Initial 3-year outcomes with left ventricular assist devices in a country with a nascent heart transplantation program

Examining a 12-year experience within Kazakhstan's national heart transplantation program

Kazakhstan has one of the lowest heart transplantation (HTx) rates globally, but there are no studies evaluating the outcomes of HTx. This study aimed to provide a comprehensive analysis of the national HTx program over a 12-year period (2012-2023). Survival analysis of the national HTx cohort was conducted using life tables, Kaplan‒Meier curves, and Cox regression methods. Time series analysis was applied to analyze historical trends in HTx per million population (pmp) and to make future projections until 2030. The number of patients awaiting HTx in Kazakhstan was evaluated with a regional breakdown. The pmp rates of HTx ranged from 0.06 to 1.08, with no discernible increasing trend. Survival analysis revealed a rapid decrease in the first year after HTx, reaching 77.0% at 379 days, with an overall survival rate of 58.1% at the end of the follow-up period. Among the various factors analyzed, recipient blood levels of creatinine and total bilirubin before surgery, as well as the presence of infection or sepsis and the use of ECMO after surgery, were found to be significant contributors to the survival of HTx patients. There is a need for public health action to improve the HTx programme.

Association of Genetic Polymorphisms with Complications of Implanted LVAD Devices in Patients with Congestive Heart Failure: A Kazakhstani Study

The left ventricular assist device (LVAD) is one of the alternative treatments for heart failure (HF) patients. However, LVAD support is followed by thrombosis, and bleeding complications which are caused by high non-physiologic shear stress and antithrombotic/anticoagulant therapy. A high risk of complications occurs in the presence of the genotype polymorphisms which are involved in the coagulation system, hemostasis function and in the metabolism of the therapy. The aim of the study was to investigate the influence of single-nucleotide polymorphisms (SNP) in HF patients with LVAD complications. We analyzed 21 SNPs in HF patients (n = 98) with/without complications, and healthy controls (n = 95). SNPs rs9934438; rs9923231 in VKORC1, rs5918 in ITGB3 and rs2070959 in UGT1A6 demonstrated significant association with HF patients’ complications (OR (95% CI): 3.96 (1.42–11.02), p = 0.0057), (OR (95% CI): 3.55 (1.28–9.86), p = 0.011), (OR (95% CI): 5.37 (1.79–16.16), p = 0.0056) and OR (95% CI): 4.40 (1.06–18.20), p = 0.044]. Genotype polymorphisms could help to predict complications at pre- and post-LVAD implantation period, which will reduce mortality rate. Our research showed that patients can receive treatment with warfarin and aspirin with a personalized dosage and LVAD complications can be predicted by reference to their genotype polymorphisms in VKORC1, ITGB3 and UGT1A6 genes.

5-year results of a newly implemented mechanical circulatory support program for terminal heart failure patients in a Swiss non-cardiac transplant university hospital

Background

In Switzerland, long-term circulatory support programs have been limited to heart transplant centers. In 2014, to improve the management of patients with end-stage heart failure not eligible for transplantation, we implemented a left ventricular assist device (LVAD) program for destination therapy at the University Hospital of Basel.

Methods

We described the program set-up with practical aspects. Patients aged 65 and above with therapy refractory end-stage heart failure without major contraindication for LVAD implantation were included. Younger patients with bridge-to-candidacy profile were also considered. Using the Kaplan-Meier estimate, we retrospectively analyzed the overall survival and freedom from major adverse events after LVAD implantation. We compared our results to internationally reported data.

Results

Between October 2014 and September 2019, 16 patients received an LVAD in our center. The mean age at implantation was 67.1 years. The mean EuroSCORE II was 24.4% and the median INTERMACS level was 4. Thirteen patients received an LVAD as destination therapy and three patients as bridge-to-candidacy. The overall survival was 87.5 and 70% at 1 and 2 years, respectively. Freedom from stroke was 81.3% at 1 and 2 years. Freedom from device infection was 67.7 and 58.7% at 1 and 2 years, respectively. Freedom from gastrointestinal bleeding was 75 and 56.3% at 1 and 2 years, respectively. Freedom from readmission was 50 and 31.3% and at 6 months and 1 year, respectively.

Conclusions

The Basel experience demonstrated the possible implementation of an LVAD program for destination therapy or bridge-to-candidacy in a non-transplant comprehensive heart-failure center with midterm survival results and freedom from major adverse events comparable to international registries. Patient selection remains crucial.

Trial registration

This study was registered on the ClinicalTrials.gov database (NCT04263012).

