Time to assess more than prognosis: advancements and challenges in transcatheter tricuspid valve interventions.

We provide an overview about the current landscape of transcatheter tricuspid valve interventions (TTVI) and summarize recent findings from trials including TRILUMINATE, TRILUMINATE Pivotal, bRIGHT, TRICLASP, TRISCEND, TRISCEND II, TRICUS, and Cardioband TR EFS. These studies have demonstrated the safety and efficacy of TTVI. Yet, they have failed to show a prognostic benefit over conservative treatment. On the other hand, significant improvements in health status assessments have been observed. Assessment of right ventricular (RV) function prior to tricuspid interventions is crucial, as changes in preload and afterload may lead to RV failure which is associated with a high mortality. Therefore, this review emphasizes the impact of TTVIs on quality of life and explores the influence of RV dysfunction on therapeutic success and prognosis.

Monitoring a Mystery: The Unknown Right Ventricle during Left Ventricular Unloading with Impella in Patients with Cardiogenic Shock.

Background: Right ventricular (RV) dysfunction or failure occurs in more than 30% of patients in cardiogenic shock (CS). However, the importance of timely diagnosis of prognostically relevant impairment of RV function is often underestimated. Moreover, data regarding the impact of mechanical circulatory support like the Impella on RV function are rare. Here, we investigated the effects of the left ventricular (LV) Impella on RV function. Moreover, we aimed to identify the most optimal and the earliest applicable parameter for bedside monitoring of RV function by comparing the predictive abilities of three common RV function parameters: the pulmonary artery pulsatility index (PAPi), the ratio of right atrial pressure to pulmonary capillary wedge pressure (RA/PCWP), and the right ventricular stroke work index (RVSWI). Methods: The data of 50 patients with CS complicating myocardial infarction, supported with different flow levels of LV Impella, were retrospectively analyzed. Results: Enhancing Impella flow (1.5 to 2.5 L/min ± 0.4 L/min) did not lead to a significant variation in PAPi (p = 0.717), RA/PCWP (p = 0.601), or RVSWI (p = 0.608), indicating no additional burden for the RV. PAPi revealed the best ability to connect RV function with global hemodynamic parameters, i.e., cardiac index (CI; p < 0.001, 95% CI: 0.181-0.663), pulmonary capillary wedge pressure (PCWP; p = 0.005, 95% CI: -6.721--1.26), central venous pressure (CVP; p < 0.001, 95% CI: -7.89-5.575), and indicators of tissue perfusion (central venous oxygen saturation (SvO2); p = 0.008, 95% CI: 1.096-7.196). Conclusions: LV Impella does not impair RV function. Moreover, PAPi seems to be to the most effective and valid predictor for early bedside monitoring of RV function.

Long-term effects of pulmonary endarterectomy on pulmonary hemodynamics, cardiac function, and exercise capacity in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Long-term changes in exercise capacity and cardiopulmonary hemodynamics after pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) have been poorly described. METHODS: We analyzed the data from 2 prospective surgical CTEPH cohorts in Hammersmith Hospital, London, and Amsterdam UMC. A structured multimodal follow-up was adopted, consisting of right heart catheterization, cardiac magnetic resonance imaging, and cardiopulmonary exercise testing before and after PEA. Preoperative predictors of residual pulmonary hypertension (PH; mean pulmonary artery pressure >20 mm Hg and pulmonary vascular resistance ≥2 WU) and long-term exercise intolerance (VO2max <80%) at 18 months were analyzed. RESULTS: A total of 118 patients (61 from London and 57 from Amsterdam) were included in the analysis. Both cohorts displayed a significant improvement of pulmonary hemodynamics, right ventricular (RV) function, and exercise capacity 6 months after PEA. Between 6 and 18 months after PEA, there were no further improvements in hemodynamics and RV function, but the proportion of patients with impaired exercise capacity was high and slightly increased over time (52%-59% from 6 to 18 months). Long-term exercise intolerance was common and associated with preoperative diffusion capacity for carbon monoxide (DLCO), preoperative mixed venous oxygen saturation, and postoperative PH and right ventricular ejection fraction (RVEF). Clinically significant RV deterioration (RVEF decline >3%; 5 [9%] of 57 patients) and recurrent PH (5 [14%] of 36 patients) rarely occurred beyond 6 months after PEA. Age and preoperative DLCO were predictors of residual PH post-PEA. CONCLUSIONS: Restoration in exercise tolerance, cardiopulmonary hemodynamics, and RV function occurs within 6 months. No substantial changes occurred between 6 and 18 months after PEA in the Amsterdam cohort. Nevertheless, long-term exercise intolerance is common and associated with postoperative RV function.

