Prescription patterns of SGLT2 inhibitors in patients with type 2 diabetes and heart failure with reduced ejection fracture admitted to a tertiary care centre in Ontario, Canada.

OBJECTIVE: To assess early adoption patterns of SGLT2 inhibitors (SGLT2i) in eligible patients with type 2 diabetes (T2DM) and heart failure with reduced ejection fracture (HFrEF) and identify gaps in practice. METHODS: A retrospective chart review of patients with T2DM and HFrEF admitted with decompensated heart failure to The Ottawa Hospital under Cardiology or GIM from June 2019-May 2021 was conducted. Patterns were assessed at 8-months intervals (1 period before the release of Diabetes Canada 2020 guidelines and 2 periods afterwards). Baseline patient characteristics, co-morbidities and prescriber information was collected. RESULTS: Of the 98 patients that met the inclusion criteria, 36.7% had a prescription for an SGLT2i either on admission, discharge or follow-up. Trends showed a gradual increase over time. On admission, 9.8% of patients were on an SGLT2i in period 1, 19.2% in period 2 and 23.3% in period 3. Patients receiving a prescription for SGLT2i on discharge were 0.0% in period 1, 10.0% in period 2 and 9.5% in period 3, all which were admitted under Cardiology. On follow-up, 13.9% of eligible patients were started on an SGLT2i in period 1, 21.1% in period 2 and 35.0% in period 3. Endocrinology was the main prescriber of SGLT2i in the outpatient setting, followed by Cardiology. CONCLUSIONS: Overall, trends show a slow but steady increase in early prescriptions of SGLT2i. However, most eligible patients were not started on therapy during our study period with variability in practice between specialties, highlighting opportunities to boost uptake in the future.

Phenotypes in Pulmonary Hypertension.

The clinical classification of pulmonary hypertension (PH) has guided diagnosis and treatment of patients with PH for several decades. Discoveries relating to underlying mechanisms, pathobiology, and responses to treatments for PH have informed the evolution in this clinical classification to describe the heterogeneity in PH phenotypes. In more recent years, advances in imaging, computational science, and multi-omic approaches have yielded new insights into potential phenotypes and sub-phenotypes within the existing clinical classification. Identification of novel phenotypes in pulmonary arterial hypertension (PAH) with unique molecular profiles, for example, could lead to new precision therapies. Recent phenotyping studies have also identified groups of patients with PAH that more closely resemble patients with left heart disease (group 2 PH) and lung disease (group 3 PH), which has important prognostic and therapeutic implications. Within group 2 and group 3 PH, novel phenotypes have emerged that reflect a persistent and severe pulmonary vasculopathy that is associated with worse prognosis but still distinct from PAH. In group 4 PH (chronic thromboembolic pulmonary disease) and sarcoidosis (group 5 PH) the current approach to patient phenotyping integrates clinical, hemodynamic and imaging characteristics to guide treatment but applications of multi-omic approaches to sub-phenotyping in these areas are sparse. The next iteration of the PH clinical classification is likely to reflect several emerging PH phenotypes and improve the next generation of prognostication tools, clinical trial design, and improve treatment selection in clinical practice.

Quality and Patient Safety Metrics: Developing a Structured Program for Improving Patient Care in the Department of Medicine at The Ottawa Hospital.

PROBLEM: Despite increasing recognition of the importance of quality and patient safety in academic medicine, challenges remain with ensuring physician participation in quality assurance and quality improvement efforts, such as lack of compensation and enabling resources. An organizational culture that includes physician leadership and a supportive infrastructure is needed to encourage physician backing of quality and patient safety initiatives. APPROACH: The authors describe the development of a robust quality and patient safety program in the Department of Medicine at The Ottawa Hospital over the past 7 years and highlight how the department changed its organizational culture by prioritizing quality and patient safety and establishing the necessary infrastructure to support this program. Program development was characterized by 4 overarching themes: incentives, administrative structure and physician leadership, training and support, and system enhancements. OUTCOMES: As a result of the program, the department broadly implemented a standardized framework for conducting quality committee meetings and morbidity and mortality rounds and reviewing patient safety incidents and patient experience across its 16 divisions. This has led to 100% departmental compliance on corporate quality assurance metrics each year (e.g., regular multidisciplinary divisional quality committee meetings), along with physician participation in formal quality improvement initiatives that align with larger corporate goals. NEXT STEPS: The authors reflect on lessons learned during the implementation of the program and the essential elements that contributed to its success. Next steps for the program include using a centralized repository of quality and patient safety data, including patient safety incident dashboards, to encourage greater divisional collaboration on quality improvement initiatives and continuous institutional learning over time. Another important avenue will be to create an academic hub for excellence in quality and a formal approach to reward and promote physicians for their quality work.

Cardiac PET Myocardial Blood Flow Quantification Assessment of Early Cardiac Allograft Vasculopathy.

BACKGROUND: Positron emission tomography (PET) has demonstrated utility for diagnostic and prognostic assessment of cardiac allograft vasculopathy (CAV) but has not been evaluated in the first year after transplant. OBJECTIVES: The authors sought to evaluate CAV at 1 year by PET myocardial blood flow (MBF) quantification. METHODS: Adults at 2 institutions enrolled between January 2018 and March 2021 underwent prospective 3-month (baseline) and 12-month (follow-up) post-transplant PET, endomyocardial biopsy, and intravascular ultrasound examination. Epicardial CAV was assessed by intravascular ultrasound percent intimal volume (PIV) and microvascular CAV by endomyocardial biopsy. RESULTS: A total of 136 PET studies from 74 patients were analyzed. At 12 months, median PIV increased 5.6% (95% CI: 3.6%-7.1%) with no change in microvascular CAV incidence (baseline: 31% vs follow-up: 38%; P = 0.406) and persistent microvascular disease in 13% of patients. Median capillary density increased 30 capillaries/mm2 (95% CI: -6 to 79 capillaries/mm2). PET myocardial flow reserve (2.5 ± 0.7 vs 2.9 ± 0.8; P = 0.001) and stress MBF (2.7 ± 0.6 vs 2.9 ± 0.6; P = 0.008) increased, and coronary vascular resistance (CVR) (49 ± 13 vs 47 ± 11; P = 0.214) was unchanged. At 12 months, PET and PIV had modest correlation (stress MBF: r = -0.35; CVR: r = 0.33), with lower stress MBF and higher CVR across increasing PIV tertiles (all P < 0.05). Receiver-operating characteristic curves for CAV defined by upper-tertile PIV showed areas under the curve of 0.74 for stress MBF and 0.73 for CVR. CONCLUSIONS: The 1-year post-transplant PET MBF is associated with epicardial CAV, supporting potential use for early noninvasive CAV assessment. (Early Post Transplant Cardiac Allograft Vasculopahty [ECAV]; NCT03217786).

Frailty and outcomes in heart failure patients from high-, middle-, and low-income countries.

BACKGROUND AND AIMS: There is little information on the incremental prognostic importance of frailty beyond conventional prognostic variables in heart failure (HF) populations from different country income levels. METHODS: A total of 3429 adults with HF (age 61 ± 14 years, 33% women) from 27 high-, middle- and low-income countries were prospectively studied. Baseline frailty was evaluated by the Fried index, incorporating handgrip strength, gait speed, physical activity, unintended weight loss, and self-reported exhaustion. Mean left ventricular ejection fraction was 39 ± 14% and 26% had New York Heart Association Class III/IV symptoms. Participants were followed for a median (25th to 75th percentile) of 3.1 (2.0-4.3) years. Cox proportional hazard models for death and HF hospitalization adjusted for country income level; age; sex; education; HF aetiology; left ventricular ejection fraction; diabetes; tobacco and alcohol use; New York Heart Association functional class; HF medication use; blood pressure; and haemoglobin, sodium, and creatinine concentrations were performed. The incremental discriminatory value of frailty over and above the MAGGIC risk score was evaluated by the area under the receiver-operating characteristic curve. RESULTS: At baseline, 18% of participants were robust, 61% pre-frail, and 21% frail. During follow-up, 565 (16%) participants died and 471 (14%) were hospitalized for HF. Respective adjusted hazard ratios (95% confidence interval) for death among the pre-frail and frail were 1.59 (1.12-2.26) and 2.92 (1.99-4.27). Respective adjusted hazard ratios (95% confidence interval) for HF hospitalization were 1.32 (0.93-1.87) and 1.97 (1.33-2.91). Findings were consistent among different country income levels and by most subgroups. Adding frailty to the MAGGIC risk score improved the discrimination of future death and HF hospitalization. CONCLUSIONS: Frailty confers substantial incremental prognostic information to prognostic variables for predicting death and HF hospitalization. The relationship between frailty and these outcomes is consistent across countries at all income levels.

Association Between the Pulmonary Artery Pulsatility Index and Prognosis in Pulmonary Arterial Hypertension: A Multicentre Study.

Background: Risk stratification is fundamental in the management of pulmonary arterial hypertension (PAH). Pulmonary artery pulsatility index (PAPi), defined as pulmonary arterial pulse pressure divided by right atrial pressure (RAP), is a hemodynamic index shown to predict acute right ventricular (RV) dysfunction in several settings. Our objective was to test the prognostic utility of PAPi in a diverse multicentre cohort of patients with PAH. Methods: A multicentre retrospective cohort study of consecutive adult patients with a new diagnosis of PAH on right heart catheterization between January 2016 and December 2020 was undertaken across 4 major centres in Canada. Hemodynamic data, clinical data, and outcomes were collected. The association of PAPi and other hemodynamic variables with mortality was assessed by receiver-operating characteristic curves and Cox proportional hazards modeling. Results: We identified 590 patients with a mean age of 61.4 ± 15.5 years, with 66.3% being female. A low PAPi (defined as < 5.3) was associated with higher mortality at 1 year: 10.2% vs 5.2% (P = 0.02). In a multivariable model including age, sex, body mass index, and functional class, a low PAPi was associated with mortality at 1 year (area under the curveof 0.64 (95% confidence interval 0.55-0.74). However, high RAP (> 8 mm Hg) was similarly predictive of mortality, with an area under the curve of 0.65. Conclusion: PAPi was associated with mortality in a large incident PAH cohort. However, the discriminative value of PAPi was not higher than that of RAP alone.

