Please select the eligibility criteria that correspond to the clinical trial below.
Title: A Randomised Double Blind Study of the Effects of Homocysteine Lowering Therapy on Mortality and Cardiac Events in Patients Undergoing Coronary Angiography
Brief Summary: PURPOSE OF STUDY Observational studies have demonstrated that elevated levels of plasma total homocysteine is a risk factor for cardiovascular disease. The purpose of this trial is to evaluate the clinical effects of homocysteine lowering treatment with B vitamins during 3-5 years follow-up of patients undergoing cardiac catheterization for suspected coronary artery disease (CAD). Special attention will be given to complication rates among patients needing subsequent percutaneous transluminal coronary angioplasty (PCI) or coronary artery by-pass grafting (CABG).

HYPOTHESIS The primary hypothesis of this study is that, among patients with CAD, a daily supplement with B vitamins will reduce the risk for cardiovascular mortality and serious cardiovascular events with at least 20%. The secondary hypothesis of this study is that, among patients with CAD, a daily supplement with B vitamins will reduce the risk for total mortality, coronary events, cerebrovascular events and other cardiovascular events. The hypothesis will be tested for an effect of any of the treatments (folic acid / vitamin B12 or B6), and the effect will be evaluated according to initial total homocysteine levels and B vitamin levels as well as to the change in these levels after 1 and 6 months. The sample size has been calculated to 3088 patients using a two-sided chi-square test with significance 0.05 and at an 80% power level, presumed event rate of 22% over 4 years, and event rate reduction of 20%, adjusted for non-compliance/drop-out of 20%.

STUDY DESIGN This is a controlled, double-blind two-centre trial with 3090 included men and women who underwent coronary angiography at Haukeland University Hospital or Stavanger University Hospital between April 1999 and April 2004. At baseline about 1300 patients underwent PCI and 600 underwent CABG. The patients were randomized into 4 groups in a 2 x 2 factorial design to receive one of the following four treatments: A, folic acid 0.8 mg plus vitamin B12 0.4 mg and vitamin B6 40 mg per day; B, folic acid 0.8 mg plus vitamin B12 0.4 mg per day; C, vitamin B6 40 mg per day; D, placebo. The active drug and the placebo tablets had identical appearance and taste. Treatment was started as soon as the patients were randomized after the coronary angiography procedure. The patients have been undergoing interviews, clinical examination and blood-sampling at baseline, at follow-up after 1 month and 1 year, and at a final study visit. In addition, information on dietary habits was obtained from 2400 patients at baseline. Among 350 patients that have undergone PCI at baseline, a full clinical examination, blood sampling and repeat coronary angiography to assess re-stenosis has been performed about 9 (6-12) months after the PCI procedure. For these patients, angiograms suitable for quantitative coronary angiography (QCA) analysis have been obtained at the baseline and follow-up invasive procedures.

The follow-up was terminated ahead of schedule in October 2005 due to lack of compliance of the participants caused by media reports from the NORVIT study (NCT00266487) on potential increased cancer risk associated by B vitamin supplementation. The patients had then been followed for 1.5 - 5 years.

STUDY END POINTS Primary clinical endpoints during follow-up are all cause death, non-fatal acute myocardial infarction, acute hospitalization for unstable angina and non-fatal thromboembolic stroke (infarction). Secondary endpoints are fatal and non-fatal acute myocardial infarction (including procedure related myocardial infarction), acute hospitalization for angina, stable angina with angiographic verified progression, myocardial revascularization, fatal and non-fatal thromboembolic stroke.


Options:
A: Inclusion Criteria:

* Women and men 55 years of age or over with established CVD and at high risk for future fatal and nonfatal CV events, defined as:

  1. Documented coronary artery disease (CAD);
  2. Documented peripheral vascular disease (PVD);
  3. Documented cerebrovascular disease;
  4. Diabetes with one of the following; additional cardiovascular risk factors:

  i) hypertension (BP \>160 mmHg systolic or \>90 mmHg diastolic or on treatment); ii) total cholesterol \>5.2 mmol/L (\>200 mg/dl); iii) HDL cholesterol \<0.9 mmol/L (3.5 mg/dl); iv) current cigarette smoker; v) any evidence of previous vascular disease
* Provision of informed consent

Exclusion Criteria:

