Myocardial perfusion scintigraphy (SPECT) during adenosine stress can be performed safely early on after thrombolytic therapy in acute myocardial infarction

Abstract

The objective of this study was to evaluate the safety of myocardial perfusion scintigraphy with Tc-99 m sestamibi during adenosine stress in patients with recent thrombolytically treated myocardial infarction. Eighty-four patients with thrombolytically treated myocardial infarction, 59 males and 25 females, aged 62.9 +/- 8.4, were eligible for myocardial perfusion scintigraphy during adenosine provocation. Exclusion criteria for adenosine stress were hypotension, unstable angina pectoris, cardiac failure, pericarditis and atrioventricular block (AV block) II-III. Adenosine-stress and resting myocardial perfusion scintigraphy was performed 2-5 days after thrombolysis. Scintigraphy at rest was done 24 h after the stress study. Sixty patients (71%) experienced some kind of side-effects during adenosine infusion. The most frequent side-effects were dyspnoea in 43/84 patients (51%) and unspecific chest discomfort in 26/84 patients (31%). During infusion, ST depressions or elevations on ECG were seen in 9 patients (11%), 5 of whom experienced atypical chest discomfort. Five patients (6%) described typical angina but none of them showed electrographic signs of myocardial ischaemia during infusion. Six patients (7%) developed transient AV block I-II. Reversible scintigraphic perfusion defects were seen in 67 patients (79%). No serious complications, such as death, reinfarction or severe arrhythmias, occurred during adenosine infusion or during a 3-day clinical follow-up period. In conclusion, MIBI-SPECT during adenosine stress is a safe diagnostic method that can be performed in most patients early on after thrombolytically treated acute myocardial infarction. Side-effects are common but benign, and not different from those seen in patients with chronic coronary artery disease.

Incidence of atrioventricular block with vasodilator stress SPECT: A meta-analysis

“…The mean patient age was available for 26 studies 3,18,19,28,29,33,37–40,42–57 and median age was available for three studies. 5,30,32 There was no significant association between mean (median) patient age and incidence of overall AVB ( P > .2).…”

“…Significant heterogeneity was also noted with respect to the way studies reported on second and third degree AVB. The majority did not specify the type of second degree AVB 3,5,16,17,19,29–33 while some reported collectively on second and third degree AVB, 22,23 first and second degree AVB, 20 or all AVB 41 (see Table 3). This hindered our ability to reliably distinguish between type I and II second degree AVB.…”

“…Another limitation is related to the design of two the studies that were included in both the adenosine as well as the regadenoson arms of our meta-analysis. 5,33 The Integrated ADVANCE MPI trial 5 and the study by Zahid et al 33 included patients who underwent pharmacologic stress SPECT-MPI using both vasodilators, however, since these were administered to different groups of patients, they were treated as two single-arm studies. It should be stressed though that this methodological approach does not take into account any non-independence between the two single-arm studies, which may exist due to the fact that they were collected under the same protocol by the same investigative team at the same time.…”