Novel Scoring System to Predict Ineligibility for Bridge to Implantable Left Ventricular Assist Device as Destination Therapy Before Extracorporeal Ventricular Assist Device Implantation - For the Coming Era of Destination Therapy in Japan

BACKGROUND

Although destination therapy (DT) is now expected to be a promising strategy for those who are not suitable for heart transplantation in Japan, there has not been any investigation into ineligibility for bridging to implantable left ventricular assist device (I-LVAD) as DT among patients with extracorporeal LVAD.

METHODS AND RESULTS

We retrospectively studied 85 patients who had received an extracorporeal LVAD. To assess ineligibility for a bridge to I-LVAD for DT, we defined DT ineligibility (DTI) as BiVAD requirement, death within 6 months, and persistent end-organ dysfunction (medium or high J-VAD risk score) at 6 months after extracorporeal LVAD implantation. DTI was recorded for 32 patients. Uni/multivariate analysis showed that smaller left ventricular diastolic dimension (<64 mm; [odds ratio (OR) 4.522]), continuous hemodiafiltration (OR 4.862), past history of cardiac surgery (OR 6.522), and low serum albumin level (<3.1 g/dl; OR 10.064) were significant predictors of DTI. By scoring 2, 2, 3, 4 points, respectively, considering each OR, we constructed a novel scoring system for DTI (DTI score), which stratified patients into 3 risk strata: low (0-3 points), medium (4-6 points), and high (7-11 points), from the view point of DTI risk (low 8%, medium 46%, high 93%, respectively).

CONCLUSIONS

DTI score is a promising tool for predicting ineligibility for I-LVAD as DT before extracorporeal VAD implantation.

Successful Treatment of Intractable Fluid Retention Using Tolvaptan After Treatment for Postoperative Mediastinitis in a Patient With a Left Ventricular Assist Device

The use of implantable continuous-flow left ventricular assist devices (LVADs) as a bridge to transplant is effective for patients with congestive heart failure (HF). However, some patients develop congestive symptoms due to right-sided HF even with LVAD support. Tolvaptan, a vasopressin type 2 receptor antagonist, corrects both congestion and hyponatremia in patients with advanced HF. We report herein a case involving a patient who underwent LVAD implantation and developed hyponatremia and congestive symptoms after negative-pressure wound therapy and omental transposition for postoperative mediastinitis. Hemodynamic evaluation performed after negative-pressure wound therapy revealed elevation of both right arterial pressure and pulmonary capillary wedge pressure, and suggested biventricular dysfunction despite LVAD support. Symptoms improved after starting administration of tolvaptan. Tolvaptan may be useful for correcting hyponatremia and volume overload in patients under LVAD support.

Quality of Life and Influential Factors in Patients Implanted With a Left Ventricular Assist Device

BACKGROUND

Improving quality of life (QOL) has become an important goal in left ventricular assist device (LVAD) therapy. We aimed (1) to assess the effect of an implantable LVAD on patients' QOL, (2) to compare LVAD patients' QOL to that of patients in different stages of heart failure (HF), and (3) to identify factors associated with patients' QOL.

METHODS AND RESULTS

The QOL of 33 Japanese implantable LVAD patients was assessed using the Minnesota Living with Heart Failure Questionnaire (MLHFQ) and Short-form 8 (SF-8), before and at 3 and 6 months afterwards. After LVAD implantation, QOL significantly improved [MLHFQ, SF-8 physical component score (PCS), SF-8 mental component score (MCS), all P<0.05]. Implanted LVAD patients had a better QOL than extracorporeal LVAD patients (n=33, 32.1±21.9 vs. n=17, 47.6±18.2), and Stage D HF patients (n=32, 51.1±17.3), but the score was comparable to that of patients who had undergone a heart transplant (n=13). In multiple regression analyses, postoperative lower albumin concentration and right ventricular failure were independently associated with poorer PCS. Female sex and postoperative anxiety were 2 of the independent factors for poorer MCS (all P<0.05).

CONCLUSIONS

Having an implantable LVAD improves patients' QOL, which is better than that of patients with an extracorporeal LVAD. Both clinical and psychological factors are influence QOL after LVAD implantation.

A deleterious MYH11 mutation causing familial thoracic aortic dissection

The L1264P and R1275L heterozygous mutations of the myosin heavy chain 11 (MYH11) gene, which are on the same allele, have been reported to cause thoracic aortic aneurysms and/or dissections (TAAD) complicated with patent ductus arteriosus (PDA); however, their contributions to the pathogenesis of TAAD/PDA have not been elucidated. Here we report the first familial case of TAAD with only a MYH11 L1264P mutation, in which PDA was not observed, indicating that L1264P, not R1275L, is responsible for TAAD formation.

