thread was pulled over the abdominal wall and diaphragmatic leg and fixed to the end of Penrose 1 out of the body, and the liver was drained. The rate of change in liver enzymes from the preoperative to postoperative stages was examined separately in the Penrose and Nathanson groups. In the y-shape+1 technique, retraction of the liver can be performed regardless of the position of the rib arch; however, intracorporeal suture ligation is necessary. This method is useful when the conventional Penrose method is inappropriate because of the position of the rib arch.

Long-Term renal function after implantation of continuous-flow left ventricular assist devices: A single center study

Background

Implantable continuous-flow left ventricular assist device (LVAD) improve renal function in advanced heart failure. However, the long-term effects of LVAD on renal function have not been investigated thoroughly. We aimed to assess long-term renal function in patients with LVAD support and to identify predictors for late deterioration in renal function (LDRF).

Methods

One hundred patients underwent LVAD implantation as a bridge to transplant at the University of Tokyo Hospital between May 2011 and December 2018. We assessed renal function at intervals (preoperative, 1, 6, 12, 18, 24 and 30 months after LVAD implantation). We divided patients into two groups: “with LDRF,” whose renal function at 30 months had decreased by >25% compared with preoperatively (n = 14), and “without LDRF” (n = 55).

Results

Renal function improved at 1 month, returned to preoperative levels at 6 months, and remained there up to 30 months after LVAD implantation. However, renal function impairment became evident in patients with LDRF 18 months after LVAD implantation. A ratio of right atrial pressure/pulmonary artery wedge pressure > 0.57 and left ventricular dimension diastole ≤ 67 mm were preoperative independent risk factors for LDRF. In addition, the incidence of perioperative acute kidney injury, ventricular arrhythmia, aortic insufficiency, and late right ventricular failure was significantly higher in patients with LDRF.

Conclusion

LDRF after LVAD implantation corresponded to several risk factors, including a small left ventricle and LVAD-related complications, such as right ventricular failure.

National survey on deceased donor organ transplantation during the COVID-19 pandemic in Japan

PURPOSE

We investigated the status of deceased organ donation and transplantation through a questionnaire distributed to transplant centers in Japan during the COVID-19 pandemic.

METHODS

The questionnaire was distributed electronically to 206 transplant centers for heart (n = 11), lung (n = 10), liver (n = 25), kidney (n = 130), pancreas (n = 18), and small intestine (n = 12) transplantation. Organ donations and organ transplantation data were extracted from the Japan Organ Transplant Network website.

RESULTS

We received questionnaire responses from 177 centers (response rate, 86%). In 2020, the number of brain-dead donors (BDDs) decreased to 68 (69% of the year-on-year average) and the number of donors after cardiac death (DCDs) decreased to 9 (32% of the year-on-year average). Eighty-five (48%) transplant centers (heart, n = 0; lung, n = 0; liver, n = 4; kidney, n = 78; pancreas, n = 22; and small intestine, n = 0) suspended transplant surgeries in response to the COVID-19 pandemic. Consequently, the number of organ transplantations from deceased donors was significantly lower in 2020 than in 2019.

CONCLUSION

Although the COVID-19 pandemic has had less impact in Japan than in other countries, it has affected transplantation activity significantly, suspending transplantation surgeries in 48% of the transplantation centers, including 78% of the kidney transplantation centers, and reducing the number of organ donations to 61% of the year-on-year average.

Carbon Monoxide Diffusing Capacity Predicts Cardiac Readmission in Patients Undergoing Left Ventricular Assist Device Implantation in Japan

Carbon monoxide diffusion capacity (DLCO) is impaired in heart failure patients; however, its clinical impact has not been well investigated in the left ventricular assist device (LVAD) population. We explored the predictive value of preoperative DLCO in the survival and cardiac readmission rates after LVAD implantation. Seventy-six patients who received continuous-flow LVAD as bridge-to-transplant therapy from November 2007 to September 2018 and underwent pulmonary function test before LVAD implantation were included. The primary study endpoints were death and readmission for heart failure or arrhythmia (cardiac readmission). Patients were stratified into two groups according to the percent of predicted DLCO (%DLCO). Pulmonary vascular resistance (PVR) was equivocal between the groups preoperatively, whereas the low DLCO group (%DLCO < 80%) showed significantly high PVR postoperatively. The mortality rate was not different between the groups. The 2 year cardiac readmission rate was 33.5% in the low DLCO group and 8.7% in the high DLCO group (%DLCO ≥ 80%) (P = 0.028). The %DLCO was associated with cardiac readmission in univariate and multivariate analyses (hazard ratio: 4.32; 95% CI: 1.50-15.9; P = 0.005). Low %DLCO was associated with high PVR postoperatively and was a risk factor for cardiac readmission after LVAD implantation.

