Cardiovascular magnetic resonance (CMR) has become the primary tool for non-invasive assessment of myocardial inflammation in patients with suspected myocarditis. The International Consensus Group on CMR Diagnosis of Myocarditis was founded in 2006 to achieve consensus among CMR experts and develop recommendations on the current state-of-the-art use of CMR for myocarditis. The recommendations include indications for CMR in patients with suspected myocarditis, CMR protocol standards, terminology for reporting CMR findings, and diagnostic CMR criteria for myocarditis (“Lake Louise Criteria”).

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Purpose The primary toxicity of trastuzumab therapy for human epidermal growth factor receptor 2-overexpressing (HER2-positive) breast cancer is dose-independent cardiac dysfunction. Angiotensin-converting enzyme inhibitors and β-blockers are recommended first-line agents for heart failure. We hypothesized that angiotensin-converting enzyme inhibitors and β-blockers could prevent trastuzumab-related cardiotoxicity. Patients and Methods In this double-blinded, placebo-controlled trial, patients with HER2-positive early breast cancer were randomly assigned to receive treatment with perindopril, bisoprolol, or placebo (1:1:1) for the duration of trastuzumab adjuvant therapy. Patients underwent cardiac magnetic resonance imaging at baseline and post-cycle 17 for the determination of left ventricular volumes and left ventricular ejection fraction (LVEF). Cardiotoxicity was evaluated as the change in indexed left ventricular end diastolic volume and LVEF. Results Thirty-three patients received perindopril, 31 received bisoprolol, and 30 received placebo. Baseline demographic, cancer, and cardiovascular profiles were similar between groups. Study drugs were well tolerated with no serious adverse events. After 17 cycles of trastuzumab, indexed left ventricular end diastolic volume increased in patients treated with perindopril (+7 ± 14 mL/m), bisoprolol (+8 mL ± 9 mL/m), and placebo (+4 ± 11 mL/m; P = .36). In secondary analyses, trastuzumab-mediated decline in LVEF was attenuated in bisoprolol-treated patients (-1 ± 5%) relative to the perindopril (-3 ± 4%) and placebo (-5 ± 5%) groups ( P = .001). Perindopril and bisoprolol use were independent predictors of maintained LVEF on multivariable analysis. Conclusion Perindopril and bisoprolol were well tolerated in patients with HER2-positive early breast cancer who received trastuzumab and protected against cancer therapy-related declines in LVEF; however, trastuzumab-mediated left ventricular remodeling-the primary outcome-was not prevented by these pharmacotherapies.

Pulmonary arterial hypertension (PAH) is a progressive vascular disease with a high mortality rate. It is characterized by an occlusive vascular remodeling due to a pro-proliferative and antiapoptotic environment in the wall of resistance pulmonary arteries (PAs). Proliferating cells exhibit a cancer-like metabolic switch where mitochondrial glucose oxidation is suppressed, whereas glycolysis is up-regulated as the major source of adenosine triphosphate production. This multifactorial mitochondrial suppression leads to inhibition of apoptosis and downstream signaling promoting proliferation. We report an increase in pyruvate dehydrogenase kinase (PDK), an inhibitor of the mitochondrial enzyme pyruvate dehydrogenase (PDH, the gatekeeping enzyme of glucose oxidation) in the PAs of human PAH compared to healthy lungs. Treatment of explanted human PAH lungs with the PDK inhibitor dichloroacetate (DCA) ex vivo activated PDH and increased mitochondrial respiration. In a 4-month, open-label study, DCA (3 to 6.25 mg/kg b.i.d.) administered to patients with idiopathic PAH (iPAH) already on approved iPAH therapies led to reduction in mean PA pressure and pulmonary vascular resistance and improvement in functional capacity, but with a range of individual responses. Lack of ex vivo and clinical response was associated with the presence of functional variants of and that predict reduced protein function. Impaired function of these proteins causes PDK-independent mitochondrial suppression and pulmonary hypertension in mice. This first-in-human trial of a mitochondria-targeting drug in iPAH demonstrates that PDK is a druggable target and offers hemodynamic improvement in genetically susceptible patients, paving the way for novel precision medicine approaches in this disease.