Changing Strategy Between Bridge to Transplant and Destination LVAD Therapy After the First 3 Months: Analysis of the STS-INTERMACS Database

BACKGROUND

Left ventricular assist devices (LVADs) have been implanted as bridge to transplantation (BTT), bridge to candidacy (BTC) or destination therapy (DT) on the basis of relative and absolute contraindications to transplantation. Multiple factors may lead to changes in the strategy of support after LVAD implantation.

METHODS

Based on INTERMACS (Interagency Registry for Mechanically Assisted Circulatory Support) 2012-2020 data, 11,262 patients survived to 3 months on continuous-flow LVADs with intent of BTT or DT. Preimplant characteristics and early events post-LVAD were analyzed in relation to changes in BTT or DT strategy during the next 12 months.

RESULTS

Among 3216 BTT patients at 3 months, later transplant delisting or death without transplant occurred in 536 (16.7%) and was more common with age, profiles 1-2, renal dysfunction, and independently for prior cardiac surgery (HR 1.25, 95% CI 1.04-1.51; P = 0.02). Post-LVAD events of infections, gastrointestinal bleeding, stroke, and right heart failure as defined by inotropic therapy, predicted delisting and death, as did in-hospital location at 3 months (HR 1.67, 95% CI 1.20-2.33; P = 0.0024). Of 8046 patients surviving to 3 months with the intent of destination therapy, 750 (9.3%) subsequently underwent listing or transplantation, often with initial histories of acute HF (HR 1.70, 95% CI 1.27-2.27; P = 0.0012) or malnutrition-cachexia (1.73, 95% CI 1.14-2.63; P = 0.0099). Multiple gastrointestinal bleeding events (≥ 4) with LVAD increased transition from BTT to DT (HR 4.22, 95% CI 1.46-12.275; P = 0.0078) but also from DT to BTT (HR 5.17, 95% CI 1.92-13.9; P = 0.0011).

CONCLUSIONS

Implant strategies change over time in relation to preimplant characteristics and adverse events post implant. Preimplant recognition of factors predicting later change in implant strategy will refine initial triage, whereas further reduction of post-LVAD complications will expand options, including eventual consideration of heart transplantation.

Right Ventricular Contractility and Pulmonary Arterial Coupling After Less Invasive Left Ventricular Assist Device Implantation

Right ventricular failure contributes significantly to morbidity and mortality after left ventricular assist device implantation. Recent data suggest a less invasive strategy (LIS) via thoracotomy may be associated with less right ventricular failure than conventional median sternotomy (CMS). However, the impact of these approaches on load-independent right ventricular (RV) contractility and RV-pulmonary arterial (RV-PA) coupling remains uncertain. We hypothesized that the LIS approach would be associated with preserved RV contractility and improved RV-PA coupling compared with CMS. We performed a retrospective study of patients who underwent durable, centrifugal left ventricular assist device implantation and had paired hemodynamic assessments before and after implantation. RV contractility (end-systolic elastance [Ees]), RV afterload (pulmonary effective arterial elastance [Ea]), and RV-PA coupling (Ees/Ea) were determined using digitized RV pressure waveforms. Forty-two CMS and 21 LIS patients were identified. Preimplant measures of Ees, Ea, and Ees/Ea were similar between groups. After implantation, Ees declined significantly in the CMS group (0.60-0.40, p  = 0.008) but not in the LIS group (0.67-0.58, p  = 0.28). Coupling (Ees/Ea) was unchanged in CMS group (0.54-0.59, p  = 0.80) but improved significantly in the LIS group (0.58-0.71, p  = 0.008). LIS implantation techniques may better preserve RV contractility and improve RV-PA coupling compared with CMS.

Impact of Donor Hemodynamics on Recipient Survival in Heart Transplantation

BACKGROUND

Heart transplantation is the gold-standard therapy for end-stage heart failure, but rates of donor-heart use remain low due to various factors that are often not evidence based. The impact of donor hemodynamics obtained via right-heart catheterization on recipient survival remains unclear.

METHODS

The United Network for Organ Sharing registry was used to identify donors and recipients from September 1999-December 2019. Donor hemodynamics data were obtained and analyzed using univariate and multivariable logistical regression, with the primary endpoints being 1- and 5-year post-transplant survival.

RESULTS

Of the 85,333 donors who consented to heart transplantation during the study period, 6573 (7.7%) underwent right-heart catheterization, of whom 5531 eventually underwent procurement and transplantation. Donors were more likely to undergo right-heart catheterization if they had high-risk criteria. Recipients who had donor hemodynamic assessment had 1- and 5-year survival rates similar to those without donor hemodynamic assessment (87% vs 86%, 1 year). Abnormal hemodynamics were common in donor hearts but did not impact recipient survival rates, even when risk-adjusted in multivariable analysis.

CONCLUSIONS

Donors with abnormal hemodynamics may represent an opportunity to expand the pool of viable donor hearts.

Outcomes of Combined Heart-Kidney Transplantation in Older Recipients

Objectives

The upper limit of recipient age for combined heart-kidney transplantation (HKT) remains controversial. This study evaluated the outcomes of HKT in patients aged ≥65 years.

Methods

The United Network of Organ Sharing (UNOS) was used to identify patients undergoing HKT from 2005 to 2021. Patients were stratified by age at transplantation: <65 and ≥ 65 years. The primary outcome was one-year mortality. Secondary outcomes included 90-day and 5-year mortality, postoperative new-onset dialysis, postoperative stroke, acute rejection prior to discharge, and rejection within one-year of HKT. Survival was compared using Kaplan-Meier analysis, and risk adjustment for mortality was performed using Cox proportional hazards modeling.