Contexte: La stratification des risques est fondamentale dans la prise en charge de l'hypertension artérielle pulmonaire (HTAP). L'indice de pulsatilité des artères pulmonaires (iPAP), défini comme la pression différentielle dans les artères pulmonaires divisée par la pression auriculaire droite (PAD), est un indice hémodynamique qui s'est révélé prédictif d'une dysfonction ventriculaire droite (VD) aiguë dans plusieurs situations. Notre objectif était d'évaluer l'utilité pronostique de l'iPAP dans une cohorte multicentrique diversifiée de patients atteints d'HTAP. Méthodologie: Une étude de cohorte multicentrique rétrospective de patients adultes consécutifs atteints d'une HTAP nouvellement diagnostiquée par cathétérisme cardiaque droit entre janvier 2016 et décembre 2020 a été effectuée dans quatre grands centres au Canada. Les données hémodynamiques, les données cliniques et les résultats ont été recueillis. La corrélation de l'iPAP et d'autres va-riables hémodynamiques avec la mortalité a été évaluée par les courbes caractéristiques opérationnelles du receveur et des modèles à risques proportionnels de Cox. Résultats: Nous avons recensé 590 patients dont l'âge moyen était de 61,4 ± 15,5 ans; la proportion de femmes était de 66,3 %. Un faible iPAP (défini comme une valeur < 5,3) a été associé à une hausse de la mortalité à 1 an : 10,2 % contre 5,2 % (p= 0,02). Dans un modèle multivarié comprenant l'âge, le sexe, l'indice de masse corporelle et la classe fonctionnelle, un faible iPAP a été associé à la mortalité à 1 an (aire sous la courbe de 0,64 [intervalle de confiance à 95 %; de 0,55 à 0,74]). Cependant, une PAD élevée (> 8 mmHg) a aussi été un facteur prédictif de mortalité, l'aire sous la courbe étant de 0,65. Conclusions: L'iPAP a été associé à la mortalité dans une vaste cohorte de patients atteints d'une HTAP. Toutefois, la valeur discriminante de l'iPAP n'a pas été supérieure à celle de la PAD seule.

Pharmacological and metabolic parameters of [18F]flubrobenguane in clinical imaging populations.

BACKGROUND: Cardiac sympathetic nervous system molecular imaging has demonstrated prognostic value. Compared with meta-[11C]hydroxyephedrine, [18F]flubrobenguane (FBBG) facilitates reliable estimation of SNS innervation using similar analytical methods and possesses a more convenient physical half-life. The aim of this study was to evaluate pharmacokinetic and metabolic properties of FBBG in target clinical cohorts. METHODS: Blood sampling was performed on 20 participants concurrent to FBBG PET imaging (healthy = NORM, non-ischemic cardiomyopathy = NICM, ischemic cardiomyopathy = ICM, post-traumatic stress disorder = PTSD). Image-derived blood time-activity curves were transformed to plasma input functions using cohort-specific corrections for plasma protein binding, plasma-to-whole blood distribution, and metabolism. RESULTS: The plasma-to-whole blood ratio was 0.78 ± 0.06 for NORM, 0.64 ± 0.06 for PTSD and 0.60 ± 0.14 for (N)ICM after 20 minutes. 22 ± 4% of FBBG was bound to plasma proteins. Metabolism of FBBG in (N)ICM was delayed, with a parent fraction of 0.71 ± 0.05 at 10 minutes post-injection compared to 0.53 ± 0.03 for PTSD/NORM. While there were variations in metabolic rate, metabolite-corrected plasma input functions were similar across all cohorts. CONCLUSIONS: Rapid plasma clearance of FBBG limits the impact of disease-specific corrections of the blood input function for tracer kinetic modeling.

Fibrotic Plaque and Microvascular Dysfunction Predict Early Cardiac Allograft Vasculopathy Progression After Heart Transplantation: The Early Post Transplant Cardiac Allograft Vasculopathy Study.

