The effect of heart failure etiology on upgrading from right ventricular to biventricular pacing
Z Kis, E Merkel, R Hatala, A Behon, Z Szakacs, R Masszi, A Kovacs, A Kosztin, B MerkelyAbstract
Background
Non-ischemic HF patients are known to have a more favorable response to de novo cardiac resynchronization therapy (CRT).
Purpose
We aimed to assess the efficacy of CRT upgrade in the BUDAPEST-CRT Upgrade trial population by heart failure (HF) etiology.
Methods
Heart Failure patients with reduced ejection fraction (HFrEF) and priorly implanted pacemaker (PM) or implantable cardioverter defibrillator (ICD) and 20% right ventricular (RV) pacing burden were randomized to CRT-D upgrade (n=215) or ICD (n=145). Primary- [HF hospitalization (HFH), all-cause mortality, or <15% reduction of left ventricular end-systolic volume] and secondary outcomes were investigated by ischemic etiology defined as prior infarction or coronary intervention.
Results
At enrolment 209 (58%) had ischemic etiology, of whose risk to the primary endpoint [adjusted odds ratio (aOR) 1.78; 95%CI 1.02-3.11; p=0.042], however they did not show a higher risk for all-cause mortality or HFH (aOR 0.84; 95%CI 0.47-1.48; p=0.54) during the mean follow-up time of 12.4 months. Having ischemic etiology decreased the odds of showing echocardiographic response (aOR 0.53; 95%CI 0.29-0.95; p=0.034).
Despite these results, the effect of CRT-D upgrade on the primary endpoint was similar in patient with ischemic and non-ischemic etiology (ischemic aOR 0.11; 95%CI 0.05-0.23; p‹0.001; non-ischemic aOR 0.12; 95%CI 0.05-0.28; p‹0.001; interaction p=0.91). Also
CRT-D upgrade improved the echocardiographic response with a heterogeneous treatment effect (ischemic adjusted left ventricular end-diastolic volume difference -25.24mL, 95%CI -40.32 to -10.17, p=0.001; non-ischemic -55.79ml, 95%CI -77.96 to -33.62, p‹0.001; interaction p=0.013).
Conclusion
In HFrEF patients and PM/ICD with high RV pacing burden, CRT-D upgrade decreased the risk of the primary endpoint regardless of the etiology. CRT-D upgrade showed a significant but less favorable echocardiographic response in ischemic HF patients.