Results

HKT in recipients aged ≥65 significantly increased from 5.6% of all recipients in 2005 to 23.7% in 2021 (p=0.002). Of 2,022 HKT patients in the study period, 372 (18.40%) were aged ≥65. Older recipients were more likely to be male and white, and fewer required dialysis prior to HKT. There were no differences between cohorts in unadjusted 90-day, 1-year, or 5-year survival in Kaplan-Meier analysis. These findings persisted after risk-adjustment, with an adjusted hazard for one-year mortality for age ≥65 of 0.91 (95% CI (0.63-1.29), p=0.572). As a continuous variable, increasing age was not associated with one-year mortality (HR 1.01 (95% CI (1.00-1.02), p=0.236) per year). Patients aged ≥65 more frequently required new-onset dialysis prior to discharge (11.56% vs. 7.82%, p=0.051). Stroke and rejection rates were comparable.

Conclusion

Combined HKT is increasing in older recipients, and advanced age ≥65 should not preclude HKT.

Sex mismatch following heart transplantation in the United States: Characteristics and impact on outcomes

BACKGROUND

Available literature indicates the possible detrimental effect of sex mismatching on mortality in patients undergoing heart transplantation. Our objective was to examine the role of sex and heart mass (predicted heart mass [PHM]) mismatch on mortality and graft rejection in patients undergoing heart transplantation in the US.

METHODS

Data on adult patients who underwent heart transplantation between January 2015 and October 2021 were queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were all-cause mortality, 1-year all-cause mortality and treated acute rejection.

RESULTS

A total of 19 805 adult patients underwent heart transplant during the study period. 92.2% of the patients in the female graft to male group had a PHM mismatch <25%, while only 38.5% had such a mismatch in the male graft to female group. In male to male and female to female groups, 79% and 76% of the patients had a PHM mismatch <25% (p = .122). Proportion of PHM mismatch was similar throughout the study period. Unadjusted analysis showed that male recipients of female grafts had increased risk for all-cause mortality (hazard ratio [HR]: 1.13; 95% confidence intervals [CI]: 1.02, 1.27; p = .026) and 1-year mortality (HR: 1.26; 95% CI: 1.09, 1.45; p = .002) compared to male recipients of male grafts. Graft failure incidence was also higher (HR: 1.12; 95% CI: 1.01, 1.25; p = .041). However, all these associations were non- significant after risk factor adjustment.

CONCLUSIONS

Sex mismatching is associated with post-transplant mortality with transplantation of female donor grafts to male recipients demonstrating worse outcomes, although this association disappears after risk factor adjustment. Further research is required to elucidate the need for potential changes in clinical practice.

Hemodynamic reserve predicts early right heart failure after LVAD implantation

BACKGROUND

Early right heart failure (RHF) remains a major source of morbidity and mortality after left ventricular assist device (LVAD) implantation, yet efforts to predict early RHF have proven only modestly successful. Pharmacologic unloading of the left ventricle may be a risk stratification approach allowing for assessment of right ventricular and hemodynamic reserve.

METHODS

We performed a multicenter, retrospective analysis of patients who had undergone continuous-flow LVAD implantation from October 2011 to April 2020. Only those who underwent vasodilator testing with nitroprusside during their preimplant right heart catheterization were included (n = 70). Multivariable logistic regression was used to determine independent predictors of early RHF as defined by Mechanical Circulatory Support-Academic Research Consortium.

RESULTS

Twenty-seven patients experienced post-LVAD early RHF (39%). Baseline clinical characteristics were similar between patients with and without RHF. Patients without RHF, however, achieved higher peak stroke volume index (SVI) (30.1 ± 8.8 vs 21.7 ± 7.4 mL/m2; p < 0.001; AUC: 0.78; optimal cut-point: 22.1 mL/m2) during nitroprusside administration. Multivariable analysis revealed that peak SVI was significantly associated with early RHF, demonstrating a 16% increase in risk of early RHF per 1 ml/m2 decrease in SVI. A follow up cohort of 10 consecutive patients from July 2020 to October 2021 resulted in all patients being categorized appropriately in regards to early RHF versus no RHF according to peak SVI.

CONCLUSION

Peak SVI with nitroprusside administration was independently associated with post-LVAD early RHF while resting hemodynamics were not. Vasodilator testing may prove to be a strong risk stratification tool when assessing LVAD candidacy though additional prospective validation is needed.

The HeartMate 3 left ventricular assist device as a strategy to bridge to transplant

PURPOSE

Recent changes in the market for left ventricular assist devices have resulted in the HeartMate 3 (HM3) being the only commercially-available device. This study evaluates the outcomes of patients with a HM3 waitlisted for and undergoing orthotopic heart transplantation (OHT).

METHODS

Patients waitlisted for isolated OHT with a HM3 or undergoing OHT after bridge-to-transplant (BTT) with a HM3 between 2015 and 2021 were identified from the UNOS registry and included in this study. Propensity matching was used to compare outcomes of BTT-HM3 versus primary OHT.

RESULTS

A total of 1321 patients supported with a HM3 underwent OHT during our study period. Unadjusted 30-day, 90-day, and 1-year survival following OHT in the BTT-HM3 cohort was 96.5%, 94.4%, and 90.7%, respectively. In propensity-matched analysis, 1103 BTT-HM3 patients were compared with 1103 primary OHT patients. Rates of post-OHT stroke were higher in the BTT-HM3 group (4.4% vs. 2.0%, p = .001). The BTT-HM3 group had lower 30-day survival (96.2% vs. 97.4%, p = .033) although 90-day (94.2% vs. 95.3%, p = .103) and 1-year survival (90.4% vs. 91.7%, p = .216) were comparable. A total of 1251 patients were supported with a HM3 at the time of OHT listing during the study period. At the time of this analysis, 60 (4.5%) remained on the waitlist, 991 (75.0%) underwent OHT, and 119 (9.0%) died or clinically deteriorated with waitlist removal.

