PATIENTS WITH AORTIC-STENOSIS - CARDIAC COMPLICATIONS IN NONCARDIAC SURGERY

Purpose: To reassess the risk or patients with aortic stenosis (AS) un dergoing non-cardiac surgery. Methods: Following institutional approva l, a retrospective chart audit of all patients with AS who underwent n on-cardiac surgery in Hamilton between 1992 and 1994 was performed. Fo r each AS case, a matching control was randomly selected, Data pertain ing to pre-operative cardiac risk factors, intra-operative, and post-o perative management were recorded. Complications were defined as the o nset of congestive heart failure (CHF), myocardial infarction (MI), or dysrhythmias requiring cardioversion within seven post-operative days ; unplanned or prolonged intensive care unit (ICU) stay due to cardiac cause; and cardiac death, Categorical data were compared using discor dant data pain and binomial distribution, with theta = 0.5. Parametric data were compared using students' t test. All comparisons were two-t ailed, with alpha < 0.05 considered significant.Results: 55 patients ( 32 male, 23 female, mean age 73 yr) with AS (mean aortic valve area 0. 9 cm(2)) were studied. Cases and controls were identical for eight of nine pre-operative risk factors. Differences in perioperative manage;m ent were found. Cardiac complications occurred in five cases and six c ontrol patients (P = 1.00), Conclusions: The current study, involving 55 patients with AS undergoing non-cardiac surgery, showed no differen ce in the risk of cardiac complications compared with matched controls . However, the intensification of management in the AS patients may ha ve attenuated the risk in this group, The sample size was adequate to detect a fourfold increase in risk.