Ischemic burden in silent and painful myocardial ischemia: a quantitative exercise sestamibi tomographic study.
OBJECTIVE
We sought to determine whether the amount of myocardial ischemic burden differs in patients with painful or silent myocardial hypoperfusion during exercise testing.


BACKGROUND
Whether a lack of symptoms during ischemia reflects an alteration in pain perception or less myocardium in jeopardy remains a controversial issue.


METHODS
We studied 300 consecutive patients with a well established history of ischemic heart disease and reversible hypoperfusion on exercise sestamibi tomography. Rest and stress sestamibi defects were quantitatively assessed and indexes of exercise left ventricular dilation derived.


RESULTS
Painful and silent reversible ischemia was observed in 97 (32%) and 203 (68%) patients, respectively. Patients with painful ischemia had lower values for work load, exercise time and peak rate-pressure product (p < 0.01) and more frequently showed significant ST segment depression during exercise than did patients with silent ischemia (69% vs. 40%, p < 0.001). On sestamibi tomography, patients with painful ischemia had more reversible hypoperfusion than did patients with silent ischemia (mean +/- SD 16 +/- 10% vs. 11 +/- 7%, p < 0.001), despite a comparable extent of stress hypoperfusion (22 +/- 12% vs. 22 +/- 13%); they also had a higher endocardial dilation index (1.32 +/- 0.32 vs. 1.10 +/- 0.26, p < 0.001). By multivariate logistic analysis, the most powerful correlate of painful ischemia was a history of effort angina; the extent of reversible perfusion defect was the sole independent scintigraphic correlate of painful ischemia.


CONCLUSIONS
To our knowledge, this is the largest study comparing the degree of hypoperfusion and the presence of symptoms during exercise stress testing in a consecutive cohort of patients with ischemic heart disease and reversible hypoperfusion. The results suggest that the ischemic burden is greater in painful than in silent ischemia.
Marcassa
C
C
Division of Cardiology and Nuclear Medicine Laboratory, S. Maugeri Foundation IRCCS, Veruno, Italy. cdl@intercom.it
Galli
M
M
Baroffio
C
C
Campini
R
R
Giannuzzi
P
P
D000328:Adult; D000368:Aged; D000787:Angina Pectoris / Q000000981:diagnostic imaging / Q000503:physiopathology; D017023:Coronary Angiography; D005080:Exercise Test; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D009206:Myocardium / Q000378:metabolism*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000627:therapeutic use*; D017256:Technetium Tc 99m Sestamibi
D019275:Radiopharmaceuticals; D017256:Technetium Tc 99m Sestamibi