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: To investigate the incidence of acute kidney injury after cardiac surgery and its association with mortality in a patient population receiving ibuprofen and gentamicin perioperatively.', 'Retrospective study with Cox regression analysis to control for possible preoperative, intraoperative and postoperative confounders.', 'University hospital-based single-center study.', 'All patients who underwent coronary artery bypass grafting ± valve surgery during 2012.', 'None.', 'Acute surgery within 24 hours of coronary angiography, previous nephrectomy, preoperative sCr >2.26 mg/dL and selective cerebral perfusion during cardiopulmonary bypass were used as exclusion criteria. Acute kidney injury was defined, using the Acute Kidney Injury Network (AKIN) criteria. Six hundred eight patients were included in the study. Mean age was 68.2 ± 9.7 years, and 81% were males. Acute kidney injury was seen in 28.1% of the patients. Overall mortality at one year was 7% and 3% in the no-AKI group. At one year, mortality was 15% in patients with AKIN stage 1 and AKIN stage 2 compared to 70% in AKIN stage 3. A hazard ratio of 2.34 (95% CI: 1.21-4.51, p = 0.011) and 5.62 (95% CI: 2.42-13.06), p<0.0001) were found for AKIN stage 1 and 2/3 combined, respectively.\Question: Is acute kidney injury independently associated with higher mortality after cardiac surgery?

Answer: More than 28% of the patients undergoing elective or subacute cardiac surgery developed AKI in this contemporary cohort. Furthermore, acute kidney injury was an independent predictor of increased mortality irrespective of the perioperative risk factors.


Question: Context: rs1333049 polymorphism on chromosome 9p21 has been shown to affect susceptibility to coronary artery disease (CAD) in Caucasians. This study examined the association of rs1333049 with myocardial infarction (MI), angiographic severity of CAD and clinical outcome after a first acute MI in Han Chinese.', 'rs1333049 polymorphism was genotyped in 520 patients with a first acute MI and in 560 controls. The number of angiographically documented diseased coronary arteries (luminal diameter stenosis > or = 50%), echocardiographic left ventricular ejection fraction (LVEF), and major adverse cardiac events (MACE) during follow-up (mean, 29+/-15 months) were recorded.', 'Patients with MI had higher frequencies of the CC genotype (30.0% vs. 20.7%) or C allele (55.5% vs. 46.2%) compared with controls (all p<0.01). rs1333049 polymorphism was strongly associated with MI [odds ratio (OR) 1.48, 95% confidence interval (CI) 1.22-1.79] after adjusting for traditional risk factors. Although longer hospitalization stay was observed in patients with the rs1333049-C allele, this polymorphism was not related to angiographic severity of CAD, LVEF, and occurrence of MACE after MI.\Question: Is chromosome 9p21 polymorphism associated with myocardial infarction but not with clinical outcome in Han Chinese?

Answer: This study demonstrates an association of rs1333049 polymorphism locus on chromosome 9p21 with risk for MI, but not with post-MI prognosis in Han Chinese.


Question: Context: Hospital readmissions after surgical operations are considered serious complications and have an impact on health care-associated costs. The Centers for Medicare and Medicaid Services strongly encourage identification and ramification of factors associated with hospital readmissions after operations. Despite advances in endovascular surgery, lower extremity arterial bypass remains the "gold standard" treatment for severe, symptomatic peripheral arterial disease. The purpose of this study was to retrospectively review the factors associated with hospital readmission after lower extremity bypass surgery.', 'The 2013 lower extremity revascularization-targeted American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database and generalized 2013 general and vascular surgery NSQIP Participant Use Data File were used for this study. Patient, diagnosis, and procedure characteristics of patients undergoing lower extremity bypass surgery were assessed. Multivariate logistic regression analysis was used to determine independent risk factors for hospital readmission within 30 days after surgery.', 'A total of 2646 patients (65% male, 35% female) were identified in the NSQIP database who underwent lower extremity open revascularization during the year 2013. Indications for operations included tissue loss (39%), rest pain (32%), and severe claudication (25%). Preoperative ankle-brachial indices were 0.4 to 0.9 (32%) and <0.4 (16.5%). A total of 425 patients (16%) were readmitted within 30 days of index operation. Risk factors associated with readmission included wound complication (odds ratio [OR], 8.54; 95% confidence interval [CI], 6.68-10.92; P < .001), need for reoperation (OR, 5.95; 95% CI, 4.45-7.97; P < .001), postoperative myocardial infarction (OR, 2.19; 95% CI, 1.25-3.83; P = .006), wound dehiscence (OR, 8.45; 95% CI, 4.54-15.71; P < .001), organ or space surgical site infection (OR, 7.62; 95% CI, 2.89-20.14; P < .001), postoperative pneumonia (OR, 2.66; 95% CI, 1.28-5.52; P = .009), progressive renal insufficiency (OR, 4.12; 95% CI, 1.52-11.11; P = .005), superficial surgical site infection (OR, 7.37; 95% CI, 5.31-10.23; P < .001), urinary tract infection (OR, 2.67; 95% CI, 1.42-5.01; P = .002), and deep wound infection (OR, 14.0; 95% CI, 7.62-24.80; P < .001).\Question: Is unplanned return to operating room after lower extremity arterial bypass an independent predictor for hospital readmission?

Answer:
Readmission after lower extremity bypass surgery is a serious complication. Various factors put a patient at high risk for readmission. Return to the operating room, wound infection, amputation, deep venous thrombosis, and major reintervention on bypass are independent risk factors for hospital readmission. Return to the operating room is associated with a 5.95-fold increase in hospital readmission.