Clinical characteristics and survival of patients with chronic heart failure and prolonged QRS duration.
BACKGROUND
Abnormal prolongation of QRS duration is a common finding in patients with chronic heart failure, and is associated with an impaired prognosis. The optimum QRS duration for separating chronic heart failure patients with respect to prognosis has not been determined. Whilst resynchronisation of ventricular conduction may benefit patients with QRS>150 ms, this has yet to be determined for patients with moderate QRS prolongation.


METHODS
We evaluated 155 patients with chronic heart failure (New York Heart Association class 2.6+/-0.8, mean+/-S.D.). The mean follow-up period was 838+/-748 days. Patients were sub-grouped according to QRS duration: <120 ms (normal QRS, n=82), 120-150 ms (moderate prolongation, n=44) and >150 ms (severe prolongation, n=29).


RESULTS
The optimal QRS duration for stratifying patients for 2-year event free survival was 120 ms (receiver operating characteristic analysis: area under curve 0.73; 95% CI 0.64-0.81). Moderate prolongation of QRS duration was associated with a worse New York Heart Association class, peak oxygen consumption and left ventricular ejection fraction when compared to patients with normal QRS duration (all P<0.05). Patients with moderate prolongation of QRS duration had similar impairment of New York Heart Association class and peak oxygen consumption as compared with patients with QRS duration >150 ms (all P>0.05).


CONCLUSIONS
The optimum QRS duration for stratifying patients for medium to long-term event-free survival was 120 ms. Heart failure patients with moderate QRS prolongation share similar impairment of exercise capacity and functional class to those with severe prolongation.
Kalra
Paul R
PR
Clinical Cardiology, National Heart and Lung Institute, Dovehouse Street, London SW3 6LY, UK.
Sharma
Rakesh
R
Shamim
Waqar
W
Doehner
Wolfram
W
Wensel
Roland
R
Bolger
Aidan P
AP
Genth-Zotz
Sabine
S
Cicoira
Mariantonietta
M
Coats
Andrew J S
AJ
Anker
Stefan D
SD
D000368:Aged; D002908:Chronic Disease; D018572:Disease-Free Survival; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000401:mortality* / Q000503:physiopathology* / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D011379:Prognosis; D012720:Severity of Illness Index; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors