The proportion of patients receiving mechanical ventilation ( 87 % ) and mean + / - SD age ( 65 + / -4 years ) , Simplified Acute Physiologic Score ( 13.3 + / -4.9 ) , Organ System Failure score ( 1.5 + / -1.0 ) , and duration of catheterization ( 8.7 + / -5.0 days ) were similar in both groups .
