穩定缺血性心臟病初始保守或介入性管理策略：我們準備從ISCHEMIA試驗學習到甚麼

Initial Invasive or Conservative Strategy for Stable Ischemic Heart Disease - What do We Plan to Learn from the ISCHEMIA Trial?

陳朝欽(Chao-Chin Chen) ； 雷孟桓(Meng-Huan Lei)

《內科學誌》 32卷4期 (2021/08) Pp. 215-229

https://doi.org/10.6314/JIMT.202108_32(4).01

摘要

缺血性心臟病是全世界的主要死亡和致殘原因。所有患有穩定缺血性心臟病（SIHD）的患者都應接受最佳藥物治療，藉以減少動脈粥狀硬化的進展並防止冠狀動脈血栓。除了藥物治療外，血管重建適用於症狀加劇或難以控制的患者。自COURAGE試驗發表以來，許多具有里程碑意義的隨機臨床試驗未能顯示經皮冠狀動脈介入治療有減少SIHD死亡和心肌梗塞方面的好處。儘管療效不確定，許多醫師卻繼續為SIHD患者進行此類介入治療。於此同時，「缺血減少範式」是管理SIHD的核心原則，雖然這種取向得到了臨床準則的認可，但幾乎沒有確鑿證據表明這種策略能改善結局。然而，這些試驗只包括那些隨機分派前已獲知冠狀動脈解剖的參與者，並且未招募足夠數量的重大缺血。此外，隨著藥物治療和血管重建技術的改進，顯然有必要對處於較高（缺血和解剖負擔）風險的SIHD患者進行新的試驗。ISCHEMIA試驗旨在比較壓力負荷測試下中度或重度缺血的SIHD患者的初始介入性或保守治療（單獨最佳藥物治療）策略。試驗設計是在患者作心導管前進行隨機分派，並招募缺血負擔較高的患者以及使用當代血管重建和藥物治療，來克服先前試驗的局限性。經過3.2年的追蹤後，兩組主要結局沒有顯著差異，而介入策略組在生活品質、心絞痛緩解和較低自發性心肌梗塞發病率方面有較好的結果。雖然ISCHEMIA試驗的結果驗證了吾等一直提倡的更為保守管理策略──人們需要認知此研究的內在局限性和其他發人深省的見地。這項試驗為心血管醫師提供了許多深入反思的迫切需要。

關鍵字

穩定缺血性心臟病（Stable ischemic heart disease） ； 比較藥物和介入方法療效的國際性研究（International Study of Comparative Health Effectiveness with Medical and Invasive Approaches, ISCHEMIA） ； 心肌血管重建（Myocardial revascularization） ； 經皮冠狀動脈介入治療（Percutaneous coronary intervention） ； 最佳藥物治療（Optimal medical therapy）

並列摘要

Ischemic heart disease is the leading cause of death and disability worldwide. All patients with stable ischemic heart disease (SIHD) should be managed with optimal medical therapy (OMT), which reduces progression of atherosclerosis and prevents coronary thrombosis. Despite medical treatment, revascularization is also indicated in SIHD patients with progressive or refractory symptoms. Ever since publication of COURAGE trial, several landmark randomized clinical trials have failed to show benefit of percutaneous coronary intervention (PCI) in reducing death and myocardial infarction (MI) in SIHD. PCI continues to be performed frequently for patients with SIHD, despite uncertain efficacy. Meanwhile, ＂ischemia reduction paradigm＂ is a central tenet in the management of SIHD. Although this approach is endorsed by clinical guidelines, there is little definitive proof that this strategy improves outcomes. However, those trials only included participants in whom coronary anatomy were known prior to randomization and did not include sufficient numbers of significant ischemia. In addition, with improvement in both medical therapy and revascularization technique, there is a clear need for a new trial for SIHD patients uniformly at higher (ischemic and anatomic burden) risk. The ISCHEMIA Trial is aimed to compare an initial invasive or conservative treatment (OMT alone) strategy for managing SIHD patients with moderate or severe ischemia on stress testing. This trial has been designed to overcome prior trial's limitations by including randomization before the patient undergoes catheterization, enrollment of patients with higher ischemic burden, and use of contemporary revascularization and medical therapy. After an average of 3.2 years of follow-up, there was no significant difference in primary outcomes, whereas the invasive group had better results related to quality of life, angina relief and a lower incidence of spontaneous MI. While the ISCHEMIA results validate a more conservative management strategy -- which we and many others have long advocated-one needs to be cognizant of the inherent limitations and other aspects that are thought-provoking of the study. This trial provides much need for deep reflection among cardiovascular practitioners.