Differences in the prognoses of patients referred to an advanced heart failure center from hospitals with different bed volumes

Few reports have discussed appropriate strategies for patient referrals to advanced heart failure (HF) centers with available left ventricular assist devices (LVADs). We examined the association between the characteristics and prognoses of referred patients with advanced HF and the bed volume of the referring hospitals. This retrospective analysis evaluated 186 patients with advanced HF referred to our center for consultation about the indication of LVAD between January 1, 2015, and August 31, 2018. We divided the patients into two groups according to the bed volume of their referring hospital (high bed volume hospitals (HBHs): ≥ 500 beds in the hospital; low bed volume hospitals (LBHs): < 500 beds). We compared the primary outcome measure, a composite of LVAD implantation and all-cause death, between the patients referred from HBHs and patients referred from LBHs. The 186 patients with advanced HF referred to our hospital, who were referred from 130 hospitals (87 from LBHs and 99 from HBHs), had a mean age of 43.0 ± 12.6 years and a median left ventricular ejection fraction of 22% [15–33%]. The median follow-up duration of the patients was 583 days (119–965 days), and the primary outcome occurred during follow-up in 42 patients (43%) in the HBH group and 20 patients (23%) in the LBH group. Patients referred from HBHs tended to require catecholamine infusion on transfer more often than those referred from LBLs (36.5% (HBH), 20.2% (LBL), P = 0.021). Kaplan–Meier analysis indicates that the occurrence of the primary outcome was significantly higher in the HBH patients than in the LBH patients (log-rank P = 0.0022). Multivariate Cox proportional hazards analysis revealed that catecholamine support on transfer and long disease duration were statistically significant predictors of the primary outcome. Patients from HBHs had a greater risk of the primary outcome. However, the multivariate analysis did not indicate an association between referral from an HBH and the primary outcome. In contrast, catecholamine support on transfer, long duration of disease, and low blood pressure were independent predictors of the primary outcome. Therefore, these should be considered when determining the timing of a referral to an advanced HF center, irrespective of the bed volume of the referring hospital.

Transcatheter Aortic Valve Implantation and Surgical Aortic Valve Replacement for Aortic Stenosis in Japan - Analysis of a Nationwide Inpatient Database

Background: Nationwide data on transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) in Japan are scarce. Methods and Results: Using a nationwide inpatient database, we analyzed patients undergoing TAVI (n=8,338) or SAVR (n=16,298) due to aortic stenosis between 2014 and 2017. The annual number of TAVI increased rapidly from 2014 to 2017, particularly in older patients. In-hospital deaths were lower and the length of hospital stay was shorter for patients undergoing TAVI than SAVR. Conclusions: TAVI has been penetrating in Japan as an alternative therapeutic option for aortic stenosis and is associated with acceptable clinical outcomes.

Association between infectious event and de novo malignancy after heart transplantation

The aim of the study was to investigate the incidence of and risk factors for de novo malignancy after heart transplantation (HTx) in a single center. We assessed 102 consecutive patients who received HTx and were followed-up in our center regularly for > 1 year from June 2006 to May 2018. We investigated the incidence of and risk factors for de novo malignancy. The cumulative incidence of each malignancy type during the follow-up period was one (0.98%) for skin cancer, four (3.92%) for nonskin solid organ cancer, and six (5.88%) for posttransplant lymphoproliferative disorder (PTLD). The percentage of patients with more than one infectious event ≤ 1 year after HTx was higher in the malignancy group than in the non-malignancy group. Furthermore, Kaplan-Meier analysis revealed that the incidence rate of infectious events was higher in patients with malignancies than in those without (log-rank P < 0.001). After dividing malignancies into a PTLD group and a solid organ malignancy group, we found that negative Epstein-Barr virus serostatus, cytomegalovirus-positive antigenemia, and the occurrence of any viral or gastrointestinal infectious event at ≤ 1 year were more frequent in patients with PTLD than in patients without it. The survival rate was significantly lower for patients with solid organ malignancy than for patients without malignancy. In conclusion, there was a correlation between infectious events and de novo malignancy, particularly in patients with PTLD. We should confirm this finding by conducting a larger cohort study.