Perioperative Hypoalbuminemia Affects Improvement in Exercise Tolerance After Left Ventricular Assist Device Implantation

BACKGROUND

Although survival rates have improved for patients receiving implantable continuous flow left ventricular assist devices (I-CF LVAD), postoperative exercise tolerance levels are not necessarily satisfactory.

METHODS AND RESULTS

We enrolled 51 patients who had received an I-CF LVAD and underwent follow-up between 2006 and 2014; all patients underwent cardiopulmonary exercise testing 3 months following surgery: 26 (51%) patients achieved peak oxygen consumption (PV̇O2) ≥14 ml·kg(-1)·min(-1)and had significantly lower readmission rates for cardiovascular events than those with PV̇O2<14 ml·kg(-1)·min(-1)during 2 years of LVAD treatment (17 vs. 43%, P=0.033). Uni- and multivariate logistic regression analyses showed that the preoperative serum albumin (S-ALB) level was an independent predictor for PV̇O2≥14 ml·kg(-1)·min(-1)at 3 months (P=0.023, odds ratio 6.132). Patients with persistently normal S-ALB levels during the perioperative period had the lowest preoperative serum C-reactive protein level (S-CRP, 0.7±0.9 mg/dl), and the majority (77%) showed improved exercise tolerance. Conversely, patients with persistently low S-ALB levels during this period had the highest preoperative S-CRP level (2.8±1.2 mg/dl) and did not achieve the test endpoint.

CONCLUSIONS

Both pre- and postoperative low S-ALB impedes recovery of exercise tolerance after I-CF LVAD surgery, and this may be attributable to inflammatory responses caused by heart failure.

Prophylactic Intra-Aortic Balloon Pump Before Ventricular Assist Device Implantation Reduces Perioperative Medical Expenses and Improves Postoperative Clinical Course in INTERMACS Profile 2 Patients

BACKGROUND

Although intra-aortic balloon pump (IABP) is sometimes used before cardiac surgery to achieve better outcome in high-risk patients, the clinical impact of prophylactic IABP support before left ventricular assist device (LVAD) implantation in patients with worsening hemodynamics was unknown.

METHODS AND RESULTS

We enrolled 22 patients with worsening hemodynamics who had received IABP support before LVAD (IABP group), and also enrolled 22 patients receiving neither IABP nor extracorporeal membrane oxygenation before LVAD, who were selected on propensity score matching (non-IABP group). Although both groups had similar preoperative background, the IABP group had shorter postoperative intensive care unit (ICU) stay, and more improved hemodynamics (P<0.05 for all). Serum total bilirubin and creatinine decreased significantly in the IABP group compared with the non-IABP group during 1 month after LVAD implantation (P<0.05 for both). Medical expenses during perioperative ICU stay were significantly lower in the IABP group compared with the non-IABP group, even including the cost of preoperative IABP support (P<0.05).

CONCLUSIONS

Prophylactic IABP support in heart failure patients with worsening hemodynamics improves post-LVAD clinical course and reduces perioperative medical expenses.

[Temporary use of centrifugal pump for pump thrombosis in patients with paracorporeal ventricular assist device]

Nipro paracorporeal ventricular assist device( VAD) is often associated with pump thrombosis which causes severe complications such as brain infarction, often requiring pump change. However, Nipro VAD pump is an expensive device and it is difficult to change pumps frequently at a short interval. We have temporarily used Rotaflow centrifugal pump for recurrent pump thrombosis in patients with Nipro VADs. From January 2012 through December 2013, 19 patients underwent Nipro VADs implantation at our institution, and 9 of them underwent pump change from Nipro pumps to Rotaflow centrifugal pumps. A total of 25 Rotaflow centrifugal pumps were used in these 9 patients, with the total circulatory support duration of 526 days. The median support period was 15 days (range;2-128 days). There were 2 cerebrovascular accidents and 1 Rotaflow pump circuit thrombosis during this period. Change from Rotaflow to Nipro VAD pump resulted in decrease in hematocrit by about 3 point. There was no difference in liver or renal function between before and after the pump change. Our results suggest that temporary use of Rotaflow centrifugal pump for recurrent pump thrombosis in patients with Nipro VADs may be a promising alternative.

Long-term outcome after the original and simple modified technique of valve-sparing aortic root reimplantation in Marfan-based population, David V University of Tokyo modification

BACKGROUND

In valve-sparing aortic root replacement (VSARR), how to reproduce Valsalva sinus has been an issue. In the original David V procedure, they put plication stitches at sinotubular junction level, although the reefing effect is limited and distal graft remains larger than native. Other modified techniques are two-grafts technique and ready-made Valsalva graft. However, the former needs graft-graft anastomosis and may not be cost-effective, while in the latter, the shape of sinus is fixed and minor adjustment is difficult. David V University of Tokyo modification (David V-UT) is our original solution to that, creating pseudosinus with one straight graft by longitudinal size-reduction running sutures above each pseudosinus. The purpose of the present study is to investigate long-term outcome of David V-UT.

