Arterial tonometry-derived subendocardial viability ratio in coronary artery disease patients: the jury is still out

Several studies have confirmed the benefits of exercisebased cardiac rehabilitation (CR) in reducing both total and cardiovascular mortality and hospital admissions (1–3) and these results justify the recommendation that participation in a CR program should be considered for all patients requiring hospitalization or invasive intervention after an acute ischemic event (4). Although most patients will benefit from such a program, identifying patients that would respond poorly, and particularly, eventual predictors of poor response, would be very useful before initiating an exercise program