Impact of tacrolimus versus cyclosporin A on renal function during the first year after heart transplant

AIMS

Nephrotoxicity of calcineurin inhibitors (CNIs) is associated with adverse events in patients undergoing heart transplant (HTx), although studies directly comparing tacrolimus (TAC) versus cyclosporin A (CsA), especially in combination with everolimus and low-dose CNIs approach, are limited. Thus, we sought to investigate the associations of TAC and CsA with clinical outcomes in HTx recipients, with specific focus on renal function.

METHODS AND RESULTS

From August 2007 to February 2017, 72 consecutive patients (39 treated with TAC vs. 33 with CsA) receiving de novo HTx in a single transplant centre were retrospectively evaluated. We used the instrumental variable method to account for unmeasured confounding. The study outcomes were percentage change in estimated glomerular filtration rates (eGFR) (safety endpoint) and biopsy-proven acute rejection (efficacy endpoint) within the first year after HTx. The enrolled patients (median age 40 years) were predominantly men (68%). There were no significant differences in baseline characteristics, including eGFR (64.8 [45.7-96.4] mL/min/1.73 m² in TAC vs. 65.6 [57.9-83.0] mL/min/1.73 m² for CsA; P = 0.48), other than sex (male, 49% for TAC vs. 91% for CsA; P < 0.001) between the two groups. Within the first year after HTx, 23 (59%) in the TAC group switched mycophenolate mofetil to everolimus, whereas 16 (48%) in the CsA group (P = 0.52). At 12 months, the rates of mortality and end-stage renal disease requiring renal replacement therapies were both 0%. In the instrumental variable analysis, no differences in renal function as well as graft rejection for 1 year after HTx existed between the TAC and CsA groups. These results were similar when taking into account of everolimus use.

CONCLUSIONS

Irrespective of everolimus use with low-dose CNIs, our analysis using the instrumental variable method showed no differences in renal function as well as graft rejection during the first year after HTx between HTx recipients who received TAC or CsA.

Hybrid Lead Extraction Technique: Combined Transatrial Laser Lead Extraction and Surgical Removal of Calcified Lesions

This report presents a new hybrid lead extraction technique combined with transatrial laser lead extraction and surgical removal of calcified lesions in a 50-year-old man with superior vena cava syndrome and bilateral subclavian vein occlusion caused by an abandoned lead, which had been infected for 11 years. (Level of Difficulty: Intermediate.).

Clinical impact of newly developed atrial fibrillation complicated with longstanding ventricular fibrillation during left ventricular assist device support: A case report

BACKGROUND

Continuous-flow left ventricular assist devices (LVADs) improve survival and morbidity in patients with stage D heart failure. Management of LVADs for longer durations is necessary in some clinical settings, and a better understanding of the hemodynamics of patients using LVADs is warranted. Arrhythmia, including atrial (AA) and ventricular (VAs) arrhythmias, is a modifying factor of hemodynamics that is highly prevalent among patients with LVADs. However, the clinical impact of arrhythmias in various clinical settings in patients with LVAD, in which the hemodynamic load is likely to present as worsening of right heart failure, remains to be completely elucidated.

CASE PRESENTATION

We describe the case of a patient under sustained ventricular fibrillation for extraordinarily long duration who was stabilized using LVAD support and in whom newly developed atrial fibrillation led to a significant worsening of right heart failure while using an LVAD.

CONCLUSION

This case demonstrates the substantial clinical impact of AAs in the management of right heart failure using an LVAD.

