Nuclear Scan Strategy and Outcomes in Chest Pain Patients Value of Stress Testing with Dipyridamole or Adenosine

Abstract

Objective:To update the prognostic value of scan strategy with pharmacological stress agent in chest pain (CP) patients presenting with normal electrocardiography (ECG) and troponin.Methods:Two consecutive nonrandomized series of patients with CP and negative first-line workup inclusive of serial ECG, serial troponin, and echocardiography underwent myocardial perfusion imaging single photon emission computed tomography (SPECT) in the emergency department. Of 170 patients enrolled, 52 patients underwent dipyridamole-SPECT and 118 adenosine-SPECT. Patients with perfusion defects underwent angiography, whereas the remaining patients were discharged and followed-up. Primary endpoint was the composite of nonfatal myocardial infarction, unstable angina, revascularization, and cardiovascular death at follow-up or the presence of coronary stenosis > 50% at angiography.Results:At multivariate analysis, the presence of perfusion defects or hypertension was independent predictor of the primary endpoint. Sensitivity and negative predictive value were higher in patients subjected to adenosine-SPECT (95% and 99%, respectively) versus dipyridamole-SPECT (56% and 89%; yield 70% and 11%, respectively; P < 0.03). Of note, sensitivity, negative, and positive predictive values were high in patients with hypertension (100%, 93%, and 60%, respectively) or nonischemic echocardiography alterations (100%, 100%, and 100%, respectively).Conclusions:In CP patients, presenting with normal ECG and troponin, adenosine-SPECT adds incremental prognostic values to dipyridamole-SPECT. Costly scan strategy is more appropriate and avoids unnecessary angiograms in patients with hypertension or nonischemic echocardiography alterations.

Aortic Stiffness Index and Aortic Distensibility Measured by Echocardiography May Help to Improve the Equivocal Results of Myocardial Perfusion Scintigraphy

“…These pharmaceutical agents are currently used in patients unable to exercise to evaluate myocardial perfusion with different diagnostic accuracy. A recent study conducted by Conti et al showed that adenosine-based SPECT had better sensitivity and specificity than dipyridamole-based SPECT (20) while diagnostic value of adenosine-based SPECT was found to be similar compared to exercise-based SPECT (21) . We also used intravenous adenosine infusion to produce coronary vasodilatation in 66% of the study population.…”

Serum copeptin level can be a helpful biomarker in evaluation of myocardial perfusion scintigraphy results

“…Adenosine based MPS was proven to have higher diagnostic ability than dipyridamole based protocols, however it had equal diagnostic ability compared to exercise based protocols [24,25]. Thus, to obtain measurable and similar level of physical stress, we applied ETT to induce coronary ischemia.…”

Adenosine triphosphate stress 99mTc-methoxyisobutylisonitrile gated myocardial perfusion imaging efficacy in diagnosing stent restenosis following coronary stent implantation

“…In addition, adenosine can significantly expand normal coronary arteries, although it does not significantly influence the increase in arterial blood flow in stenosis. The blood flow resistance is lower in the non-ischemic zone compared with that in the ischemic areas into the non ischemia areas are through the collateral circulation reflux to the non-ischemia area, which is namely the transverse vascular steal phenomenon (16). Furthermore, adenosine increases the coronary blood flow, which not only increases the pressure difference cross the stenosed coronary arteries, but also decrease the distal blood flows of stenosed vessels, and cause the blood flows of epicardium increasing and blood flows of endocardium decreasing, this is known as the longitudinal vascular steal phenomenon.…”