Elsevier

Journal of Nuclear Cardiology

Volume 23, Issue 6, December 2016, Pages 1251-1261
Journal of Nuclear Cardiology

Original Article
Quantitation of left ventricular ejection fraction reserve from early gated regadenoson stress Tc-99m high-efficiency SPECT

https://doi.org/10.1007/s12350-016-0519-yGet rights and content

Abstract

Background

Ejection fraction (EF) reserve has been found to be a useful adjunct for identifying high risk coronary artery disease in cardiac positron emission tomography (PET). We aimed to evaluate EF reserve obtained from technetium-99m sestamibi (Tc-99m) high-efficiency (HE) SPECT.

Methods

Fifty patients (mean age 69 years) undergoing regadenoson same-day rest (8-11 mCi)/stress (32-42 mCi) Tc-99m gated HE SPECT were enrolled. Stress imaging was started 1 minute after sequential intravenous regadenoson .4 mg and Tc-99m injections, and was composed of five 2 minutes supine gated acquisitions followed by two 4 minutes supine and upright images. Ischemic total perfusion deficit (ITPD) ≥5 % was considered as significant ischemia.

Results

Significantly lower mean EF reserve was obtained in the 5th and 9th minute after regadenoson bolus in patients with significant ischemia vs patients without (5th minute: −4.2 ± 4.6% vs 1.3 ± 6.6%, P = .006; 9th minute: −2.7 ± 4.8% vs 2.0 ± 6.6%, P = .03).

Conclusions

Negative EF reserve obtained between 5th and 9th minutes of regadenoson stress demonstrated best concordance with significant ischemia and may be a promising tool for detection of transient ischemic functional changes with Tc-99m HE-SPECT.

Spanish Abstract

Antecedentes

Se ha encontrado que la reserva de la Fracción de Eyección (FE) en la tomografía de emisión de positrones cardiaca (PET, positron emission tomography por sus siglas en ingles) es una herramienta útil adicional en la identificación de pacientes con enfermedad arterial coronaria de alto riesgo. Nuestro objetivo fue evaluar la reserva de la FE obtenida por SPECT de alta eficiencia (AE) con Tecnecio-99m (Tc-99m) sestamibi.

Métodos

Cincuenta pacientes (edad promedio 69 años) a quienes se les realizo un SPECT de AE con Tc‐99m sincronizado con el electrocardiograma en un solo día reposo (8-11mCi)/estrés 32-42mCi) con regadenoson fueron incluidos La adquisición de las imágenes de estrés se inicio un minuto después de la administración secuencial intravenosa de regadenoson .4mg y Tc-99m, compuesta de 5 adquisiciones sincronizadas con el electrocardiograma de 2 minutos cada una en supino seguidas de dos adquisiciones de 4 minutos cada una en supino y sentado. Un defecto total de perfusión isquémico (DTPI) ≥5% fue considerado como isquemia significativa.

Resultados

El promedio obtenido de la Reserva de la FE fue significativamente menor en los minutos 5to y 9no posterior al bolo de regadenoson en pacientes con isquemia significativa comparados con pacientes sin isquemia (5to minuto: −4.2 ± 4.6% vs 1.3 ± 6.6%, p= 0.006; 9no minuto: −2.7 ± 4.8% vs 2.0 ± 6.6%, p = 0.03).

Conclusiones

Una Reserva de la FE negativa obtenida en los minutos 5to y 9no del estrés con regadenoson demostró una mejor concordancia con la presencia de isquemia significativa y podría ser un herramienta promisoria para la detección de cambios funcionales isquémicos transitorios con un estudio SPECT de AE con Tc-99m.

Chinese Abstract

背景

对于心脏PET显像, 射血分数 (EF) 储备 已成为评判高风险冠心病的有效辅助手段。本文旨在评价采用Tc-99m甲氧基异丁基异睛显影剂和高能SPECT测定EF储备的可行性。

方法

入选55行类伽腺苷一日法静息 (8-11mCi) /负荷 (32-42mCi) 门控高能SPECT显像的患者, 平均年龄为69岁。在连续静脉注射类伽腺苷 (0.4mg) 和Tc-99m一分钟后开始负荷图像的采集。负荷图像包括5个2分钟的仰卧位门控采集和后续2个分别为仰卧位和直立位的4分钟门控采集。总灌注缺损≧5%为显著缺血。