Mechanical circulatory support for the right ventricle in combination with a left ventricular assist device

Introduction: Right heart failure (RHF) in patients with a left ventricular assist device (LVAD) carries a poor prognosis although the treatment strategy including mechanical circulatory support for the failing right ventricle (RV) has not been well established. Areas covered: In this review, we describe an overview of RHF post-LVAD implant including natural history, prevalence, pathophysiology, outcomes, and challenges to predict RHF post-LVAD implant. Then, we focus on right ventricular assist devices (RVADs) and their clinical outcomes. Recently developed percutaneous RVADs are the major advance in this field. Finally, we discuss future perspectives to overcome limitations of the current treatment options. Expert opinion: In the absence of dedicated RVAD system RHF post-LVAD implant may have been undertreated. Now that dedicated percutaneous RVADs have emerged, surgeons are encouraged to use these new devices to improve outcomes of LVAD therapy. As experience accumulates, we should be able to establish the best possible strategy to treat early RHF post-LVAD implant. Late RHF is another form of RHF post-LVAD implant and has been underappreciated. Further research is mandatory to clarify the mechanism and risk factors. There are still unmet needs for a dedicated implantable RVAD for a subset of patients who need long-term RV support.

Implication of Preoperative Existence of Atrial Fibrillation on Hemocompatibility-Related Adverse Events During Left Ventricular Assist Device Support

BACKGROUND

Hemocompatibility-related adverse events (HRAEs) are substantial issues in patients with left ventricular assist devices (LVADs). Atrial fibrillation (AF) is associated with worse prognosis in patients with heart failure (HF), but its effect on HRAEs following LVAD implantation remain uncertain.Methods and Results:Data from the Japanese Mechanically Assisted Circulatory Support registry of consecutive patients who received HeartMate II LVADs and were followed for 1 year were retrospectively reviewed. Among 190 patients, 23 had AF and 167 had sinus rhythm. The AF group had comparable baseline characteristics with the non-AF group except for their higher age (53 vs. 42 years, P<0.001). Following LVAD implantation, most cases of AF (73%) persisted. Antiplatelet therapy, anticoagulation therapy, and LVAD speed following LVAD implantation were comparable between groups (P>0.05 for all). The 1-year survival free from HRAEs was comparable between groups (83% vs. 76%, P=0.52). Event rates of the breakdown of HRAEs were comparable between groups except for a relatively higher rate of surgically managed pump thrombosis in the AF group (0.16 vs. 0.04, incidence rate ratio 3.75, 95% confidence interval 0.87-16.1, P=0.075). These trends still remained with propensity score-matched comparison.

CONCLUSIONS

Existence of AF had no effect on the development of HRAEs following LVAD implantation. The need to aggressively treat AF before or after LVAD implantation needs further investigation.

Long-term support by left ventricular assist device for arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a heart muscle disorder characterized by right ventricular enlargement, right heart failure (HF), and ventricular arrhythmias which lead to sudden death especially in young adults. Current recommendations for management of patients with ARVC are antiarrhythmic medications, catheter ablation, and implantable cardioverter defibrillator therapy to prevent sudden cardiac death. However, despite these treatments, few patients suffer from recurrent ventricular arrhythmias or HF unresponsive to conventional management. Heart transplantation (HTx) is a preferred treatment for these cases, but because of a persistent donor heart shortage in Japan, ventricular assist device (VAD) support has become an important option for a management of the end-stage ARVC. Previous articles reported 4 cases of a successful management by left ventricular assist device (LVAD), but the longest interval of LVAD support was only 333 days. We present 3 cases of ARVC patients who were successfully managed by LVAD implantation for more than a year. These 3 cases are unconventional examples of ARVC patients, considering the nature of the disease. The novelty of these cases should be taken in the context of the extremely long waiting period for HTx in Japan.

Left ventricular assist device-associated endocarditis involving multiple clones of Staphylococcus aureus with distinct antimicrobial susceptibility patterns

The case of a patient with left ventricular assist device (LVAD)-associated endocarditis involving multiple clones of Staphylococcus aureus is presented. Different clones with distinct colony morphology were identified from blood cultures collected on the same day and showed diverse antimicrobial resistance patterns. In addition, a difference in antimicrobial susceptibility was observed even within an identical clone recovered 400 days apart due to the loss of SCCmec for methicillin and modification of the 23S rRNA target site for linezolid during a long-term treatment course.

