Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Example Input: Context: Ischemic mitral regurgitation (MR) often persists after restrictive mitral valve annuloplasty, in which case it is associated with worse clinical outcomes. The goal of the present study was to determine whether persistence of MR and/or clinical outcome could be predicted from preoperative analysis of mitral valve configuration.', 'In 51 consecutive patients undergoing restrictive annuloplasty for ischemic MR, posterior leaflet (PL) angle, anterior leaflet angle, coaptation distance, and tenting area were quantified by echocardiography before surgery (6+/-3 days), and MR severity was assessed before and early after surgery (9+/-4 days). Postoperatively, persistence of mild to moderate MR (vena contracta > 3 mm) was observed in 11 (22%) of the patients. The best predictor of postoperative persistence of MR was a PL angle > or = 45 degrees (sensitivity 100%, specificity 97%, positive predictive value 92%, negative predictive value 100%). Patients with persistent MR had markedly lower 3-year event-free survival (26+/-20%) compared with those with nonpersistent MR (75+/-12%, P=0.01). Preoperative presence of a PL angle > or = 45 degrees also was associated with a markedly lower 3-year event-free survival (22+/-17% versus 76+/-12%; P<0.001).
Answer: In patients undergoing restrictive annuloplasty for ischemic MR, persistence of MR and 3-year event-free survival can accurately be predicted by preoperative analysis of mitral valve configuration. Patients with a PL angle > or = 45 degrees (ie, with high PL restriction) should thus be considered poor candidates for this procedure, and concomitant or alternative procedures should be contemplated.
Example Output: Does preoperative posterior leaflet angle accurately predict outcome after restrictive mitral valve annuloplasty for ischemic mitral regurgitation?

Example Input: Context: Preconditioning neurons with noninjurious hypoxia (hypoxic preconditioning, HPC) or the anesthetic isoflurane (APC) induces tolerance of severe ischemic stress. The mechanisms of both types of preconditioning in the hippocampus require moderate increases in intracellular Ca and activation of protein kinase signaling. The authors hypothesized that the expression of signal transduction genes would be similar after APC and HPC.', 'Hippocampal slice cultures prepared from 9-day-old rats were preconditioned with hypoxia (5 min of 95% nitrogen/5% carbon dioxide) or 1% isoflurane in air/5% carbon dioxide for 1 h. A day later, cultures were subjected to 10 min oxygen and glucose deprivation (simulated ischemia). Intracellular Ca, measured in CA1 neurons at the completion of preconditioning, and cell death in CA1, CA3, and dentate regions was assessed 48 h after simulated ischemia. Message RNA encoding 119 signal transduction genes was quantified with rat complimentary DNA microarrays from pre-oxygen-glucose deprivation samples.', 'Both APC and HPC increased intracellular Ca approximately 50 nm and decreased CA1, CA3, and dentate neuron death by about 50% after simulated ischemia. Many signaling genes were increased after preconditioning, with hypoxia increasing more apoptosis/survival genes (8 of 10) than isoflurane (0 of 10). In contrast, isoflurane increased more cell cycle/development/growth genes than did hypoxia (8 of 14 genes, vs. 1 of 14).
Answer: Despite sharing similar upstream signaling and neuroprotective outcomes, the genomic response to APC and HPC is different. Increased expression of antiapoptosis genes after HPC and cell development genes after APC has implications both for neuroprotection and long-term effects of anesthetics.
Example Output: Does expression of signal transduction genes differ after hypoxic or isoflurane preconditioning of rat hippocampal slice cultures?

Example Input: Context: Although early primary repair of tetralogy of Fallot has gained wider acceptance, there is some speculation that repair at a younger age may be associated with increased morbidity and resource utilization.', 'A retrospective review of all consecutive patients undergoing tetralogy of Fallot repair between September 2004 and December 2011 was performed. Primary end points were hospital charges, and surrogates of postoperative hospital resource utilization, including ventilation time, intensive care unit (ICU) stay, and hospital stay. The secondary end point was operative death. Logistic regression analysis was used to determine factors associated with increased postoperative hospital resource utilization.', 'Among 164 patients in the study, there was 1 hospital death (0.6%). After excluding 9 patients who had palliative procedures before their repair, 155 comprised the primary repair group. Multivariate linear regression analysis revealed prematurity (p\xa0= 0.018), a nonelective operation (p < 0.001), and major extracardiac anomalies (p\xa0= 0.003) were independent predictors of increased postoperative hospital charges. Prematurity (p < 0.002), low birth weight (p\xa0= 0.047), and major extracardiac anomalies (p < 0.001) were significant predictors of increased ventilation time. Prematurity (p < 0.001), a nonelective operation (p < 0.001), and low birth weight (p\xa0= 0.048) significantly increased ICU length of stay. A nonelective operation (p\xa0= 0.025) and major extracardiac anomalies (p < 0.001) were predictors of an increased hospital stay. Younger age at repair was not associated with any increase in ventilation time, ICU stay, hospital stay, or with an increase in hospital charges.
Answer: Extracardiac anomalies, prematurity, low birth weight, and nonelective surgical intervention are predictors of increased morbidity and increased hospital resource utilization and impose a significant cost burden to the care of these patients. Early primary repair of tetralogy of Fallot can be safely performed without any increase in morbidity or increased hospital resource utilization.
Example Output:
Does early primary repair of tetralogy of Fallot lead to increased postoperative resource utilization?