Keitaro Domae

Late Aortic Insufficiency Related to Poor Prognosis During Left Ventricular Assist Device Support

BACKGROUND Management of native aortic insufficiency (AI) during left ventricular assist device (LVAD) support is challenging. We investigated the occurrence of de novo AI during long-term LVAD support to identify its effect on late clinical and echocardiographic outcomes. METHODS Left ventricular assist devices were implanted in 99 patients with dilated cardiomyopathy, of whom 47 without preoperative AI were investigated using serial echocardiography examinations for more than 1 year after the operation. RESULTS The mean duration of LVAD support was 838±327 days, and 26 patients (55%) were supported for more than 2 years. Twenty-nine patients (62%) had no AI (group A), whereas de novo AI developed in the remaining 18 (38%; group B) at 1 year after LVAD implantation (≥grade 2 in 5, grade 1 in 13). The LV end-diastolic diameter was significantly reduced after LVAD implantation in both groups, with no significant difference between them. Overall survival was better in group A (p=0.0195). Multivariate analysis revealed that preoperative mitral regurgitation of more than grade 2 (odds ratio, 7.8; 95% confidence interval, 1.2 to 48.6; p=0.028) and an aortic valve that remained closed at 1 month after implantation (odds ratio, 6.7; 95% confidence interval, 1.0 to 43.9; p=0.048) were significant independent predictors of de novo AI at 1 year after LVAD implantation. CONCLUSIONS Survival was significantly worse when de novo AI developed in patients during long-term LVAD. Our findings indicate that preoperative functional mitral regurgitation and postoperative aortic valve opening are related to the progression of AI during long-term LVAD support.

Less invasive surgical treatment for aortic arch aneurysms in high-risk patients: A comparative study of hybrid thoracic endovascular aortic repair and conventional total arch replacement

OBJECTIVE For aortic arch aneurysms, conventional total arch replacement has been the standard surgical option. In selected high-risk patients, we have attempted less invasive hybrid procedure involving supra-aortic bypass and endovascular stent-graft placement. We review the early and midterm outcomes to clarify the impact of the hybrid procedure. METHODS Between October 2007 and December 2010, 27 patients were treated with the hybrid procedure. During the same period, 191 patients underwent elective conventional total arch replacement. On retrospective analysis, the hybrid procedure was feasible in 103 patients (hybrid feasible) and not feasible in 88 patients (hybrid impossible). Patients undergoing the hybrid procedure attained significantly higher additive (11.6 ± 2.2 vs 9.5 ± 2.4, 10.3 ± 2.8, P < .001, P = .044) and logistic (31.1 ± 14.1 vs 18.8 ± 12.6, 23.7 ± 16.0, P < .001, P = .047) European System for Cardiac Operative Risk Evaluation scores than hybrid-feasible and hybrid-impossible groups. RESULTS Although the patients in the hybrid group had significantly higher risk, the early outcomes including mortality and morbidity were similar among the 3 groups, as were the 2-year survivals during the follow-up period: 85.9% for the hybrid group, 89.6% for the hybrid-feasible group, and 86.7% for the hybrid-impossible group (P = .510, .850, log-rank test). In the hybrid group, 2 patients required reintervention for type I endoleak. CONCLUSIONS The early and midterm outcomes of the hybrid procedure for aortic arch aneurysms were satisfactory. This procedure has the potential to be an alternative for conventional total arch replacement for high-risk patients.

Phase I Clinical Trial of Autologous Stem Cell–Sheet Transplantation Therapy for Treating Cardiomyopathy

Background When transplanted into failing heart, autologous somatic tissue–derived cells yield functional recovery via paracrine effects that enhance native regeneration. However, the therapeutic effects are modest. We developed a method in which scaffold‐free cell sheets are attached to the epicardial surface to maximize paracrine effects. This Phase I clinical trial tested whether transplanting autologous cell–sheets derived from skeletal muscle is feasible, safe, and effective for treating severe congestive heart failure. Methods and Results Fifteen ischemic cardiomyopathy patients and 12 patients with dilated cardiomyopathy, who were in New York Heart Association functional class II or III and had been treated with the maximum medical and/or interventional therapies available, were enrolled. Scaffold‐free cell sheets of 3 to 9×108 cells derived from autologous muscle were transplanted over the LV free wall via left thoracotomy, without additional interventional treatments. There were no procedure‐related major complications during follow‐up. The majority of the ischemic cardiomyopathy patients showed marked symptomatic improvement in New York Heart Association classification (pre: 2.9±0.5 versus 6 months: 2.1±0.4, P<0.01; 1 year: 1.9±0.3, P<0.01) and the Six‐Minute Walk Test with significant reduction of serum brain natriuretic peptide level (pre: 308±72 pg/mL versus 6 months: 191±56 versus 1 year: 182±46, P<0.05), pulmonary artery pressure, pulmonary capillary wedge pressure, pulmonary vein resistance, and left ventricular wall stress after transplantation instead of limited efficacy in dilated cardiomyopathy patients. Conclusions Cell‐sheet transplantation as a sole therapy was feasible for treating cardiomyopathy. Promising results in the safety and functional recovery warrant further clinical follow‐up and larger studies to confirm this treatments efficacy for severe congestive heart failure. Clinical Trial Registration URL: http://www.umin.ac.jp/english/. Unique identifier: UMIN000003273.

