Stone P H, Thompson B, Zaret B L, Chaitman B, Gibson R S, Schweiger M J, Steingart R, Kirshenbaum J, Thompson C, Fung A, McCabe C H, Knatterud G L, Braunwald E
Cardiovascular Division, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Eur Heart J. 1999 Aug;20(15):1084-93. doi: 10.1053/euhj.1998.1480.
Current management of patients with unstable angina and non-Q wave myocardial infarction generally consists of intensive medical therapy, with angiography and revascularization sometimes limited to those who fail such therapy.
To determine if certain baseline characteristics are predictive of patients who fail medical therapy, since such patients could then be expeditiously directed to a more invasive strategy in a cost-effective manner.
The study cohort consisted of the 733 patients in the Thrombolysis in Myocardial Ischemia (TIMI) IIIB study who were randomized to conservative strategy. Patients were to be treated with bedrest, anti-ischaemic medications, aspirin, and heparin, and were to undergo risk-stratifying tests, consisting of an exercise test with ECG and thallium scintigraphy, scheduled to be performed within 3 days prior to, or 5 days after, hospital discharge and 24 h Holter monitoring scheduled to begin 2-5 days after randomization. Baseline clinical and ECG characteristics were compared between patients who 'failed' medical therapy and those who did not 'fail'. Failure was defined using clinical end-points (death, myocardial infarction, or spontaneous ischaemia by 6 weeks after randomization) or a strongly positive risk-stratifying test. For each test an ordered failure profile of results was calculated and consisted of death, myocardial infarction, or rest ischaemia occurring prior to performance of the test, a markedly abnormal test result, and no abnormality.
Clinical end-points occurred in 241 (33%) patients and were more likely to occur in patients who at presentation were older, had ST-segment depression on the qualifying ECG, or were being treated with heparin or aspirin. Characteristics independently predictive of developing a clinical event or an abnormal exercise treadmill test included: ST-segment depression on the qualifying ECG, history of prior angina, family history of premature coronary disease (i.e. onset <55 years of age), prior use of heparin or aspirin, and increasing age. By combining these baseline risk characteristics for each outcome the incidence of developing a clinical event ranged from 8% if none was present to 63% if all six were present, and of developing a markedly abnormal risk stratifying test from 8-21% if none were present to approximately 90% if all six were present.
Baseline characteristics associated with developing a clinical event or a markedly abnormal risk stratifying test were similar: rest anginal episode accompanied by ST-segment depression and occurring despite treatment with aspirin and heparin, a history of angina, older age, and family history of coronary disease. Patients with these characteristics are appropriate candidates for expeditious cardiac catheterization and consideration for revascularization, while patients without them may be suitable for medical management alone.
目前，不稳定型心绞痛和非Q波心肌梗死患者的治疗通常包括强化药物治疗，血管造影和血运重建有时仅适用于药物治疗无效的患者。
确定某些基线特征是否可预测药物治疗无效的患者，以便能够以具有成本效益的方式迅速将这类患者导向更具侵入性的治疗策略。
研究队列包括心肌缺血溶栓治疗（TIMI）IIIB研究中随机接受保守治疗策略的733例患者。患者需卧床休息，接受抗缺血药物、阿司匹林和肝素治疗，并进行风险分层测试，包括运动试验及心电图和铊闪烁扫描，计划在出院前3天内或出院后5天内进行，以及在随机分组后2 - 5天开始进行24小时动态心电图监测。比较“药物治疗失败”患者和“未失败”患者的基线临床和心电图特征。失败的定义采用临床终点（随机分组后6周内死亡、心肌梗死或自发性缺血）或风险分层测试结果呈强阳性。对于每项测试，计算结果的有序失败概况，包括在测试前发生的死亡、心肌梗死或静息缺血、明显异常的测试结果以及无异常。
241例（33%）患者出现临床终点，且更有可能出现在就诊时年龄较大、基线心电图有ST段压低或正在接受肝素或阿司匹林治疗的患者中。独立预测发生临床事件或运动平板试验异常的特征包括：基线心电图ST段压低、既往心绞痛病史、早发冠心病家族史（即发病年龄<55岁）、既往使用肝素或阿司匹林以及年龄增加。通过将这些针对每个结局的基线风险特征进行组合，发生临床事件的发生率范围为：若无一特征存在则为8%，若所有六个特征均存在则为63%；发生明显异常风险分层测试的发生率范围为：若无一特征存在则为8% - 21%，若所有六个特征均存在则约为90%。
与发生临床事件或明显异常风险分层测试相关的基线特征相似：静息性心绞痛发作伴有ST段压低，尽管接受了阿司匹林和肝素治疗仍发生，心绞痛病史，年龄较大以及冠心病家族史。具有这些特征的患者适合迅速进行心导管检查并考虑血运重建，而没有这些特征的患者可能仅适合药物治疗。