CONCLUSIONS

The HM3 is a viable method for BTT with acceptable waitlist outcomes. Although 1-year survival is comparable to primary OHT, early outcomes are worse, suggesting that refinement of patient selection and perioperative management is prudent to optimizing outcomes.

Characteristics and outcomes of left ventricular assist device recipients transplanted before and after the new donor heart allocation system

Background

Concerns about the impact of the new donor heart allocation system on post-transplant outcomes have emerged after its implementation. We sought to evaluate the characteristics and outcomes of left ventricular assist device (LVAD) recipients transplanted before and after the implantation of the new policy on October 18, 2018.

Methods

Data on bridge to transplantation adult LVAD patients January 2015 and October 2021, with durable LVAD as a (BTT), was queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were 30-day all-cause mortality, 30-day fatal graft failure, 1-year all-cause mortality, treated acute rejection at one year and renal replacement therapy (RRT) for acute renal failure.

Results

In our study, 7096 patients met the inclusion criteria including 2,435 in the new allocation system. The transplanted patients in the new allocation system era had older donor age, longer ischemic time and higher proportion of newer generation LVADs. Adjusted 30-day all-cause mortality was significantly lower for LVAD recipients in the new allocation system era (sub-hazard ratio [SHR] 0.36, 95% Confidence intervals [CI] 0.27–0.48, p&lt;0.001) without differences in the risk of fatal graft failure and one-year mortality. Significantly lower adjusted 30-day mortality with HVAD and HM3 devices than HM2 in the new allocation system era was found, without differences in one-year mortality. Acute allograft rejection requiring treatment was significantly lower (Odds Ratio 0.78, 95% CI 0.65–0.94, p=0.01) whereas a trend towards higher risk of renal failure requiring RRT was identified.

Conclusions

Despite changing donor characteristics and longer ischemic times, post-transplant outcomes in LVAD recipients have not worsened with the implementation of the new allocation system and this finding is related to the use of newer generation continuous flow LVADs.

Funding Acknowledgement

Type of funding sources: None.

Characteristics and Outcomes of Left Ventricular Assist Device Recipients Transplanted Before and After the New Donor Heart Allocation System

BACKGROUND

Concerns about the impact of the new donor heart allocation system on post-transplant outcomes have emerged after its implementation. We sought to evaluate the characteristics and outcomes of left ventricular assist device (LVAD) recipients transplanted before and after the implantation of the new policy on October 18, 2018.

METHODS

Data on bridge to transplantation adult LVAD patients January 2015 and October 2021, with durable LVAD as a (BTT), was queried from the United Network of Organ Sharing (UNOS) registry. The main outcomes were 30-day all-cause mortality, 30-day fatal graft failure, 1-year all-cause mortality, treated acute rejection at one year and renal replacement therapy (RRT) for acute renal failure.

RESULTS

In our study, 7096 patients met the inclusion criteria including 2,435 in the new allocation system. The transplanted patients in the new allocation system era had older donor age, longer ischemic time and higher proportion of newer generation LVADs. Adjusted 30-day all-cause mortality was significantly lower for LVAD recipients in the new allocation system era (2.5% vs 3.6%; sub-hazard ratio [SHR] 0.36, 95% Confidence intervals [CI] 0.27-0.48, p<0.001) without differences in the risk of fatal graft failure and one-year mortality (7.8% vs 9.6%). Significantly lower adjusted 30-day mortality with HVAD and HM3 devices than HM2 in the new allocation system era was found, without differences in one-year mortality. Acute allograft rejection requiring treatment was significantly lower (Odds Ratio 0.78, 95% CI 0.65-0.94, p=0.01) whereas a trend towards higher risk of renal failure requiring RRT was identified.

CONCLUSIONS

Despite changing donor characteristics and longer ischemic times, post-transplant outcomes in LVAD recipients have not worsened with the implementation of the new allocation system and this finding is related to the use of newer generation continuous flow LVADs.

Hemodynamic and Clinical Determinants of Left Atrial Enlargement in Liver Transplant Candidates

New-onset heart failure is a frequent complication after orthotopic liver transplantation (OLT). Left atrial enlargement (LAE) may be a sign of occult left heart disease. Our primary objective was to determine invasive hemodynamic and clinical predictors of LAE and then investigate its effect on post-transplant outcomes. Of 609 subjects who received OLT between January 1, 2010, and October 1, 2018, 145 who underwent preoperative right-sided cardiac catheterization and transthoracic echocardiography were included. Seventy-eight subjects (54%) had pretransplant LAE. Those with LAE had significantly lower systemic vascular resistance with higher cardiac and stroke volume index (61.0 vs 51.7 ml/m²; p <0.001), but there was no difference in pulmonary artery wedge pressure. There was a linear relation between left atrial volume index and stroke volume index (R² = 0.490, p<0.001), but not pulmonary artery wedge pressure. The presence of severe LAE was associated with a reduced likelihood (hazard ratio = 0.26, p = 0.033) of reaching the composite end point of new-onset systolic heart failure, heart failure hospitalization, or heart failure death within 12 months post-transplant. There was also a significant reduction in LAE after transplantation (p = 0.013). In conclusion, LAE was common in OLT recipients and was more closely associated with stroke volume than left heart filling pressures. The presence of LAE was associated with a reduced likelihood of reaching composite outcomes and tended to regress after transplant.