A case of cardiogenic shock due to acute coronary syndrome successfully recovered by percutaneous and paracorporeal left ventricular assist device

We recently experienced a 70-year-old woman with left main trunk-acute coronary syndrome who was initially supported by Impella 5.0 which converted to paracorporeal left ventricular assist device (LVAD) implantation as a bridge to recovery. Optimized guideline-directed medical therapy with cardiac rehabilitation resulted in successful explantation of LVAD and she discharged on foot.

Abdominal skeletal muscle mass as a predictor of mortality in Japanese patients undergoing left ventricular assist device implantation

Aims

We assessed preoperative muscle wasting in patients undergoing left ventricular assist device (LVAD) implantations using abdominal skeletal muscle images on computed tomography (CT) and explored the associations between the preoperative muscle wasting and clinical outcomes after LVAD implantation.

Methods and results

We retrospectively examined the records of 111 patients who underwent continuous‐flow LVAD implantations as bridge‐to‐transplant therapy from January 2010 to December 2016 at our institution. After 33 patients were excluded, the study cohort consisted of 78 individuals. CT images used to calculate the skeletal muscle index (SMI) at the third lumbar vertebra level were obtained before the LVAD implantation procedures. Patients were classified as having muscle wasting if their SMI fell into the lowest gender‐based tertile. The median SMI for the study patients was 37.6 cm²/m². The SMI cut‐off values for the lowest tertiles were 36.7 cm²/m² for men and 28.2 cm²/m² for women, resulting in 26 patients (33.3%) with muscle wasting in this study. During the mean follow‐up of 738 ± 379 days, there were 10 deaths (12.8% mortality). Seven of the 26 patients with muscle wasting (26.9%) died, and 3 of the 52 patients without muscle wasting (5.8%) died. The times to all‐cause mortality were significantly different between patients with and without muscle wasting (P = 0.0094). Muscle wasting was found to be associated with mortality in univariate and multivariate Cox analyses (hazard ratio: 4.32; 95% CI: 1.19–20.2).

Conclusions

Preoperative muscle wasting was associated with a higher mortality in patients with LVAD. Assessment of the abdominal skeletal muscle area on CT prior to LVAD implantation can help predict mortality.

Emergency percutaneous coronary intervention for left main trunk thrombus following orthotopic heart transplantation

Heart transplantation (HTx) is the gold standard therapy to improve quality and quantity of life in end‐stage heart failure patients. However, recipients are at risk of experiencing allograft rejection and post‐transplant complications, in the acute as well as chronic phase. A 43‐year‐old man with a history of left ventricular non‐compaction underwent orthotopic HTx. On Day 7, transthoracic echocardiography showed a sudden decrease in cardiac function with hypokinesis in a left ventricular anterior wall distribution. Coronary angiography revealed a large thrombus in the left main trunk. With intra‐aortic balloon pump support, emergency percutaneous coronary intervention was performed. Endomyocardial biopsy showed no rejection. A left main trunk thrombus is rare in the early phase after HTx, but it can be a life‐threatening complication. Transthoracic echocardiography is well known to be important in the management of heart transplant recipients, and coronary angiography as well as myocardial biopsy should be considered when left ventricular wall motion is impaired.

Simultaneous resection of gastric and gallbladder metastasis from renal cell carcinoma treated by laparoscopic and endoscopic cooperative surgery: a case report

Background

Metastases to the stomach or gallbladder from any malignancy is rarely noted, and simultaneous metastases to both organs are atypical. We present a unique case of simultaneous multifocal metastases of the stomach and gallbladder from renal cell carcinoma (RCC).

Case presentation

The case involved a 60-year-old man, with a past history of RCC (clear cell type, G2, T1b N0 M0 Stage I) treated by a right nephrectomy. Three years after the nephrectomy, a routine gastrointestinal endoscopy found an ulcerative lesion in the greater curvature of the gastric body. The gastric tumor was pathologically proven to be a metastasis from RCC. Furthermore, computed tomography incidentally revealed a mass lesion in the fundus of the gallbladder, which was also diagnosed as a potential metastasis from RCC. As endoscopic ultrasonography of the gastric tumor suggested the tumor potentially invaded to the submucosal layer, gastric wedge resection via a laparoscopic and endoscopic cooperative surgery (LECS) technique was applied to the gastric tumor, and laparoscopic cholecystectomy to the gallbladder tumor was simultaneously performed. Histological examination confirmed that the tumors of the stomach and gallbladder were both metastatic RCC. The hospitalization period after surgery was not eventful, and the patient was discharged on postoperative day 7. Thereafter, the patient required examination every 3 months, did not use anticancer agents, and has survived without relapse to 9 months after the surgery.