Heart transplantation of patients with ventricular assist devices: impact of normothermic ex-vivo preservation using organ care system compared with cold storage

Background

Organ Care System (OCS) minimizes the cold ischemic time and allows for optimization of logistics and meticulous recipient preparation. Impact of normothermic ex-vivo preservation using OCS compared with cold storage (CS) for prolonged heart preservation especially beneficial for high-risk recipients bridged to transplantation with Mechanical Circulatory Support (MCS).

Methods

Between 2012 and 2018, we performed a retrospective single-center review of prospectively collected data. All patients who underwent heart transplantation with MCS using the OCS Heart (n = 25) versus standard cold storage (n = 10) were included in this study.

Results

During this period, 353 patients were implanted with left ventricular assisted device (LVAD) and 35 (10%) were bridged to heart transplantation. There was no significant difference in donor and recipient characteristics and risk factors. The Index for Mortality Prediction after Cardiac Transplantation (IMPACT) score was a trend towards higher estimated risk of death at 1y in the OCS group (14.2 vs. 10.8% p = 0.083). Mean total ischemic time during preservation was statistically significantly longer in CS vs OCS group (210 (23) Vs 74.6 (13) min p = 0.001). Median ex vivo normothermic heart perfusion time in OCS was 348.4(132; 955) min. There was significant difference in total out of body time between OCS group 423(67) Vs CS group 210(23) min p = 0.002). All patients were alive on the 30th days post implant in CS groups and 96% in OCS group (p = 0.5).

Conclusion

Normothermic ex-vivo preservation of the allograft during transportation with the organ care system might be beneficial for long-time out of body organ preservation in comparison of cold storage especially for recipients on mechanical circulatory support.

Comparison of Custodiol vs warm blood cardioplegia and conditioning of donor hearts during transportation with the organ care system

Objectives

Cold crystalloid cardioplegia for donor heart harvesting and cold ischemic storage conditions during the transportation is the standard of care during heart transplantation procedure. Organ care system (OCS) was introduced for more prolonged and reliable ex vivo organ management. This study evaluated the two different techniques used for myocardial preservation during the procurement and transportation of the heart using the OCS.

Methods

We performed prospective analysis of 43 patients with heart failure undergoing heart transplantation and using the OCS for donor organ transport. Donor hearts were arrested using blood cardioplegia and conditioning (n = 30) or standard Custodiol (SC) solution ( n = 13). Perfusion and cardiac function parameters were continuously monitored while the donor hearts were perfused in the OCS. Impact of preservation techniques on biochemical parameters and clinical outcomes were evaluated.

Results

All donor hearts had stable perfusion and lactate characteristics in the OCS, with similar measures between the two groups at the beginning of the ex vivo perfusion. Ex vivo heart perfusion mean ending concentration of Interleukin (IL)‐6 and IL‐8 was significantly lower in the blood cardioplegia group compared to the standard care group. Clinical outcomes were comparable between the two groups of patients.

Conclusions

The use of blood cardioplegia and conditioning could be a safe method for myocardial protection in distant procurement and preservation of donor hearts in the OCS.

Impact of preoperative extracorporeal life support on left ventricular assist device outcomes: A comparative study

Background:

To investigate whether preoperative short-term extracorporeal life support therapy in patients undergoing continuous-flow left ventricular assist device implantation has an impact on the outcome regarding survival and adverse events.

Methods:

Between January 2011 and May 2018, 100 consecutive patients received HeartMate II, HeartWare, or HeartMate III for end-stage heart failure. Mean age was 64.2 ± 10.3 years. Three patient groups were identified: without preoperative extracorporeal life support (non-extracorporeal life support group, n = 80), with preoperative extracorporeal life support due to postcardiotomy shock after conventional cardiac surgery (postcardiotomy shock group, n = 9), and with preoperative extracorporeal life support without previous surgery (non-postcardiotomy shock group, n = 11). The primary endpoint was overall survival after device implantation. Secondary endpoints were adverse events during the follow-up period.

Results:

Survival was significantly different between the groups (p < 0.05): 30-day, 6-month, and 1-year survival rates were 85%, 68%, and 61% for non-extracorporeal life support group; 44%, 22%, and 22% for postcardiotomy shock group; and 45%, 27%, and 24% for non-postcardiotomy shock group, respectively. Furthermore, in both extracorporeal life support groups (postcardiotomy shock and non-postcardiotomy shock), there were a higher incidence (p < 0.05) of postoperative right heart failure (30% vs 66.7% vs 54.5%), acute renal failure requiring dialysis (20% vs 77.8% vs 54.5%), and respiratory failure (31.3% vs 88.9% vs 81.8%).

