Bara C, Zhang R, Haverich A De Vega annuloplasty for tricuspid valve repair in posttraumatic tricuspid insufficiency--16 years experience. Int J Cardiol. 2008 Jun 6;126(3):e61-2. Epub 2007 Mar 29.
Hassan HT, Veit A, Maurer HR Synergistic interactions between differentiation-inducing agents in inhibiting the proliferation of HL-60 human myeloid leukaemia cells in clonogenic micro assays. J Cancer Res Clin Oncol. 1991;117(3):227-31.
Kaplon RJ, Pham SM, Salerno TA Beating-heart valvular surgery: a possible alternative for patients with severely compromised ventricular function. J Card Surg. 2002 Mar-Apr;17(2):170-2.
Karolak W, Hirsch G, Buth K, Légaré JF Medium-term outcomes of coronary artery bypass graft surgery on pump versus off pump: results from a randomized controlled trial. Am Heart J. 2007 Apr;153(4):689-95.
Salhiyyah K, Taggart D Beating-heart valve surgery: A systematic review. Asian Cardiovasc Thorac Ann. 2009 Dec;17(6):650-8. doi: 10.1177/0218492309348942. Review.
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.