Conclusions

For patients with locally resectable RCC metastases, complete metastasectomy may bring long-term tumor control. Moreover, LECS for gastric metastasis is a reasonable approach for minimal invasiveness and an oncologically feasible outcome.

Lanthanum carbonate, a phosphate binder, inhibits calcification of implanted aortic allografts in a rat model

OBJECTIVES

Calcification is one of the major postoperative problems after aortic allograft implantation. We hypothesized that phosphate binders, lanthanum carbonate and calcium carbonate inhibit calcification of implanted aortic allografts and verified this hypothesis using a rat model.

METHODS

Aortas were harvested from 4-week-old Brown Norway rats and implanted into the subdermal space of 4-week-old Lewis rats. Twenty-seven recipient Lewis rats were divided into Group N, Group L, and Group C (9 rats per group), which were fed a normal diet, a normal diet containing 3% lanthanum carbonate, and a normal diet containing 3% calcium carbonate, respectively. Implanted aortic allografts were explanted 2 weeks later. Calcification of aortic allografts was evaluated using von Kossa staining and calcium content assay. Calcification score was defined in von Kossa staining as 0 (none), 1 (mild), 2 (moderate), and 3 (severe). Serum calcium and phosphorus levels at euthanasia were measured.

RESULTS

Calcification scores were 2.6, 1.2, and 0.8, and calcium content was 48.9, 15.8, and 8.9 mg/dry·g, in Groups N, L, and C, respectively. Calcification was significantly reduced in Groups L and C. Serum calcium level was 11.5, 12.2, and 13.5 mg/dl, and serum phosphorus level was 15.4, 12.5, and 11.7 mg/dl, in Groups N, L, and C, respectively. Serum calcium level in Group C was significantly higher than in the other two groups.

CONCLUSIONS

Lanthanum carbonate and calcium carbonate significantly reduced calcification of implanted aortic allografts in young rats. Although calcium carbonate induced hypercalcemia, lanthanum carbonate has significant potential to inhibit calcification of implanted aortic allografts.

Novel extraction technique of retained pacemaker and defibrillator lead during heart transplantation

Background

Removal of cardiac implantable electronic devices (CIEDs) by manual traction during orthotopic heart transplantation (OHT) sometimes results in retained lead fragments. Moreover, abandoned leads and retained lead fragments are a contraindication for magnetic resonance imaging (MRI) and may be a cause of CIED infection.

Objective

To eliminate complications of retained lead fragments, we completely removed residual leads using an excimer laser sheath technique during OHT. We report our clinical experience and high success rate of lead extraction using the excimer laser sheath compared with manual traction during OHT.

Methods and results

We obtained data on 84 consecutive patients receiving OHT between August 2007 and August 2017. Thirty-nine of 84 patients had undergone CIED implantation before OHT and removal of all their leads was attempted during OHT. From 2007 to 2014, defibrillator and pacemaker leads were extracted by manual traction in all patients (N = 22). After 2015, all leads were extracted with the excimer laser sheath, and surgical assistance was prepared for the procedure (N = 17). Complete procedural success was achieved in 100% of patients in the excimer laser group and 77% of patients in the manual traction group.

Conclusion

Extraction of abandoned leads using the excimer laser sheath system during OHT is novel and safe technique, and has a higher success rate than extraction using manual traction during OHT.

Novel driveline route for prevention from driveline infection: Triple tunnel method

BACKGROUND

The most prevalent and serious infection related to left ventricular assist devices (LVADs) is driveline infection (DLI). From 2014, we employed a revised surgical technique (triple tunnel method), which deployed a longer subfascial driveline (DL) route.

