Development and Validation of a Risk Score Predicting Death Without Transplant in Adult Heart Transplant Candidates.

Importance: The US heart allocation system prioritizes medically urgent candidates with a high risk of dying without transplant. The current therapy-based 6-status system is susceptible to manipulation and has limited rank ordering ability. Objective: To develop and validate a candidate risk score that incorporates current clinical, laboratory, and hemodynamic data. Design, Setting, and Participants: A registry-based observational study of adult heart transplant candidates (aged ≥18 years) from the US heart allocation system listed between January 1, 2019, and December 31, 2022, split by center into training (70%) and test (30%) datasets. Adult candidates were listed between January 1, 2019, and December 31, 2022. Main Outcomes and Measures: A US candidate risk score (US-CRS) model was developed by adding a predefined set of predictors to the current French Candidate Risk Score (French-CRS) model. Sensitivity analyses were performed, which included intra-aortic balloon pumps (IABP) and percutaneous ventricular assist devices (VAD) in the definition of short-term mechanical circulatory support (MCS) for the US-CRS. Performance of the US-CRS model, French-CRS model, and 6-status model in the test dataset was evaluated by time-dependent area under the receiver operating characteristic curve (AUC) for death without transplant within 6 weeks and overall survival concordance (c-index) with integrated AUC. Results: A total of 16 905 adult heart transplant candidates were listed (mean [SD] age, 53 [13] years; 73% male; 58% White); 796 patients (4.7%) died without a transplant. The final US-CRS contained time-varying short-term MCS (ventricular assist-extracorporeal membrane oxygenation or temporary surgical VAD), the log of bilirubin, estimated glomerular filtration rate, the log of B-type natriuretic peptide, albumin, sodium, and durable left ventricular assist device. In the test dataset, the AUC for death within 6 weeks of listing for the US-CRS model was 0.79 (95% CI, 0.75-0.83), for the French-CRS model was 0.72 (95% CI, 0.67-0.76), and 6-status model was 0.68 (95% CI, 0.62-0.73). Overall c-index for the US-CRS model was 0.76 (95% CI, 0.73-0.80), for the French-CRS model was 0.69 (95% CI, 0.65-0.73), and 6-status model was 0.67 (95% CI, 0.63-0.71). Classifying IABP and percutaneous VAD as short-term MCS reduced the effect size by 54%. Conclusions and Relevance: In this registry-based study of US heart transplant candidates, a continuous multivariable allocation score outperformed the 6-status system in rank ordering heart transplant candidates by medical urgency and may be useful for the medical urgency component of heart allocation.

Financial Implication of Sodium Zirconium Cyclosilicate Therapy in Patients with Systolic Heart Failure and Hyperkalemia.

Sodium zirconium cyclosilicate (SZC), a newly-introduced potassium binder, can be used to manage hyperkalemia especially in patients with chronic kidney disease and in those on medical therapy which may raise serum potassium levels. The medication may incur additional costs but may in turn have a significant benefit in the effect of maintaining guideline-directed medical therapy for heart failure. We aimed to investigate the financial impact of SZC therapy in patients with systolic heart failure.Patients with systolic heart failure who received SZC for hyperkalemia between July 2020 and March 2023 were included. In-hospital medical costs were compared between the patients who discontinued SZC and those who continued SZC. For the continue group, the cost of SZC was added. All patients were followed for 2 years or until May 2023.A total of 36 patients (median age 81 years, 56% male, median left ventricular ejection fraction 43%) were included. Total medical costs were significantly lower in the continue group (n = 12) compared to the discontinue group (n = 24) (3.1 [3.1, 6.2] versus 12.1 [3.8, 48.6] × 104 JPY per month, P = 0.039). In the continue group, serum potassium levels were decreased, renin-angiotensin-aldosterone system inhibitor doses were up-titrated, and the left ventricular ejection fraction was increased, whereas these parameters remained unchanged or worsened in the discontinue group.SZC may have the potential to assist in the up-titration of potassium-sparing heart failure-specific medications, prevent readmissions, and minimize medical costs, by preventing recurrent hyperkalemia in patients with systolic heart failure.

Chronotropic Assessment in Patients with Constrictive Pericarditis.

Management of constrictive pericarditis is often clinically challenging. Heart rate (HR) modulation using ivabradine is associated with improved clinical outcomes in patients with systolic heart failure, although it remains uninvestigated for other clinical purposes. We aimed to assess the impact of HR control in patients with constrictive pericarditis. In this retrospective study, consecutive patients who were diagnosed with constrictive pericarditis were included. Transthoracic echocardiography was performed at index discharge (day 0). The impact of HR difference between actual HR and ideal HR, which was calculated using a formula consisting of deceleration time, on heart failure readmission rates was investigated. A total of 15 patients (73 years old on median, 11 men) with constrictive pericarditis were included. On median, actual HR was 71 bpm and ideal HR was 81 bpm. Heart failure readmission rates were stratified into three groups by the HR difference: (1) optimal HR group satisfying "-10 bpm ≤ HR difference ≤ 10 bpm" (n = 4, 0.067 events per year); (2) lower HR group satisfying "HR difference < -10 bpm" (n = 7, 0.118 events per year, incidence rate ratio 1.98, 95% confidence interval 0.06-61.6); (3) higher HR group satisfying "HR difference > 10 bpm" (n = 4, 0.231 events per year, incidence rate ratio 9.22, 95% confidence interval 0.36-237.8). In conclusion, non-optimized HR was associated with an increased risk of heart failure recurrence in patients with constrictive pericarditis. Prospective assessment of deceleration time-guided HR optimization in patients with constrictive pericarditis is needed.

