244 Angiographic features of perioperative myocardial infarction (POMI)

Abstract

Over 5 million adults worldwide experience a perioperative myocardial infarction (POMI) after non-cardiac surgery annually. These patients have approximately double the 30 day mortality rate of patients presenting to the emergency room with an MI. However, less than 10% of patients suffering a POMI are referred for cardiac catheterization during the first 30 days. Our objective was to study the angiographic and clinical features of patients experiencing a perioperative MI (POMI) following non-cardiac surgery who were referred for cardiac catheterization. Using hospital administrative data from the Hamilton Health Sciences Centre from January 1, 2005 until June 30, 2009, we screened consecutive patients aged 18 or older who underwent non-cardiac surgery, suffered a POMI and were referred for cardiac catheterization in the same admission. The angiograms of all identified patients were reviewed by an independent observer blinded to clinical presentation and in-hospital outcome. Among the 95 patients included in the study, the mean age was 70.8 years, 54.7% of patients were male, and a majority had a high burden of cardiac risk factors (e.g., 44.7% had diabetes). Fifty-nine percent of the patients underwent coronary angiography after 4 days with a median time to angiography of 124 hours. Normal or non-obstructive CAD was seen in 26 (27.3%) patients, one or two vessel disease in 34 (35.8%) patients and left main and/or triple vessel disease in 35 (36.9%) patients. Forty-seven (49.5%) patients had a chronic total occlusion and 2 (2.1%) patients had an acute total occlusion. Twenty-three (24.2%) patients had an LVEF < 35%. Revascularization was attempted in 43 (45.3%) patients. Successful PCI occurred in 19 (20%) patients and CABG was performed in 21 (22.1%) patients. An additional 14 patients were referred for CABG but were deemed non-operable (11 patients) or died awaiting CABG (3 patients). In-hospital mortality varied by angiographic subgroup, from 0% in the group with normal or non-obstructive CAD compared to 12% in patients with obstructive CAD (P < 0.01). Angiography in patients suffering a POMI demonstrated a single or multi-vessel CAD in 72.7% of patients and non-obstructive CAD in 27.3%. Chronic total occlusions were more common than acute occlusions, but the timing of angiography may have influenced these results. The presence of obstructive CAD was associated with higher in-hospital mortality. Further research to identify high risk POMI patients is needed in order to improve clinical outcomes.