NEW YORK (Reuters Health) – Elevated pre-operative blood levels of brain natriuretic peptide (BNP) or N-terminal-proBNP identify patients who are at increased risk for cardiovascular events within 30 days of noncardiac surgery, the results of a meta-analysis suggest.

Pre-operative assessment of clinical cardiac risk factors is of only limited value in predicting cardiovascular events postoperatively, Dr. P. J. Devereaux, from McMaster University Health Sciences Centre, Hamilton, Ontario, Canada, and colleagues note. BNP testing has been shown to have prognostic value in a number of nonsurgical settings, but its usefulness in surgical patients is unclear.

To investigate, the research team conducted a systematic review and meta-analysis of data from 9 observational studies, identified through a search of MEDLINE, EMBASE, and other sources. A total of 3281 patients were included in the analysis.

Overall, 314 patients experienced at least one cardiovascular complication within 30 days of surgery, according to the report in the Journal of the American College of Cardiology for October 20.

On average, 24.8% of patients had an elevated BNP or NT-proBNP value. A direct link between the pre-operative BNP or NT-proBNP level and the risk of cardiovascular complications was seen in all of the studies.

On pooled analysis of data from 7 studies, an elevated BNP or NT-proBNP value was associated with a 19.3-fold increased risk of a cardiovascular complication. In studies that only looked at death, cardiovascular death, or MI, an elevated value increased the odds of this composite outcome by 44.2-fold. In studies that examined these and other cardiovascular outcomes, a 14.7-fold increased risk was seen.

The present study “gives important and clear evidence for a high prognostic potential of natriuretic peptides in patients scheduled for noncardiac surgery. However, studies to evaluate whether specific NP-based treatment modifications will result in improved outcome of surgical patients still need to be performed,” note Dr. Daniel Bolliger, Dr. Manfred D. Seeberger, and Dr. Miodrag Filipovic, from the University of Basel Hospital, Switzerland, in a related editorial.

Reference:
J Am Coll Cardiol 2009;54:1599-1606,1607-1608.