METHODS AND PATIENTS

We retrospectively analyzed 34 patients fitted with either of the two types of axial pumps: HeartMate II (n=23) and Jarvik 2000 (n=11). Prior to 2014, the DL proceeded from the pump pocket just above the posterior sheath of the rectus muscle toward a vertical skin incision at the right lateral border of the rectus muscle. Then, DL was turned leftward into the subcutaneous tissue to redirect its exit to the left side [subcutaneous tissue group (Group S): n=14]. From 2014, we made an additional skin incision below the umbilicus with the aim of lengthening the subfascial DL route [muscle group (Group M): n=20].

RESULTS

DLI occurred in 10 patients (71.4%) in Group S and in 1 patient (5%) in Group M (p<0.05, Chi-square test). The freedom rate from re-admission at 1 year due to DLI was 64% in Group S and 95% in Group M, respectively (p=0.021, log-rank test). Furthermore, logistic regression analysis revealed that DL route was significantly associated with DLI (odds ratio, 10.1; 95% confidence interval, 1.15-275.3).

CONCLUSION

Although a longer follow-up period will be needed, the triple tunnel method may be beneficial in the prevention of DLI.

Successful bridge to recovery in fulminant myocarditis using a biventricular assist device: a case report

Background

Fulminant myocarditis is a life-threatening disease, and myocardial damage expands the right ventricle as well as the left ventricle in some cases. There is a mortality rate of over 40% in patients with fulminant myocarditis who need mechanical circulatory support by peripheral venoarterial extracorporeal membrane oxygenation.

Case presentation

We report a case of a 27-year-old Japanese woman who was successfully bridged to recovery by using a biventricular assist device. She was diagnosed with fulminant myocarditis, and peripheral venoarterial extracorporeal membrane oxygenation was established on the same day. Her left ventricular ejection fraction rapidly decreased from 40% to 5% in 3 days and weaning from venoarterial extracorporeal membrane oxygenation was deemed difficult. Therefore, we performed a ventricular assist device implantation on day 4. A left ventricular assist device was implanted first. However, adequate blood flow did not circulate to the left side of her heart because of right-sided heart failure. Thus, an additional implant of a right ventricular assist device was performed during the operation. Her left ventricular ejection fraction recovered to 50% on day 10. The biventricular assist device was successfully removed on day 14. She has not experienced worsening of biventricular function during her follow-ups for 4 years.

Conclusions

Ventricular assist device therapy should be considered if there is no improvement in cardiac function in patients with fulminant myocarditis regardless of several days of support by venoarterial extracorporeal membrane oxygenation. A right ventricular assist device should always be implemented when necessary because biventricular involvement is not uncommon in fulminant myocarditis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13256-017-1466-1) contains supplementary material, which is available to authorized users.

Association of the Number of HLA-DR Mismatches With Early Post-transplant Acute Cellular Rejection Among Heart Transplantation Recipients: A Cohort Study in Japanese Population

BACKGROUND

Although many risk factors are reported about graft rejection after heart transplantation (HTx), the effect of HLA mismatch (MM) still remains unknown, especially in the Japanese population. The aim of the present study was to investigate the influence of HLA MM on graft rejection among HTx recipients in Japan.

METHODS

We retrospectively investigated the association of the number of HLA MM including class I (A, B) and class II (DR) (for each locus MM: 0 to 2, total MM: 0 to 6) and the incidence of moderate to severe acute cellular rejection (ACR) confirmed by endomyocardial biopsy (International Society for Heart and Lung Transplantation grade ≥ 3A/2R) within 1 year after HTx.

RESULTS

Between 2007 and 2014, we had 49 HTx cases in our institute. After excluding those with insufficient data and positive donor-specific antigen, finally 35 patients were enrolled. Moderate to severe ACR was observed in 16 (45.7%) patients. The number of HLA-DR MM was significantly associated with the development of ACR (ACR+: 1.50 ± 0.63, ACR-: 1.11 ± 0.46, P = .029). From univariate analysis, DR MM = 2 was the only independent risk factor for ACR episodes (P = .017). The frequency of ACR within 1 year was significantly higher in those with DR MM = 2 (DR MM = 0 to 1: 0.3 ± 0.47, DR MM = 2: 1.17 ± 1.34 times, P = .007).

CONCLUSIONS

The number of HLA-DR MMs was associated with the development and recurrence of ACR episodes among HTx recipients within 1 year after transplantation in Japanese population.