Stratmann H G, Williams G A, Wittry M D, Chaitman B R, Miller D D
Division of Cardiology, St Louis Veterans Administration Medical Center, Mo.
Circulation. 1994 Feb;89(2):615-22. doi: 10.1161/01.cir.89.2.615.
This study was designed to evaluate the prognostic value of symptom-limited maximal exercise treadmill testing with tomographic technetium-99m sestamibi (MIBI) myocardial imaging in patients referred for evaluation of stable angina. Exercise stress thallium-201 myocardial imaging provides prognostic information in coronary artery disease subsets including patients with stable chest pain. The prognostic value of exercise technetium-99m MIBI myocardial tomography has not been established.
Of 548 consecutive patients with stable angina pectoris who underwent maximal exercise treadmill stress testing in combination with a same-day "rest-stress" tomographic technetium-99m MIBI myocardial imaging protocol, 521 patients were followed for 13 +/- 5 months to determine the univariate and multivariate variables associated with cardiac events and to define their cardiac event-free survival. Ten patients were lost to follow-up (98% complete), and 17 who had coronary revascularization within 6 months of testing were excluded. Major cardiac events occurred in 24 patients (9%)--nonfatal myocardial infarction in 11 and cardiac death in 13. Univariate Cox survival analysis demonstrated significant relative risk (RR) and 95% confidence intervals (CI) for exercise ST segment depression (RR = 2.3; 95% CI, 1.0 to 5.3), an abnormal MIBI scan (RR = 13.8; 95% CI, 1.9 to 102.3), and a reversible MIBI perfusion defect (RR = 3.2; 95% CI, 1.4 to 7.5). Multivariate models demonstrated that both exercise MIBI perfusion abnormalities (RR = 11.9; 95% CI, 1.6 to 89.4) and reversible MIBI perfusion defects (RR = 2.9; 95% CI, 1.2 to 7.0) had independent predictive value. During 1 year of follow-up, cardiac events occurred in only 0.5% of patients with normal MIBI scans compared with 7% of those with abnormal MIBI scans (P < .001). One-year, cardiac event-free survival was 92% in patients with reversible MIBI perfusion defects (P < .01 versus normal), 96% in patients with fixed defects (P < .01), and 93% in patients with combined reversible and fixed MIBI myocardial perfusion abnormalities (P < .02).
As with exercise thallium-201 myocardial imaging, exercise stress technetium-99m MIBI myocardial tomography provides significant independent information concerning the subsequent risk of serious cardiac events (death, myocardial infarction) in patients with stable angina pectoris. The identification of MIBI perfusion abnormalities, in particular, the presence of reversible MIBI defects, was associated with reduced 1-year, event-free survival. The recognized imaging and radiotracer biokinetic differences between thallium-201 and MIBI do not appear to modulate the prognostic value associated with scintigraphic evidence of ischemic myocardial jeopardy in the stable angina population.
本研究旨在评估症状限制性最大运动平板试验联合断层99m锝甲氧基异丁基异腈（MIBI）心肌显像对因稳定性心绞痛前来评估的患者的预后价值。运动负荷铊-201心肌显像可为包括稳定性胸痛患者在内的冠状动脉疾病亚组提供预后信息。运动99m锝MIBI心肌断层显像的预后价值尚未确立。
548例连续性稳定性心绞痛患者接受了最大运动平板负荷试验，并结合同日的“静息-负荷”断层99m锝MIBI心肌显像方案，其中521例患者随访13±5个月，以确定与心脏事件相关的单变量和多变量因素，并明确其无心脏事件生存期。10例患者失访（随访完成率98%），17例在试验后6个月内行冠状动脉血运重建的患者被排除。24例患者（9%）发生主要心脏事件，其中11例为非致死性心肌梗死，13例为心源性死亡。单变量Cox生存分析显示，运动时ST段压低（相对危险度[RR]=2.3；95%可信区间[CI]，1.0至5.3）、MIBI扫描异常（RR=13.8；95%CI，1.9至102.3）以及可逆性MIBI灌注缺损（RR=3.2；95%CI，1.4至7.5）具有显著的相对危险度和95%可信区间。多变量模型显示，运动MIBI灌注异常（RR=11.9；95%CI，1.6至89.4）和可逆性MIBI灌注缺损（RR=2.9；95%CI，1.2至7.0）均具有独立预测价值。在1年随访期间，MIBI扫描正常的患者心脏事件发生率仅为0.5%，而MIBI扫描异常的患者为7%（P<0.001）。可逆性MIBI灌注缺损患者的1年无心脏事件生存率为92%（与正常组相比P<0.01），固定缺损患者为96%（P<0.01），可逆性与固定性MIBI心肌灌注异常并存的患者为93%（P<0.02）。
与运动铊-201心肌显像一样，运动负荷99m锝MIBI心肌断层显像可为稳定性心绞痛患者提供有关严重心脏事件（死亡、心肌梗死）后续风险的重要独立信息。MIBI灌注异常的识别，尤其是可逆性MIBI缺损的存在，与1年无事件生存率降低相关。铊-201与MIBI之间公认的显像及放射性示踪剂生物动力学差异似乎并未改变与稳定性心绞痛人群中缺血性心肌危险的闪烁显像证据相关的预后价值。
