Division of Cardiology, Heart and Vascular Institute, Hartford Hospital, 80 Seymour Street, Hartford, CT, 06102, USA.
Division of Cardiology, Maine Medical Center, Portland, ME, USA.
J Nucl Cardiol. 2018 Aug;25(4):1178-1187. doi: 10.1007/s12350-017-0832-0. Epub 2017 Mar 13.
Stress-only Tc-99m SPECT MPI saves time and reduces radiation exposure while a normal study has a benign prognosis. However, no guidelines exist as to which patients should undergo stress-first MPI. The purpose of this study was to validate a previously published pre-test prediction scoring model and refine the stress-first triage process further if possible.
We retrospectively reviewed all patients who underwent an attenuation-corrected Tc-99m SPECT MPI over a 39-month period. Based on 17-segment model semi-quantitative scoring, a successful stress-first MPI was defined as a summed stress attenuation-corrected score ≤ 1. Based on results from multivariate analysis, the previously published prediction score (comprised eight clinical and demographic variables) was compared to triage based on coronary artery disease (CAD) status alone and with the addition of other highly associated variables. Logistic regression and Chi-squared analyses were used to determine the magnitude of variable effect and to compare model results.
A total of 2,277 patients were included, and the prediction score successfully stratified patients into low-risk (91.1% successful stress-first), intermediate-risk (79.4%), and high-risk (50.7%) groups. Comparing the use of the prediction score to the use of a history of CAD as the only triage factor, 69.0% of patients would be accurately triaged using the prediction score with a cutoff of 7 (maximized sensitivity and specificity), while 78.6% were correctly triaged with CAD status alone (P < .0001). The addition of variables highly associated with a successful stress-first protocol (congestive heart failure [OR 3.4] and an abnormal resting ECG [OR 2.1]) to CAD status further enhanced triage accuracy to 81% (P < .0001).
While the previously described prediction score effectively identifies patients who can successfully undergo stress-first MPI, it is cumbersome. Triaging based solely on CAD status and with the addition of other key variables is practical and provides improved predictive accuracy for successful stress-first MPI. Utilizing this simplified pre-test scoring model may allow for wider adoption of stress-first imaging protocols which have clear advantages over traditional rest-stress protocols.
仅行应激状态下的 Tc-99m SPECT MPI 检查可节省时间并减少辐射暴露，同时正常研究具有良性预后。但是，目前尚无指南规定哪些患者应进行应激优先的 MPI 检查。本研究的目的是验证以前发表的预测试验预测评分模型，并尽可能进一步完善应激优先分诊流程。
我们回顾性分析了在 39 个月期间接受衰减校正 Tc-99m SPECT MPI 的所有患者。根据 17 节段模型半定量评分，成功的应激优先 MPI 定义为总和应激衰减校正评分≤1。基于多变量分析的结果，将以前发表的预测评分（由 8 个临床和人口统计学变量组成）与仅基于冠状动脉疾病（CAD）状态的分诊以及添加其他高度相关变量进行比较。使用逻辑回归和卡方分析来确定变量效果的大小，并比较模型结果。
共纳入 2277 例患者，预测评分成功地将患者分为低危（91.1%的患者成功进行应激优先）、中危（79.4%）和高危（50.7%）组。与仅使用 CAD 病史作为唯一分诊因素相比，使用预测评分的情况下，69.0%的患者可以使用截断值为 7（最大灵敏度和特异性）的预测评分进行准确分诊，而单独使用 CAD 病史的情况下，78.6%的患者可以正确分诊（P<0.0001）。将与成功进行应激优先方案高度相关的变量（充血性心力衰竭[OR 3.4]和异常静息心电图[OR 2.1]）添加到 CAD 状态中，可进一步提高分诊准确性至 81%（P<0.0001）。
尽管以前描述的预测评分可有效地识别可成功进行应激优先 MPI 的患者，但该评分比较繁琐。仅基于 CAD 状态和添加其他关键变量进行分诊是实用的，可为成功进行应激优先 MPI 提供更高的预测准确性。利用这种简化的预测试验评分模型可能会促进应激优先成像方案的更广泛应用，该方案相对于传统的静息-应激方案具有明显优势。
