Review: short duration of bed rest was as safe as long duration after acute uncomplicated myocardial infarction
Q In patients with acute uncomplicated myocardial infarction (MI), does the duration of bed rest affect outcomes?
Cochrane Central Register of Controlled Trials, Medline, EMBASE/Excerpta Medica, PASCAL BioMed, PsycINFO, and BIOSIS Previews (to August 2005); reference lists; and experts.
Study selection and assessment:
randomised controlled trials (RCTs) and quasi-RCTs that compared short (1–14 d) and long (5–28 d) durations of bed rest after acute uncomplicated MI. 15 RCTs (n = 2958; median mean age 60 y; median 81% men) published between 1954 and 1989 met the selection criteria. Quality of individual trials was assessed based on randomisation method, blinded assessment of outcomes, and intention-to-treat analysis.
all-cause mortality, death from cardiac causes, reinfarction, arrhythmia, and thromboembolic complications.
Short durations of bed rest did not differ from long durations of bed rest for all-cause mortality, cardiac mortality, reinfarction, arrhythmia, or thromboembolic complications (table).
In patients with acute uncomplicated myocardial infarction, short durations of bed rest did not adversely affect outcomes compared with longer durations.
- Irene Travale, RN, MScN, ACNP/CNS
The meta-analysis by Herkner et al highlights the lack of evidence underpinning the recommendations of various cardiology associations that bed rest for patients with uncomplicated MI should not exceed 12–24 hours.1,2 As well as increasing the risks of venous thromboembolism, pneumonia, skin ulcers, and deconditioning, bed rest after MI decreases maximal oxygen uptake and increases sympathetic activity and maximal heart rate. These effects may increase cardiac workload, extend the infarction, or cause potentially lethal arrhythmias.3
13 of the 15 RCTs were published before 1983, the same decade in which the advent of aggressive interventional cardiology resulted in a two-thirds decrease in MI mortality.4 The poor methodological quality of the included trials also raises questions about the validity of their findings and conclusions: only 1 study reported blinding of the outcome assessor and intention-to-treat analysis, and the possibility of publication bias could not be excluded. Clinical heterogeneity within the 2 groups was considerable, with patients in the short duration group on bed rest for as little as 24 hours and as long as 14 days, and those in the long duration group kept in bed for 5–28 days. Both study groups included some patients who were allowed to use commodes as soon as possible, so they were not strictly on “bed rest.” Therefore, the findings need to be considered cautiously and in the context of contemporary interventions and treatment goals for patients with uncomplicated MI.
The treatment goal of thrombolytic agents, angioplasty, or stenting is to re-establish and maintain Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow in the occluded coronary artery. Patients achieving this goal without complications may be discharged from hospital at 4 days after infarction.2 Consequently, the meta-analysis by Herkner et al, which suggests that short duration of bed rest (median 6 d) is as safe as long duration (median 13 d), may not be relevant to nurses in all units.
The authors appropriately noted that the current recommendation of no more than 12–24 hours of bed rest in this patient population is not supported by RCTs. However, the recommendations did include specific patient criteria that reflect an uncomplicated clinical course.1 This review highlights the need to develop evidence-based clinical criteria for bed rest and to evaluate these using RCTs before any definitive statements on safe timelines for bed rest in uncomplicated MI can be made.
For correspondence: Professor H Herkner, University of Vienna, Vienna, Austria.
Source of funding: no external funding.