Page 116 - Simplicity is Key in CRT

Figure 5. Kaplan-Meier estimates of survival free from HF hospitalization with the 1st year after implantation.
(A) The combination of QRS duration and morphology divides patients into subgroups according to presence of LBBB and QRS duration < or ≥ 150ms (corresponding to current guideline recommendations). (B) Subgroups of QRS area are based on quartiles. (C) Patients without a guideline class I indication [10] (without LBBB and QRS duration ≥150ms) are stratified to QRS area < or ≥ 109ųVs. (D) Patients with a guideline class I indication [10] (with LBBB and QRS duration ≥150ms) are stratified to QRS area < or ≥ 109ųVs. HF, heart failure; LBBB, left bundle branch block; LVAD, left ventricular assist device.
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Heart failure hospitalization
Data on HF hospitalization within 1-year after CRT implantation was available for 1,269 patients (85%). 85 (5.7%) patients had been hospitalized.
Patient groups stratified according to the combination of QRS duration and morphology did not significantly differ in the occurrence of HF hospitalization (Figure 5A). Patients stratified according to QRS area differed significantly with respect to the occurrence of HF hospitalization (p=0.007).
In the ROC analysis the AUC was higher for QRS area than for QRS morphology or duration (0.62 vs. 0.54 and 0.56 respectively). (Supplementary figure 1) In a multivariable analysis, QRS area remained the only significant ECG parameter of HF hospitalization (p=0.019, HR 0.76 [0.60, 0.96]). (Table 2).
Echocardiographic outcome
Paired LVESV measurements at baseline and follow-up were available in 929 patients (62%). The average reduction in LVESV was 19±32%. Echocardiographic response to CRT, defined as LVESV reduction ≥ 15%, occurred in 516 (56%) patients.
LVESV reduction was significantly larger in patients with LBBB with QRS duration >150ms compared to those with