Differences in Donor Heart Acceptance by Race and Gender of Patients on the Transplant Waiting List.

Importance: Barriers to heart transplant must be overcome prior to listing. It is unclear why Black men and women remain less likely to receive a heart transplant after listing than White men and women. Objective: To evaluate whether race or gender of a heart transplant candidate (ie, patient on the transplant waiting list) is associated with the probability of a donor heart being accepted by the transplant center team with each offer. Design, Setting, and Participants: This cohort study used the United Network for Organ Sharing datasets to identify organ acceptance with each offer for US non-Hispanic Black (hereafter, Black) and non-Hispanic White (hereafter, White) adults listed for heart transplant from October 18, 2018, through March 31, 2023. Exposures: Black or White race and gender (men, women) of a heart transplant candidate. Main Outcomes and Measures: The main outcome was heart offer acceptance by the transplant center team. The number of offers to acceptance was assessed using discrete time-to-event analyses, nonparametrically (stratified by race and gender) and parametrically. The hazard probability of offer acceptance for each offer was modeled using generalized linear mixed models adjusted for candidate-, donor-, and offer-level variables. Results: Among 159 177 heart offers with 13 760 donors, there were 14 890 candidates listed for heart transplant; 30.9% were Black, 69.1% were White, 73.6% were men, and 26.4% were women. The cumulative incidence of offer acceptance was highest for White women followed by Black women, White men, and Black men (P < .001). Odds of acceptance were less for Black candidates than for White candidates for the first offer (odds ratio [OR], 0.76; 95% CI, 0.69-0.84) through the 16th offer. Odds of acceptance were higher for women than for men for the first offer (OR, 1.53; 95% CI, 1.39-1.68) through the sixth offer and were lower for the 10th through 31st offers. Conclusions and Relevance: The cumulative incidence of heart offer acceptance by a transplant center team was consistently lower for Black candidates than for White candidates of the same gender and higher for women than for men. These disparities persisted after adjusting for candidate-, donor-, and offer-level variables, possibly suggesting racial and gender bias in the decision-making process. Further investigation of site-level decision-making may reveal strategies for equitable donor heart acceptance.

Cardiac output assessment methods in left ventricular assist device patients: A problem of heteroscedasticity.

Equipoise remains about how best to measure cardiac output (CO) in patients with left ventricular assist devices (LVAD). In this study, direct Fick CO was compared with thermodilution (TD) and indirect Fick (iFick) CO in 61 LVAD patients. TD and LaFarge iFick showed moderate correlation with direct Fick (R2 = 0.49 and R2 = 0.38, p < 0.001 for both), while Dehmer and Bergstra iFick showed poor correlation with direct Fick (R2 = 0.29 and R2 = 0.31, p < 0.001 for both). Absolute bias between all CO estimation techniques and direct Fick CO was lowest for TD compared to iFick methods but significant for all methods. All methods tended to overestimate CO compared to direct Fick, with greatest overestimation present in those with the lowest measured direct Fick CO. Bias and frequency of significant discrepancy were least using TD and Lafarge iFick CO estimation methods in this study, with TD CO demonstrating modestly better correlation and less heteroscedasticity compared to Lafarge.

Outcomes in Patients With Chronic Kidney Disease and End-stage Renal Disease and Durable Left Ventricular Assist Device: Insights From the United States Renal Data System Database.

BACKGROUND: There is paucity of data regarding durable left ventricular assist device (LVAD) outcomes in patients with chronic kidney disease (CKD) stages 3-5 and CKD stage 5 on dialysis (end-stage renal disease [ESRD]). METHODS AND RESULTS: We conducted a retrospective study of Medicare beneficiaries with ESRD and a 5% sample of patients with CKD with an LVAD (2006-2018) to determine 1-year outcomes using the United States Renal Data System database. The LVAD implantation, comorbidities, and outcomes were identified using appropriate International Classification of Diseases, 9th and 10th edition codes. We identified 496 patients with CKD and 95 patients with ESRD who underwent LVAD implantation. The patients with ESRD were younger (59 years vs 66 years; P < .001), had more Blacks (40% vs 24.6%, P = .009), compared with the CKD group. The 1-year mortality (49.5% vs 30.9%, P < .001) and index mortality (27.4% vs 16.7%, P = .014) rates were higher for patients with ESRD. A subgroup analysis showed significantly higher mortality in ESRD vs CKD 3 (49.5% vs 30.2%, adjusted P = .009), but no significant difference in mortality between stage 3 vs 4/5 (30.2% vs 30.8%, adjusted P = .941). There was no significant difference in secondary outcomes (bleeding, stroke, and sepsis/infection) during follow-up between the 2 groups. CONCLUSIONS: Patients with ESRD undergoing LVAD implantation had significantly higher index and 1-year mortality rates compared with patients with CKD.

