Prognostic value of the baseline CAVIAR response score after cardiac resynchronization therapy: ten-year outcomes from the Markers and Response to CRT (MARC) study

BACKGROUND: A substantial proportion of patients derive limited benefit from cardiac resynchronization therapy (CRT). The CRT-Age-QRS OBJECTIVE: To assess the association between baseline CAVIAR response score and long-term outcomes in the prospective Markers and Response to CRT (MARC) study. METHODS: Primary outcome was cardiovascular (CV) hospitalization or all-cause mortality. Secondary outcomes were all-cause mortality, ventricular tachyarrhythmia, and major adverse cardiac events (MACE: CV death, CV hospitalization, appropriate implantable cardioverter-defibrillator therapy). Outcomes were assessed with Kaplan-Meier and Cox models adjusted for clinical characteristics and 6-month echocardiographic response (left ventricle (LV) end-systolic volume reduction ≥15% and LV ejection fraction ≥35%). RESULTS: Of 240 MARC participants, 224 (93%) were included for long-term follow-up (median 9.0 years [interquartile range 4.7-11.6]) and the CAVIAR score was calculated in 185 (83%). The primary outcome occurred in 145 (65%) patients; 117 (52%) died; 62 (28%) experienced ventricular tachyarrhythmia; and 93 (42%) had MACE. Higher CAVIAR tertiles were associated with lower hazard ratio (HR) of the primary outcome and all-cause mortality in baseline-adjusted models (HR 0.562, p=0.001; HR 0.485, p<0.001, respectively) and after adjustment for echocardiographic response (HR 0.599, p<0.001; HR 0.524, p<0.001, respectively). CAVIAR was associated with ventricular tachyarrhythmia and MACE only after adjustment for echocardiographic response (HR 0.576, p=0.007; HR 0.600, p=0.003, respectively). CONCLUSION: A higher baseline CAVIAR response score predicted a lower risk of CV hospitalization and/or all-cause mortality after CRT.