Decreased likelihood of response to cardiac resynchronization in patients with severe heart failure

Abstract

AimsWe hypothesized that a very advanced stage of dilated cardiomyopathy is associated with lower response to cardiac resynchronization therapy (CRT).Methods and resultsA consecutive cohort of 147 patients was studied before device implantation and at 12 months follow-up. All patients were in NYHA functional class III-IV and had left-ventricular (LV) systolic dysfunction (LV ejection fraction 24 ± 7) and a wide QRS (171 ± 29 ms). A patient who was alive without heart transplantation and had improved by at least 10 in the 6 min walking test at 12 months follow-up was considered a clinical responder. Fifty-four patients (36) did not respond to CRT (15 cardiac deaths, 4 heart transplantations). Quality of life indicators (>41 points), LV end-diastolic volumes (>200 mL) and mitral regurgitant orifice area (>16 mm2) at baseline were independent predictors of response to CRT. Patients were assigned 1 point for each predictive parameter. Patients with higher scores showed a significantly higher likelihood of non-response to CRT (χ2 = 12 891, P = 0.005).ConclusionThe results show that non-responder patients have a more advanced stage of the disease, which suggests that CRT should be indicated earlier in the disease process.