结果

注射类伽腺苷后, 显著缺血患者的平均EF储备在第5和第9分钟时较无缺血患者显著降低 (第5分钟: −4.2 ± 4.6% vs. 1.3 ± 6.6%, p = 0.006; 第9分钟: −2.7 ± 4.8% vs. 2.0 ± 6.6%, p=0.03)。

结论

在类伽腺苷负荷时, 第5至9分钟测得的EF储备负值与显著缺血的一致性最佳, 这很可能成为Tc-99m高能SPECT检测一过性心肌缺血伴随的心功能改变的有效手段。

Introduction

Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) is a well-established non-invasive procedure for evaluation and risk stratification of patients with coronary artery disease (CAD).1 However, it has been recognized that with certain patients, SPECT MPI does not allow to detect the presence nor to estimate the extent of CAD. Indeed, the moderate to severe perfusion defects are revealed in less than half of the patients with significant left main disease.2 A number of studies have been conducted to improve the sensitivity of SPECT MPI, through the analysis of post-stress left ventricular (LV) ejection fraction (EF),3,4 post-stress wall motion abnormalities,5 and transient LV dilation,6 but these investigations have been made using conventional Anger cameras with waiting periods after stress tracer injection as long as 60 minutes. Such delayed EF measurements seem to be relatively ineffective for the detection of significant CAD, as a result of their transient nature. The ability of PET MPI to measure EF and to determine EF reserve during peak of stress using highly sensitive detectors and high-dose short-lived tracers has been reported.7 Recently, a novel high-efficiency (HE) SPECT camera with solid state cardiac-focused detectors has shown to be significantly more sensitive for the detection of cardiac activity than the conventional Anger scintillation camera,8, 9, 10 giving SPECT a “PET-like” ability to image rapidly during a peak of stress. The aim of this study was to explore the feasibility of evaluating EF reserve using HE-SPECT.

Section snippets

Study Population

The patients of the study were selected from consecutive subjects who were referred to clinically indicated regadenoson pharmacologic stress MPI to the Nuclear Medicine Department, Sacred Heart Medical Center, Springfield, Oregon, between August 2012 and August 2013. The selection of the patients depended on the limitations related to the scheduling of a non-routine imaging protocol, in particular the availability of the stress lab staff and nurses during the entire procedure. Fifty consecutive

Results

Baseline clinical characteristics of studied patients are presented in Table 1. Overall, 22 patients (44%) had stress TPD = 0 %; stress TPD >0 % was seen in 28 patients. 40 patients did not have significant ischemia (ITPD <5%), and 10 patients had significant ischemia (ITPD ≥5%). Gated resting EF <50% was recorded in 14 patients (28%).

Discussion

To the best of our knowledge, this is the first study evaluating feasibility of EF reserve quantification obtained from early gated acquisitions using Tc-99m HE-SPECT MPI. The main discovery in our study is that the EF reserve obtained from early gated acquisitions (obtain 5 and 9 minutes after injection) showed concordance with significant myocardial ischemia, while later acquisitions (at 13th, 17th and 21st minute) or standard HE-SPECT gated acquisitions did not. According to our findings,

Conclusions

We have demonstrated the feasibility of early EF reserve measurement with HE-SPECT. Negative EF reserve obtained between 5th and 9th minutes of regadenoson stress demonstrated best concordance with significant ischemia and could be a promising clinical tool for detection of early ischemic functional changes with Tc-99m HE-SPECT.

Acknowledgment

This research was supported in part by Grant R01HL089765 from the National Heart, Lung, and Blood Institute/National Institutes of Health (NHLBI/NIH) (PI: Piotr Slomka). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the NHLBI/NIH. Yafim Brodov, MD, PhD is a Michael Kogan Save a Heart Foundation fellow in Cardiac Imaging and Nuclear Cardiology, Cedars-Sinai Medical Center, Los Angeles, California.

Disclosure

Drs Piotr Slomka, Guido Germano,

References (23)

Cited by (25)

View all citing articles on Scopus

JNC thanks Dr. E. Alexanderson, UNAM, Mexico, for providing the Spanish abstract, and Weihua Zhou, PhD, University of Southern Mississippi, USA, for providing the Chinese abstract. An audio interview between Dr. Slomka and the editor-in-chief, Dr. Iskandrian, discussing the article can be found as Electronic Supplementary Material at SpringerLink.

See related editorial, doi:10.1007/s12350-016-0570-8.

View full text