Altered trans-mitral flow velocity pattern after exercise predicts development of new-onset atrial fibrillation in elderly patients with impaired left ventricular relaxation at rest: prognostic value of diastolic stress echocardiography.
OBJECTIVE
This study attempted to determine whether exercise induced left ventricular (LV) diastolic dysfunction estimated by altered trans-mitral flow (TMF) velocity pattern after exercise is associated with increased risk of cardiac events including new-onset atrial fibrillation (AF) in elderly patients with impaired LV relaxation at rest.


BACKGROUND
Diastolic stress echocardiography has been applied to evaluate LV diastolic function during and post-exercise. Prognostic importance of exercise-induced diastolic dysfunction remains uncertain.


METHODS
We studied 126 patients (70±5 years; 70 males) who underwent treadmill stress echocardiography. Doppler measurements were done before exercise and immediately after the post-stress image acquisition, and the ratio between early (E) and atrial (A) TMF velocities was measured. Patients with impaired LV relaxation (E/A<1.0) at rest were studied. Altered TMF velocity pattern was present when patients with E/A<1.0 at rest developed E/A≥1.0 after exercise. Primary endpoints for follow-up were combination of major cardiac events and new-onset AF.


RESULTS
There were 42 patients with altered TMF velocity pattern after exercise. During the 5-year follow-up period, there were 30 cardiac events including 13 new-onset AF. Kaplan-Meier survival plot demonstrated that altered TMF velocity pattern after exercise is associated with increased risk of cardiac events (p<0.0001) including development of new-onset AF (p=0.0003). Cox hazard ratio analysis demonstrated that altered TMF velocity pattern after exercise was the best predictor of cardiac events (hazard ratio 3.939; 95%confidence interval 1.662-9.337; p=0.0018).


CONCLUSIONS
Altered TMF velocity pattern after exercise provides significant prognostic information for predicting cardiac events including new-onset AF in elderly patients with impaired left ventricular relaxation at rest.
Takagi Cardiology Clinic, Nakagyo-ku, Kyoto, Japan. tcardiol@qb4.so-net.ne.jp
Tsutomu
T
Takagi
Atsushi
A
Takagi
Junichi
J
Yoshikawa
D000368:Aged; D001281:Atrial Fibrillation / Q000209:etiology*; D003971:Diastole / Q000502:physiology; D015150:Echocardiography, Doppler; D025401:Echocardiography, Stress; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D011379:Prognosis; D016016:Proportional Hazards Models; D012146:Rest; D016277:Ventricular Function, Left / Q000502:physiology*