BACKGROUND: Early cardiac allograft vasculopathy (CAV) prognostication is needed to improve long-term outcomes after heart transplantation. We characterized first year posttransplant coronary anatomic-physiologic alterations to determine predictors of early CAV progression. METHODS: Heart transplant recipients at 2 institutions (enrolled January 2018 to March 2021) underwent prospective evaluation 3 and 12-month posttransplant with angiography and left anterior descending artery intravascular ultrasound, optical coherence tomography, fractional flow reserve, coronary flow reserve, and index of microcirculatory resistance measurements. CAV progression was assessed by intravascular ultrasound change in percentage intimal volume from baseline to 12-month follow-up. RESULTS: Eighty-two patients (mean age, 51 years; 60% men) completed evaluation at mean 13.8 and 56.3 weeks posttransplant. Donor atherosclerosis (baseline intravascular ultrasound maximal intimal thickness, ≥0.5 mm) was evident in 50%. De novo (follow-up maximal intimal thickness, ≥0.5 mm) and rapidly progressive CAV (maximal intimal thickness, ≥0.5-mm increase from baseline) developed in 24% and 13%, respectively. On optical coherence tomography, baseline to follow-up median intimal volume increased 42% (0.58 mm3/mm), percentage intimal volume increased 44% (4.6%), vessel volume decreased 4% (-0.50 mm3/mm) and lumen volume decreased 9% (-1.02 mm3/mm); P<0.05 for all. Fibrotic plaque was the predominant morphology: baseline, 29% and follow-up, 50%. Coronary physiology was abnormal in 41% at baseline and 45% at follow-up, with 1 in 5 patients having microvascular dysfunction (index of microcirculatory resistance, ≥25). On multivariable linear regression analysis, recipient male sex, fibrotic plaque, and index of microcirculatory resistance were independent predictors of coronary disease progression. CONCLUSIONS: Fibrotic plaque on optical coherence tomography and index of microcirculatory resistance early posttransplant predict CAV progression in the first year of transplantation. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03217786.

Right Ventricular Maladaptation to Pressure Overload in Fischer Rats Is Associated With Profound Deficiency in Adenylate Kinase 1 and Impaired Ventricular Energetics.

BACKGROUND: We explored the mechanism of maladaptive right ventricular (RV) remodeling in Fischer compared with Sprague-Dawley (SD) rats exposed to pressure overload. METHODS: Pulmonary hypertension was induced by injection of the VEGFR antagonist, SU5416, followed by a 3-week exposure to hypoxia (Sugen chronic hypoxia). In vivo oxidative metabolism was assessed by RV/left ventricle ratio of [11C]acetate positron emission tomography clearance (kmono). Unbiased, global transcriptional and proteomic profiling was performed in Fischer and SD rats at baseline and after Sugen chronic hypoxia. RESULTS: All Fischer rats succumbed to RV failure by 5 weeks, whereas SD rats showed preserved RV function and 88% survival beyond 9 weeks (P<0.0001). Fischer rats exhibited increased oxidative metabolism at 4 weeks (P<0.05) and impaired RV efficiency compared with SD (work metabolic index: 52±10 versus 91±27 mmHg·mL/cm2, respectively; P<0.05), but no differences in mitochondrial complex activity. AK1 (adenylate kinase 1) was among the top 10 differentially expressed genes between Fischer and SD rats, with markedly lower RV expression in Fischer rats (FC: 3.36, P<0.05), confirmed by proteomic analysis and validated by Western blotting (>10-fold reduction, P<0.001). While whole-genome sequencing failed to reveal any coding region mutations in Fischer rats, there was a unique variant in a highly conserved upstream flanking region likely involved in the regulation of AK1 expression. CONCLUSIONS: Therefore, Fischer rats exhibit profound AK1 deficiency and inefficient cardiac energetics likely related to reduced adenosine triphosphate shuttling from the mitochondria to the contractile fibers. This represents a novel mechanism for RV failure in response to chronic increases in afterload.

Oral anticoagulants (NOAC and VKA) in chronic thromboembolic pulmonary hypertension.

EXPERT was an international, multicenter, prospective, uncontrolled, non-interventional cohort study in patients with pulmonary hypertension treated with riociguat. Patients were followed for 1-4 years, and the primary outcomes were adverse events (AEs) and serious AEs (SAEs), including embolic/thrombotic and hemorrhagic events. Here we report data on patients with chronic thromboembolic pulmonary hypertension (CTEPH) receiving a vitamin K antagonist (VKA; n = 683) or a non-vitamin K antagonist oral anticoagulant (NOAC; n = 198) at baseline. AEs and SAEs were reported in 438 patients (64.1%) and 257 patients (37.6%), respectively, in the VKA group, and in 135 patients (68.2%) and 74 patients (37.4%) in the NOAC group. Exposure-adjusted hemorrhagic event rates were similar in the two groups, while exposure-adjusted embolic and/or thrombotic event rates were higher in the NOAC group, although the numbers of events were small. Further studies are required to determine the long-term effects of anticoagulation strategies in CTEPH.

A standardized definition for right ventricular failure in cardiac surgery patients.