Advanced hemodynamic and cluster analysis for identifying novel RV function subphenotypes in patients with pulmonary hypertension.

BACKGROUND: Quantifying right ventricular (RV) function is important to describe the pathophysiology of in pulmonary hypertension (PH). Current phenotyping strategies in PH rely on few invasive hemodynamic parameters to quantify RV dysfunction severity. The aim of this study was to identify novel RV phenotypes using unsupervised clustering methods on advanced hemodynamic features of RV function. METHODS: Participants were identified from the University of Arizona Pulmonary Hypertension Registry (n = 190). RV-pulmonary artery coupling (Ees/Ea), RV systolic (Ees), and diastolic function (Eed) were quantified from stored RV pressure waveforms. Consensus clustering analysis with bootstrapping was used to identify the optimal clustering method. Pearson correlation analysis was used to reduce collinearity between variables. RV cluster subphenotypes were characterized using clinical data and compared to pulmonary vascular resistance (PVR) quintiles. RESULTS: Five distinct RV clusters (C1-C5) with distinct RV subphenotypes were identified using k-medoids with a Pearson distance matrix. Clusters 1 and 2 both have low diastolic stiffness (Eed) and afterload (Ea) but RV-PA coupling (Ees/Ea) is decreased in C2. Intermediate cluster (C3) has a similar Ees/Ea as C2 but with higher PA pressure and afterload. Clusters C4 and C5 have increased Eed and Ea but C5 has a significant decrease in Ees/Ea. Cardiac output was high in C3 distinct from the other clusters. In the PVR quintiles, contractility increased and stroke volume decreased as a function of increased afterload. World Symposium PH classifications were distributed across clusters and PVR quintiles. CONCLUSIONS: RV-centric phenotyping offers an opportunity for a more precise-medicine-based management approach.

Impact of right ventricular-to-pulmonary artery coupling on remodeling and outcome in patients undergoing transcatheter edge-to-edge mitral valve repair.

BACKGROUND: Right ventricular-to-pulmonary artery (RV-PA) coupling has recently been shown to be associated with outcome in valvular heart disease. However, longitudinal data on RV dysfunction and reverse cardiac remodeling in patients following transcatheter edge-to-edge mitral valve repair (M-TEER) are scarce. METHODS: Consecutive patients with primary as well as secondary mitral regurgitation (MR) were prospectively enrolled and had comprehensive echocardiographic and invasive hemodynamic assessment at baseline. Kaplan-Meier estimates and multivariable Cox-regression analyses were performed, using a composite endpoint of heart failure hospitalization and death. RESULTS: Between April 2018 and January 2021, 156 patients (median 78 y/o, 55% female, EuroSCORE II: 6.9%) underwent M-TEER. On presentation, 64% showed impaired RV-PA coupling defined as tricuspid annular plane systolic excursion to pulmonary artery systolic pressure (TAPSE/PASP) ratio < 0.36. Event-free survival rates at 2 years were significantly lower among patients with impaired coupling (57 vs. 82%, p < 0.001), both in patients with primary (64 vs. 91%, p = 0.009) and secondary MR (54 vs. 76%, p = 0.026). On multivariable Cox-regression analyses adjusted for baseline, imaging, hemodynamic, and procedural data, TAPSE/PASP ratio < 0.36 was independently associated with outcome (adj.HR 2.74, 95% CI 1.17-6.43, p = 0.021). At 1-year follow-up, RV-PA coupling improved (TAPSE: ∆ + 3 mm, PASP: ∆ - 10 mmHg, p for both < 0.001), alongside with a reduction in tricuspid regurgitation (TR) severity (grade ≥ II: 77-54%, p < 0.001). CONCLUSIONS: TAPSE/PASP ratio was associated with outcome in patients undergoing M-TEER for primary as well as secondary MR. RV-PA coupling, alongside with TR severity, improved after M-TEER and might thus provide prognostic information in addition to established markers of poor outcome.

