Should extensive myocardial ischaemia prompt revascularization to improve outcomes in chronic coronary artery disease?

Abstract

A 44-year-old man presents with a 1-month history of substernal chest pressure. His only risk factor is hypercholesterolaemia. His physical exam, electrocardiogram (ECG) and chest X-ray are normal. The patient undergoes an exercise treadmill test. He exercises for 6.5 min on a Bruce protocol to a peak heart rate of 150 beats/min and a blood pressure of 212/112 mmHg. He stops due to angina. His exercise ECG shows 1 mm of ST segment elevation in lead V1. The patient is offered either exercise single photon emission computed tomography (SPECT) or coronary angiography. He chooses exercise SPECT. This demonstrates a large area of apical, anterior, and septal ischaemia. Subsequent coronary angiography demonstrates a 95% stenosis in the middle of the left anterior descending coronary artery and insignificant disease elsewhere. Does the patient merit early revascularization to improve his prognosis? The existing clinical dogma is that stress-induced myocardial ischaemia is important in the management of chronic coronary artery disease (CAD) because it can identify patients with a worse prognosis who are more likely to benefit from revascularization. R.J.G. has presented this case vignette to multiple audiences of cardiologists and cardiovascular surgeons in Europe and the USA over the last 5 years. The audiences have overwhelmingly favoured treatment with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). A previous review suggested that revascularization ‘should be considered for persons with… a large ischemic burden on… stress testing’.1 This review summarizes the older evidence that led to the development of the existing dogma, and the more contemporary evidence that has raised questions about it, leading to confusion in clinical practice and internal and external inconsistencies in clinical …