Conclusion:

Continuous-flow left ventricular assist device implantation with prior extracorporeal life support appears to have a worse outcome regarding survival, right heart failure, renal and respiratory dysfunction (p < 0.05). Future studies have to be done to evaluate the outcome after extracorporeal life support bridge pre-left ventricular assist device, especially as ultima ratio in postcardiotomy shock patients.

Successful establishment of a left ventricular assist device program in an emerging country: one year experience

Background

The primary goal of this study was to evaluate the outcomes of patients with end-stage heart failure (HF) who underwent continuous flow left ventricular assist device (CF-LVAD) in a developing country and to compare to those reported by more developed countries. The secondary goal was on determining factors that may be connected to improved survival.

Methods

We prospectively analyzed 47 consecutive patients who underwent CF-LVAD at our institution. After one year the survival and adverse event profiles of patients were evaluated. At 3, 6 and 12 months, the cardiac, renal and liver function outcomes were assessed.

Results

The 30-day, 6-month and 1-year survival rates were 89%, 85% and 80%, respectively. A significant improvement in dimensions and ejection fraction of left ventricle, BNP, functional capacity, blood urea nitrogen (BUN) and total bilirubin (P<0.05 for all) were noticed 3 months post-CF-LVAD implantation, and patients were stable throughout the entire first year follow up. In the group of patients with baseline renal dysfunction (RD) there were significant improvements of renal function (P=0.004), with no changes on follow up. 57% of patients exhibited some kind of adverse event, commonly in the form of bleeding. In multivariate Cox regression analysis renal failure was found to be as an independent risk factor for the overall survival (HR =13.1, P<0.001).

Conclusions

In conclusion, our data extends previous findings from centers of developed countries, that CF-LVAD is an adequate treatment option for patients suffering from end-stage HF, and encourages expansion of CF-LVAD implantation in developing countries with nascent HT program.

Adverse Event Rates Change Favorably Over Time for Patients Bridged With the HeartWare Left Ventricular Assist Device

The HeartWare Ventricular Assist System (HVAD) provides significant improvements in survival and quality of life, and here, we seek to evaluate temporal differences in the adverse event (AE) rates. Patients (n = 382) in the ADVANCE bridge-to-transplant and continued access protocol trial were assessed for bleeding, cardiac arrhythmia, infection, ischemic and hemorrhagic stroke, and right heart failure during predetermined time periods (≤30, >30-180, >180-365, >365-730, >730-1,095 days) after HVAD implant. The Kaplan-Meier survival at 30 days, 6 months, 1, 2, and 3 years was 98%, 90%, 84%, 71%, and 63%, respectively. There were significantly fewer total AEs in days >30-180 (events per patient year [EPPY] = 5.34) compared with the first 30 days post HVAD implantation (EPPY = 30.36; p < 0.0001). The total AE rate in days >180-365 (EPPY = 4.09) was also significantly lower than the event rate in days >30-180 (EPPY = 5.34; p < 0.0001). Incidence of cardiac arrhythmias, infections, strokes, and right heart failure were highest immediately post implant and lower rates occurred after 6 months. After 1 year, all AEs exhibited stable rates that were comparable up to 3 years of support (all p > 0.05). This changing risk over time has clinically meaningful implications toward improving patient management.

Initial 3-year outcomes with left ventricular assist devices in a country with a nascent heart transplantation program

AIMS

The need for the left ventricular assist devices (LVAD) in patients with end-stage heart failure is well established, but prior to 2011, this was not available to patients in Kazakhstan. We describe the development of the sole LVAD programme in the context of a nascent heart transplantation programme and clinical outcomes for the first three years.

METHODS AND RESULTS

From November 2011 to November 2014, 146 patients underwent implantation of 152 VADs (approximately 50 devices implanted per year). We retrospectively analyzed data from 135 LVAD patients who received HeartMate II (n = 95) or HeartWare (n = 40) devices. In 75 patients LVAD was used as a bridge-to-transplantation and in 60 patients as destination therapy, but only 3 of 135 LVAD patients received heart transplant. Forty-three patients of the LVAD cohort had died by the end of the follow-up period. The mean time on LVAD was 466 ± 330 days (range 5-1200 days). Kaplan-Meier survival estimates for patients who continued on LVAD support were 93% after 1 month, 86% after 6 months and 77% after 12 months. The most common complications within the first 30 days after implant included right ventricular failure (n = 20, 1.85 events/patient-year), renal failure (n = 19, 1.76 events/patient-year) and bleeding (n = 33, 3.0 events/patient-year). Beyond 30 days adverse events included driveline infections (n = 46, 0.56 events/patient-year) and stroke (n = 33, 0.21 events/patient-year).

CONCLUSIONS

LVADs are an important therapeutic alternative to heart transplantation in the context of a developing heart transplant programme with outcomes that are comparable to those reported by other centres.