Elevated preoperative phosphorus levels are an independent risk factor for cardiovascular mortality

Serum phosphorus levels have been associated with adverse long-term outcome in several populations, however, no prior studies evaluated short-term postoperative outcome. The present study evaluated the predictive value of phosphorus levels on 30-day outcome after vascular surgery.

The study included patients scheduled for major vascular surgery (aortic aneurysm repair, lower extremity revascularization or carotid surgery), divided into four quartiles based on the preoperative fasting phosphorus level. The endpoints of the analyses were all-cause and cardiovascular mortality during the first 30 postoperative days and during long-term follow-up (median 3.6 years, interquartile range 1.8-8.0).

Prior to surgery, 1,798 patients were categorized into the following quartiles: <2.9 mg/dl (n = 459), 2.9-3.4 mg/dl (n = 456), 3.4-3.8 mg/dl (n = 444) and >3.8 mg/dl (n = 439), respectively. During the first 30 postoperative days, 81 (4.5%) patients died of which 66 (81%) secondary to a cardiovascular cause. In multivariate analyses, an independent association was observed between phosphorus level >3.8 mg/dl and all-cause (OR 2.53, 95% CI 1.2-5.4) or cardiovascular mortality (OR 2.37, 95% CI 1.1-5.7). Baseline serum phosphorus >3.8 mg/dl was also significantly associated with long-term all-cause mortality (HR 1.38, 95% CI 1.1-1.7).

Preoperative elevated serum phosphorus demonstrated an independent relationship with the occurrence of all-cause and cardiovascular mortality during the first 30 days after major vascular surgery. In addition, an elevated serum phosphorus was independently associated with long-term mortality.