The prognostic impact of coronary flow-reserve assessed by Doppler echocardiography in non-ischaemic dilated cardiomyopathy.
OBJECTIVE
Coronary flow-reserve (CFR) can be impaired in non-ischaemic dilated cardiomyopathy (DCM), unmasking a coronary microcirculatory dysfunction of potential prognostic impact. The aim of the present study is to evaluate the prognostic value of Doppler echocardiographic-derived CFR in patients with DCM.


RESULTS
We evaluated 129 DCM patients (85 male; age 62+/-11) by transthoracic dipyridamole (0.84 mg/kg in 10 min) stress echocardiography. All patients had an ejection fraction<40% (mean 32+/-7) and angiographically normal coronary arteries with NYHA class<or=3. CFR was assessed on left anterior descending artery using pulsed Doppler as the ratio of maximal peak vasodilation (dipyridamole) to rest diastolic flow velocity. All patients were followed-up for a median of 22 months. Mean CFR was 2.0+/-0.5. At individual patient analysis 46 patients had normal (CFR>2.0) and 83 had abnormal CFR. During follow-up, 18 patients died and 33 showed worsening of NYHA class. The worse event-free survival was observed in those patients with an abnormal CFR when compared with those having a normal CFR at high dose of dipyridamole (70 vs. 22%, at 75 months of follow-up, P<0.0001). In the multivariable analysis, severity of mitral insufficiency (HR=1.9, 95% CI=1.06-2.87), abnormal CFR (HR=4.0, 95% CI=1.1-15.6), resting wall motion score index (HR=6.9, 95% CI=1.5-30.7) were independent predictors of survival.


CONCLUSIONS
In DCM patients, CFR is often impaired. A reduced CFR during vasodilator stress is an independent prognostic marker of bad prognosis.
Rigo
Fausto
F
Cardiology Division, Umberto I Hospital, Mestre-Venice, and Department of Clinical and Experimental Medicine, Federico II University, Naples, Italy.
Gherardi
Sonia
S
Galderisi
Maurizio
M
Pratali
Lorenza
L
Cortigiani
Lauro
L
Sicari
Rosa
R
Picano
Eugenio
E
D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology*; D003326:Coronary Circulation / Q000502:physiology*; D015150:Echocardiography, Doppler; D025401:Echocardiography, Stress; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D013318:Stroke Volume / Q000502:physiology; D016019:Survival Analysis