A Comprehensive Echocardiographic Assessment of Neonatal Right Ventricular Function in Neonatal Intensive Care Unit Babies.

Background The right ventricle (RV) in the fetus is the predominant chamber, accounting for about 60% of the total cardiac output. The majority of the RV outflow volume is diverted from the pulmonary artery via the ductus arteriosus to the descending aorta. After birth, the RV undergoes extensive structural and functional modifications. The RV undergoes an improper transition from fetal to neonatal circulation in sick neonatal intensive care unit (NICU) babies. Functional echocardiography is now commonly being used in most NICUs as it is a noninvasive and bedside investigation that gives an immediate evaluation of hemodynamics and can be taken into consideration as an extension of clinical assessment to study a critically unwell neonate. Therefore, a study of RV functions in NICU neonates will help in better understanding the neonatal cardiopulmonary response to different diseases. Thus, this study aimed to assess RV functions in neonates getting admitted to the NICU of a tertiary care institute. Methodology This observational, cross-sectional study was approved by the Research & Recognition Committee of Dr. D. Y. Patil Vidyapeeth, Pune. In total, 35 cases of term neonates admitted to the NICU at Dr. D. Y. Patil Medical College, Hospital & Research Centre, Pune who fulfilled the inclusion criteria were enrolled in this study after obtaining consent from their parents. Two-dimensional echocardiography was performed by a trained pediatric cardiologist, and the findings were substantiated by a neonatologist trained in echocardiography. Results Our study found a strong association between tricuspid inflow velocity and neonates with sepsis. Similarly, a significant association was observed between abnormal tricuspid Inflow velocity (E/A and E/E') and neonates requiring inotropic support. Conclusions Data on the normal values of different echocardiographic parameters of the systolic and diastolic function of the RV during the neonatal phase of life are currently limited. Our data offer preliminary insights into this topic. Early echocardiography and intervention are advisable, especially in neonates with sepsis and requiring inotropic support.

Prognostic Impact of Right Ventricular Strain in Isolated Severe Tricuspid Regurgitation.

BACKGROUND: Right ventricular (RV) systolic function is an established marker of outcomes in patients with severe tricuspid regurgitation (TR). Timely detection of RV dysfunction using conventional two-dimensional echocardiography is challenging. RV strain has emerged as an accurate and sensitive tool for the evaluation of RV function, with the capability to detect subclinical RV dysfunction. The aim of this study was to evaluate the prognostic value of RV strain parameters in early stages of severe TR. METHODS: Consecutive patients with at least severe TR (severe, massive, or torrential) and the absence of a formal indication for tricuspid valve intervention in secondary TR evaluated in the Heart Valve Clinic were prospectively included. RV systolic function was measured using conventional echocardiographic indices (RV fractional area change, tricuspid annular plane systolic excursion, and Doppler tissue imaging S wave [S']) and speckle-tracking echocardiography-derived automatic peak global longitudinal strain and free wall longitudinal strain (FWLS) using an automated two-dimensional strain analytic software. A combined end point of hospital admission due to heart failure or all-cause mortality was defined. RESULTS: A total of 266 patients were enrolled in the study, and 151 were ultimately included. Strain parameters detected a higher percentage of abnormal RV values compared with conventional indices. During a median follow-up period of 26 months (interquartile range, 13-42 months), 35% of the patients reached the combined end point. Cumulative event-free survival was significantly worse in patients with impaired RV global longitudinal strain and RV FWLS. Conventional indices of RV systolic function were not associated with outcomes (P > .05 for all). On multivariate analysis, RV FWLS was independently associated with mortality and heart failure (adjusted hazard ratio for abnormal RV FWLS, 5.90; 95% CI, 3.17-10.99; P < .001). CONCLUSION: In early stages of severe TR, RV FWLS is more frequently impaired compared with conventional indices of RV function. Among all parameters, RV FWLS is the strongest predictor of mortality and heart failure, independent of additional prognostic markers.

A computational study of aortic insufficiency in patients supported with continuous flow left ventricular assist devices: Is it time for a paradigm shift in management?

