The role of myocardial perfusion scanning, heart rate variability and D-dimers in predicting the risk of perioperative cardiac complications after peripheral vascular surgery.
OBJECTIVE
To study the value of a number of proposed prognostic factors in prediction of the risk of perioperative cardiac events after vascular surgery.


METHODS
Two hundred and ninety-seven patients undergoing peripheral vascular surgery were prospectively studied. Patients underwent preoperative 24 h ambulatory electrocardiography, measurement of haemostatic variables, myocardial assessment of perfusion by dipyridamole-thallium scintigraphy and radionuclide ventriculography. The primary endpoint was cardiac death or nonfatal myocardial infarction within 30 days of surgery. A combined endpoint included the primary endpoint plus occurrence of cardiac failure, unstable angina or serious arrhythmias.


RESULTS
The primary endpoint occurred in 21 (7%), and the combined endpoint in 41 (14%) of patients. On multivariate analysis, increased age, previous myocardial infarction, aortic surgery, impaired heart rate variability and a positive thallium scan were independent predictors of primary end-points. Preoperative atrial fibrillation and increased fibrin D-dimer were additional predictors of the combined endpoint. Construction of receiver-operator characteristic curves to examine the incremental value of predictive models showed that sensitivity and specificity of clinical data alone for primary endpoints was 71% and 72% respectively, while for the full model (incorporating heart rate variability and thallium data) this rose to 84% and 80% (p=0.0001).


CONCLUSIONS
Preliminary screening using clinical data has limited value in risk assessment prior to vascular surgery but preoperative heart rate variability, D-dimers and thallium scanning provide modest incremental predictive value.
Mamode
N
N
Department of Vascular Surgery, Medical Cardiology and Medicine, Glasgow, UK.
Docherty
G
G
Lowe
G D
GD
Macfarlane
P W
PW
Martin
W
W
Pollock
J G
JG
Cobbe
S M
SM
D000368:Aged; D003326:Coronary Circulation; D004176:Dipyridamole; D015716:Electrocardiography, Ambulatory; D023381:Endpoint Determination; D006321:Heart / Q000000981:diagnostic imaging*; D006331:Heart Diseases / Q000175:diagnosis / Q000209:etiology* / Q000401:mortality; D006339:Heart Rate; D006801:Humans; D016015:Logistic Models; D015233:Models, Statistical; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000175:diagnosis / Q000209:etiology; D016017:Odds Ratio; D011183:Postoperative Complications; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D015635:Radionuclide Ventriculography; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013793:Thallium; D014656:Vascular Surgical Procedures / Q000009:adverse effects*
D004176:Dipyridamole; D013793:Thallium