Right ventricular failure (RVF) is a significant cause of mortality and morbidity after cardiac surgery. Despite its prognostic importance, RVF remains under investigated and without a universally accepted definition in the perioperative setting. We foresee that the provision of a standardized perioperative definition for RVF based on practical and objective criteria will help to improve quality of care through early detection and facilitate the generalization of RVF research to advance this field. This article provides an overview of RVF aetiology, pathophysiology, current diagnostic modalities, as well as a summary of existing RVF definitions. This is followed by our proposal for a standardized definition of perioperative RVF, one that captures RV structural and functional abnormalities through a multimodal approach based on anatomical, echocardiographic, and haemodynamic criteria that are readily available in the perioperative setting (Central Image).

Positron Emission Tomography Imaging of Regional Versus Global Myocardial Sympathetic Activity to Improve Risk Stratification in Patients With Ischemic Cardiomyopathy.

BACKGROUND: Current risk assessment approaches fail to identify the majority of patients at risk of sudden cardiac arrest (SCA). Noninvasive imaging of the cardiac sympathetic nervous system using single-photon emission computed tomography and positron emission tomography offers the potential for refining SCA risk assessment. While various [11C]meta-hydroxyephedrine quantification parameters have been proposed, it is currently unknown whether regional denervation or global innervation yields greater SCA risk discrimination. The aim of the study was to determine whether the global innervation parameters yield any independent and additive prognostic value over the regional denervation alone. METHODS: In a post hoc competing-risks analysis of the PAREPET trial (Prediction of Arrhythmic Events With Positron Emission Tomography), we compared global innervation and regional denervation parameters using the norepinephrine analog [11C]meta-hydroxyephedrine for SCA risk discrimination. Patients with ischemic cardiomyopathy (n=174) eligible for an implantable cardioverter-defibrillator for the primary prevention of SCA were recruited into the trial. [11C]meta-hydroxyephedrine uptake and clearance rates were measured to assess global (left ventricle mean) retention index and volume of distribution. Regional defects were quantified as the percentage of the left ventricle having values <75% of the maximum. RESULTS: During a median follow-up of 4.2 years, there were 56 cardiac-related deaths, of which 26 were SCAs. For any given regional denervation volume, there was substantial heterogeneity in global innervation scores. Global retention index and distribution volume did not decrease until regional defects exceeded 40% left ventricle. Global scale parameters, retention index, and distribution volume (area under the curve=0.61, P=0.034, P=0.046, respectively), yielded inferior SCA risk discrimination compared to regional heterogeneity (area under the curve=0.74). CONCLUSIONS: Regional denervation volume has superior cause-specific mortality prediction for SCA versus global parameters of sympathetic innervation. These results have widespread implications for future cardiac sympathetic imaging, which will greatly simplify innervation analysis. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01400334.

Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry.

OBJECTIVE: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase 3 randomized trials. The EXPosurE Registry RiociguaT in patients with pulmonary hypertension (EXPERT) study was designed to monitor the long-term safety of riociguat in clinical practice. METHODS: EXPERT was an international, multicenter, prospective, uncontrolled, non-interventional cohort study of patients treated with riociguat. Patients were followed for at least 1 year and up to 4 years from enrollment or until 30 days after stopping riociguat treatment. Primary safety outcomes were adverse events (AEs) and serious adverse events (SAEs) coded using Medical Dictionary for Regulatory Activities preferred terms and System Organ Classes version 21.0, collected during routine clinic visits and collated via case report forms. RESULTS: In total, 956 patients with CTEPH were included in the analysis. The most common AEs in these patients were peripheral edema/edema (11.7%), dizziness (7.5%), right ventricular (RV)/cardiac failure (7.7%), and pneumonia (5.0%). The most common SAEs were RV/cardiac failure (7.4%), pneumonia (4.1%), dyspnea (3.6%), and syncope (2.5%). Exposure-adjusted rates of hemoptysis/pulmonary hemorrhage and hypotension were low and comparable to those in the long-term extension study of riociguat (Chronic Thromboembolic Pulmonary Hypertension Soluble Guanylate Cyclase-Stimulator Trial [CHEST-2]). CONCLUSION: Data from EXPERT show that in patients with CTEPH, the safety of riociguat in routine practice was consistent with the known safety profile of the drug, and no new safety concerns were identified.

[11C]meta-hydroxyephedrine PET evaluation in experimental pulmonary arterial hypertension: Effects of carvedilol of right ventricular sympathetic function.