Background: De novo aortic insufficiency (AI) following continuous flow left ventricular assist device (CF-LVAD) implantation is a common complication. Traditional early management utilizes speed augmentation to overcome the regurgitant flow in an attempt to augment net forward flow, but this strategy increases the aortic transvalvular gradient which predisposes the patient to progressive aortic valve pathology and may have deleterious effects on aortic shear stress and right ventricular (RV) function. Materials and methods: We employed a closed-loop lumped-parameter mathematical model of the cardiovascular system including the four cardiac chambers with corresponding valves, pulmonary and systemic circulations, and the LVAD. The model is used to generate boundary conditions which are prescribed in blood flow simulations performed in a three-dimensional (3D) model of the ascending aorta, aortic arch, and thoracic descending aorta. Using the models, impact of various patient management strategies, including speed augmentation and pharmacological treatment on systemic and pulmonary (PA) vasculature, were investigated for four typical phenotypes of LVAD patients with varying degrees of RV to PA coupling and AI severity. Results: The introduction of mild/moderate or severe AI to the coupled RV and pulmonary artery at a speed of 5,500 RPM led to a reduction in net flow from 5.4 L/min (no AI) to 4.5 L/min (mild/moderate) to 2.1 L/min (severe). RV coupling ratio (Ees/Ea) decreased from 1.01 (no AI) to 0.96 (mild/moderate) to 0.76 (severe). Increasing LVAD speed to 6,400 RPM in the severe AI and coupled scenario, led to a 42% increase in net flow and a 16% increase in regurgitant flow (RF) with a nominal decrease of 1.6% in RV myocardial oxygen consumption (MVO2). Blood pressure control with the coupled RV with severe AI at 5,500 RPM led to an 81% increase in net flow with a 15% reduction of RF and an 8% reduction in RV MVO2. With an uncoupled RV, the introduction of mild/moderate or severe AI at a speed of 5,500 RPM led to a reduction in net flow from 5.0 L/min (no AI) to 4.0 L/min (mild/moderate) to 1.8 L/min (severe). Increasing the speed to 6,400 RPM with severe AI and an uncoupled RV increased net flow by 45%, RF by 15% and reduced RV MVO2 by 1.1%. For the uncoupled RV with severe AI, blood pressure control alone led to a 22% increase in net flow, 4.2% reduction in RF, and 3.9% reduction in RV MVO2; pulmonary vasodilation alone led to a 18% increase in net flow, 7% reduction in RF, and 26% reduction in RV MVO2; whereas, combined BP control and pulmonary vasodilation led to a 113% increase in net flow, 20% reduction in RF and 31% reduction in RV MVO2. Compared to speed augmentation, blood pressure control consistently resulted in a reduction in WSS throughout the proximal regions of the arterial system. Conclusion: Speed augmentation to overcome AI in patients supported by CF-LVAD appears to augment flow but also increases RF and WSS in the aorta, and reduces RV MVO2. Aggressive blood pressure control and pulmonary vasodilation, particularly in those patients with an uncoupled RV can improve net flow with more advantageous effects on the RV and AI RF.

Classification and Stratification of Pulmonary Embolisms.

Pulmonary embolism remains a leading cause of cardiovascular mortality. Presentation and outcomes are variable among patients and require rapid risk stratification for assessment and prognosis, as well as selection of appropriate treatment. Over the past several decades, several different models and parameters have become available to assess risk and classify pulmonary embolism into different risk categories. Some patients may be candidates for early discharge or complete outpatient treatment, while some may require invasive diagnostics and intensive monitoring. In this review, we summarize contemporary guidelines and methods for classification and risk stratification in an effort to provide tools for physicians to use in their management of patients with acute pulmonary embolisms.

Lateral annular systolic excursion ratio: A novel measurement of right ventricular systolic function by two-dimensional echocardiography.

