In a large randomized trial, noninvasive ventilation provided no survival advantage to patients with cardiogenic pulmonary edema.
Noninvasive methods of ventilation are being used in patients with acute heart failure, even though the evidence for a net benefit of such a strategy is not very strong. Investigators in the U.K. conducted a large, randomized, multicenter trial to determine if noninvasive ventilation, compared with oxygen administration alone, improves survival in patients with cardiogenic pulmonary edema. Two methods of noninvasive ventilation were compared: continuous positive airway pressure (CPAP) and noninvasive positive-pressure ventilation (NIPPV). The primary endpoint was death or intubation within 7 days after treatment initiation.
A total of 1069 patients with cardiogenic pulmonary edema were randomized to standard oxygen therapy, CPAP, or NIPPV. The patients' mean age was 78, and about one fifth of them had symptoms of MI. Mean heart rate in all three groups was about 113 beats per minute, and mean systolic blood pressures were about 161 mm Hg.
At 7 days, there was no difference in mortality between noninvasive-ventilation recipients and oxygen-therapy recipients. The composite of death or intubation at 7 days was not significantly different among the three groups, nor was length of hospital stay. More patients discontinued noninvasive ventilation than standard oxygen therapy because of discomfort. By contrast, standard oxygen therapy was discontinued because of worsening blood gas values or respiratory distress more frequently than was noninvasive ventilation.
Comment: The results of this open randomized trial of noninvasive ventilation failed to show a reduction in the risk for death or intubation. The finding that fewer noninvasive-ventilation recipients than oxygen-therapy recipients experienced respiratory distress or metabolic abnormalities did not translate into any clinically meaningful change in outcome. The authors conclude with a "glass-is-half-full" assessment of their findings; nonetheless, this trial provides little support for noninvasive ventilation as an initial approach to patients with acute heart failure.
Published in Journal Watch Cardiology July 9, 2008
Gray A et al. for the 3CPO Trialists. Noninvasive ventilation in acute cardiogenic pulmonary edema. N Engl J Med 2008 Jul 10; 359:142.