Clinical Phenotypes of Heart Failure across the spectrum of Ejection Fraction: A Cluster Analysis.

INTRODUCTION: Heart failure (HF), and especially HF with preserved ejection fraction (HFpEF), remains a challenging condition to define. The heterogenous nature of this population may be related to a variety of underlying etiologies interacting myocardial dysfunction. METHOD: Alberta HEART study was a prospective, observational cohort that enrolled participants along the spectrum of heart failure including: healthy controls, people at risk of HF, and patients with HF and preserved (HFpEF) or reduced ejection fraction (HFrEF). We aimed to explore phenotypes of patients with HF and at-risk of developing HF. Utilising 27 detailed clinical, echocardiographic and biomarker variables, latent class analysis with and without multiple imputation was undertaken to identify distinct clinical phenotypes. RESULTS: Of 621 participants, 191 (30.8%) and 169 (27.2%) were adjudicated by cardiologists to have HFpEF and HFrEF respectively. In the overall cohort, latent class analysis identified four distinct phenotypes. Phenotype A (n=152, 24.5%) was a healthy and low risk group. Phenotype B (n=129, 20.8%) demonstrated increased left ventricular mass and end-diastolic volumes, with elevated natriuretic peptides and clinical features of congestion. Phenotype C (n=128, 20.6%) was primarily characterised by obesity (80%) and normal indexed cardiac chamber sizes, low natriuretic peptide levels and minimal features of congestion.  Phenotype D (n=212, 34.1%) consisted of elderly patients with clinical features of congestions. Phenotypes B and D demonstrated the highest risk of mortality and hospitalization over a median follow-up of 3.7 years. CONCLUSION: Phenotypes with congestive features demonstrated increased risk profiles. Heart failure is a heterogenous classification which requires further work to appropriately categorise patients based on the underlying etiology or mechanism of impairment.

Longitudinal Changes in Skeletal Muscle Metabolism, Oxygen Uptake, and Myosteatosis During Cardiotoxic Treatment for Early-Stage Breast Cancer.

BACKGROUND: While cardiotoxic chemotherapy is known to negatively impact cardiac function and hemoglobin levels, the impact on skeletal muscle has been understudied among patients. The purpose was to longitudinally characterize myosteatosis (muscle fat), skeletal muscle metabolism, and oxygen (O2) consumption during cardiotoxic chemotherapy for breast cancer. PATIENTS AND METHODS: Thirty-four patients with stage I-III breast cancer were enrolled before trastuzumab-containing and/or anthracycline-containing chemotherapy. We used magnetic resonance imaging to non-invasively quantify thigh myosteatosis (fat-water imaging), and lower leg metabolism (31P spectroscopy), O2 consumption (custom techniques), and peak power output during single-leg plantarflexion exercise at pre-, mid-, end-chemotherapy, and 1-year. We also measured pulmonary VO2peak and maximal leg press strength. RESULTS: During chemotherapy, VO2peak and leg press strength decreased while peak plantarflexion power output was maintained. At mid-chemotherapy, hemoglobin decreased (16%) and lower leg blood flow increased (37%) to maintain lower leg O2 delivery; exercise Pi:PCr and myosteatosis increased. Between mid- and end-chemotherapy, lower leg O2 extraction (28%) and O2 consumption (21%) increased, while plantarflexion exercise efficiency (watts/O2 consumed) decreased. At one year, VO2peak and leg press strength returned to pre-chemotherapy levels, but lower leg exercise O2 extraction, consumption and Pi:PCr, and myosteatosis remained elevated. CONCLUSION: Lower leg skeletal muscle blood flow and O2 extraction adapt to compensate for chemotherapy-related hemoglobin reduction for small muscle mass exercise but are insufficient to maintain large muscle mass exercise (pulmonary VO2peak, leg press strength). The excess O2 required to perform work, increased Pi:PCr ratio and myosteatosis together suggest suppressed fat oxidation during chemotherapy.

2021 Update on Safety of Magnetic Resonance Imaging: Joint Statement From Canadian Cardiovascular Society/Canadian Society for Cardiovascular Magnetic Resonance/Canadian Heart Rhythm Society.

Magnetic resonance imaging (MRI) is often considered the gold-standard test for characterizing cardiac as well as noncardiac structure and function. However, many patients with cardiac implantable electronic devices (CIEDs) and/or severe renal dysfunction are unable to undergo this test because of safety concerns. In the past 10 years, newer-generation CIEDs and gadolinium-based contrast agents (GBCAs) as well as coordinated care between imaging and heart rhythm device teams have mitigated risk to patients and improved access to MRI at many hospitals. The purpose of this statement is to review published data on safety of MRI in patients with conditional and nonconditional CIEDs in addition to patient risks from older and newer GBCAs. This statement was developed through multidisciplinary collaboration of pan-Canadian experts after a relevant and independent literature search by the Canadian Agency for Drugs and Technologies in Health. All recommendations align with the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. Key recommendations include: (1) the development of standardized protocols for patients with a CIED undergoing MRI; (2) patients with MRI nonconditional pacemakers and pacemaker dependency should be programmed to asynchronous mode and those with MRI nonconditional transvenous defibrillators should have tachycardia therapies turned off during the scan; and (3) macrocyclic or newer linear GBCAs should be used in preference to older GBCAs because of their better safety profile in patients at higher risk of nephrogenic systemic fibrosis.

Correction to: Rationale and design of the Caloric Restriction and Exercise protection from Anthracycline Toxic Effects (CREATE) study: a 3-arm parallel group phase II randomized controlled trial in early breast cancer.

Following publication of the original article [1], we have been notified that one of the author names was listed incorrectly.