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.
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Question: Context: Data on combined coronary artery bypass grafting (CABG) and restrictive annuloplasty in patients with ischemic cardiomyopathy are scarce, and the effect on reverse left ventricular (LV) remodeling is unknown.', '51 patients with ischemic LV dysfunction (LV ejection fraction 31+/-8%) and severe mitral regurgitation (grade 3 to 4+) underwent CABG and restrictive annuloplasty with stringent downsizing of the mitral annulus (by 2 sizes, Physio-ring, mean size 28+/-2). Serial transthoracic echocardiographic studies were performed (before surgery and within 3 months and 1.5 years after surgery) to assess mitral regurgitation, transmitral gradient, leaflet coaptation, and left atrial and LV reverse remodeling. Clinical follow-up (New York Heart Association [NYHA] class, survival, events) was assessed at 2-year follow-up. Early operative mortality was 5.6%; at 2-year follow-up, all patients were free of endocarditis and thromboembolism, and 1 needed re-operation for recurrent mitral regurgitation; 2-year survival was 84%. NYHA class improved from 3.4+/-0.8 to 1.3+/-0.4 (P<0.01), with all patients in class I/II. Intraoperative transesophageal echo showed minimal (grade 1+) mitral regurgitation in 8 patients and none in 43, without stenosis. Leaflet coaptation was 0.8+/-0.2 cm. These values remained unchanged; all patients had no or minimal (grade 1+) mitral regurgitation at 2-year follow-up. LV end-systolic and end-diastolic dimensions decreased from 51+/-10 to 43+/-12 mm (P<0.001) and from 64+/-8 to 58+/-11 mm (P<0.001). Left atrial dimension decreased from 53+/-8 to 47+/-7 mm (P<0.001).\Question: Does restrictive annuloplasty and coronary revascularization in ischemic mitral regurgitation result in reverse left ventricular remodeling?

Answer: Excellent results of combined restrictive annuloplasty and CABG were obtained. Residual mitral regurgitation was absent/minimal at 2-year follow-up, associated with a significant reduction in left atrial dimension and LV reverse remodeling.


Question: Context: To compare rates of undertriage and overtriage of six ambulance dispatch protocols for the presenting complaint of nontraumatic abdominal pain, and to identify the optimal protocol.', 'Retrospective prehospital and emergency department chart review to classify patients\' conditions as "emergency" or "nonemergency." Utility analysis was used to identify the preferred protocol and monetary cost-effectiveness analysis to identify the least expensive protocol.', 'County emergency medical services (EMS) system with five receiving hospitals serving a mainly urban population of approximately 350,000.', 'Records of 902 patients who called 911 for nontraumatic abdominal pain were reviewed; patients not transported were excluded. Twenty-seven county EMS medical directors completed questionnaires.', 'Six ambulance dispatch protocols for nontraumatic abdominal pain were developed: indiscriminate-dispatch, four selective protocols, and no-dispatch. A dichotomous classification system was derived prospectively from the prehospital and medical records of patients who had activated the EMS system before the study period to define "emergency" and "nonemergency" conditions associated with nontraumatic abdominal pain. Emergency criteria identified patients with conditions requiring medical treatment within 1 hour. Reviewers determined, for each patient, whether an ambulance would have been dispatched by each of the protocols. Undertriage and overtriage rates were calculated for each protocol. County EMS medical directors assigned utility values to four potential outcomes of ambulance dispatch by the direct scaling method. The outcomes comprised correct and incorrect decisions to dispatch ambulances to patients with and without emergencies. The protocols were compared by decision analysis. A cost analysis was also performed, using an estimated marginal cost per transport of $302. Sensitivity analysis demonstrated the effect of varying the cost of an undertriage error and the cost per response. Of the 788 patients included in the study, 7.8% had conditions defined as emergencies. The four selective ambulance dispatch protocols had overtriage rates ranging from 10% to 51% and undertriage rates of 4% to 7%. None of the protocols was proven superior on the basis of the medical directors\' assignment of utility values. The marginal cost of dispatching advanced life support ambulances to all patients with this complaint was $3,838 per emergency.\Question: Do comparison of ambulance dispatch protocols for nontraumatic abdominal pain?

Answer: The majority of patients with nontraumatic abdominal pain who requested ambulance transport during the study period did not have conditions that were classified as emergencies. In the study model, if an undertriage error costs more than $3,674, indiscriminate ambulance dispatch is the least expensive protocol, and if an undertriage error costs less than $3,674, no ambulance dispatch is the least expensive strategy.


Question: Context: To clarify the lowering effect of metabolic syndrome (MetS) on serum prostate-specific antigen (PSA) levels in a Chinese screened population.', 'A total of 45 540 ostensibly healthy men aged 55-69 years who underwent routine health check-ups at Beijing Shijitan Hospital between 2008 and 2015 were included in the study. All the men underwent detailed clinical evaluations. PSA mass density was calculated (serum PSA level × plasma volume ÷ prostate volume) for simultaneously adjusting plasma volume and prostate volume. According to the modified National Cholesterol Education Programme-Adult Treatment Panel (NCEP-ATP) III criteria, patients were dichotomized by the presence of MetS, and differences in PSA density and PSA mass density were compared between groups. Linear regression analysis was used to evaluate the effect of MetS on serum PSA levels.', 'When larger prostate volume in men with MetS was adjusted for, both PSA density and PSA mass density in men with MetS were significantly lower than in men without MetS, and the estimated difference in mean serum PSA level between men with and without MetS was greater than that before adjusting for prostate volume. In the multivariate regression model, the presence of MetS was independently associated with an 11.3% decline in serum PSA levels compared with the absence of MetS. In addition, increasing number of positive MetS components was significantly and linearly associated with decline in serum PSA levels.\Question: Is actual lowering effect of metabolic syndrome on serum prostate-specific antigen levels partly concealed by enlarged prostate : results from a large-scale population-based study?

Answer:
The actual lowering effect of MetS on serum PSA levels was partly concealed by the enlarged prostate in men with MetS, and the presence of MetS was independently associated with lower serum PSA levels. Urologists need to be aware of the effect of MetS on serum PSA levels and should discuss this subject with their patients.