Impact of the 2018 change in US allocation policy on adults with congenital heart disease.

BACKGROUND: The US adult heart allocation policy was changed on October 18, 2018. This study aims to evaluate its impact on orthotopic heart transplantation (OHT) for adults with congenital heart disease (ACHD). METHODS: The United Network for Organ Sharing database was used to perform 2 comparisons: waitlist outcomes among listed ACHD candidates, and post-transplant outcomes in those transplanted. Waitlisted candidates were stratified by date of waitlisting: Period 1: 2010 to 2013; Period 2: 2014 to October 17, 2018 and Period 3: October 18, 2018 to March 20, 2020. Transplanted ACHD patients were similarly stratified but by date of transplantation. Competing risk regression for waitlist outcomes was performed. Post-transplant survival was analyzed using the Kaplan-Meier method and multivariable Cox regression. RESULTS: Nine hundred and seventy-six patients with ACHD were waitlisted for OHT in our study: 343(35.1%), 466(47.8%), and 167(17.1%) in periods 1, 2, and 3. Post-policy change, 1-year cumulative incidence of waitlist mortality or deterioration decreased (p = 0.02). Six hundred and forty-eight patients were transplanted: 221(34.1%), 329(50.8%) and 98(15.1%) respectively. In those transplanted, post-policy median waitlist time (174, 161 and 38 days, p < 0.001) decreased and the use of intra-aortic balloon pumps increased (1.4%, 4.9% and 19.4%, p < 0.001). Compared to periods 1 and 2, risk-adjusted post-transplant 1-year mortality was similar to period 3 (HR 1.10, 95% CI 0.52-2.32; p = 0.81) (HR 1.19, 95% CI 0.58-2.46, p = 0.63). CONCLUSIONS: The recent US allocation policy change may have resulted in reduced waitlist times and 1-year waitlist mortality for OHTs in ACHD patients. Early post-transplant outcomes appear comparable post-policy change.

Assessment of right ventricular reserve utilizing exercise provocation in systemic sclerosis.

Right ventricular (RV) capacity to adapt to increased afterload is the main determinant of outcome in pulmonary hypertension, a common morbidity seen in systemic sclerosis (SSc). We hypothesized that supine bicycle echocardiography (SBE), coupled with RV longitudinal systolic strain (RVLSS), improves detection of limitations in RV reserve in SSc. 56 SSc patients were prospectively studied during SBE with RV functional parameters compared at rest and peak stress. We further dichotomized patients based on resting RV systolic pressure (RVSP) to determine the effects of load on contractile response. Our pooled cohort analysis revealed reduced global RVLSS at rest (-16.2 ± 3.9%) with normal basal contractility (-25.6 ± 7.7%) and relative hypokinesis of the midventricular (-14.1 ± 6.0%) and apical (-8.9 ± 5.1%) segments. With exercise, global RVLSS increased significantly (p = 0.0005), however despite normal basal contractility at rest, there was no further augmentation with exercise. Mid and apical RVLSS increased with exercise suggestive of RV contractile reserve. In patients with resting RVSP < 35 mmHg, global and segmental RVLSS increased with exercise. In patients with resting RVSP ≥ 35 mmHg, global and segmental RVLSS did not increase with exercise and there was evidence of exertional RV dilation. Exercise provocation in conjunction with RVLSS identified differential regional contractile response to exercise in SSc patients. We further demonstrate the effect of increased loading conditions on RV contractile response exercise. These findings suggest subclinical impairments in RV reserve in SSc that may be missed by resting noninvasive 2DE-based assessments alone.

