Pulmonary edema with low pulmonary capillary wedge pressure after acute myocardial infarction: Clinical features and prognostic implications

Abstract

Pulmonary edema is a frequent finding after acute myocardial infarction, and is generally thought to be the result of myocardial dysfunction, particularly when an elevated pulmonary capillary wedge pressure (PCWP) is observed. Several recent reports suggest that pulmonary edema without an elevated PCWP can also occur after myocardial infarction. Therefore, we performed a retrospective review of patients with acute infarction to see whether individuals with this complication could be identified. Among 104 patients with myocardial infarction, persistent (>24 hours) pulmonary edema with a low PCWP (≤16 mm mercury) was present in ten patients. In these cases, pulmonary edema was preceded by hypotension in five patients. Individuals with this clinical picture compared to those with pulmonary edema and a high PCWP (≥16 mm mercury, cardiogenic), had more severe hypoxemia ( P < .01), more frequent inferior wall infarctions (70% v 44%), more frequent use of morphine and peri-infarction angiography, and a lower mortality in spite of an increased use of mechanical ventilation. We conclude that persistent pulmonary edema with a low PCWP is a complication of myocardial infarction and is possibly a form of permeability pulmonary edema. Recognition of this complication may allow the clinician to avoid empiric and potentially excessive diuresis which might lead to hypotension and infarct extension. Supportive therapy, including mechanical ventilation, if necessary, can lead to a favorable outcome.