BACKGROUND: Little is known about the sequelae of chronic sympathetic nervous system (SNS) activation in patients with pulmonary arterial hypertension (PAH) and right heart failure (RHF). We aimed to, (1) validate the use of [11C]-meta-hydroxyephedrine (HED) for assessing right ventricular (RV) SNS integrity, and (2) determine the effects of ß-receptor blockade on ventricular function and myocardial SNS activity in a PAH rat model. METHODS: PAH was induced in male Sprague-Dawley rats (N = 36) using the Sugen+chronic hypoxia model. At week 5 post-injection, PAH rats were randomized to carvedilol (15 mg·kg-1·day-1 oral; N = 16) or vehicle (N = 16) for 4 weeks. Myocardial SNS function was assessed with HED positron emission tomography(PET). RESULTS: With increasing PAH disease severity, immunohistochemistry confirmed selective sympathetic denervation within the RV and sparing of parasympathetic nerves. These findings were confirmed on PET with a significant negative relationship between HED volume of distribution(DV) and right ventricular systolic pressure (RVSP) in the RV (r = -0.90, p = 0.0003). Carvedilol did not reduce hemodynamic severity compared to vehicle. RV ejection fraction (EF) was lower in both PAH groups compared to control (p < 0.05), and was not further reduced by carvedilol. Carvedilol improved SNS function in the LV with significant increases in the HED DV, and decreased tracer washout in the LV (p < 0.05) but not RV. CONCLUSIONS: PAH disease severity correlated with a reduction in HED DV in the RV. This was associated with selective sympathetic denervation. Late carvedilol treatment did not lead to recovery of RV function. These results support the role of HED imaging in assessing SNS innervation in a failing right ventricle.

Riociguat treatment in patients with pulmonary arterial hypertension: Final safety data from the EXPERT registry.

OBJECTIVE: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension following Phase 3 randomized trials. The EXPosurE Registry RiociguaT in patients with pulmonary hypertension (EXPERT) study was designed to monitor the long-term safety of riociguat in clinical practice. METHODS: EXPERT was an international, multicenter, prospective, uncontrolled, non-interventional cohort study of patients treated with riociguat. Patients were followed for at least 1 year and up to 4 years from enrollment or until 30 days after stopping riociguat treatment. Primary safety outcomes were adverse events (AEs) and serious adverse events (SAEs) coded using Medical Dictionary for Regulatory Activities preferred terms and System Organ Classes version 21.0, collected during routine clinic visits (usually every 3-6 months) and collated via case report forms. RESULTS: In total, 326 patients with PAH were included in the analysis. The most common AEs in these patients were dizziness (11.7%), right ventricular (RV)/cardiac failure (10.7%), edema/peripheral edema (10.7%), diarrhea (8.6%), dyspnea (8.0%), and cough (7.7%). The most common SAEs were RV/cardiac failure (10.1%), pneumonia (6.1%), dyspnea (4.0%), and syncope (3.4%). The exposure-adjusted rate of hemoptysis/pulmonary hemorrhage was 2.5 events per 100 patient-years. CONCLUSION: Final data from EXPERT show that in patients with PAH, the safety of riociguat in clinical practice was consistent with clinical trials, with no new safety concerns identified and a lower exposure-adjusted rate of hemoptysis/pulmonary hemorrhage than in the long-term extension of the Phase 3 trial in PAH.

Validation of multiparametric rubidium-82 PET myocardial blood flow quantification for cardiac allograft vasculopathy surveillance.

BACKGROUND: We previously demonstrated high diagnostic accuracy of Rubidium-82 positron emission tomography (PET) myocardial blood flow (MBF) quantification for CAV. The purpose of this study was to validate multiparametric PET detection of CAV by combined rate-pressure-product-corrected myocardial flow reserve (cMFR), stress MBF, and coronary vascular resistance (CVR) assessment. METHODS AND RESULTS: Diagnostic CAV cut-offs of cMFR < 2.9, stress MBF < 2.3, CVR > 55 determined in a previous study (derivation) were assessed in heart transplant recipients referred for coronary angiography and intravascular ultrasound (IVUS) (validation). CAV was defined as International Society of Heart and Lung Transplantation CAV1-3 on angiography; and maximal intimal thickness ≥ 0.5 mm on IVUS. Eighty patients (derivation n = 40, validation n = 40) were included: 80% male, mean age 54±14 years, 4.5±5.6 years post transplant. The prevalence of CAV was 44% on angiography and 78% on IVUS. Combined PET cMFR < 2.9, stress MBF < 2.3, CVR > 55 CAV assessment yielded high 88% (specificity 75%) and 83% (specificity 40%) sensitivity for ≥ 1 abnormal parameter and high 88% (sensitivity 59%) and 90% (sensitivity 43%) specificity for 3 abnormal parameters, in the derivation and validation cohorts, respectively. CONCLUSION: We validate the diagnostic accuracy of multiparametric PET flow quantification by cMFR, stress MBF, and CVR for CAV.

Increased myocardial oxygen consumption rates are associated with maladaptive right ventricular remodeling and decreased event-free survival in heart failure patients.