Introduction: Accurate assessment of right ventricular (RV) systolic function has prognostic and therapeutic implications in many disease states. Echocardiography remains the most frequently deployed imaging modality for this purpose, but estimation of RV systolic function remains challenging. The purpose of this study was to evaluate the diagnostic performance of a novel measurement of RV systolic function called lateral annular systolic excursion ratio (LASER), which is the fractional shortening of the lateral tricuspid annulus to apex distance, compared to right ventricular ejection fraction (RVEF) derived by cardiac magnetic resonance imaging (CMR). Methods: A retrospective cohort of 78 consecutive patients who underwent clinically indicated CMR and transthoracic echocardiography within 30 days were identified from a database. Parameters of RV function measured included: tricuspid annular plane systolic excursion (TAPSE) by M-mode, tissue Doppler S', fractional area change (FAC) and LASER. These measurements were compared to RVEF derived by CMR using Pearson's correlation coefficients and receiver operating characteristic curves. Results: LASER was measurable in 75 (96%) of patients within the cohort. Right ventricular systolic dysfunction, by CMR measurement, was present in 37% (n = 29) of the population. LASER has moderate positive correlation with RVEF (r = 0.54) which was similar to FAC (r = 0.56), S' (r = 0.49) and TAPSE (r = 0.37). Receiver operating characteristic curves demonstrated that LASER (AUC = 0.865) outperformed fractional area change (AUC = 0.767), tissue Doppler S' (AUC = 0.744) and TAPSE (AUC = 0.645). A cohort derived dichotomous cutoff of 0.2 for LASER was shown to provide optimal diagnostic characteristics (sensitivity of 75%, specificity of 87% and accuracy of 83%) for identifying abnormal RV function. LASER had the highest sensitivity, accuracy, positive and negative predictive values among the parameters studied in the cohort. Conclusions: Within the study cohort, LASER was shown to have moderate positive correlation with RVEF derived by CMR and more favorable diagnostic performance for detecting RV systolic dysfunction compared to conventional echocardiographic parameters while being simple to obtain and less dependent on image quality than FAC and emerging techniques.

The Association of Severe Tricuspid Regurgitation with Poor Survival Is Modified by Right Ventricular Pressure and Function: Insights from SHEBAHEART Big Data.

BACKGROUND: Contemporary data on the independent association of severe tricuspid regurgitation (TR) with excess mortality are needed. The aims of this study were to describe contemporary outcomes of patients with severe TR and to identify outcome modifiers. METHODS: Consecutive echocardiographic reports linked to clinical data from the largest medical center in Israel (2007-2019) were reviewed. The primary outcome was all-cause mortality. Cox regression and propensity score matching models were applied. RESULTS: The final cohort included 97,096 patients. Mild, moderate, and severe TR was documented in 27,147 (28%), 2,844 (3%) and 1,805 (2%) patients, respectively. During a median follow-up period of 5 years (interquartile range, 2-8 years), 22,170 patients (23%) died. Kaplan-Meier survival analysis demonstrated an increased risk for death with an increasing degree of TR (log-rank P < .001). Propensity score matching of 1,265 patients with severe TR and matched control subjects showed that compared with those with nonsevere TR, patients with severe TR were 17% more likely to die (95% CI, 1.05-1.29; P = .003). The association of severe TR with survival was dependent on estimated right ventricular (RV) pressure, with a more pronounced effect among patients with estimated systolic pressure ≤ 40 mm Hg (hazard ratio, 2.12 vs 1.04; P for interaction < .001). A landmark subanalysis of 17,967 patients demonstrated that RV function deterioration on follow-up echocardiography modified the association of severe TR with survival. It was more significant among patients with preserved and stable RV function (P for interaction = .035). CONCLUSIONS: The outcome of severe TR is modified by RV pressure and function. Once RV function deteriorates, differences in the outcomes of patients with and without severe TR are less pronounced.

Right Ventricular Ejection Fraction Assessed by Three-Dimensional Echocardiography Is Associated with Long-Term Adverse Clinical Cardiac Events in Patients with Anthracycline-Induced Cardiotoxicity.

