The additive values of left ventricular function and extent of myocardium at risk to dipyridamole perfusion imaging for optimal risk stratification prior to vascular surgery.
Although the increased risk of cardiac complications in surgical patients with diminished left ventricular ejection fraction (LVEF) is well-established, this method has been supplanted in recent years by assessment of ischaemic burden using myocardial perfusion imaging (MPI). This study was conducted to determine if MPI and LVEF determination provide complementary or redundant information in preoperative evaluation of vascular surgery patients. A total of 101 patients were studied with dipyridamole MPI and radionuclide ventriculography before surgery. Single photon emission tomographic MPI images were scored for defect severity and categorized as either fixed or reflecting ischaemia. Resting left ventricular cavity was also categorized as normal or dilated. LVEF was subdivided into normal (> or = 50%) and abnormal (< 50%). Seventeen patients had cardiac events. Events were more frequent in patients with ischaemia, in patients with a LVEF < 50% and in those with dilated left ventricular chambers. The mean number of ischaemic segments was also higher in the cardiac event group. Higher event rates were seen when a combination of these factors was present. A history of myocardial infarct, congestive heart failure or coronary artery disease was also a significant predictor of subsequent events. Thus, both abnormal left ventricular function and extent of ischaemic myocardium have independent and complementary predictive power for cardiac events in vascular surgery patients.
Heiba
S I
SI
Division of Nuclear Medicine, Faculty of Medicine, Kuwait University. heibas@pol.net
Jacobson
A F
AF
Shattuc
S
S
Ferreira
M J
MJ
Sharma
P N
PN
Cerqueira
M D
MD
D000368:Aged; D000369:Aged, 80 and over; D004176:Dipyridamole; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D007431:Intraoperative Complications / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000000981:diagnostic imaging; D010477:Perfusion; D015635:Radionuclide Ventriculography; D018570:Risk Assessment; D013794:Thallium Radioisotopes; D014656:Vascular Surgical Procedures; D014665:Vasodilator Agents; D016277:Ventricular Function, Left / Q000502:physiology*
D013794:Thallium Radioisotopes; D014665:Vasodilator Agents; D004176:Dipyridamole