Preoperative risk stratification for aortic surgery using pharmacologic stress myocardial imaging

Abstract

Background: Not only patients with aortic disease have a high prevalence of coronary artery disease, but also aortic surgery itself is highly invasive. Therefore, preoperative risk stratification for this high-risk subset is essential. We evaluated the usefulness of the perioperative cardiac risk stratification using pharmacologic single photon emission computed tomography (SPECT) in patients undergoing aortic surgery. Methods: Pharmacologic stress SPECT using ATP or dipyridamole was performed in 302 patients: aortic dissection in 56, TAA in 124, and AAA in 122. Open vascular surgery was performed in 75, and endovascular surgery by stent-graft placement in 227. Not only the presence or absence of perfusion defects, but also the 20-segment model analysis was performed. Results: Pharmacologic thallium SPECT revealed negative findings in 210 patients and positive findings in 92. Among 92 patients with positive tests, 33 patients were evaluated by catheterization; 25 out of these 33 patients revealed to have CAD. Of these 25 patients, 9 underwent successful revascularization prior to or during surgery. Perioperative cardiac events occurred in 9 patients; 7 occurred in patients with positive SPECT, whereas only 2 occurred in those with negative SPECT (2/210 vs 7/92; p<0.05). Moreover, no hard event occurred in patients with negative SPECT. Multivariate analysis using logistic regression model revealed that the summed stress score of >13 was the most important factor to identify patients who subsequently had perioperative cardiac events. Conclusions: Pharmacologic stress SPECT has a significant value in the risk stratification of patients before aortic surgery. In patients with positive SPECT, especially extensive myocardial perfusion defects, aggressive approach for preoperative risk reduction is necessary, whereas aortic surgery can be performed safely in patients with negative SPECT.