RT Journal Article SR Electronic T1 Scar burden is an independent and incremental predictor of cardiac resynchronisation therapy response JF Open Heart JO Open Heart FD British Cardiovascular Society SP e001067 DO 10.1136/openhrt-2019-001067 VO 6 IS 2 A1 Serge C Harb A1 Saleem Toro A1 Jennifer A Bullen A1 Nancy A Obuchowski A1 Bo Xu A1 Kevin M Trulock A1 Niraj Varma A1 John Rickard A1 Richard Grimm A1 Brian Griffin A1 Scott D Flamm A1 Deborah H Kwon YR 2019 UL http://openheart.bmj.com/content/6/2/e001067.abstract AB Objective Determine 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.Methods Consecutive 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.Results A 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).Conclusion Scar 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.