METHODS

We analyzed 59 David V-UT patients from February 2004 to February 2013 and long-term outcomes were investigated by Kaplan-Meier methods. Risk factors for adverse events "death or recurrent aortic insufficiency (AI) with or without aortic valve reoperation" were analyzed by using Cox proportional hazard models.

RESULTS

Mean age was 33.1±14.5 years, and 38 patients (64%) were male. Marfan syndrome (MFS) accounts for 47 patients (80%). Only one patient was with bicuspid aortic valve. No in-hospital mortality was observed. Mean follow-up was 4.9±2.4 years. Estimated survival was 94.0±3.4% at 5 years. Freedoms from aortic valve reoperation and recurrent AI greater than mild were 95.7±3.0% and 88.9±4.7% at 5 years, respectively. In Cox proportional hazard analysis, preoperative AI greater than mild and Z score of annular diameter were significant risks for adverse events (p=0.027 and 0.045, hazard ratio 6.084 and 1.432, 95% C.I. 1.225-30.21 and 1.008-2.035, respectively).

CONCLUSIONS

Even in Marfan-characterized population, David V-UT provided satisfactory long-term outcome, comparable to other VSARR modifications. It is simple but can freely reproduce trilobed sinus with one straight graft.

Biventricular failure with low pulmonary vascular resistance was managed by left ventricular assist device alone without right-sided mechanical support

How to manage preoperative right ventricular dysfunction (RVD) in heart failure patients without cardiogenic shock remains as a matter to be debated because implantable biventricular assist device treatment has not been established thus far. We here presented a patient with significant RVD indicated by low RV stroke work index (0.3 g/m) and RV dilatation as well as low pulmonary vascular resistance (PVR, 0.8 Wood Unit), who was managed by the introduction of pimobendan and sildenafil after the implantation of DuraHeart and tricuspid annuloplasty without right VAD, although his New York Heart Association symptom remained class III. Preoperative low PVR may be a key for successful LVAD treatment alone without right VAD in patients with INTERMACS profile 3 suffering RVD.

Plasma neutrophil gelatinase-associated lipocalin and worsening renal function during everolimus therapy after heart transplantation

Recently, the mammalian target of rapamycin inhibitor everolimus (EVL) has been introduced as a novel immunosuppressant for heart transplant (HTx) recipients, and is expected to preserve renal function compared to conventional calcineurin inhibitors (CNIs). However, a considerable number of recipients treated with EVL were not free from worsening renal function regardless of CNI reduction. Data were collected retrospectively from 27 HTx recipients who had received EVL (trough concentration, 3.1-9.2 ng/mL) along with reduced CNIs (%decreases in trough concentration, 27.3 ± 13.0%) because of switching from mycophenolate mophetil due to digestive symptoms or neutropenia, progressive coronary artery vasculopathy, or persistent renal dysfunction, and had been followed over 1 year between August 2008 and January 2013. Estimated glomerular filtration rate (eGFR) decreased in 5 recipients (18.5%) during the study period. Univariate logistic regression analysis demonstrated that a higher plasma neutrophil gelatinase-associated lipocalin (P-NGAL) level was the only significant predictor for a decrease in eGFR over a 1-year EVL treatment period among all baseline parameters (P = 0.008). eGFR and proteinuria worsened almost exclusively in patients with baseline P-NGAL ≥ 85 ng/mL, which was the cutoff value calculated by an ROC analysis (area under the curve, 0.955; sensitivity, 1.000; specificity, 0.955). In conclusion, higher P-NGAL may be a novel predictor for the worsening of renal function after EVL treatment that is resistant to CNI reduction in HTx recipients.

Parasympathetic reinnervation accompanied by improved post-exercise heart rate recovery and quality of life in heart transplant recipients

Although sympathetic reinnervation is accompanied by the improvement of exercise tolerability during the first years after heart transplantation (HTx), little is known about parasympathetic reinnervation and its clinical impact. We enrolled 21 recipients (40 ± 16 years, 71% male) who had received successive cardiopulmonary exercise testing at 6 months, and 1 and 2 years after HTx. Exercise parameters such as peak oxygen consumption or achieved maximum load remained unchanged, whereas recovery parameters including heart rate (HR) recovery during 2 minutes and the delay of peak HR, which are influenced by parasympathetic activity, improved significantly during post-HTx 2 years (P < 0.05 for both). HR variability was analysed at post-HTx 6 months in 18 recipients, and high frequency power, representing parasympathetic activity, was significantly associated with the 2 recovery parameters (P < 0.05 for all). We also assessed quality of life using the Minnesota Living with Heart Failure (HF) Questionnaire at post-HTx 6 months and 2 years in the same 18 recipients, and those with improved recovery parameters enjoyed a better HF-specific quality of life (P < 0.05 for both). In conclusion, parasympathetic reinnervation emerges along with improved post-exercise recovery ability of HR and quality of life during post-HTx 2 years.

