Prognostic value of myocardial perfusion scintigraphy for patients suspected of and diagnosed with coronary artery disease

Abstract

BACKGROUND: The prognostic value of myocardial perfusionscintigraphy (MPS) continues to attract interest and provoke discussions.This study was an attempt to investigate the methods.Objective: Determination of the prognostic value of MPSfor patients suspected of and diagnosed with coronary arterydisease (CAD).

MATERIAL AND METHODS: The study group included 215patients, 134 males and 81 females, aged 21–66, mean age48. Tc-99m-MIBI myocardial perfusion scintigraphy was performedand information concerning the diagnosis, aim of theexamination, past coronary episodes, clinical condition, durationand type of complaints, concomitant diseases, test results,revascularisation procedures and pharmacological treatmentwas gathered. Further history of the patients was monitoredthroughout the observation period of 52 months on average. The patients were divided into the following two groups: GroupI — suspected coronary artery disease: 124 patients aged 21–65,59 males and 65 females; Group II — diagnosed coronary arterydisease: 91 patients aged 31–66, 75 males and 16 femalesdiagnosed with CAD, including 39 s/p myocardial infarct, 31s/p infarct and revascularisation, 21 s/p revascularisation. Theprobability of CAD was calculated using the Diamond methodfor the patients suspected of CAD. The obtained results wereexamined in a statistical analysis.RESULTS: Normal MPS results were obtained for 94/124 patientssuspected of CAD, 15/91 patients diagnosed with CAD,64/81 females and 45/134 males. In Group I, apart from pathologicalMPS results, reversible ischemia was determined in asmany as 27/30 patients, and only 17/91 patients in Group II. Nopatients with normal MPS results suffered major cardiac events,only one of them underwent revascularisation. Major cardiacevents occurred in the case of patients with pathological MPSresults: Group I — 2 myocardial infarcts and 2 cardiac deaths,Group II — 3 infarcts and 10 cardiac deaths. Minor cardiacevents, apart from one case, were also only observed in thecase of patients with pathological MPS results: Group I — 10revascularisations and one case of unstable CAD, Group II— 12 revascularisations and 7 cases of unstable CAD. Patientswith normal MPS results and stenosis in coronary angioraphysuffered no cardiac events. Cardiac events occur mostly in thegroup with a medium and high risk of CAD and in the case ofpatients diagnosed with CAD.

CONCLUSIONS: 1. Normal MPS results for patients suspectedof or diagnosed with CAD: s/p infarct and/or CABG prognosticatea mild course of the disease, without or with a minimalnumber of cardiac events, also in a longer observation period.2. Pathological MPS results clearly imply a greater risk of cardiacevents, and the number of events increases with the greaterprobability of CAD and with the patient’s age. 3. Normal MPS results, even with significant stenosis in coronary angiography,prognosticate a low risk of cardiac events.