Scar burden is an independent and incremental predictor of cardiac resynchronisation therapy response

Abstract

ObjectiveDetermine the prognostic impact of scar quantification (scar %) by cardiac magnetic resonance (CMR) in predicting heart failure admission, death and left ventricular (LV) function improvement following cardiac resynchronisation therapy (CRT), after controlling for the presence of left bundle branch block (LBBB), QRS duration (QRSd) and LV lead tip location and polarity.MethodsConsecutive patients who underwent CMR between 2002 and 2014 followed by CRT were included. The primary endpoint was death or heart failure admission. The secondary endpoint was change in ejection fraction (EF) ≥3 months after CRT. Cox proportional hazards, linear regression models and change in the area under the receiver operating characteristic curve (AUC) were used.ResultsA total of 84 patients were included (63% male, 51% with ischaemic cardiomyopathy). After adjusting for clinical factors, presence of LBBB and QRSd and LV lead tip location and polarity, greater scar % remained associated with a higher risk for clinical events (HR=1.06; 95% CI 1.02 to 1.10; p<0.001) and a smaller improvement in EF (slope: −0.61%; 95% CI −0.93% to 0.29%; p<0.001). When adding scar % to QRSd and LBBB, there was significant improvement in predicting clinical events at 3 years (AUC increased to 0.831 from 0.638; p=0.027) and EF increase ≥10% (AUC 0.869 from 0.662; p=0.007).ConclusionScar quantification by CMR has an incremental value in predicting response to CRT, in terms of heart failure admission, death and EF improvement, independent of the presence of LBBB, QRSd, LV lead tip location and polarity.

Upgrade of cardiac resynchronization therapy by utilizing additional His-bundle pacing in a patient with lamin A/C cardiomyopathy: an autopsy case report

“… 4 Avoiding scarred areas pacing is critical since nonviable tissue can no longer be resynchronized. 5 In the present case, scar formation was evident around the left ventricle and right ventricle apex pacing sites. No studies have so far evaluated the importance of myocardial substrate and remodelling for RV lead placement.…”

Global longitudinal strain as a prognostic marker in cardiac resynchronisation therapy: A systematic review

“…Despite this, nearly a third of patients treated with CRT enjoy no benefit. The burden of myocardial fibrosis is an important independent predictor of response to CRT [5] , with extensive LV myocardial scar contributing to impaired LV reverse remodelling. This may explain why individuals with underlying ischemic cardiomyopathy respond less frequently to CRT compared to individuals with non-ischemic cardiomyopathy [27] .…”

“…Importantly, only two thirds of patients meeting guideline criteria for CRT implantation garner optimal benefits from this device therapy [4] . Furthermore, myocardial fibrosis and scar burden are principal factors that adversely affect the response from CRT at a substrate level [5] , [6] . Cardiac MRI is the reference standard for detecting and quantifying myocardial fibrosis and scar [5] .…”

“…Furthermore, myocardial fibrosis and scar burden are principal factors that adversely affect the response from CRT at a substrate level [5] , [6] . Cardiac MRI is the reference standard for detecting and quantifying myocardial fibrosis and scar [5] . However, this modality may not be technically feasible in a significant proportion of patients due to pre-existing device implantation, poor renal function and limited access to this investigation in many healthcare systems.…”

Cardiac magnetic resonance in cardiac resynchronization therapy: How useful it can be?

“…Serge C. Harb et al have shown that nonresponders have a higher level of myocardial scar burden. Also, myocardial scar burden is an independent factor in predicting heart failure and death, and also in predicting ejection fraction recovery after CRT implantation (Figure 1) [17]. The higher level of myocardial scar burden regardless of the scar location in terms of affected segments is marked as a predictor of adverse outcomes.…”