Pulmonary Vascular Disease: Hemodynamic Assessment and Treatment Selection-Focus on Group II Pulmonary Hypertension.

PURPOSE OF REVIEW: Pulmonary hypertension due to left heart disease (PH-LHD) is the most common cause of pulmonary hypertension worldwide, yet therapies used to treat pulmonary arterial hypertension have failed to show efficacy in this population. Proper hemodynamic assessment and differentiation of pulmonary hypertension phenotypes is therefore critical for both current clinical practice and future research and therapeutic efforts. RECENT FINDINGS: Substantial recent efforts have sought to improve the hemodynamic characterization of pulmonary hypertension for both diagnostic and prognostic purposes. These efforts include identifying occult LHD using provocative maneuvers as well as sub-classifying PH-LHD based on the presence or absence of a pre-capillary component. How to best define the pre-capillary component remains controversial as several studies have drawn conflicting conclusions. The lack of standardization of hemodynamic measurements as well as measurement fidelity concerns may explain some of the discrepant results. Non-hemodynamic methods of PH-LHD classification may also have an emerging role. Despite recent advances, therapeutic studies have largely remained disappointing. In this review, we discuss the nuances and controversies surrounding diagnostic and prognostic hemodynamic characterization of PH-LHD as well as summarize the recent therapeutic efforts and ongoing challenges in this population.

Thermodilution vs Estimated Fick Cardiac Output Measurement in Clinical Practice: An Analysis of Mortality From the Veterans Affairs Clinical Assessment, Reporting, and Tracking (VA CART) Program and Vanderbilt University.

Importance: Thermodilution (Td) and estimated oxygen uptake Fick (eFick) methods are widely used to measure cardiac output (CO). They are often used interchangeably to make critical clinical decisions, yet few studies have compared these approaches as applied in medical practice. Objectives: To assess agreement between Td and eFick CO and to compare how well these methods predict mortality. Design, Setting, and Participants: This investigation was a retrospective cohort study with up to 1 year of follow-up. The study used data from the Veterans Affairs Clinical Assessment, Reporting, and Tracking (VA CART) program. The findings were corroborated in a cohort of patients cared for at Vanderbilt University, an academic referral center. Participants were more than 15 000 adults who underwent right heart catheterization, including 12 232 in the Veterans Affairs cohort between October 1, 2007, and September 30, 2013, and 3391 in the Vanderbilt cohort between January 1, 1998, and December 31, 2014. Exposures: A single cardiac catheterization was performed on each patient with CO estimated by both Td and eFick methods. Cardiac output was indexed to body surface area (cardiac index [CI]) for all analyses. Main Outcomes and Measures: All-cause mortality over 90 days and 1 year after catheterization. Results: Among 12 232 VA patients (mean [SD] age, 66.4 [9.9] years; 3.3% female) who underwent right heart catheterization in this cohort study, Td and eFick CI estimates correlated modestly (r = 0.65). There was minimal mean difference (eFick minus Td = -0.02 L/min/m2, or -0.4%) but wide 95% limits of agreement between methods (-1.3 to 1.3 L/min/m2, or -50.1% to 49.4%). Estimates differed by greater than 20% for 38.1% of patients. Low Td CI (<2.2 L/min/m2 compared with normal CI of 2.2-4.0 L/min/m2) more strongly predicted mortality than low eFick CI at 90 days (Td hazard ratio [HR], 1.71; 95% CI, 1.47-1.99; χ2 = 49.5 vs eFick HR, 1.42; 95% CI, 1.22-1.64; χ2 = 20.7) and 1 year (Td HR, 1.53; 95% CI, 1.39-1.69; χ2 = 71.5 vs eFick HR, 1.35; 1.22-1.49; χ2 = 35.2). Patients with a normal CI by both methods had 12.3% 1-year mortality. There was no significant additional risk for patients with a normal Td CI but a low eFick CI (12.9%, P = .51), whereas a low Td CI but normal eFick CI was associated with higher mortality (15.4%, P = .001). The results from the Vanderbilt cohort were similar in the context of a more balanced sex distribution (46.6% female). Conclusions and Relevance: There is only modest agreement between Td and eFick CI estimates. Thermodilution CI better predicts mortality and should be favored over eFick in clinical practice.

