Blauwet, Lori

AbstractObjectiveEndomyocardial biopsy (EMB) is a useful diagnostic tool though the yield may be limited in many myocardial diseases. Data on the diagnostic yield and prognostic significance of EMB guided by abnormal electrograms (EGM‐Bx) in suspected cardiac sarcoidosis (CS) are scarce.MethodsSeventy‐nine patients (mean age: 56 ± 12 years; 61% men) with suspected CS based on clinical and imaging features underwent right or left ventricular EGM‐Bx guided by electroanatomic mapping. Tissue samples were obtained from sites with abnormal EGMs and/or abnormal cardiac imaging. The diagnostic yield of EGM‐Bx was evaluated in reference to histopathologic analysis. Left ventricular assist device (LVAD) and transplantation‐free survival were compared between patients with positive and negative EGM‐Bx for CS.ResultsA total of 254 samples were obtained from abnormal EGM sites, and 126 samples from normal EGM sites guided by pre‐procedure imaging findings. Abnormal histopathology was noted in 65 (26%) and 10 (8%) samples from abnormal and normal EGM sites, respectively. Histopathology confirmed CS in 16 (20%) patients, while an alternative tissue diagnosis emerged in 10 (13%) patients. Abnormal EGMs at the biopsy site had sensitivity 89% and specificity 33% for a histopathologic diagnosis of CS. LVAD and transplantation‐free survival were not significantly associated with the EGM‐Bx result (log‐rank p = .91).ConclusionIn patients with suspected CS, abnormal EGM‐Bx has high sensitivity and low specificity for establishing a definite CS diagnosis. Consideration of substrate abnormalities apparent on preprocedural imaging as an adjunct for selection of biopsy sites may further improve EGM‐Bx yield.

AbstractPulmonary hypertension (PH) is characterized by elevated pulmonary arterial pressure, which leads to right ventricular (RV) hypertrophy and failure. The pathophysiological mechanisms of PH remain unclear but oxidative stress is believed to contribute to RV dysfunction. Melatonin is a powerful antioxidant and is cardioprotective against ischemia–reperfusion injury and hypertension. Therefore, we hypothesized that a chronic treatment with melatonin, given as a curative or preventive therapy, may confer cardiovascular benefits in PH. PH was induced in Long Evans rats (n ≥ 6 per group), with a single subcutaneous injection of monocrotaline (MCT, 80 mg/kg). Melatonin was given daily in the drinking water, with the treatment starting either on the day of the injection of MCT (dose testing: melatonin 75 ng/L and 6 mg/kg), 14 days after the injection of MCT (curative treatment: 6 mg/kg), or 5 days before the injection (preventive treatment: 6 mg/kg). The development of PH was assessed by measuring RV hypertrophy, RV function, cardiac interstitial fibrosis, and plasma oxidative stress. Compared with controls, MCT‐treated rats displayed RV hypertrophy and dysfunction, increased interstitial fibrosis, and elevated plasma oxidative stress. A chronic melatonin treatment (75 ng/L or 6 mg/kg) reduced RV hypertrophy, improved RV function and reduced plasma oxidative stress. Curative and preventive treatment improved RV functional and plasma oxidative stress parameters and reduced cardiac interstitial fibrosis. Our data demonstrate that melatonin confers cardioprotection in this model of PH. As melatonin is an inexpensive and safe drug, we propose that clinical investigation of the effects of melatonin on RV function in patients with PH should be considered.

Introduction Pulmonary hypertension (PH) is a devastating, progressive disease with increasingly debilitating symptoms and usually shortened overall life expectancy due to a narrowing of the pulmonary vasculature and consecutive right heart failure. Little is known about PH in Africa, but limited reports suggest that PH is more prevalent in Africa compared with developed countries due to the high prevalence of risk factors in the region. Methods and analysis A multinational multicentre registry-type cohort study was established and tailored to resource-constraint settings to describe disease presentation, disease severity and aetiologies of PH, comorbidities, diagnostic and therapeutic management, and the natural course of PH in Africa. PH will be diagnosed by specialist cardiologists using echocardiography (right ventricular systolic pressure >35 mm Hg, absence of pulmonary stenosis and acute right heart failure), usually accompanied by shortness of breath, fatigue, peripheral oedema and other cardiovascular symptoms, ECG and chest X-ray changes in keeping with PH as per guidelines (European Society of Cardiology and European Respiratory Society (ESC/ERS) guidelines). Additional investigations such as a CT scan, a ventilation/perfusion scan or right heart catheterisation will be performed at the discretion of the treating physician. Functional tests include a 6 min walk test and the Karnofsky Performance Score. The WHO classification system for PH will be applied to describe the different aetiologies of PH. Several substudies have been implemented within the registry to investigate specific types of PH and their outcome at up to 24 months. Data will be analysed by an independent institution following a data analyse plan. Ethics and dissemination All local ethics committees of the participating centres approved the protocol. The data will be disseminated through peer-reviewed journals at national and international conferences and public events at local care providers.