Prevalence of Cerebral Microbleeds in Patients With Continuous‐Flow Left Ventricular Assist Devices

Background The prevalence of cerebral microbleeds (CMBs) in gradient echo T2*‐weighted brain MRI has a positive correlation with hemorrhagic stroke incidence. However, the prevalence of CMBs in patients with left ventricular assist devices (LVADs) has not been evaluated. We evaluated the prevalence of CMBs and the relationship with hemorrhagic stroke incidence in patients with LVADs. Method and Results We analyzed results from brain MRI in prospective examinations of 35 consecutive patients who had undergone LVAD explantation for heart transplantation or recovery since 2011. The number and distribution of CMBs were counted, then the relationship between baseline characteristics and adverse events during LVAD support were analyzed. The mean age was 37.7±12.4 years and the mean LVAD duration was 2.43±1.08 years. Thirty‐four (97%) patients had at least one CMB. Nine (26%) developed hemorrhagic stroke during LVAD support, and patients with hemorrhagic stroke had a significantly greater number of CMBs compared with patients without hemorrhagic stroke (5 [interquartile range (IQR), 4–7] versus 9 [IQR, 5–23]; odds ratio 1.14 [95% Confidence Interval (CI), 1.02–1.32], P=0.05). There was no significant relationship between age, LVAD support duration, or systolic blood pressure during LVAD. However, patients who had at least one episode of bacteremia (9 [IQR, 4–16] versus 5 [IQR, 3–7], P=0.06) and pump pocket infection (14 [IQR, 4–27] versus 5 [IQR, 3–7], P=0.08) showed a trend toward a greater number of CMBs than patients without bacteremia. Conclusions Thirty‐four (97%) patients with continuous‐flow LVAD had at least one CMB, and the number of CMBs were more prevalent in patients with hemorrhagic stroke and in patients with LVAD‐related infection.

Relationship Between Bacteremia and Hemorrhagic Stroke in Patients With Continuous-Flow Left Ventricular Assist Device

BACKGROUND Blood stream infection is thought to increase the risk of hemorrhagic stroke, a major adverse event with devastating outcome, in patients with continuous-flow left ventricular assist devices (LVADs). We analyzed the risk factors of hemorrhagic stroke in LVAD patients, as well as the time relationship between systemic bacteremia and hemorrhagic stroke.Methods and Results:We evaluated the incidence of systemic bacteremia and stroke in 164 patients who underwent continuous-flow LVAD implantation between 2005 and 2016. At 1 and 2 years after implantation, the incidence of bacteremia was 29% and 36%, and the incidence of hemorrhagic stroke was 22% and 22% in patients without bacteremia, and 32% and 44% in those with bacteremia, respectively (P=0.035). This higher prevalence of hemorrhagic stroke in patients with bacteremia was notable particularly in the chronic phase (>90 days after implantation). Multivariate analysis revealed that bacteremia was an independent risk factor of hemorrhagic stroke in the chronic phase [hazard ratio, 2.36 (1.02-5.62); P=0.044]. The hazard rate was the highest immediately after the onset of bacteremia, and the risk steadily declined by 90 days after the last episode of bacteremia and flattened thereafter. CONCLUSIONS Bacteremia was an independent risk factor of hemorrhagic stroke in patients in the chronic phase, with the highest risk seen in the early phase following an episode of bacteremia.

Hybrid repair combined with open surgery and endografting for lesions in right aortic arch: report of three cases.

Three cases with lesions in the right aortic arch (RAA) are presented. For two patients, whose RAA contained a retroesophageal segment, the primary treatment was total arch replacement (TAR) for acute type A dissection or severe arch angulation with thoracic endovascular aneurysm repair (TEVAR) as second-stage surgery. The third patient, who had RAA with mirror image branching, underwent supra-aortic bypass followed by TEVAR. There was no operative mortality, but the condition of two patients who underwent TAR was complicated by bilateral recurrent nerve palsy, which can be critical. The combination of TEVAR and supra-aortic bypass might thus be preferable for patients with RAA.