Outcomes in LVAD Patients Undergoing Simultaneous Heart-Kidney Transplantation

BACKGROUND

Multiple studies have shown better outcomes for simultaneous heart kidney transplant (sHKT) compared with isolated orthotopic heart transplant (iOHT) in recipients with chronic kidney disease (CKD). However, outcomes in patients supported by durable LVAD have not been well studied.

METHODS

Patients with durable LVADs and stage 3 or greater CKD (eGFR <60ml/min/1.73m2) undergoing iOHT or sHKT between 2008-2020 were identified from the United Network for Organ Sharing (UNOS) registry. Kaplan Meier survival analysis with associated log-rank test was conducted to compare post-transplant survival. Multivariable modeling was used in order to identify risk adjusted predictors of one-year posttransplant mortality.

RESULTS

4375 patients were identified, 366 underwent sHKT and 4009 iOHT. The frequency of sHKT increased over the study period. One-year post-transplant survival was worse in sHKT compared with iOHT (80.3% vs 88.3%, p<0.001), and persisted up to 5 years post-transplant (p=0.001). sHKT recipients were more likely to require dialysis after transplant and had longer hospital length of stay (p<0.001). Multivariable analysis showed sHKT remained an independent risk factor for mortality at 1 year (OR 1.58, p=0.002).

CONCLUSIONS

HKT is becoming more common in patients with durable LVADs. Compared with iOHT, sHKT have worse short and long-term survival are more likely to require posttransplant dialysis.

The impact of changes in renal function during waitlist time on outcomes after heart transplantation

BACKGROUND AND AIM

This study evaluated the impact of changes in renal function during the waitlist period on posttransplant outcomes of orthotopic heart transplantation (OHT).

METHODS

The United Network for Organ Sharing registry was used to identify adult patients undergoing isolated OHT from 2010 to 2020. Patients were stratified by whether their National Kidney Foundation chronic kidney disease (CKD) stage improved, worsened, or remained unchanged between listing and transplantation. Univariate analysis and multivariable Cox regression were conducted to determine whether a change in estimated glomerular filtration rate (eGFR) or change in CKD stage predicted 1-year mortality after OHT.

RESULTS

Of 22,746 patients, the majority of patients remained in the same CKD stage (59.6%), and the frequencies of patients progressing to improved (19.3%) and worsened (21.1%) CKD stages were similar. Temporary mechanical circulatory support (MCS) was associated with improved CKD stage and durable MCS with worsened CKD stage (p < .001). Post-OHT dialysis was most common in patients with worsened CKD stage (13.2%) and least common in the improved cohort (9.4%) (p < .001). Kaplan-Meier unadjusted 1-year survival rates after OHT were similar between CKD change groups (log-rank p = .197). Multivariable analysis demonstrated no risk-adjusted effect of change in eGFR (p = .113) or change in CKD stage (p = .076) on 1-year mortality after OHT.

CONCLUSIONS

Approximately 20% of patients improve CKD stage and 20% worsen CKD stage between listing and OHT, with the remaining 60% having unchanged CKD stage. Worsening CKD stage predicts increased likelihood of post-OHT dialysis, but CKD stage change does not predict 1-year survival following OHT.

Pulmonary Hypertension in the Context of Heart Failure With Preserved Ejection Fraction

Heart failure with preserved ejection fraction (HFpEF) is the most common form of heart failure and frequently is associated with pulmonary hypertension (PH). HFpEF associated with PH may be difficult to distinguish from precapillary forms of PH, although this distinction is crucial because therapeutic pathways are divergent for the two conditions. A comprehensive and systematic approach using history, clinical examination, and noninvasive and invasive evaluation with and without provocative testing may be necessary for accurate diagnosis and phenotyping. After diagnosis, HFpEF associated with PH can be subdivided into isolated postcapillary pulmonary hypertension (IpcPH) and combined postcapillary and precapillary pulmonary hypertension (CpcPH) based on the presence or absence of elevated pulmonary vascular resistance. CpcPH portends a worse prognosis than IpcPH. Despite its association with reduced functional capacity and quality of life, heart failure hospitalizations, and higher mortality, therapeutic options focused on PH for HFpEF associated with PH remain limited. In this review, we aim to provide an updated overview on clinical definitions and hemodynamically characterized phenotypes of PH, pathophysiologic features, therapeutic strategies, and ongoing challenges in this patient population.

Treatment of right ventricular dysfunction and heart failure in pulmonary arterial hypertension

Right heart dysfunction and failure is the principal determinant of adverse outcomes in patients with pulmonary arterial hypertension (PAH). In addition to right ventricular (RV) dysfunction, systemic congestion, increased afterload and impaired myocardial contractility play an important role in the pathophysiology of RV failure. The behavior of the RV in response to the hemodynamic overload is primarily modulated by the ventricular interaction and its coupling to the pulmonary circulation. The presentation can be acute with hemodynamic instability and shock or chronic producing symptoms of systemic venous congestion and low cardiac output. The prognostic factors associated with poor outcomes in hospitalized patients include systemic hypotension, hyponatremia, severe tricuspid insufficiency, inotropic support use and the presence of pericardial effusion. Effective therapeutic management strategies involve identification and effective treatment of the triggering factors, improving cardiopulmonary hemodynamics by optimization of volume to improve diastolic ventricular interactions, improving contractility by use of inotropes, and reducing afterload by use of drugs targeting pulmonary circulation. The medical therapies approved for PAH act primarily on the pulmonary vasculature with secondary effects on the right ventricle. Mechanical circulatory support as a bridge to transplantation has also gained traction in medically refractory cases. The current review was undertaken to summarize recent insights into the evaluation and treatment of RV dysfunction and failure attributable to PAH.

