The VANQWlSH trial: Support for the noninvasive strategy for risk stratification after acute myocardial infarction

Abstract

The data from the VANQWISH trial coupled with the results of published studies in the literature during the past 15 years clearly show no advantage of an initial routine invasive strategy for risk stratification and management of uncomplicated postinfarction patients. This conclusion has been derived from observational studies, from randomized studies and from epidemiologic studies looking at variation in practice patterns within regions of the United States and between the United States and Canada. The variables derived from exercise or pharmacologic stress myocardial perfusion imaging can separate the high- and low-risk subgroups perhaps even better than achieved by identification of the extent and severity of coronary anatomic stenoses alone by coronary angiography. Currently the noninvasive risk stratification approach can be undertaken very early (2 to 4 days) using vasodilator stress during hospitalization for patients judged to have an uncomplicated course. Alternatively, submaximal treadmill testing can safely be performed at 4 to 6 days after admission with information obtained relevant to both exercise tolerance and the extent of inducible ischemia. Finally, gated 99mTc SPECT imaging not only permits the assessment of infarct size and the extent of inducible ischemia but also can be used to quantify the resting left ventricular ejection fraction and determine the extent of regional systolic thickening abnormalities that also have prognostic value. The VANQWISH trial was the first large randomized trial to use stress myocardial perfusion imaging in the noninvasive strategy for risk stratification and was highly effective in identifying a low-risk group, even though planar 201Tl imaging was used rather than the more sensitive SPECT imaging approach. Hopefully, clinicians will now be convinced that routine coronary angiography after uncomplicated non-Q-wave or Q-wave infarction with a view toward revascularization of all stenotic vessels is not the desirable approach for achieving optimal cost-effective patient care.