Burgess DC, Kilborn MJ, Keech AC Interventions for prevention of post-operative atrial fibrillation and its complications after cardiac surgery: a meta-analysis. Eur Heart J. 2006 Dec;27(23):2846-57. doi: 10.1093/eurheartj/ehl272. Epub 2006 Oct 2.
Crystal E, Connolly SJ, Sleik K, Ginger TJ, Yusuf S Interventions on prevention of postoperative atrial fibrillation in patients undergoing heart surgery: a meta-analysis. Circulation. 2002 Jul 2;106(1):75-80. doi: 10.1161/01.cir.0000021113.44111.3e.
Harling L, Rasoli S, Vecht JA, Ashrafian H, Kourliouros A, Athanasiou T Do antioxidant vitamins have an anti-arrhythmic effect following cardiac surgery? A meta-analysis of randomised controlled trials. Heart. 2011 Oct;97(20):1636-42. doi: 10.1136/heartjnl-2011-300245. Epub 2011 Aug 23.
Herring N, Lokale MN, Danson EJ, Heaton DA, Paterson DJ Neuropeptide Y reduces acetylcholine release and vagal bradycardia via a Y2 receptor-mediated, protein kinase C-dependent pathway. J Mol Cell Cardiol. 2008 Mar;44(3):477-85. doi: 10.1016/j.yjmcc.2007.10.001. Epub 2007 Oct 11.
Maisel WH, Rawn JD, Stevenson WG Atrial fibrillation after cardiac surgery. Ann Intern Med. 2001 Dec 18;135(12):1061-73. doi: 10.7326/0003-4819-135-12-200112180-00010.
Interventional studies are often prospective and are specifically tailored to evaluate direct impacts of treatment or preventive measures on disease.
Observational studies are often retrospective and are used to assess potential causation in exposure-outcome relationships and therefore influence preventive methods.
Expanded access is a means by which manufacturers make investigational new drugs available, under certain circumstances, to treat a patient(s) with a serious disease or condition who cannot participate in a controlled clinical trial.
Clinical trials are conducted in a series of steps, called phases - each phase is designed to answer a separate research question.
Phase 1: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase 2: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase 3: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase 4: Studies are done after the drug or treatment has been marketed to gather information on the drug's effect in various populations and any side effects associated with long-term use.