The Prognostic Value of the Diastolic Stress Test in Patients Undergoing Treadmill Stress Echocardiography

Background: Exercise stress echocardiography (SE) is well validated for the evaluation of myocardial ischemia. Diastolic stress testing (DST) is recommended in the 2016 American Society of Echocardiography and European Association of Cardiovascular Imaging Guidelines for unexplained dyspnea. This study's aim was to prognostically evaluate the DST prospectively in a large stress testing population. Methods: Patients underwent SE with mitral E/e' measured before and after maximal treadmill exertion to estimate diastolic function. Patients were divided into four groups: group 1 (n = 201)-ischennic; group 2 (n = 1,563) - negative DST (E/e(pre)' < 12, E/e(post)(') < 12); group 3 (n = 68)-positive DST (E/e(pre)' < 12, E/e(post)(') >= 12); group 4 (n = 314)-high baseline E/e' (E/e(pre)' >= 12). Results: Consecutive patients (n = 2,201, 770 [35%] female; 58 +/- 12 years) were followed after SE for 27,964 patient-months. Time to first heart failure event (composite of heart failure admission, worsening New York Heart Association class, worsening ejection fraction, or cardiovascular death) was analyzed and adjusted using Cox proportional hazards regression. Ischemic patients hazard ratio (HR) was 28, 95% CI, 17-44, P < .0005, for subsequent heart failure compared with negative DST patients. Nonischemic, positive DSTs were highly predictive (HR = 4.2; 95% CI, 1.6-11.0; P = .001); while high E/e(pre)' was not predictive (HR = 1.3; 95% CI, 0.7-2.4; P = .49) of future heart failure events. Conclusions: DST differentiates heart failure prognosis in patients with induced diastolic dysfunction. Ischemia predictably portends the worst heart failure outcomes, and nonischemic, positive diastolic stress tests predicted more events compared with negative tests. These prognostic data support and add to the recommendations of the 2016 guidelines.