Association of Borderline Pulmonary Hypertension With Mortality and Hospitalization in a Large Patient Cohort: Insights From the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program.

BACKGROUND: Pulmonary hypertension (PH) is associated with increased morbidity across the cardiopulmonary disease spectrum. Based primarily on expert consensus opinion, PH is defined by a mean pulmonary artery pressure (mPAP) ≥25 mm Hg. Although mPAP levels below this threshold are common among populations at risk for PH, the relevance of mPAP <25 mm Hg to clinical outcome is unknown. METHODS AND RESULTS: We analyzed retrospectively all US veterans undergoing right heart catheterization (2007-2012) in the Veterans Affairs healthcare system (n=21,727; 908-day median follow-up). Cox proportional hazards models were used to evaluate the association between mPAP and outcomes of all-cause mortality and hospitalization, adjusted for clinical covariates. When treating mPAP as a continuous variable, the mortality hazard increased beginning at 19 mm Hg (hazard ratio [HR]=1.183; 95% confidence interval [CI], 1.004-1.393) relative to 10 mm Hg. Therefore, patients were stratified into 3 groups: (1) referent (≤18 mm Hg; n=4,207); (2) borderline PH (19-24 mm Hg; n=5,030); and (3) PH (≥25 mm Hg; n=12,490). The adjusted mortality hazard was increased for borderline PH (HR=1.23; 95% CI, 1.12-1.36; P<0.0001) and PH (HR=2.16; 95% CI, 1.96-2.38; P<0.0001) compared with the referent group. The adjusted hazard for hospitalization was also increased in borderline PH (HR=1.07; 95% CI, 1.01-1.12; P=0.0149) and PH (HR=1.15; 95% CI, 1.09-1.22; P<0.0001). The borderline PH cohort remained at increased risk for mortality after excluding the following high-risk subgroups: (1) patients with pulmonary artery wedge pressure >15 mm Hg; (2) pulmonary vascular resistance ≥3.0 Wood units; or (3) inpatient status at the time of right heart catheterization. CONCLUSIONS: These data illustrate a continuum of risk according to mPAP level and that borderline PH is associated with increased mortality and hospitalization. Future investigations are needed to test the generalizability of our findings to other populations and study the effect of treatment on outcome in borderline PH.

Outcomes and worsening renal function in patients hospitalized with heart failure with preserved ejection fraction.

Heart failure with preserved ejection fraction (HFpEF) has been described as a disease of elderly subjects with female predominance and hypertension. Our clinical experience suggests patients with HFpEF from an urban population are far more heterogenous, with greater co-morbidities and significant inhospital morbidity. There are limited data on the hospitalization course and outcomes in acute decompensated HFpEF. Hospitalizations for acute heart failure at our institution from July 2011 to June 2012 were identified by International Classification of Diseases, Ninth Revision, codes and physician review for left ventricular ejection fraction ≥50% and were reviewed for patient characteristics and clinical outcomes. Worsening renal function (WRF) was defined as creatinine increase of ≥0.3 mg/dl by 72 hours after admission. Hospital readmission and mortality data were captured from electronic medical records and the Social Security Death Index. Of 434 heart failure admissions, 206 patients (47%) with HFpEF were identified. WRF developed in 40%, the highest reported in HFpEF to date, and was associated with higher blood pressure and lower volume of diuresis. Compared to previous reports, hospitalized patients with HFpEF were younger (mean age 63.2 ± 13.6 years), predominantly black (74%), and had more frequent and severe co-morbidities: hypertension (89%), diabetes (56%), and chronic kidney disease (55%). There were no significant differences in 1- and 12-month outcomes by gender, race, or WRF. In conclusion, we found hospitalized patients with HFpEF from an urban population develop a high rate of WRF are younger than previous cohorts, often black, and have greater co-morbidities than previously described.