Implication of Hemodynamic Assessment during Durable Left Ventricular Assist Device Support.

Durable left ventricular assist device therapy has improved survival in patients with advanced heart failure refractory to conventional medical therapy, although the readmission rates due to device-related comorbidities remain high. Left ventricular assist devices are designed to support a failing left ventricle through relief of congestion and improvement of cardiac output. However, many patients still have abnormal hemodynamics even though they may appear to be clinically stable. Furthermore, such abnormal hemodynamics are associated with an increased risk of future adverse events including recurrent heart failure, gastrointestinal bleeding, stroke, and pump thrombosis. Correction of residual hemodynamic derangements post-implantation may be a target in improving longitudinal clinical outcomes during left ventricular assist device support. Automatic and timely device speed adjustments considering a patients' hemodynamic status (i.e., with a smart pump) are potential improvements in forthcoming devices.

Discordance Between Clinical Assessment and Invasive Hemodynamics in Patients With Advanced Heart Failure.

BACKGROUND: Historically, invasive hemodynamic guidance was not superior compared to clinical assessment in patients admitted with acute decompensated heart failure (ADHF). This study assessed the accuracy of clinical assessment vs invasive hemodynamics in patients with ADHF. METHODS AND RESULTS: We conducted a prospective cohort study of patients admitted with ADHF. Prior to right-heart catheterization (RHC), physicians categorically predicted right atrial pressure, pulmonary capillary wedge pressure, cardiac index and hemodynamic profile (wet/dry, warm/cold) based on physical examination and clinical data evaluation (warm = cardiac index > 2.2 L/min/m2; wet = pulmonary capillary wedge pressure > 18 mmHg). We collected 218 surveys (of 83 cardiology fellows, 55 attending cardiologists, 45 residents, 35 interns) evaluating 97 patients. Of those patients, 46% were receiving inotropes prior to RHC. The positive and negative predictive values of clinical assessment compared to RHC for the cold and wet subgroups were 74.7% and 50.4%. The accuracy of categorical prediction was 43.6% for right atrial pressure, 34.4% for pulmonary capillary wedge pressure and 49.1% for cardiac index, and accuracy did not differ by clinician (P > 0.05 for all). Interprovider agreement was 44.4%. Therapeutic changes following RHC occurred in 71.1% overall (P < 0.001). CONCLUSIONS: Clinical assessment of patients with advanced heart failure presenting with ADHF has low accuracy across all training levels, with exaggerated rates of misrecognition of the most high-risk patients.

Accuracy of estimating resting oxygen uptake and implications for hemodynamic assessment.

The Fick principle (cardiac output [Q(c)] = oxygen uptake [Vo(2)]/arteriovenous oxygen difference) can be used to calculate Q(c), with VO(2) frequently estimated by derived equations. To compare the accuracy of measured versus estimated VO(2), data were analyzed from 2 studies in which VO(2) at rest was measured using the Douglas bag technique. One study comprised adults with diabetes, and the other was an exercise study of healthy adults. VO(2) at rest was estimated as VO(2) (ml/min) = 125 ml/min/m(2) × body surface area (m(2)), with sensitivity analyses evaluating 2 other commonly used equations. Mean absolute difference (milliliters per minute) and ordinary least products regression were used to assess agreement between measured and estimated VO(2). Overall, mean measured versus estimated VO(2) differed significantly (307.2 ± 75.2 vs 259.9 ± 36.7 ml/min, p <0.0001), with a mean absolute difference of 52.9 ± 43.2 ml/min (p <0.0001); 20% of the estimates differed by >25% from the measured VO(2). Mean absolute difference increased from 36.7 ml/min in the lowest body mass index group (<25 kg/m(2)) to 91.7 ml/min in the highest group (≥40 kg/m(2)) (p for trend = 0.001) and was significantly higher in men than in women (65.6 vs 33.9 ml/min, p = 0.001); error was similar by median-split age (p = 0.65) and race (p = 0.34). Similar results were obtained when evaluating each of the other 2 estimating equations. Estimation of VO(2) at rest is inaccurate, especially in men and with increasing adiposity. In conclusion, when clinical hemodynamic assessment is performed, VO(2) should be measured, not estimated.

Assessment of cardiac structure and function in patients without and with peripheral oedema during rosiglitazone treatment.

BACKGROUND: Thiazolidinediones cause peripheral oedema, the aetiology of which remains poorly understood. METHODS: In a sub-study of a 6-month trial comparing rosiglitazone (Rsg) versus placebo, we compared those with versus without oedema among the 74 subjects treated with Rsg with respect to peak oxygen consumption indexed to fat-free mass (VO(2peak-FFM) ), cardiac MRI and markers of plasma volume expansion. RESULTS: Almost half (49%) of the Rsg-treated patients developed oedema. Baseline VO(2peak-FFM) was not different between those with versus without oedema (25.8 versus 28.2 ml/kg/min; p = 0.22) and declined 5% in the oedema group (Δ -1.3 ml/min/kg; p = 0.005) with no change in those without oedema. Stroke volume increased in both groups (Δ 8.7 and 8.8 ml; p < 0.001 for each); end-diastolic volume increased only in those with oedema (+13.1 ml; p = 0.001). No other cardiac function changes were observed. In both groups, weight increased (3.6 and 2.2 kg) and haematocrit decreased (-3.2% and -2.1%; p < 0.001 for each). In those with oedema, albumin decreased (-0.2 g/dl) and brain natriuretic peptide increased (11.9 pg/ml; p < 0.03 for each). CONCLUSIONS: Oedema was associated with a small decline in VO(2peak FFM), no adverse effects on cardiac function, and changes in selected measures suggesting that volume expansion underpins Rsg oedema.