* Current use of any vitamin supplements containing folic acid \>200 micrograms/day. The patients taking such vitamin supplements can be asked if they agree to discontinue these supplements. If they agree, they can be randomized to the study following a one month wash-out period.
* Known previous adverse reactions to folic acid and/or vitamin B6 and/or B12.
* Planned cardiac, peripheral or cerebrovascular revascularization, defined as a decision taken by the patient and his or her physician(s) to perform surgical or percutaneous transluminal revascularization within the next 6 months.
* Hemodynamically significant primary valvular outflow tract obstruction (e.g. mitral stenosis, asymmetric septal hypertrophy, malfunctioning prosthetic valve).
* Constrictive pericarditis.
* Complex congenital heart disease.
* Syncopal episodes presumed to be due to uncontrolled life-threatening arrhythmias (asymptomatic arrhythmias including ventricular tachycardia are not exclusion criteria.
* Uncontrolled hypertension.
* Cor pulmonale.
* Heart transplant recipient.
* Other important non-cardiovascular disease(s) expected to limit compliance and/or impact on patient's ability to complete the study, such as: \*history of alcohol or drug abuse, \*psychiatric disorders, \*senility, \*severe physical disability, \*illnesses including terminal stage of cancer and other major systemic illnesses expected to limit the patient's ability to comply with the study protocol and to complete the study.
B: Inclusion Criteria:

* adults ≥ 18 years able to give informed consent
* patients prepared to undergo long-term follow-up
* patients with and without significant coronary artery disease (CAD) who have undergone coronary angiography just before inclusion

Exclusion Criteria:

* patients who are not available for follow-up
* patients who have previously participated in this study
* patients with known alcohol abuse or serious mental illness
* patients with known active malignant disease
* patients who have undergone coronary angiography for specific reasons, i.e. assessment for cardiac transplantation, kidney donor, heart donor, diagnostic assessment of cardiomyopathy
C: Inclusion Criteria:

1. One neoplastic polyp removed within three months of study entry or within 16 months of study entry if over 1 cm in size or if subject has had a lifetime history of at least two polyps, with the entire large bowel seen by colonoscopy to be free of further polyps within 3 months of entry.
2. An ability and willingness to follow the study protocol, as indicated by the subject's giving informed consent to participate.
3. Good general health, with no severely debilitating diseases or active malignancy that might compromise the patient's ability to complete the study.
4. Anticipated colonoscopic follow-up three years after the qualifying colonoscopy.
5. Age between 21 and 80 years at the time of the intake colonoscopy.
6. For women of childbearing potential, agreement to use effective birth control for the duration of the study.
7. Intent not to take aspirin or aspirin-containing products, NSAIDs or folic acid for the length of the study unless required by a physician.
8. Not randomized previously or currently in a chemoprevention trial, except for the: "Nutritional Prevention of Large Bowel Polyps" Study (Polyps Prevention Study I); and brief participation in the "VA Cooperative Study" with no continuing involvement.

Exclusion Criteria:

1. Invasive carcinoma in any colonic polyp removed.
2. Familial colonic polyposis syndromes.
3. Ulcerative colitis or Crohn's disease.
4. Malabsorption syndrome (e.g. pancreatic insufficiency).
5. Large bowel resection for any reason.
6. Diagnosed narcotic or alcohol dependence
7. Contraindication to aspirin use, including:

   1. documented peptic ulcer disease in the past 20 years
   2. aspirin sensitivity
   3. bleeding diathesis, including hemorrhagic stroke
8. Likelihood of NSAID use

   1. recurring arthritis or other musculo-skeletal problems
   2. frequent NSAID use in 5 years preceding
   3. history of stroke or TIAs
   4. history of angina or myocardial infarction
   5. desire to take aspirin for the prevention of cardiovascular disease
9. Required or contraindicated folic acid use pernicious anemia or folic acid deficiency
10. Pregnancy or lactation.
D: Inclusion Criteria:

Patients will be screened by their plasma homocysteine concentration. They must have a level of at least 15 mM/L to be enrolled in the study.

Patients will be excluded by any of the following criteria: age less than 21 years, expected life span less than 6 months, pregnancy, metastatic cancer, end-stage liver disease, treatment with methotrexate, other anti-folate medication or anticonvulsants, unreliable or likely noncompliant, participation in another long-term trial, or unwilling or unable to give informed consent.

Exclusion Criteria:

Answer: B