BACKGROUND: Reduced left ventricular (LV) function is associated with increased myocardial oxygen consumption rate (MVO2) and altered sympathetic activity, the role of which is not well described in right ventricular (RV) dysfunction. METHODS AND RESULTS: 33 patients with left heart failure were assessed for RV function/size using echocardiography. Positron emission tomography (PET) was used to measure 11C-acetate clearance rate (kmono), 11C-hydroxyephedrine (11C-HED) standardized uptake value (SUV), and retention rate. RV MVO2 was estimated from kmono. 11C-HED SUV and retention indicated sympathetic neuronal function. A composite clinical endpoint was defined as unplanned cardiac hospitalization within 5 years. Patients with (n = 10) or without (n = 23) RV dysfunction were comparable in terms of sex (male: 70.0 vs 69.5%), LV ejection fraction (39.6 ± 9.0 vs 38.6 ± 9.4%), and systemic hypertension (70.0 vs 78.3%). RV dysfunction patients were older (70.9 ± 13.5 vs 59.4 ± 11.5 years; P = .03) and had a higher prevalence of pulmonary hypertension (60.0% vs 13.0%; P = .01). RV dysfunction was associated with increased RV MVO2 (.106 ± .042 vs .068 ± .031 mL/min/g; P = .02) and decreased 11C-HED SUV and retention (6.05 ± .53 vs 7.40 ± 1.39 g/mL (P < .001) and .08 ± .02 vs .11 ± .03 mL/min/g (P < .001), respectively). Patients with an RV MVO2 above the median had a shorter event-free survival (hazard ratio = 5.47; P = .01). Patients who died within the 5-year follow-up period showed a trend (not statistically significant) for higher RV MVO2 (.120 ± .026 vs .074 ± .038 mL/min/g; P = .05). CONCLUSIONS: RV dysfunction is associated with increased oxygen consumption (also characterized by a higher risk for cardiac events) and impaired RV sympathetic function.

Low-Density Lipoprotein Cholesterol Level Trends and the Development of Cardiac Allograft Vasculopathy After Heart Transplantation.

BACKGROUND: Unlike the relationship with atherosclerotic coronary artery disease, that between low-density lipoprotein cholesterol (LDL-C) and cardiac allograft vasculopathy (CAV) is unclear. Our objectives were to characterize lipid profiles early after heart transplantation (HT) and evaluate the relationship between early LDL-C and the development of CAV. METHODS: We retrospectively reviewed consecutive adults who underwent HT at 2 centres during the time period 2010-2018. The primary outcome was the incidence of angiographic CAV. The relationship between LDL-C and CAV was assessed using Cox proportional hazards and logistic regression models adjusted a priori for clinically important covariates, including recipient and donor age, recipient sex, ischemic time, and pre-HT diabetes. RESULTS: A total of 386 patients followed for a median (range) of 4.4 (2.8-6.8) years were included. LDL-C at baseline (2.11 ± 0.86 mmol/L) and 1 year after HT (2.20 ± 0.88 mmol/L) was similar (P = 0.21), but it was lower at the end of follow-up (1.89 ± 0.74 mmol/L, P < 0.01). Of 309 patients who underwent angiography, 54% had CAV. The risk of CAV did not vary according to baseline, 1-year, or change from baseline to 1-year LDL-C. The odds of CAV at 1 year were equally likely across LDL-C values (adjusted odds ratio 1.00, 95% confidence interval: 0.61-1.63 for baseline, and adjusted odds ratio 1.25, 95% confidence interval: 0.74-2.10 for 1-year LDL-C). CONCLUSIONS: No association was identified between early LDL-C and the development of CAV. Our findings do not support targeting a specific LDL-C for patients who do not otherwise meet criteria for guideline-recommended LDL-C target levels. Randomized studies are warranted to determine if lipid-lowering to a specific LDL-C target level modifies the risk of CAV.

INTRODUCTION: Contrairement à la relation avec l'athérosclérose coronarienne, la relation entre les concentrations de cholestérol de lipoprotéines à faible densité (cholestérol LDL) et la vasculopathie d'allogreffe cardiaque (VAC) n'est pas claire. Nos objectifs étaient de caractériser les profils lipidiques rapidement après la transplantation cardiaque (TC) et d'évaluer la relation entre les concentrations initiales de cholestérol LDL et l'apparition de la VAC. MÉTHODES: Nous avons passé en revue de façon rétrospective les adultes consécutifs qui avaient subi une TC dans deux établissements durant la période 2010-2018. Le critère d'évaluation principal était la fréquence de la VAC à l'angiographie. Nous avons évalué la relation entre les concentrations de cholestérol LDL et la VAC à l'aide des modèles à risques proportionnels de Cox et de régression logistique ajustés a priori sur les covariables importantes sur le plan clinique, notamment l'âge du receveur et du donneur, le sexe du receveur, la durée de l'ischémie et le diabète pré-TC. RÉSULTATS: Nous avons inclus un total de 386 patients suivis durant une médiane (étendue) de 4,4 (2,8-6,8) ans. Les concentrations initiales de cholestérol LDL (2,11 ± 0,86 mmol/l) et après 1 an (2,20 ± 0,88 mmol/l) étaient similaires (P = 0,21), mais elles étaient plus faibles à la fin du suivi (1,89 ± 0,74 mmol/l, P < 0,01). Parmi les 309 patients qui avaient subi une angiographie, 54 % avaient une VAC. Le risque de VAC ne variait pas en fonction des concentrations de cholestérol LDL du début, après un an, ou ne changeait pas entre le début et après un an. Les cotes de la VAC après 1 an étaient équiprobables dans toutes les valeurs de cholestérol LDL (rapport de cotes ajusté 1,00, intervalle de confiance [IC] à 95 % : 0,61-1,63 au début, et rapport de cotes ajusté 1,25, IC à 95 % : 0,74-2,10 pour les concentrations de cholestérol LDL après un an). CONCLUSIONS: Aucune association n'a été établie entre les concentrations initiales de cholestérol LDL et l'apparition de la VAC. Nos résultats n'étayent pas le ciblage de concentrations particulières de cholestérol LDL chez les patients qui ne satisfaisaient par ailleurs pas aux critères des concentrations cibles de cholestérol LDL recommandées par les lignes directrices. Des études à répartition aléatoire sont justifiées pour déterminer si la diminution des lipides à des concentrations cibles particulières de cholestérol LDL modifie le risque de VAC.

