Assessment of peripheral artery tonometry in the detection of treadmill exercise-induced myocardial ischemia.
OBJECTIVE
We sought to assess the added diagnostic value of peripheral artery tonometric (PAT) measurements, based on finger pulsatile arterial volume changes, to standard 12-lead stress electrocardiography (ECG), for detecting exercise-induced myocardial ischemia, using single-photon emission computed tomography (SPECT) as the standard of comparison in a double-blinded, multicenter protocol.


METHODS
An automated algorithm for identifying myocardial ischemia from PAT was derived from 345 training cases. The PAT outcome was combined with the ECG result (ischemic, nonischemic, or equivocal), giving a PAT-enhanced value. A threshold of normality was determined to optimize agreement with the SPECT results in the training sample. The PAT-enhanced analysis was then validated in 616 subjects, only two of whom had technically unacceptable PAT studies.


RESULTS
In the validation cohort, receiver operating characteristic curve analysis of the PAT-enhanced diagnosis yielded an area under the curve of 0.72, a sensitivity of 63.5%, compared with 44.7% for ECG alone (p < 0.0001), and a specificity of 67.8% common to both ECG and PAT-enhanced diagnoses. Similar results were found in the training sample. Although over 10% of validation subjects had equivocal ECG results, with the aid of PAT, it was possible to provide diagnostic information for all but one subject.


CONCLUSIONS
Peripheral artery tonometry may be useful for improving the diagnosis of exercise-induced myocardial ischemia by both enhancing the sensitivity without impairing the specificity and increasing the percentage of definitive test results.
Chouraqui
Pierre
P
Nuclear Cardiology Unit, The Heart Institute, Chaim Sheba Medical Center, Tel Hashomer, Israel. chouraq@post.tau.ac.il
Schnall
Robert P
RP
Dvir
Itsik
I
Rozanski
Alan
A
Qureshi
Ehtasham
E
Arditti
Alexander
A
Saef
Jerold
J
Feigin
Paul D
PD
Sheffy
Jacob
J
D000368:Aged; D001794:Blood Pressure; D004311:Double-Blind Method; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D005385:Fingers / Q000098:blood supply*; D006801:Humans; D008297:Male; D008365:Manometry / Q000295:instrumentation; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon