November 9, 2010
Classification of Recommendations and Level of Evidence6
*Data available from clinical trials or registries about the usefulness/efficacy in different subpopulations, such as gender, age, history of diabetes, history of prior myocardial infarction, history of heart failure, and prior aspirin use. A recommendation with Level of Evidence B or C does not imply that the recommendation is weak. Many important clinical questions addressed in the guidelines do not lend themselves to clinical trials. Even though randomized trials are not available, there may be a very clear clinical consensus that a particular test or therapy is useful or effective.
In 2003, the ACCF/AHA Task Force on Practice Guidelines developed a list of suggested phrases to use when writing recommendations. All guideline
recommendations have been written in full sentences that express a complete thought, such that a recommendation, even if separated and presented apart from the rest of the document (including headings above sets of recommendations), would still convey the full intent of the recommendation. It is hoped that this will increase readers’ comprehension of the guidelines and will allow queries at the individual recommendation level.
optimize the care of patients with AHFS. With respect to the ED several key points warrant mention: (1) the included procedures and treatments represent a combina- tion that target acute (24 to 48 hours) and subacute (48 hours) stages of AHFS and are not specific to the imme- diate management; (2) although they provide general guidance for treatment, there is limited direction for the care of particular subgroups or phenotypes commonly seen in the ED setting, especially those who have acute hyper- tension with fluid redistribution rather than excess accu- mulation7; (3) potential applicability of critically important acute interventions typically initiated in the ED, such as nonin- vasive ventilatory measures8 and endotracheal intubation, are not discussed; (4) there is no consideration of risk stratification or proposal to provide objective measures for disposition deci- sion making, which has crucial bearing on resource utilization,
in particular, for those patients whose condition may be amena- ble to a short-term, observation stay; and (5) the vast majority of recommendations are considered class I, yet, overall, and in contrast to those presented in the sections for chronic manage- ment, only one was based on level A evidence. This final point is perhaps the most pressing and serves to highlight a critical limitation in the quest to develop data-driven, best-practice approaches to the care of AHFS patients in the ED.
Reasons for the lack of definitive evidence for AHFS management are multifactorial but can be largely attributed to the absence of a cohesive research agenda among respective stakeholders. Whereas registry databases such as ADHERE (Acute Decompensated Heart Failure National Registry)9,10 and OPTIMIZE-HF (Organized Program to Initiate Lifesav- ing Treatment in Hospitalized Patients With Heart Fail- ure)11,12 have compiled important information on initial
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