Effect of posterolateral left ventricular scar on mortality and morbidity following cardiac resynchronization therapy.
OBJECTIVE
To determine the effect of a posterolateral (PL) left ventricular scar on mortality and morbidity following cardiac resynchronization therapy (CRT).


METHODS
Sixty-two patients with heart failure (age 67.3 +/- 9.6 yrs [mean +/- SD], 45 males, New York Heart Association class [NYHA] class III or IV, left ventricular ejection fraction [LVEF]= 35%, left bundle branch block, QRS > or = 120 ms) underwent late gadolinium enhancement cardiovascular magnetic resonance (LGE-CMR) for scar imaging. Patients were followed up for 741 (75-1602) days (mean [range]).


RESULTS
The presence of a PL scar emerged as an independent predictor of the composite endpoint of cardiovascular death or hospitalization for worsening heart failure (HR: 3.06 [1.63, 7.7, P < 0.0001]) as well as the endpoint of cardiovascular death (HR: 2.63 [1.39, 6.65], P = 0.0016). A transmural PL scar was the strongest predictor of these endpoints (both P < 0.0001). The symptomatic responder rate (improvement by > or =1 NYHA classes or > or =25% in 6-min walking distance) was 83% in the group with non-PL scars, but only 47% in the group with transmural PL scars (P < 0.0001). Pacing over the scar was associated with a higher mortality and morbidity than pacing outside the scar (all P < 0.05).


CONCLUSIONS
A PL scar is associated with a worse clinical outcome following CRT, particularly if it is transmural. Pacing scarred left ventricular myocardium carries a greater risk of mortality and morbidity than pacing nonscarred myocardium.
Chalil
S
S
Department of Cardiology, University of Birmingham, Good Hope Hospital, Sutton Coldfield, West Midlands, UK.
Stegemann
B
B
Muhyaldeen
S A
SA
Khadjooi
K
K
Foley
P W
PW
Smith
R E A
RE
Leyva
F
F
D000368:Aged; D002037:Bundle-Branch Block / Q000473:pathology; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects* / Q000401:mortality*; D002921:Cicatrix / Q000473:pathology; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000150:complications; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010138:Pacemaker, Artificial; D013318:Stroke Volume