In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Ex Input:
Context: Mechanical support leads to an increased risk of both bleeding and thrombotic events, but little is known about the risk of device support in patients with a baseline predisposition to these events. The aim of this study was to examine outcomes among patients with baseline hematologic conditions who underwent continuous-flow LVAD implantation (CF-LVAD).', 'We retrospectively reviewed records of 286 patients who underwent CF-LVAD implantation at the Columbia University Medical Center between April 2008 and December 2013. Patients diagnosed with the following hematologic conditions were enrolled: idiopathic thrombocytopenic purpura (ITP); Factor V Leiden; elevated Factor VIII; heparin-induced thrombocytopenia (HIT); or undefined hypercoagulable state.', 'Of the 286 CF-LVAD patients implanted during the study period, 12 were considered to have a significant hematologic condition predisposing them to either bleeding or thrombotic events. The study included 5 patients with ITP, 1 with Factor V Leiden, 1 with elevated Factor VIII, 2 with HIT and 3 patients with undefined hypercoagulable state. Patients were supported for a total of 168.46 months, with a median of 10.76 months (IQR 4.78 to 21.36 months). There was a high frequency of thrombotic (0.57 event per patient-year), neurologic (0.36 event per patient-year) and bleeding (0.64 event per patient-year). Actuarial survival rates at 6 and 12 months were 81.8%, but fell to 49% at 2 years.\Question: Do prior hematologic conditions carry a high morbidity and mortality in patients supported with continuous-flow left ventricular assist devices?

Ex Output:
Patients with a history of prior hematologic conditions are at high risk for bleeding, thrombotic and neurologic events during device support, leading to early mortality. This case series questions the benefit of CF-LVAD in these patients and the appropriate management with regard to anti-coagulation. Further studies on the outcomes of these patients are warranted.


Ex Input:
Context: T-wave alternans (TWA) is an indicator of vulnerability to ventricular arrhythmias and is useful for predicting sudden cardiac death (SCD) in patients with various structural heart diseases. We evaluated whether high levels of time-domain TWA on ambulatory ECG (AECG) are associated with a history of ventricular fibrillation (VF) in Brugada syndrome (BrS) patients.', 'We examined the associations among VF history, family history of SCD, spontaneous type 1 electrocardiogram (ECG), late potentials, VF induction by programmed electrical stimulation, and TWA in 45 BrS patients (44 males; mean age, 45 ± 15 years). TWA analyzed from 24-h AECG recordings using the modified moving average method was positive in 13 of 43 patients (30%). Patients with a history of VF had a significantly higher incidence of a positive TWA test (82% vs. 13%; P < 0.001) and spontaneous type 1 ECG (92% vs. 38%; P = 0.007) than those without VF history. Multivariate analysis indicated that positive TWA (OR 7.217; 95% CI 2.503-35.504; P = 0.002) and spontaneous type 1 ECG (OR 5.530; 95% CI 1.651-34.337; P = 0.020) were closely associated with VF history. Spontaneous type 1 ECG had high sensitivity (92%) but low specificity (63%). Positive TWA was a reliable marker with high sensitivity and specificity (82% and 88%, respectively).\Question: Is time-domain T-wave alternans strongly associated with a history of ventricular fibrillation in patients with Brugada syndrome?

Ex Output:
Elevated time-domain TWA on AECG confirms arrhythmia risk in symptomatic BrS patients without the need for provocative stimuli.


Ex Input:
Context: Progress in the management of patients with medically intractable epilepsy is impeded because we do not fully understand why pharmacoresistance happens and how it can be predicted. The presence of multiple seizures prior to medical treatment has been suggested as a potential predictor of poor outcome. In the present study, we used an animal model of temporal lobe epilepsy to investigate whether pharmacoresistant rats differ in seizure frequency from pharmacoresponsive animals.', 'Epilepsy with spontaneous recurrent seizures (SRS) was induced by status epilepticus. Frequency of SRS was determined by video/EEG (electroencephalography) monitoring in a total of 33 epileptic rats before onset of treatment with phenobarbital (PB).', 'Thirteen (39%) rats did not respond to treatment with PB. Before treatment with PB, average seizure frequency in PB nonresponders was significantly higher than seizure frequency in responders, which, however, was due to six nonresponders that exhibited > 3 seizures per day. Such high seizure frequency was not observed in responders, demonstrating that high seizure frequency predicts pharmacoresistance in this model, but does not occur in all nonresponders.\Question: Is high seizure frequency prior to antiepileptic treatment a predictor of pharmacoresistant epilepsy in a rat model of temporal lobe epilepsy?

Ex Output:

The data from this study are in line with clinical experience that the frequency of seizures in the early phase of epilepsy is a dominant risk factor that predicts refractoriness. However, resistance to treatment also occurred in rats that did not differ in seizure frequency from responders, indicating that disease severity alone is not sufficient to explain antiepileptic drug (AED) resistance. These data provide further evidence that epilepsy models are useful in the search for predictors and mechanisms of pharmacoresistance.