Definitive Determinant of Late Significant Tricuspid Regurgitation After Aortic Valve Replacement

BACKGROUND Uncertainties remain regarding the course of existing tricuspid regurgitation (TR) after aortic valve replacement (AVR), and its long-term impact on outcome. We investigated changes in existing TR after isolated AVR for severe aortic stenosis (AS), the impact of preoperative TR on long-term outcome, and predictors of late significant TR.Methods and Results:After excluding mild mitral regurgitation and severe TR, 226 consecutive patients undergoing isolated AVR for severe AS between 2002 and 2015 were reviewed. Patients were classified into a non-TR (none/trivial preoperative TR, n=159) and a TR group (mild/moderate preoperative TR, n=67). During follow-up (median, 4.3 years), late significant TR was more prevalent in the TR group (n=20; 35.0%) than in the non-TR group (n=13; 9.6%; HR, 10.0; 95% CI: 4.44-24.7; P<0.001). The TR group developed more right heart failure (n=3; 5% vs. no patients in the non-TR group, P=0.007), and had a decreased estimated glomerular filtration rate (relative to baseline) until 5 years postoperatively. The tricuspid annulus diameter index was an independent predictor of late significant TR development. CONCLUSIONS Preoperative mild or moderate TR is aggravated after isolated AVR, resulting in a high incidence of renal dysfunction and right heart failure. Concomitant tricuspid valve intervention should be considered in patients undergoing AVR for severe AS with mild or moderate TR accompanied by dilated tricuspid annulus.

Mitral Valve Structure in Addition to Myocardial Viability Determines the Outcome of Functional Mitral Regurgitation After Coronary Artery Bypass Grafting

BACKGROUND Coronary artery bypass grafting (CABG) reduces functional mitral regurgitation (MR) associated with ischemic heart disease, although the predictive factors or mechanisms of reversibility of functional MR after CABG are not fully understood.We investigated whether mitral valve structure is associated with the outcome of functional MR after CABG.Methods and Results:From a consecutive series of 98 patients with mild-moderate functional MR preoperatively who underwent isolated CABG, we enrolled 66 patients who were followed up for >1 year postoperatively using echocardiography. The degree of MR was reduced in 34 patients (52%) postoperatively, in association with a lower rate of in-hospital treatment for cardiac failure in the long term, compared with the 32 patients (48%) with residual MR postoperatively. The patients with reduced MR postoperatively had longer estimated coaptation length and more anteriorly or centrally directed MR jets than those without reduced MR. On statistical analysis, the addition of estimated coaptation length and jet direction to the reported predictors (ejection fraction, left ventricular end-diastolic dimension, and tenting height) more accurately predicted changes in post-CABG MR than the reported 3 factors alone. CONCLUSIONS Residual MR was associated with the emergence of congestive heart failure in the long term after CABG. A specific mitral valve structure, such as large mitral leaflet size or predominant tethering of the posterior leaflet, was a predictive factor for the reversibility of post-CABG functional MR.

Diagnosis, medical treatment, and stepwise mechanical circulatory support for fulminat myocarditis

Fulminant myocarditis is one of the most challenging diseases. We sought to examine the outcomes of our multidisciplinary treatment strategy for fulminant myocarditis. A retrospective review of consecutive 30 patients with fulminant myocarditis was conducted. Of the 30 patients, 25 required mechanical circulatory support (MCS). Percutaneous extracorporeal membrane oxygenation (ECMO) was the first-line therapy to rescue the patients and inserted in 23 of them. The other 2 were implanted with temporary ventricular assist device (t-VAD) with extracorporeal centrifugal pump(s). Sixteen of the ECMO-supported patients were later transitioned to t-VAD. Of the 18 patients who underwent t-VAD support, heart function recovered and the VAD was explanted in 10. Four patients were bridged to long-term VAD and the other 4 died on t-VAD. Two patients were directly bridged to long-term VAD by ECMO. Heart function recovered only with ECMO in 4 patients and 1 died on ECMO. Overall survival rate was 83.3%. The duration of ECMO support significantly correlated with total bilirubin level, which was a significant risk factor for mortality. Pathologically, 7 patients (23.3%) had eosinophilic myocarditis and 1 (3.3%) had giant-cell myocarditis, and all the 8 patients underwent immunosuppressive therapy including steroids. Heart function recovered to normal level in 7 of them (87.5%). Timely conversion from the percutaneous ECMO to the temporary VAD before elevation of total bilirubin level is crucial for improving the clinical outcomes. Endomyocardial biopsy is needed to be done as soon as possible, because immunosuppressive therapy carries promising outcomes in certain etiologies.

Libman-Sacks Endocarditis Due to Systemic Lupus Erythematosus Activation After Mitral Valve Plasty

Libman-Sacks endocarditis is a cardiac manifestation of systemic lupus erythematosus (SLE) and antiphospholipid syndrome. We report a case of mitral valve destruction due to Libman-Sacks endocarditis, which was caused by activation of SLE, despite prompt initiation of systemic steroid therapy. The prevention of SLE activation is critically important in valve surgery for patients with SLE. To the best of our knowledge, this is the first case of repaired mitral valve destruction due to activation of SLE, which was caused by valve surgery itself.