The impact of insurance type on listing status and wait-list mortality of patients with left ventricular assist devices as bridge to transplantation

Aims

Adequate health insurance coverage is necessary for heart transplantation (HT) candidates. Prior studies have suggested inferior outcomes post HT with public health insurance. We sought to evaluate the effects of insurance type on transplantation rates, listing status and mortality prior to HT.

Methods and results

Patients ≥18 years old with a left ventricular assist device implanted and listed with 1A status were identified in the United Network for Organ Sharing registry between January 2010 and December 2017, with follow‐up through March 2018. Patients were grouped based on the type of insurance private/self‐pay (PV), Medicare (MC), and Medicaid (MA) at the time of listing. We conducted multivariable competing risks regression analysis on listing status and mortality on the waiting list, stratified by insurance type at the time of listing. We identified 2604 patients listed in status 1A (PV: 51.4%, MC: 32.1%, and MA: 16.5%). MA patients were younger (43.5 vs. 56.4 for MC vs. 51.5 for PV, P < 0.001) and less frequently White (P < 0.001). The cumulative incidence of HT did not differ among the three insurance types (PV: 74.8%, MC 76.3%, and MA 71.1%, P = 0.14). The cumulative mortality on the waiting list prior to HT was not different among groups (PV: 29.3%, MC 26.3%, and MA 21.8%, P = 0.94). Μore patients with MA were removed from the list because of improvement of their condition (MA 40.3% vs. MC 28.3% and PV 32.8%).

Conclusions

We did not detect any disparities in listing status and mortality among different insurance types.

Characteristics and outcomes in patients with atrial fibrillation receiving direct oral anticoagulants in off-label doses

Background

We evaluated adherence to dosing criteria for patients with atrial fibrillation (AF) taking dabigatran or rivaroxaban and the impact of off-label dosing on thromboembolic and bleeding risk.

Methods

We used data for a retrospective cohort from a large U.S. health plan for Medicare beneficiaries age > =65 years with AF who initiated dabigatran or rivaroxaban during 2010–2016. Stroke and major bleeding were quantified in patients who were eligible for low dose but received standard dose, and in patients who were eligible for standard dose but received low dose.

Results

We identified 8035 and 19,712 patients who initiated dabigatran or rivaroxaban, respectively. Overall, 1401 (17.4%) and 7820 (39.7%) patients who received dabigatran and rivaroxaban met criteria for low dose, respectively. Of those, 959 (68.5%) and 3904 (49.9%) received standard dose. In contrast, 1013 (15.3%) and 2551 (21.5%) of patients eligible for standard dose dabigatran and rivaroxaban received low dose. Mean follow-up for patients eligible for low and standard dose dabigatran and rivaroxaban were 13.9, 15.1, 10.1, and 12.3 months, respectively. In unadjusted analyses, patients eligible for low or standard dose dabigatran and rivaroxaban but receiving off-label dose, had no differences in the rates of ischemic stroke. Among patients who met criteria for standard dose direct oral anticoagulants (DOAC), use of low dose was associated with significantly higher risk of any major bleeding (Dabigatran: HR = 1.44; 95% CI 1.14–1.8, P = 0.002, Rivaroxaban HR 1.34, 95% CI 1.11–1.6, P = 0.002) and gastrointestinal bleeding (Dabigatran: HR = 1.48; 95% CI 1.08–2, P = 0.016). In patients who met criteria for low dose DOACs, there was lower risk of major bleeding (Dabigatran: HR = 0.59; 95% CI 0.43–0.8, P < 0.001), gastrointestinal (Rivaroxaban: HR 0.79; 95% CI 0.64–0.98, P = 0.03) and intracranial bleeding (Dabigatran: HR = 0.33; 95% CI 0.12–0.9, P = 0.001) with standard dosing. After propensity matching, use of off-label doses was not associated with stroke, major, gastrointestinal or intracranial bleeding for either dabigatran or rivaroxaban.

Conclusions

While a significant number of patients receive higher or lower dose of dabigatran and rivaroxaban than recommended, we found no evidence of significant impact on thromboembolic or hemorrhagic outcomes.

Characteristics and Outcomes of Patients With Cardiogenic Shock Utilizing Hemodialysis for Acute Kidney Injury

In the setting of cardiogenic shock (CS), impaired biventricular function can cause acute decrease in renal function via reduced renal perfusion and increased renal venous pressure. We sought to analyze the characteristics and outcomes of patients hospitalized with CS who utilized renal replacement therapy (hemodialysis) for acute kidney injury (AKI-HD). We utilized data from the National Inpatient Sample to calculate national rates of in-hospital mortality, use of temporary mechanical support, vascular injury requiring surgery, length of stay (LOS) and hospitalization cost from 2010 to September 2015. We compared the in-hospital outcomes between CS with AKI-HD and a propensity score-matched group without AKI-HD. We identified 6,076 hospitalizations (weighted n = 24,272) with CS and AKI-HD and 76,878 (weighted n = 378,553) with CS not AKI-HD. Among these cases 48.1% (n = 39,403, weighted n = 193,746) had ST elevation myocardial infarction as the cause of CS. Patients with CS and AKI-HD had higher comorbidity burden and they were also more likely to receive mechanical circulatory support device (absolute standardized difference >10% for all comparisons) compared with CS patients without AKI-HD. After matching 4,457 cases for patient-level and hospital-level characteristics, CS with AKI-HD was associated with significantly higher in-hospital mortality (75.74% vs 51.58%, p <0.001), use of temporary mechanical support (24.0% vs 19.3%, p <0.001), LOS (21.4 vs14.4 days, p <0.001) and cost ($80,406 vs $52,833, p <0.0001). AKI-HD occurred in approximately 6% of patients with CS in years 2010 to 2015 and was associated with significantly increased in-hospital morbidity and mortality, LOS, and cost.

