Although lumbar imaging for acute low back pain is generally only indicated if there is concern for serious underlying disease (e.g. infection, malignancy), many physicians continue to order imaging studies on a routine basis for patients presenting with acute low back pain.  In support of previous research, a recent systematic review of 6 randomized trials evaluating immediate radiography, MRI or CT in 1,804 patients (without markers for serious underlying disease) showed no benefit for this practice in either short-term (< 3 months) or long-term (6-12 months) follow-up (level 2 [mid-level] evidence).  There were no significant differences between immediate imaging and standard care in pain, function, quality of life, mental health or overall improvement (Lancet 2009 Feb 7;373(9662):463).  For more information, see the Acute low back pain topic in DynaMed.

Rhythm control strategies for atrial fibrillation have not been shown to be more beneficial in most patients compared to rate control. Most patients with rhythm control will have some amount of intermittent atrial fibrillation that will necessitate anticoagulation. The principal benefit is for patients who cannot tolerate the symptoms of atrial fibrillation.

A recent randomized trial compared dronedarone (400 mg twice daily) to placebo in 4,628 patients (mean age 72 years) with paroxysmal or persistent atrial fibrillation or flutter.  All patients had at least 1 additional risk factor, including age ≥ 70 years, arterial hypertension, diabetes, previous stroke, TIA or systemic embolism, left atrial diameter ≥ 50 mm or left ventricular ejection fraction ≤ 40%.  At mean follow-up of 21 months, dronedarone was associated with lower rates of hospitalization for any cardiovascular event (29.3% vs. 36.9%, p < 0.001, NNT 14) or for atrial fibrillation (14.6% vs. 21.9%, p < 0.001, NNT 14) (level 2 [mid-level] evidence).  Cardiovascular mortality was also lower for the dronedarone group (2.7% vs. 3.9%, p = 0.03, NNT 84), but there was not a significant difference in all-cause mortality (5% vs. 6%).  About 30% of patients in each group discontinued treatment due to adverse events.  Dronedarone was associated with significantly more bradycardia, QT-interval prolongation, gastrointestinal events and skin-related events (N Engl J Med 2009 Feb 12;360(7):668). For more information, see the Rhythm control in atrial fibrillation topic in DynaMed.