Late rejection occurred in recipients who experienced acute cellular rejection within the first year after heart transplantation

Serial endomyocardial biopsies (EMBs) are scheduled even several years after heart transplantation (HTx) to monitor for late rejection (LR). However, repeated EMBs are associated with an increased risk for fatal complications and decrease the quality of life of the recipient. We retrospectively analyzed clinical data from 42 adult recipients who had received HTx and were followed > 1 year at the University of Tokyo Hospital. Five recipients experienced LR at 1130 ± 157 days after HTx, and all 5 had experienced acute cellular rejection (ACR) with ISHLT grade ≥ 2R within the first year, which was treated with methylprednisolone pulse therapy (sensitivity, 1.000; specificity, 0.7027). Logistic regression analyses demonstrated that positive panel reactive antibody (PRA) was the only significant predictor for LR among all parameters at 1 year after HTx (P = 0.020, odds ratio 24.00). Among the 5 recipients with LR, LR occurred earlier in the two PRA positive recipients than in those with a negative PRA (981 ± 12 versus 1230 ± 110 days, P = 0.042). Among the perioperative parameters, gender mismatch [n = 13 (31%)] was the only significant predictor for ACR within the first year in logistic regression analyses (P = 0.042, odds ratio 4.200). In conclusion, the current schedule of serial EMBs should perhaps be reconsidered for recipients without any history of ACR within the first year due to their lower risk of LR.

Readmission due to driveline infection can be predicted by new score by using serum albumin and body mass index during long-term left ventricular assist device support

Survival in patients with continuous flow left ventricular assist device (CF LVAD) had been increased owing to improved perioperative management procedures. The second target for successful long-term LVAD treatment was to reduce readmission especially due to device-specific infection, which was one of the major unsolved complications. Among 57 enrolled patients who had received CF LVAD and been followed for 530 days on median at our institute between 2008 and 2014, 21 patients experienced readmission due to driveline infection (DLI) at 190 days after the surgery on median. Considering the result of Uni/Multivariate Cox regression analyses demonstrating lower serum albumin concentration (S-ALB) (hazard ratio 0.144) and body mass index (BMI) (hazard ratio 0.843) both obtained at discharge were independent predictors of readmission due to DLI, we constructed a New Score "7 × [S-ALB (g/dL)] + [BMI]", which significantly stratified readmission-free rate into 3 groups [low (>50 Pt), intermediate (44-50 Pt), and high risk group (<44 Pt)] during 2-year study period (p = 0.008). Survival remained unchanged irrespective of DLI, whereas those with DLI needed longer in-hospital treatment (p < 0.05). In conclusion, readmission due to DLI could be predicted by using two simple nutrition parameters at discharge. Early nutrition assessment and intervention may reduce readmission and improve patients' quality of life during long-term LVAD support.

Aortic insufficiency in patients with sustained left ventricular systolic dysfunction after axial flow assist device implantation

BACKGROUND

Predicting the occurrence of aortic insufficiency (AI) during left ventricular assist device (LVAD) support has remained unsolved.

METHODS AND RESULTS

We enrolled 52 patients who had received continuous flow LVAD (14 axial and 38 centrifugal pumps) and who been followed for ≥6 months between Jun 2006 and Dec 2013. Native aortic valve (AV) opening was observed in 18 patients (35%) with improved LV systolic function, and none of them had AI. On multivariate logistic regression analysis preoperative shorter heart failure duration was the only independent predictor of postoperative native AV opening (P=0.042; odds ratio [OR], 0.999). Of the remaining 34 patients (65%) with closed AV, 11 had AI with enlargement of the aortic root and narrow pulse pressure. Among those with closed AV, axial pump use (n=13) was the only significant predictor of the development of AI (P=0.042; OR, 4.950). Patients with AI had lower exercise capacity and a higher readmission rate than those without AI during 2-year LVAD support (55% vs. 8%; P<0.001).

CONCLUSIONS

Native AV opening during LVAD support is profoundly associated with reversal of LV systolic function, especially in patients with preoperative shorter heart failure duration. Among those in whom the native AV remains closed, low pulsatility of axial flow pump may facilitate aortic root remodeling and post-LVAD AI development that results in worse clinical outcome.