Trends in utilization, mortality, major complications, and cost after total artificial heart implantation in the United States (2009-2015)

OBJECTIVE

Total artificial heart (TAH) is a viable bridge to transplant (BTT) strategy for patients with severe biventricular failure or complex congenital heart disease. These patients have higher mortality and morbidity than patients undergoing left ventricular assist device (LVAD) implantation. To assess national trends in in-hospital mortality, major complications, cost, length of stay, and disposition of patients undergoing TAH implantation.

METHODS

Data from the National Inpatient Sample, the largest all-payer inpatient data set in the United States, and the US Census Bureau, for the years 2009 to 2015 were analyzed. Participants included all adult patients who received TAH from 2009 to 2015. Endpoints included in-hospital mortality, in-hospital complications, heart transplantation (HT) in the same admission, length of stay, cost, and disposition at the time of discharge.

RESULTS

We identified a total of 143 (weighted = 703) TAH implantations. The number of TAH implants increased during the study period (average annual change +5.8%, p = 0.03). Rates of in-hospital mortality and major complications including ischemic stroke, major bleeding, postoperative infections, acute kidney injury requiring dialysis, and HT did not change significantly over the study period. Although the length of stay and disposition patterns did not change over time, we found a significant increase in cost of hospitalization (average annual change +44,362, p = 0.01). The number of HT during the same hospital stay decreased significantly (average annual change -8.1%, p = 0.02).

CONCLUSION

In-hospital mortality and complication rates associated with TAH implantation remain increased and did not change in the era of continuous flow LVADs.

Usefulness of Cardiac Resynchronization Therapy in Patients With Continuous Flow Left Ventricular Assist Devices

The benefit of cardiac resynchronization therapy in patients supported by a left ventricular assist device (LVAD) is unknown. There are currently no guidelines regarding the continuation, discontinuation or pacemaker (PM) settings post-LVAD implant. The aim of the study was to assess the hemodynamic benefit of biventricular (BiV) pacing in LVAD patients. We studied 22 patients supported by LVADs (age 62 ± 9, 21 males) who had received a BiV PM before LVAD implant. A total of 123 complete sets of hemodynamics were obtained during BiV pacing (n = 54), right ventricular (RV) pacing (n = 54), and intrinsic rhythm (n = 15). There were no significant differences in right atrial (RA) pressure, mean pulmonary artery pressure (mPA), PCWP, cardiac output, PA saturation (PASat) and right ventricular stroke work index between BiV and RV pacing. Hemodynamics obtained during intrinsic rhythm in 15 non-PM-dependent patients were not significantly different compared with those obtained during BiV or RV pacing. Furthermore, hemodynamics were similar at different heart rates ranging 50 to 110 beats/min. Right ventricular stroke work index was significantly lower at the highest heart rate compared with baseline and lowest heart rates suggesting decreased RV performance at higher heart rate. In conclusion, BiV pacing does not have any acute hemodynamic benefit compared with RV pacing or intrinsic rhythm in LVAD patients. A lower heart rate may confer better RV performance.

Effect of Hospital Ownership on Outcomes After Left Ventricular Assist Device Implantation in the United States

BACKGROUND

We evaluated the effects of hospital ownership, classified into three tiers (nonfederal government, not-for-profit, and for-profit hospitals), on in-hospital outcomes after implantation of continuous-flow left ventricular assist devices (LVADs) in the United States from 2009 to 2014.

METHODS

Data from the National Inpatient Sample were used to calculate annual national estimates in utilization, in-hospital mortality, major complications, lengths of stay, cost of hospitalization, and disposition at discharge for years 2009 to 2014. Complications were calculated using patient safety indicators and International Classification of Diseases, Ninth Revision, Clinical Modification codes.

RESULTS

Of the 3,571 patients (weighted, 17,547) with LVAD implants in the United States between 2009 and 2014, 82.1% were in not-for-profit hospitals, 15.6% in nonfederal government hospitals, and 2.3% in for-profit hospitals. In-hospital mortality significantly decreased over time only in not-for-profit hospitals by average annual change of -7.4% (p = 0.001) and was higher in for-profit hospitals than other tiers of hospital ownership. Our analysis did not suggest any differences in postoperative complications among different hospital ownership types. LVAD implantation in nonfederal government hospitals was associated with the highest cost ($227,930; interquartile range [IQR], $173,259 to $301,566) and implantation in for-profit hospitals was associated with lower cost ($148,406; IQR, $133,149 to $199,317; p = 0.03). The length of stay was similar across the three tiers of hospital ownership. Nonroutine discharge was significantly more frequent in not-for-profit hospitals (73.6%; IQR 69.5% to 77.7%) compared with nonfederal government (48.8%; IQR, 42.4% to 55.1%) and for-profit (59.8%; IQR, 43.0% to 76.6%) hospitals (p < 0.001).

CONCLUSIONS

Disparities in in-hospital mortality, cost, and disposition exist between various hospital ownerships during admission for LVAD implant.

