Fibrinolytic Agents in Thromboembolic Diseases: Historical Perspectives and Approved Indications.

Fibrinolytic agents catalyze the conversion of the inactive proenzyme plasminogen into the active protease plasmin, degrading fibrin within the thrombus and recanalizing occluded vessels. The history of these medications dates to the discovery of the first fibrinolytic compound, streptokinase, from bacterial cultures in 1933. Over time, researchers identified two other plasminogen activators in human samples, namely urokinase and tissue plasminogen activator (tPA). Subsequently, tPA was cloned using recombinant DNA methods to produce alteplase. Several additional derivatives of tPA, such as tenecteplase and reteplase, were developed to extend the plasma half-life of tPA. Over the past decades, fibrinolytic medications have been widely used to manage patients with venous and arterial thromboembolic events. Currently, alteplase is approved by the U.S. Food and Drug Administration (FDA) for use in patients with pulmonary embolism with hemodynamic compromise, ST-segment elevation myocardial infarction (STEMI), acute ischemic stroke, and central venous access device occlusion. Reteplase and tenecteplase have also received FDA approval for treating patients with STEMI. This review provides an overview of the historical background related to fibrinolytic agents and briefly summarizes their approved indications across various thromboembolic diseases.

Can perioperative electroencephalogram and adverse hemodynamic events predict neurodevelopmental outcomes in infants with congenital heart disease?

OBJECTIVE: The study objective was to characterize preoperative and postoperative continuous electroencephalogram metrics and hemodynamic adverse events as predictors of neurodevelopment in congenital heart disease infants undergoing cardiac surgery. METHODS: From 2010 to 2021, 320 infants underwent congenital heart disease surgery at our institution, of whom 217 had perioperative continuous electroencephalogram monitoring and were included in our study. Neurodevelopment was assessed in 76 patients by the Bayley Scales of Infant and Toddler Development, 3rd edition, consisting of cognitive, communication, and motor scaled scores. Patient and procedural factors, including hemodynamic adverse events, were included by means of the likelihood of covariate selection in our predictive model. Median (25th, 75th percentile) follow-up was 1.03 (0.09, 3.44) years with 3 (1, 6) Bayley Scales of Infant and Toddler Development, 3rd Edition evaluations per patient. RESULTS: Median age at index surgery was 7 (4, 23) days, and 81 (37%) were female. Epileptiform discharges, encephalopathy, and abnormality (lethargy and coma) were more prevalent on postoperative continuous electroencephalograms, compared with preoperative continuous electroencephalograms (P < .005). In 76 patients with Bayley Scales of Infant and Toddler Development, 3rd edition evaluations, patients with diffuse abnormality (P = .009), waveform discontinuity (P = .007), and lack of continuity (P = .037) on preoperative continuous electroencephalogram had lower cognitive scores. Patients with synchrony (P < .005) on preoperative and waveform continuity (P = .009) on postoperative continuous electroencephalogram had higher fine motor scores. Patients with postoperative adverse events had lower cognitive (P < .005) and gross motor scores (P < .005). CONCLUSIONS: Phenotypic patterns of perioperative continuous electroencephalogram metrics are associated with late-term neurologic injury in infants with congenital heart disease requiring surgery. Continuous electroencephalogram metrics can be integrated with hemodynamic adverse events in a predictive algorithm for neurologic impairment.

Insulin Therapy is Associated With Increased Myocardial Interstitial Fibrosis and Cardiomyocyte Apoptosis in a Rodent Model of Experimental Diabetes.

The incidence of diabetes mellitus (DM) is rising. DM is a risk factor for developing left ventricular (LV) dysfunction and adverse cardiovascular outcomes. Insulin, commonly used to treat DM, is associated with further worsening of such outcomes. Yet, the pathophysiology of the adverse properties of insulin on the heart remains poorly defined. Therefore, the objective of this study was to determine the biological effects of insulin on the heart in DM, which we tested in vivo in a diabetic rat model and in vitro on human cardiomyocytes and fibroblasts. Male Wistar rats were divided into 3 groups: controls (n = 17), untreated diabetics (UDM, n = 15), and insulin-treated diabetics (IDM, n = 9). Diabetes was induced with Streptozotocin. Insulin pumps in IDM and saline pumps in UDM and controls were implanted for 4 weeks before tissue collection. Separately, cultures of human cardiomyocytes (AC16) and human cardiac fibroblasts (HCF) were treated with insulin to assess apoptosis and fibrosis, respectively. In rats, insulin partially rescued the DM-associated weight loss while fully restoring euglycemia. However, IDM had 2 × the rate of LV fibrosis (p < 0.0001) compared to UDM, and triple the rate of cardiomyocyte apoptosis compared to controls (p < 0.05). Similarly, in vitro, insulin triggered apoptosis in a dose-dependent fashion in AC16 cells, and it increased fibrosis and upregulated SMAD2 in HCF to levels comparable to Transforming Growth Factor Beta 1. Therefore, we conclude that insulin therapy is associated with increased cardiomyocyte apoptosis and myocardial interstitial fibrosis. Longer studies are needed to explore the long-term effects of insulin on cardiac structure and function.