Regional Distribution of Fluorine-18-Flubrobenguane and Carbon-11-Hydroxyephedrine for Cardiac PET Imaging of Sympathetic Innervation.

OBJECTIVES: The aim of this study was to investigate the regional distribution of novel 18F-labeled positron emission tomographic (PET) tracer flubrobenguane (FBBG) (whose longer half-life could enable more widespread use) to assess myocardial presynaptic sympathetic nerve function in humans in comparison to [11C]meta-hydroxyephedrine (HED). BACKGROUND: The sympathetic nervous system (SNS) is vitally linked to cardiovascular regulation and disease. SNS imaging has shown prognostic value. HED is the most commonly used PET tracer for evaluation of sympathetic function in humans, but widespread clinical use is limited because of the short half-life of 11C. METHODS: A total of 25 participants (n = 6 healthy; n = 14 ischemic cardiomyopathy, left ventricular [LV] ejection fraction [EF] = 34 ± 5%; and n = 5 nonischemic cardiomyopathy, EF = 33 ± 3%) underwent 2 separate PET imaging visits 8.7 ± 7.6 days apart. On 1 visit, participants underwent dynamic HED PET imaging. On a different visit, participants underwent dynamic FBBG PET imaging. The order of testing was random. HED and FBBG global innervation (retention index [RI] and distribution volume [DV]) and regional denervation (% nonuniformity) were quantified to assess regional presynaptic sympathetic innervations. RESULTS: FBBG RI (r2 = 0.72; ICC = 0.79; p < 0.0001), DV (r2 = 0.62; ICC = 0.78; p < 0.0001), and regional denervation (r2 = 0.97; ICC = 0.98; p < 0.0001) correlated highly with HED. Average LV RI values were highly similar between HED (7.3 ± 2.4%/min) and FBBG (7.0 ± 1.7%/min; p = 0.33). Post-hoc analysis did not reveal any between-tracer differences on a regional level (17-segment), suggesting equivalent regional distributions in both patients with and without ischemic cardiomyopathy. CONCLUSIONS: FBBG and HED yield equivalent global and regional distributions in both patients with and without ischemic cardiomyopathy. 18F-labeled PET tracers, such as FBBG, are critical for widespread distribution necessary for multicenter clinical trials and to maximize patient impact.

Pulmonary Hypertension Due to Left Heart Disease-A Practical Approach to Diagnosis and Management.

Pulmonary hypertension (PH) due to left heart disease (LHD) is a frequent complication of heart failure (HF) and is associated with exercise intolerance, poor quality of life, increased risk of hospitalisations, and reduced overall survival. Since the recent Sixth World Symposium on Pulmonary Hypertension in 2018, there have been significant changes in the hemodynamic definitions and clinical classification of PH-LHD. PH-LHD can be subdivided into (1) isolated postcapillary PH (IpcPH) and (2) combined precapillary and postcapillary PH (CpcPH). This categorisation of PH-LHD is important because CpcPH shares certain pathophysiologic, clinical, and hemodynamic characteristics with pulmonary arterial hypertension and is associated with worse outcomes compared with IpcPH. A systematic approach using clinical history and noninvasive investigations is required in the diagnosis of PH-LHD. Right heart catheterisation with and without provocative testing is performed in expert centres and is indicated in selected individuals. Although the definition of IpcPH and CpcPH is based on measurements made with right heart catheterisation, distinguishing between these two entities is not always necessary. Despite strong evidence for medical therapy in patients with pulmonary arterial hypertension, those options have limited benefit in PH-LHD. Expert PH centres in Canada have been established to provide ongoing care for the more complex patient subgroups.