Regional Variation in Mortality, Major Complications, and Cost After Left Ventricular Assist Device Implantation in the United States (2009 to 2014)

The objective of this analysis was to provide evidence on regional differences in outcomes, cost and disposition among patients who undergo continuous-flow LVAD implantation. Using data from the National Inpatient Sample and US Census Bureau, annual national estimates in utilization, in-hospital mortality, major complications, cost, length of stay (LOS), and disposition were estimated for years 2009 to 2014. Main outcomes and complications were identified using patient safety indicators and International Classification of Diseases-Ninth Revision, Clinical Modification codes. We analyzed a total of 3,572 (weighted = 17,552) patients with LVAD implants among the 4 Census regions of the United States. The patient population in the Southern region was younger with higher percentage of African-Americans. Overall, the comorbidity burden was higher in the Midwest. The risk-adjusted rate of in-hospital mortality did not differ significantly among the geographical regions (p = 0.8). With the exception of cardiac tamponade rates which were higher in the Northeast and West, all other post-operative complications did not differ between regions. LOS was higher in the Northeast (median 32 days) and lower in the South (median 27 days). The cost analysis suggested higher median cost in the West (median $246,292) and lowest in the Northeast region (median $192,604). Finally, higher percentages of patients were transferred to an extended care facility in the Northeast, whereas more patients were discharged to home in the Western region. We identified region disparities in LOS, cost and disposition but not in-hospital mortality and complications, among patients who underwent LVAD implantation between 2009 and 2014.

Trends in Utilization, Mortality, Major Complications, and Cost After Left Ventricular Assist Device Implantation in the United States (2009 to 2014)

The utilization of contemporary continuous-flow left ventricular assist device (CF-LVADs) has increased, accounting for >90% of implants from 2009 to 2014. The present study aimed to identify the annual national estimates in utilization, in-hospital mortality, and major complications with CF-LVAD using data from the National Inpatient Sample, the largest all-payer inpatient data set in the United States, and the US Census Bureau, for the years 2009 to 2014. Participants included all adult patients who received CF-LVADs from 2009 to 2014. End points included in-hospital mortality, in-hospital complications, length of stay, cost, and disposition at the time of discharge. A total of 3,572 (weighted = 17,552) patients with left ventricular assist device (LVAD) implants were analyzed. LVAD implants increased significantly, with average annual change (%) of +12.6% (p <0.001). Rates of in-hospital mortality decreased by average annual rate of -5.3% (p = 0.02). The rates of major complications including ischemic stroke, major bleeding, and cardiac tamponade did not change significantly over the study period. However, we found a significant decrease in postoperative infections (p = 0.001) and respiratory complications (p = 0.03). Although the length of stay and disposition patterns did not change over time, we found a significant decrease in cost of hospitalization (p = 0.001). In conclusion, from 2009 to 2014, utilization of LVADs increased with concomitant decrease in in-hospital mortality rates, without significant changes in major complications.

Safety and Efficacy of Novel Oral Anticoagulants Versus Warfarin in Medicare Beneficiaries With Atrial Fibrillation and Valvular Heart Disease

Background

We examined a large community‐based sample of patients with atrial fibrillation (AF) and valvular heart disease (VHD) (excluding prosthetic valves) with a goal to compare outcomes among patients with AF, with and without VHD, taking warfarin, dabigatran, and rivaroxaban.

Methods and Results

We identified Medicare beneficiaries enrolled in Medicare Part D benefit plan from 2011 to 2013 with newly diagnosed AF (18 137 patients with VHD [dabigatran, 1979; rivaroxaban, 2027; warfarin, 14 131] and 85 596 patients without VHD [dabigatran, 13 522; rivaroxaban, 14 257; warfarin, 57 817]). Primary outcomes of all‐cause mortality, ischemic strokes, major bleeding, and myocardial infarction were compared across the 3 anticoagulants using 3‐way propensity‐matched samples. After propensity matching, a total of 5871 patients with VHD and 40 221 patients without VHD and AF were studied. Both dabigatran and rivaroxaban were associated with significantly lower risk of death in patients with VHD with AF (dabigatran versus warfarin: hazard ratio, 0.71; 95% confidence interval, 0.52–0.98; P=0.038; rivaroxaban versus warfarin: hazard ratio, 0.68; 95% confidence interval, 0.49–0.95; P=0.022). Nongastrointestinal bleeding was significantly reduced with dabigatran and rivaroxaban versus warfarin in those with VHD (dabigatran versus warfarin: hazard ratio, 0.17; 95% confidence interval, 0.06–0.49; P=0.001; rivaroxaban versus warfarin: hazard ratio, 0.37; 95% confidence interval, 0.17–0.84; P=0.017). Ischemic stroke and gastrointestinal bleeding rates did not differ between rivaroxaban, dabigatran, and warfarin in patients with VHD. The effects of the 3 anticoagulants on outcomes were comparable in patients with and without VHD and with AF.

Conclusions

In this cohort of Medicare beneficiaries with VHD (excluding patients with prosthetic valves) and new‐onset AF between 2011 and 2013, novel oral non–vitamin K anticoagulants were safe and effective options for prevention of systemic thromboembolism.

Therapeutic Approach to Patients with Heart Failure with Reduced Ejection Fraction and End-stage Renal Disease

BACKGROUND

Several risk factors including Ischemic heart disease, uncontrolled hypertension, high output Heart Failure (HF) from shunting through vascular hemodialysis access, and anemia, contribute to development of HF in patients with End-Stage Renal Disease (ESRD). Guidelinedirected medical and device therapy for Heart Failure with Reduced Ejection Fraction (HFrEF) has not been extensively studied and may have limited safety and efficacy in patients with ESRD.