BACKGROUND: Patients with cancer treated with chemotherapy are at risk for cardiovascular toxicity. Global longitudinal strain has been reported to play important roles in predicting cardiovascular adverse events (CAEs) in patients treated with anthracycline. In addition to various left ventricular indicators, the authors hypothesized that right ventricular (RV) parameters might be associated with CAEs related to anthracycline treatment. METHODS: In this retrospective study, 96 patients diagnosed with diffuse large B-cell lymphoma who received chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone plus rituximab) were studied using three-dimensional transthoracic echocardiography. Baseline demographic data and oncologic and echocardiographic parameters were analyzed. The main outcome was the proportion of patients with grade 3 to 5 CAEs. The association of all three-dimensional transthoracic echocardiographic parameters with long-term CAEs was analyzed using Cox proportional-hazard analysis. RESULTS: Over a median follow-up period of 6.1 years (range, 4.9-7.6 years) after the completion of anthracycline chemotherapy, 18 of 96 patients (19%) experienced CAEs. Percentage changes (%Δ) in left ventricular global longitudinal strain (LVGLS), global circumferential strain, RV ejection fraction (RVEF), and RV end-systolic volume were associated with CAEs (P < .05). A relative reduction of RVEF (hazard ratio, 0.847; 95% CI, 0.785-0.915; P < .001) was the strongest associated factor for CAEs. An increase in CAEs was also observed in patients with impaired %ΔLVGLS > 15% and impaired %ΔRVEF > 12.7% compared with those with impaired %ΔLVGLS > 15% and impaired %ΔRVEF < 12.7% (P = .032). CONCLUSIONS: Three-dimensional echocardiography-based assessments of %ΔRVEF and %Δ in RV end-systolic volume were significantly associated with CAEs in patients with lymphoma treated with anthracycline chemotherapy.

Assessment of right ventricular function using cardiovascular magnetic resonance in patients with type 2 diabetes mellitus.

BACKGROUND: Accurate evaluation of right ventricular (RV) function is always difficult due to its irregular shape and movement. Many indices have been proposed to assess RV function, but none have been universally accepted. This study evaluated RV function in type 2 diabetes mellitus (T2DM) patients using long-axis strain (LAS) and other traditional indices. METHODS: Fifty-seven patients with T2DM and 39 healthy controls were prospectively enrolled. Four-chamber cardiovascular magnetic resonance (CMR) and RV short-axis cine images were obtained from all participants to measure the tricuspid annular plane systolic excursion (TAPSE), RV ejection fraction (EF), peak longitudinal strain (PLS) and four LAS indices. The inter-and intraobserver variabilities were also calculated. RESULTS: Compared with healthy controls, T2DM was associated with a decreased LAS (apex/lateral wall) (-17.4%±4.2% vs. control, -19.7%±3.7%, P=0.008) and LAS (apex/middle point) (-17.5%±4.5% vs. control, -19.5%±3.9%, P=0.026), but both groups had a similar LAS (RV/lateral wall) and LAS (RV/middle point) (all P>0.05). After adjustments for age and body mass index, a significant difference was observed only for LAS (apex/lateral wall) (P=0.028). There were no significant differences in the TAPSE, RVEF and PLS (all P>0.05). LAS (apex/lateral wall) correlated with the TAPSE (r=-0.723, P<0.001), RVEF (r=-0.270, P=0.008) and PLS (r=0.210, P=0.040). The inter- and intraobserver variability of the LAS (apex/lateral wall) were lower than the other three LAS indices. CONCLUSIONS: Compared with traditional RV function indices, such as the TAPSE, RVEF and PLS, LAS is easy to obtain and shows high repeatability. LAS (apex/lateral wall) may provide a more sensitive T2DM-related RV dysfunction index.

Cardiopulmonary transit time: A novel PET imaging biomarker of in vivo physiology for risk stratification of heart transplant recipients.

