Effect of Posterolateral Left Ventricular Scar on Mortality and Morbidity following Cardiac Resynchronization Therapy

• Published in: Pacing and clinical electrophysiology Vol. 30; no. 10; pp. 1201 - 1209
• Main Authors: CHALIL, S., STEGEMANN, B., MUHYALDEEN, S. A., KHADJOOI, K., FOLEY, P. W., SMITH, R.E.A., LEYVA, F.
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.10.2007
• Subjects: Aged; Bundle-Branch Block - pathology; cardiac dyssynchrony; Cardiac Pacing, Artificial - adverse effects; Cardiac Pacing, Artificial - mortality; cardiac resynchronization therapy; Cicatrix - pathology; Echocardiography; Female; Follow-Up Studies; heart failure; Heart Failure - complications; Heart Ventricles - pathology; Humans; Magnetic Resonance Imaging; Male; myocardial viability; Pacemaker, Artificial; Stroke Volume
• ISSN: 0147-8389; 1540-8159
• DOI: 10.1111/j.1540-8159.2007.00841.x

Objectives: 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  ≥ 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 ≥1 NYHA classes 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.