RESULTS

Maintenance of interdialytic and intradialytic euvolemia is a key component of HF management in these patients but often difficult to achieve. Beta-blockers, especially carvedilol which is poorly dialyzed is associated with cardiovascular benefit in this population. Despite paucity of data, Angiotensin-converting Enzyme Inhibitors (ACEI) or Angiotensin II Receptor Blockers (ARBs) when appropriately adjusted by dose and with close monitoring of serum potassium can also be administered to these patients who tolerate beta-blockers. Mineralocorticoid receptors in patients with HFrEF and ESRD have been shown to reduce mortality in a large randomized controlled trial without any significantly increased risk of hyperkalemia. Implantable Cardiac-defibrillators (ICDs) should be considered for primary prevention of sudden cardiac death in patients with HFrEF and ESRD who meet the implant indications. Furthermore in anemic iron-deficient patients, intravenous iron infusion may improve functional status. Finally, mechanical circulatory support with leftventricular assist devices may be related to increased mortality risk and the presence of ESRD poses a relative contraindication to further evaluation of these devices.

Angiogenesis in peripheral arterial disease

Peripheral arterial disease (PAD) refers to narrowing of the peripheral arteries and atherosclerosis is the most important cause. In patients with PAD, revascularization is the preferred therapeutic strategy; nonetheless several patients are not deemed candidates for it due to advanced disease or several comorbidities. The main target of therapeutic angiogenesis is to promote development of new arterial vessels and improve perfusion of ischemic tissue. Angiogenic growth factors such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), hepatocyte growth factor (HGF), administered intramuscularly or intra-arterially, have been shown to promote angiogenesis and development of collateral vasculature in preclinical studies. However, clinical studies failed to confirm their efficacy in ulcer healing and prevention of amputation, among patients with claudication or critical limb ischemia (CLI). Autologous progenitor cell therapy with bone marrow or adipose-derived progenitor cells administered intra-arterially or intra-muscularly, was shown to improve claudication symptoms and ankle-brachial index in small studies. However, subsequent randomized controlled studies did not demonstrate any beneficial effects of stem cell therapy on amputation rates and survival. Although, therapeutic angiogenesis remains an area of interest in PAD with several ongoing studies of investigational therapies, so far the use of these strategies in clinical practice has not been successful.

Trends in the rates of hospitalizations for acute stroke among patients over 90 years of age with atrial fibrillation in the United States: from 2005 to 2014

BACKGROUND

Acute stroke (AS) rates in patients over 90 years of age (very elderly) with atrial fibrillation (AF) in the United States (US) are not known. We assessed trends in hospitalizations for AS among very elderly with AF in the US from 2005 to 2014.

METHODS

We used the nationwide inpatient sample (NIS) from the USA; 2005-2014. AF and AS diagnoses were abstracted using international classification of diseases, 9th Revision, clinical modification (ICD-9-CM) codes.

RESULTS

From 2005 to 2014, 3,606,073 hospitalizations of very elderly with AF were reported. Of these, 188,948 hospitalizations (141,822 hospitalizations in women and 47,126 hospitalizations in men) had AS as the primary diagnosis. Age adjusted AS hospitalizations increased in the total cohort (3217/million in 2005 to 3871/million in 2014), in women (3540/million in 2005 to 4487/million in 2014) and in men (2490/million in 2005 to 3173/million in 2014) (P < 0.001). Anticoagulation rates increased in women (8% in 2005 to 19.9% in 2014) and in men (8.9% in 2005 to 21.6% in 2014). AS rates, though numerically lower than the total cohort, showed an increasing trend in anticoagulated patients as well (all anticoagulated patients: 212/million in 2005 to 513/million in 2014; anticoagulated women: 224/million in 2005 to 529/million in 2014, anticoagulated men: 184/million in 2005 to 518/million in 2014).

CONCLUSIONS

There is an increasing trend in AS hospitalizations among nonagenarians with AF in the US despite improving utilization of anticoagulants in this patient population. The etiologies driving this alarming trend are unclear and require further study.

Sex-Specific Associations of Oral Anticoagulant Use and Cardiovascular Outcomes in Patients With Atrial Fibrillation

BACKGROUND

Sex-specific effectiveness of rivaroxaban (RIVA), dabigatran (DABI), and warfarin in reducing myocardial infarction (MI), heart failure (HF), and all-cause mortality among patients with atrial fibrillation are not known. We assessed sex-specific associations of RIVA, DABI, or warfarin use with the risk of MI, HF, and all-cause mortality among patients with atrial fibrillation.

METHODS AND RESULTS

Medicare beneficiaries (men: 65 734 [44.8%], women: 81 135 [55.2%]) with atrial fibrillation who initiated oral anticoagulants formed the study cohort. Inpatient admissions for MI, HF, and all-cause mortality were compared between the 3 drugs separately for men and women using 3-way propensity-matched samples. In men, RIVA use was associated with a reduced risk of MI admissions compared with warfarin use (hazard ratio [95% confidence interval (CI): 0.59 [0.38-0.91]), with a trend towards reduced risk compared with DABI use (0.67 [0.44-1.01]). In women, there were no significant differences in the risk of MI admissions across all 3 anticoagulants. In both sexes, RIVA use and DABI use were associated with reduced risk of HF admissions (men: RIVA; 0.75 [0.63-0.89], DABI; 0.81 [0.69-0.96]) (women: RIVA; 0.64 [0.56-0.74], DABI; 0.73 [0.63-0.83]) and all-cause mortality (men: RIVA; 0.66 [0.53-0.81], DABI; 0.75 [0.61-0.93]) (women: RIVA; 0.76 [0.63-0.91], DABI; 0.77 [0.64-0.93]) compared with warfarin use.

CONCLUSIONS

RIVA use and DABI use when compared with warfarin use was associated with a reduced risk of HF admissions and all-cause mortality in both sexes. However, reduced risk of MI admissions noted with RIVA use appears to be limited to men.