Usefulness of the severity and extent of reversible perfusion defects during thallium-dipyridamole imaging for cardiac risk assessment before noncardiac surgery

Journal Article · Tue Aug 01 00:00:00 EDT 1989 · American Journal of Cardiology; (USA)

DOI:https://doi.org/10.1016/0002-9149(89)90519-5· OSTI ID:5545317

Lette, J; Waters, D; Lapointe, J; Gagnon, A; Picard, M; Cerino, M; Kerouac, M ^[1]

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1. Maisonneuve-Rosemont Hospital, Montreal, Quebec (Canada)

Thallium-dipyridamole imaging is a very sensitive test for predicting cardiac events after noncardiac surgery, but it lacks specificity. To improve specificity, a semiquantitative scoring system was developed that combined dipyridamole-induced reversible left ventricular dilatation with scintigraphic indexes for severity and extent of reversible perfusion defects. Using this scoring system, patients were classified into low, intermediate and high risk subgroups. Thallium-dipyridamole imaging was performed in 66 patients before major general and vascular surgery. Thirty-nine patients classified as low risk (30 with normal scans and 9 with fixed defects) underwent surgery uneventfully. Surgery was cancelled in 6 patients with extensive thallium redistribution and coronary angiography was performed because of severe coronary artery disease in 5 and idiopathic dilated cardiomyopathy in 1. In the remaining 21 patients with thallium redistribution, a positive statistical correlation (p = 0.001) between scintigraphic indexes of severity and extent, and cardiac events was noted. Using cutoff values for the scintigraphic indexes, patients with reversible defects could be classified into intermediate and high risk subgroups. Only 1 of 11 patients at intermediate risk developed a complication, whereas 8 of 10 patients at high risk had a postoperative event (7 deaths and 1 myocardial infarction). Thus, using scintigraphic indexes for severity and extent, patients with reversible defects can be stratified into an intermediate risk subgroup that can safely undergo surgery and a high risk subgroup that requires coronary angiography.

• OSTI ID: 5545317
• Journal Information: American Journal of Cardiology; (USA), Journal Name: American Journal of Cardiology; (USA) Vol. 64:5; ISSN AJCDA; ISSN 0002-9149
• Country of Publication: United States
• Language: English

Related Subjects

550600 -- Medicine
550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ARTERIES
BIOMEDICAL RADIOGRAPHY
BLOOD VESSELS
BODY
CARDIOVASCULAR AGENTS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CORONARIES
COUNTING TECHNIQUES
DIAGNOSIS
DIAGNOSTIC TECHNIQUES
DISEASES
DRUGS
EXERCISE
HEART
ISOTOPES
MEDICINE
NUCLEAR MEDICINE
ORGANS
PATIENTS
PERFUSED ORGANS
RADIOISOTOPE SCANNING
RADIOLOGY
RISK ASSESSMENT
SCINTISCANNING
SURGERY
THALLIUM ISOTOPES
VASODILATORS