Assessment of cardiac risk before peripheral vascular surgery: A comparison of myocardial perfusion imaging and left ventricular long axis echocardiography at rest

Abstract

CAD is frequently present in patients with peripheral vascular disease (PVD) and it is a major cause of peri-operative mortality and morbidity. In this study we aimed to compare resting long axis (LAx) echocardiography with thallium-201 perfusion tomography in assessing surgical risk in 65 pts with PVD, age 63±10 years (25 female) before peripheral vascular surgery. LAx 95% Cl values were taken from 21 normals of similar age. Thallium perfusion was abnormal in 50/65 pts: 27 had fixed and 23 had reversible abnormalities (summed segmental stress perfusion score of 36). LAx was considered abnormal when either a systolic (total excursion <1.0cm or/and abnormal shortening >1mm in early diastole) or a diastolic (delayed onset of lengthening >80ms from A2 or/and peak lengthening rate <4.5cm/s) was present. LAx score (maximum 12) was based on the presence or absence of these 4 disturbances at each LAx site. Myocardial perfusion imaging classified the patients into 13/50 at high risk (thallium score 22/36) in whom LAx score was 6/12 or more and 18/50 pts at low risk (thallium score 32/36) in whom LAx score was <6/12. The remaining 19/50 pts were at moderate risk with a wide range long axis scores. Conclusion: The combination of both systolic and diastolic long axis disturbances in patients with PVD can be used to predict the thallium assessment of surgical risk. Resting long axis echocardiography may thus have value as a screening test before vascular surgery as well as providing a means of monitoring myocardial perfusion.