BACKGROUND: Myocardial blood flow (MBF) can be quantified using dynamic PET studies. These studies also inherently contain tomographic images of early bolus displacement, which can provide cardiopulmonary transit times (CPTT) as measure of cardiopulmonary physiology. The aim of this study was to assess the incremental prognostic value of CPTT in heart transplant (OHT) recipients. METHODS: 94 patients (age 56 ± 16 years, 78% male) undergoing dynamic 13N-ammonia stress/rest studies were included, of which 68 underwent right-heart catherization. A recently validated cardiac allograft vasculopathy (CAV) score based on PET measures of regional perfusion, peak MBF and left-ventricular (LV) ejection fraction (LVEF) was used to identify patients with no, mild or moderate-severe CAV. Time-activity curves of the LV and right ventricular (RV) cavities were obtained and used to calculate the difference between the LV and RV bolus midpoint times, which represents the CPTT and is expressed in heartbeats. Patients were followed for a median of 2.5 years for the occurrence of major adverse cardiac events (MACE), including cardiovascular death, hospitalization for heart failure or acute coronary syndrome, or re-transplantation. RESULTS: CPTT was significantly correlated with cardiac filling pressures (r = .434, P = .0002 and r = .439, P = .0002 for right atrial and pulmonary wedge pressure), cardiac output (r = - .315, P = .01) and LVEF (r = - .513, P < .0001). CPTT was prolonged in patients with MACE (19.4 ± 6.0 vs 14.5 ± 3.0 heartbeats, P < .001, N = 15) with CPTT ≥ 17.75 beats showing optimal discriminatory value in ROC analysis. CPTT ≥ 17.75 heartbeats was associated with a 10.1-fold increased risk (P < .001) of MACE and a 7.3-fold increased risk (P < .001) after adjusting for PET-CAV, age, sex and time since transplant. CONCLUSION: Measurements of cardiopulmonary transit time provide incremental risk stratification in OHT recipients and enhance the value of multiparametric dynamic PET imaging, particularly in identifying high-risk patients.

Prognostic value of absent left ventricular ejection fraction reserve with regadenoson SPECT MPI.

BACKGROUND: An absent left ventricular ejection fraction (LVEF) reserve with vasodilator stress with PET cardiac imaging has been shown to provide significant independent and incremental value to the perfusion images for prediction of future cardiovascular adverse events. However, the prognostic value of LVEF reserve has not been well characterized with SPECT myocardial perfusion imaging (MPI). METHODS: We studied 858 consecutive patients with normal and abnormal perfusion pattern with regadenoson SPECT MPI. Change in LVEF was calculated as post-stress LVEF-rest LVEF. Absent LVEF reserve was defined as a drop in LVEF by 5% or more on the post-stress images. The primary outcome was a composite of cardiac death, non-fatal myocardial infarction and late coronary revascularization. RESULTS: An absent LVEF reserve was more common in patients with abnormal vs normal MPI (31% vs 19%, P = .001). During a median follow-up of 32 months, the primary outcome was experienced by 31% of the study population. An absent LVEF reserve was not associated with an increased risk of the primary outcome in patients with normal (hazard ratio 1.1, 95% CI .4-2.7, P = .8) or abnormal (.75, .56-1.00, P = .05) MPI. There was no significant correlation between extent of ischemia and post-stress change in LVEF (Pearson r = - .072, P = .07). CONCLUSIONS: In patients undergoing regadenoson SPECT MPI, absent LVEF reserve is not associated with worse cardiac outcomes. Thus, routine reporting of both post-stress and rest LVEF measurements in this setting may not be necessary.

Effect of left ventricular mechanical dyssynchrony assessed pre-renal transplantation on cardiovascular death post transplantation.

BACKGROUND: SPECT myocardial perfusion imaging (MPI) provides an assessment of LV mechanical dyssynchrony (LVMD) which correlates with CVD outcomes in diverse populations including those awaiting renal transplant (RT). The current study examines the association of LVMD on pre-transplant MPI with long-term CVD mortality post RT. METHODS: We identified consecutive patients who underwent RT at the University of Alabama at Birmingham between 2008 and 2012 from our prospectively collected database. 675 patients in the database underwent MPI and had images amenable for phase analysis. A blinded investigator retrieved the studies and derived LVMD indices including histogram bandwidth (BW), standard deviation (SD), phase peak, phase skewness, and phase kurtosis. The primary outcome was CVD death after RT. RESULTS: The study cohort had a median age of 54 years, 56% were men, 43% had diabetes, and 7% had prior myocardial infarction. Patients were on dialysis for a median of 3.4 years prior to RT and 34% received living donor transplants. During a median follow-up time after RT of 4.7 years (IQR 3.5 to 6.3 years) 59 patients (9%) succumbed to CVD death. Patients with wider BW, wider SD, lower skewness, and lower kurtosis had an increased risk of CVD death. On multivariate adjustment, BW and skewness remained as independent predictors of CVD deaths. CONCLUSIONS: LVMD by phase analysis of gated SPECT MPI is associated with increased risk of CVD death after RT. This association is independent of demographics, comorbidities, and traditional findings on MPI and added incremental prognostic information. Assessment of LVMD should be considered for risk stratification in these patients.